A Prospective Randomised Control Trial Comparing the Effect of Functional Alignment With Mechanical Axis Alignment on Outcomes After Total Knee Arthroplasty.
Phase: NA
Conditions: Osteoarthritis, Osteo Arthritis Knee
Sponsor: Perth Hip and Knee

Full title: 
A Prospective Randomised Control Trial Comparing Functional with  Mechanical 
Axis Alignment in Total Knee Arthroplasty.  
 
 
Short title: 
 
RCT: FA TKA vs MA TKA 
 
 
Chief Investigator: 
 
Dr Gavin Clark M.B.,B.S., F.R.A.C.S.(Orth), F.A.Orth.A. 
Consultant Orthopaedic Surgeon St John of God Subiaco Hospital 
Orthopaedic Surgeon Perth Hip and Knee Clinic 
 
 
 
An Investigator Innitated Study  
 
Protocol version number and date: 
Protocol Version 1.6.1, 14/10/2021 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

STUDY SUMMARY 
 
 
Identifiers 
ANZCTR Registry Number 
ACTRN12621000060842   
HREC St. John of God Subiaco 
Number 
 
Full (Scientific) title 
A prospective randomised controlled trial comparing 
Functional with  Mechanical Axis Alignment in  total knee 
arthroplasty. 
Health condition(s) or 
problem(s) studied 
Knee osteoarthritis 
Study Type i.e. Cohort etc. 
Prospective, randomised, blinded, single-centre study 
Target sample size 
100 
Location 
St John of God Subiaco Hospital 
Salvado Rd Subiaco 6008 
Study timelines 
Study Duration/length 
4 years 
Expected Start Date 
 01/12/2020 
End of Study Date 
 01/12/2024 
Key Study milestones 
12/07/2020 - HREC applications 
 02/2021 - HREC meeting and ethical approval to commence study  
  03/2021- Commence patient recruitment and record outcomes of 
interest  
 12/2021 - Complete patient recruitment 
 12/2023 - Complete recording 2 yr outcomes of interest on all 
patients  
06/2024 - Collate data and perform statistical analyses 
02/2025 - Disseminate findings with publication in peer reviewed journal 
Funding 
Investigator initiated study 
Sponsor 
 
St John of God Healthcare 
Chief Investigator 
Dr Gavin Clark 
1/1 Wexford St Subiaco 6008 
Australia 
Email: gavin@hipnknee.com.au 
Co-Investigators 
Dr Dermot Collopy 
1/1 Wexford St Subiaco 6008 
Australia 
Email: dermot@hipnknee.com.au 
Principal 
Investigator/Study 
student 
Dr Gavin Clark 
1/1 Wexford St Subiaco 6008 
Australia 
Email: gavin@hipnknee.com.au 

KEY WORDS 
 
Functional Alignment  
Kinematic Alignment 
Mechanical Alignment 
Total Knee Arthroplasty 
Clinical Outcomes 
 
 
LIST OF ABBREVIATIONS 
 
 
AE 
 
Adverse Event   
 
 
 
 
 
 
 
 
 
AOANJRR  
Australian Orthopaedic Association National joint Registry  
AP 
 
Anteroposterior  
 
CI 
 
Chief Investigator 
CRF 
 
Case Report Form 
EQ5D-5L 
 
European Quality of Life Measurement – 5 Dimension 
FA  
 
Functional Alignment  
FJS 
 
Forgotten Joint Score 
HKA 
 
Hip Knee Angle 
HREC 
 
Human Research Ethics Committee 
KA 
 
Kinematic Alignment 
kFA 
 
Kinematic axis alignment planned Functional Alignment  
KOOS JR 
 
Knee osteoarthritis outcome score. Junior version 
 
 
LAT 
 
Lateral  
MA 
 
Mechanical alignment 
mFA 
 
Mechanical axis alignment planned Functional Alignment 
OA 
 
Osteoarthritis 
OKS 
 
Oxford Knee Score 
PHK 
 
Perth Hip & Knee Clinic 
PICF 
 
Patient Information and Consent Form  
PROMS 
 
Patient Reported Outcome Measures 
QA 
 
Quality Assurance 
RATKA 
 
Robotically Assisted Total Knee Arthroplasty 
RCT 
 
Randomised Control Trial 
RP 
 
Research Physiotherapist 
SAE 
 
Serious Adverse Event 
TKA 
 
Total Knee Arthroplasty 
 

CONTENTS  
 
1. INTRODUCTION 
 
1.1 CURRENT EVIDENCE 
 
1.2 NEED FOR A TRIAL 
 
 
 
 
 
 
2. OBJECTIVES  
2.1 PRIMARY OBJECTIVE 
2.2 SECONDARY OBJECTIVES 
 
 
 
 
 
 
 
3. STUDY DESIGN 
3.1 STUDY TYPE 
3.2 STUDY LOCATION 
3.3 INVESTIGATIONAL TEAM 
3.4 STUDY POPULATION AND GROUPS 
3.5 SAMPLE SIZE 
3.6 RANDOMISATION PROCEDURE 
3.7 SURGICAL INTERVENTION 
3.8 DESCRIPTION OF THE DEVICE  
3.9 POST OPERATIVE FOLLOW UP 
3.10 CLINICAL AND RADIOLOGICAL ASSESSMENT  
4. STUDY SHEDULE 
4.1 STUDY TIMELINE 
4.2 PATIENT WITHDRAWAL CRITERIA AND PROCEDURE  
5. CONSENT 
5.1 ELIGIBILITY CRITERIA 
6. STASTICAL METHODS 
6.1 POWER / SAMPLE SIZE CALCULATION 
6.2 ENDPOINT ANALYSIS 
 
6.2.1 PRIMARY ENDPOINT 
 
6.2.2 SECONDARY ENDPOINTS 

6.3 INTENTION TO TREAT POPULATION 
6.4 PER PROTOCOL POPULATION 
6.5 BASELINE DATA 
7. PATIENT AND PUBLIC INVOLVEMENT 
8. FUNDING AND SUPPLY OF EQUIPMENT 
9. DATA HANDLING AND MANAGEMENT 
10.1 DATA QUALITY ASSURANCE AND MONITORING  
10.2 ONSITE MONITORING 
10. CASE REPORT FORM STORAGE 
11. ASSESSMENT AND MANAGEMENT OF RISKS 
12. RECORDING AND REPORTING OF ADVERSE EVENTS 
12.1 DEFINITIONS 
12.2 OUTCOMES 
12.3 CAUSALITY 
13. RECORDING OF SERIOUS ADVERSE EVENTS 
14. REPORTING INCIDENTS  
14.1 PROTOCOL DEVIATIONS AND NOTIFICATION OF PROTOCOL VIOLATIONS 
14.2 REPORTING INCIDENTS INVOLVING A MEDICAL DEVICE 
15. TRAINING 
16. ARCHIVING 
17. PUBLICATION AND DISSEMINATION POLICEY 
18. REFERENCES 
19. APPENDICES  
19.1  PATIENT CASE REPORT FORMS  
19.2  END OF STUDY FORM  
19.3 CLINICAL TRIAL LETTER TO GP 
19.4 LOCAL SITE SAE / AE FORM 
19.5 PROMS  

19.6 FUNCTIONAL TESTING PROTOCOLS 
19.7 PATIENT INFORMATION FORM AND CONSENT 
19.8 INTRAOP DATA COLLECTION FORM 
19.9 DETAILED SURGICAL PLANNING  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

1. Introduction 
 
Total knee arthroplasty (TKA) is the most effective treatment for patients with symptomatic end-stage knee 
osteoarthritis that has not responded to appropriate non-operative management. The aims of TKA are to provide 
pain relief and improve function. Accuracy of limb alignment, implant positioning, and soft tissue balance after 
TKA are important prognostic factors that affect postoperative clinical outcomes and long-term implant 
survivorship. Published literature has shown between 80% and 90% of patients are satisfied following this 
procedure. (1,2) 
 
To this end there are two much debated theories of postoperative alignment after TKA. In total knee arthroplasty 
with mechanical alignment the aim is to achieve neutral limb alignment. This was to optimise longevity of TKA 
and prevent early failure. Total knee arthroplasty with kinematic alignment aims to restore the patient’s own pre-
arthritic knee anatomy with more natural alignment and preservation of native function. Enthusiasts debate both 
theories and it is yet to be established whether one is superior to the other.  
 
An issue with both of these alignment theories is that  they are purely related to bony anatomy. Neither considers 
soft tissue tension or balance before the bony cuts are made. Once the bony cuts are made the soft tissue balance 
is assessed and ligaments released until the TKA is balanced to the surgeon’s satisfaction. In an initial cohort 
study well over 50% of patients in both groups required soft tissue releases to balance the TKA if these alignment 
theories were strictly adhered to. 
 
The accuracy of soft tissue balancing is surgeon dependent and there is evidence that even experienced knee 
surgeons are poor at manually determining if a knee is balanced (3). This becomes particularly important when 
considering over half of these procedures throughout the world are performed by surgeons who undertake less 
than 25 TKA per year.  
 
Robotic assisted TKA with the Mako robot (Stryker, Florida, USA) has enabled a pre-resection balancing 
technique. This enables assessment of soft tissue laxity and adjustment of the initial plan to achieve balanced soft 
tissue with alteration of component alignment. Once the knee has been virtually balanced on the planning 
software, robotic arm assisted surgery is undertaken to accurately replicate the plan resulting in a balanced TKA. 
 
Functional alignment depends on the soft tissue tension to determine the TKA alignment and thereby minimizes 
the need for soft tissue release. As the collateral ligaments due not contract through the disease process of 
osteoarthritis, re-tensioning these ligaments following the removal of osteophytes should act as a surrogate of 
individual limb alignment. Although the overall limb alignment in this technique is independent of the initial plan 
the individual component position and joint line obliquity will vary depending on whether the knee was planned 
with a mechanical axis(mFA) or a kinematic axis(kFA) alignment. Assessment of the Perth Hip and Knee 

Registry data would suggest on average a two degree difference in component position in both joint line obliquity 
and femoral rotation.  
 
The need for soft tissue release to balance the knee in both MA and KA alignment makes them unsuitable for a 
computer enabled planning and balancing algorithm. This is due to variation in surgical skill and the difficulty in 
standardizing soft tissue releases.  Functional Alignment is well suited to automated algorithms as the surgical 
steps to balance the knee (bony cuts) would be robot assisted and therefore have an in-built quality control. The 
development of computer algorithms to plan and balance the knee arthroplasty could potentially improve the 
overall quality of TKA performed. 
 
 Limits are placed in Functional alignment to prevent the severely arthritic knee with attenuated ligaments being 
placed in extremes of alignment. Understanding the “safe zone” for functional alignment is important for patient 
selection, implant choice, extent of intraoperative deformity correction, and long-term follow up. Furthermore, 
some disease pathology such as bone tumors, previous trauma, and congenital deformities may be present in 
conjunction with the arthritic knee and will have altered the native alignment of the limb. In such cases, using 
functional alignment to reproduce the altered anatomical alignment and mechanical function may have a 
detrimental effect on knee mechanics and wear. 
 
A preliminary series by the principal investigator involved 122 TKR with mFA and over 350 kFA aligned knees 
since the introduction of RATKA into my practice. In an initial cohort of patients with functional alignment 
substantial differences were seen in femoral and tibial component position depending on whether a mechanical or 
kinematic plan was used. The final HKA angle was not changed as the coronal limb alignment is dictated by the 
collateral ligaments. The femur was 2 degrees valgus and the tibia 4 degrees varus with the kinematic plan 
compared to a neutral femur and 2 degree varus tibia with a mechanical plan. These small changes in position 
effect the three-dimensional relationships of the implants with the soft tissues. The initial cohort showed 
improved outcomes with the KA plan. There were confounding factors in that the groups were sequential, with 
MA plan group forming part of the surgeon’s learning curve. For the planned study a KA plan will be used as  
superior results have been seen in this group in the initial series..  
 
 
1.1 Current evidence 
 
There are no prospective studies looking at Functional alignment. Prospective studies comparing functional 
outcomes between the MA and KA groups have been performed but the main limitation of these studies has been 
the inability to accurately measure the desired deviation from neutral alignment as well as achieving the implant 
position to a high degree of accuracy. There is a paucity of studies using standardised techniques for 
intraoperative alignment and limited data relating these findings to clinical outcomes with long- term follow up. 

 
Matsumoto et al (7) conducted a prospective randomised study on 60 patients with varus osteoarthritis  
undergoing computer navigated TKA and showed kinematic alignment was associated with improved 
postoperative angles of flexion, functional activity scores, and more parallel joint line orientation in relation to the 
floor during single- and double-leg standing compared to patients with TKA using mechanical alignment. The 
true mechanical axis, which runs from the centre of the femoral head to the inferior aspect of the calcaneus passed 
through a neutral position in the kinematic group and a slightly lateral position in the mechanical group. The 
authors suggested that this more natural weight-bearing position in TKA with kinematic alignment may reduce 
pre-existing concerns of increased polyethylene wear and implant loosening in this patient group. However, 
patient follow-up was limited to one year following surgery, two separate types of implants were used within each 
treatment group, patients with severe valgus/varus deformities were excluded, and intraoperative kinematic 
assessment was not performed despite the use of computer navigation. 
 
Waterson et al (8) conducted a prospective randomised trial on 71 patients undergoing primary TKA and showed 
that there was no difference between kinematically aligned and mechanically aligned TKA with respect to the 
Knee injury and osteoarthritis outcome score (KOOS), American knee society score, 36-item short form survey 
(SF 36), European Quality of Life questionnaire with 5 dimensions for adults (EQ-5D), range of movement, two-
minute walk, and timed up and go tests at one year following surgery. In this study, patient-specific cutting blocks 
were used to achieve kinematic alignment and standard extra- or intramedullary instrumentation was used to 
achieve mechanical alignment. No intraoperative navigation or robotic systems were used to confirm limb 
alignment, functional outcomes were only assessed for up to one year, and findings were poorly correlated to 
radiological outcomes. 
 
Dossett et al (9) conducted a prospective randomised study on 88 patients and showed patients undergoing 
kinematic knee alignment had improved Oxford knee score (OKS), Western Ontario and Mcmaster Universities 
Arthritis Index (WOMAC), and improved range of motion compared to mechanically aligned TKA at a minimum 
of two-years follow-up. The odds ratio for having a pain-free knee was 3.2 with mechanical alignment compared 
to 4.9 with kinematic alignment in TKA. However, in this study accuracy of the cutting blocks was not assessed, 
preoperative scores were universally better in the kinematic alignment group compared to the mechanical 
alignment group, and the study was performed on private patients in the United States, which may have 
introduced a selection bias. 
1.2   Need for a trial 
There is a need for high quality evidence on the clinical and radiological benefits of functionally aligned TKA. 
This study would show if there is any superior outcomes to be obtained from functional alignment. Clinical and 
functional outcomes should also be correlated to longer-term outcomes to better establish the “safe zone” for 
functional alignment.  
 

Currently the vast majority of TKA throughout the world is undertaken utilizing MA alignment. Any change to a 
newer technique from the current ‘gold standard’ would need to be justified by improved clinical outcomes as 
there is no long term longevity data for Functional Alignment. Both surgeons and patients are only able to 
consider the relative risks and benefits of this technique once they are defined by sound scientific evidence. This 
study will contribute to the body of this evidence. 
 
2. Objectives  
The overall aims of this prospective, randomised double-blinded controlled trial are to compare functional, 
clinical, and radiological outcomes in FA TKA versus MA TKA. Patients undergoing MA TKA will form the 
control group and those undergoing FA TKA will form the investigation group. A superiority design will be used 
to evaluate whether FA TKA provides superior outcomes compared to MA TKA. Primary and secondary 
objectives will be used to quantify and draw inferences on differences in the efficacy of treatment between the 
two groups. To ensure accuracy of planning and implantation robotic arm assisted surgery will be utilized in both 
groups (Stryker MAKO, Fort Lauderdale, FL). Standardised post-operative care will be undertaken to ensure the 
only difference between groups is alignment of implants. 
 
2.1    Primary objective 
 
The primary objective of this study is to compare clinical outcomes at two years following surgery 
between FA TKA and MA TKA. The primary outcome measure for this study is the Forgotten Joint 
Score (FJS) at two years after surgery. The null hypothesis is that there is no difference in functional 
scores at two years following surgery between patients undergoing MA TKA (control group) versus FA 
TKA (investigation group). The hypothesis is that outcome measures obtained at two years after surgery 
in patients undergoing FA TKA are not achievable using MA TKA. Further PROMs will be used to 
further assess clinical outcomes including Forgotten Joint Score (FJS), Oxford Knee Score (OKS), Knee 
injury and osteoarthritis outcome Junior score (KOOS Jr), VAS Pain, and Kujala scores preoperatively 
and postoperatively at 3 months, 1 year and 2 years. Also health-related quality of life will be measured 
using European Quality of Life questionnaire with 5 dimensions for adults (EQ-5D-5L) preoperatively 
and postoperatively at 3 months, 1 year and 2 years. Range of movement (degrees) in knee joint during 
inpatient admission and postoperatively at 6 weeks, 3 months, 1 year and 2 years. 
 
 
 
2.2 Secondary objectives The secondary objectives of the study are: 
 
Determine lower limb alignment achieved with both alignment techniques. Lower limb alignment as 
assessed using standing long leg x-rays performed postoperatively at 3 months. Measurements of the hip-
knee-angle (HKA), medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA). Also 
evidence of imbalance with implant lift off will be measured.  

 
Determine if there are any differences in analgesic requirements based on alignment method used. 
Analgesia requirements during inpatient admission and postoperatively at 6 weeks, 3 months, 1 year and 
2 years will be measured. 
 
Determine whether alignment method utilized has an effect on the sagittal stability of the TKA. 
Assessment of sagittal stability at Preop, 3 months, 1 year and 2 years will be undertaken with an 
arthrometer “Lachmeter”. 
 
Determine whether alignment method utilized has an effect on functional outcomes. This will be assessed 
by a combination of  
o Maximum voluntary isometric force using a hand-held dynamometer at Preop, 3 months, 1 year 
and 2 years.  
o Sit to stand values as measure of function at Preop, 3 months, 1 year and 2 years. 
 
Intra-operative balance achieved with both alignment techniques. Surgeon blinded measurement of 
intraoperative balance achieved with Verasense sensor (smaller cohort) 
 
To determine if there is a difference in knee kinematics between the two techniques. Measurement of 
knee kinematics with Verasense sensor to assess presence or absence of medial pivot (smaller cohort) 
 
3. 
 Study Design 
     3.1 Study Type 
This study is a prospective, single-centre, randomised, double-blinded, controlled study. Patients undergoing MA 
TKA will form the control group and those undergoing the FA TKA will form the investigation group. 
 
3.2 Study Location  
The study base will be Perth Hip and Knee Clinic, 1/1 Wexford St, Subiaco 6008, WA. All Patients will have 
surgery and their inpatient stay will be at St John of God Subiaco Hospital with recruitment and follow up at 
either Perth Hip and Knee Clinic, (Subiaco or Murdoch rooms) or Midland Orthopaedics (Suite 11 St John of God 
Midland Hospital, Clayton Rd. Midland). All confidential study information will be stored on designated-
password protected research computers and assigned research offices at Perth Hip and Knee Clinic. 
 
3.3 Investigation Team The Chief investigator, Mr Gavin Clark is the Head of Department at St John of God 
Midland Hospital and Consultant Orthopaedic Surgeon at St John of God Subiaco Hospital. The majority 
of Mr Clark’s research stems from arthroplasty and optimising postoperative clinical and radiological 
outcomes. Mr Clark is fully trained and experienced in performing Mako robotic arm-assisted TKA. 
Mr Dermot Collopy is a senior Orthopaedic Consultant Surgeon at St John of God Subiaco Hospital and co-
investigator in this study. Mr Collopy is fully trained and experienced in performing Mako robotic arm-assisted 
TKA.  
All operative procedures will be undertaken by Mr Clark and Mr Collopy.  

Mrs Beth Tippett is a Research Physiotherapist that will assist in patient recruitment, data collection and statistical 
analysis. There is also a clinical fellow, additional physiotherapists in the practice, and two Orthopaedic registrars 
that can provide further assistance if required. 
 
3.4 Study population and groups 
Patients with symptomatic knee osteoarthritis requiring TKA will be recruited from the Mr. Clark’s and Mr 
Collopy’s private rooms at Perth Hip & Knee Clinic. All patients will be screened for eligibility based on the 
predefined inclusion and exclusion criteria (section 5.1). Patients interested in participating in the study will be 
provided with an information leaflet and contact telephone number for further information (Appendix 19.7).  
Details of those patients expressing an interest to participate in the study will be recorded and then be forwarded 
to the Research Physiotherapist.  
 
TheResearch Physiotherapist will telephone or meet with the patient to answer any additional queries and confirm 
whether or not the patient would like to participate in the study. More complex queries will be escalated to the 
Chief Investigator who will telephone the patient directly to discuss these issues further. Ideally, the time frame 
from the orthopaedic consultation to the decision to participate in the study will be approximately one week, 
which will give the patient sufficient time to perform further research, discuss study participation with family 
and/or friends, and contact the Research Physiotherapist for any additional information. This time frame may be 
shortened if a patient is agreeable with the study, due to patient flow and appointment availability at the 
consulting rooms. Contact details of the Research Physiotherapist and Chief Investigator are provided within the 
patient information leaflet. 
 
If the patient agrees to participate in the study, the Orthopaedic fellow will randomise the patient into one of the 
two treatment groups. Patients allocated to mFA TKA will form the ‘control group’ whilst those allocated to kFA 
TKA will form the ‘investigation group’. The method for randomisation is discussed in section 3.6. Written 
informed consent for both the operative procedure and inclusion into the study will be signed at the preadmission 
visit (Appendix 19.7). The procedure for obtaining written informed consent is discussed in more detail in section 
5. 
 
3.5 Sample Size In total, 100 patients will be enrolled in a 1:1 ratio between the two treatment groups. This 
will ensure that the minimum of 90 patients required to answer the study question are followed up for the 
duration of the study. The enrolment goal is to have at least 45 patients in each of the two treatment groups 
completing the study. Sample size calculation and statistical analysis are more comprehensively detailed in 
section 6. 
 
 
3.6 Randomisation procedure 

The system for randomisation will be the same throughout the study period and must be strictly adhered to. The 
following method will be used to allocate a trial patient to either the mFA TKA (‘Control group’) or to the kFA 
TKA (‘Investigation group’).  
 
Randomisation will be carried out using a blocked effect. This method is designed to randomize subjects into two 
groups that result in equal sample sizes over time. The blocks will be small (n=4), and balanced within the 
predetermined group assignments, which will keep the number of subjects in each group similar at all times. 
There will be no stratification factors involved in the randomization as randomization will occur before the trial 
starts.  Using a randomization website (www.random.org), a random number (between 1 and 100000) will be 
generated. This will form the “seed” number for the blocked randomization process. Using a randomization 
website (www.sealedenvelope.com) the randomization list will be created. Patients will be allocated in a 
sequential order of consent, strictly adhering to the allocation of groups. Screen shots of the randomization 
process and seed number will be taken throughout, and held from the CI to minimize randomization bias. The 
orthopedic fellow will then privately communicate to the CI the allocated group, to enable alignment and 
templating planning to be performed using the MAKO software. All patients and clinical staff recording the post 
operative clinical outcomes of interest will remain blinded to minimize performance and detection bias.  
 
If the patient initially agrees to participate in the study and then changes his/her mind at a later stage, they 
are free to do so without any compromise to their further care. If this occurs before obtaining informed 
consent then the patient’s decision will be relayed to the operating surgeon who will discuss suitable options 
directly with the patient, and organise postoperative follow-up care as per all routine (non-study) patients 
undergoing TKA at Perth Hip and Knee Clinic. There randomisation number will not be reallocated to the 
next patient, to ensure the blocks remain concealed. Drop in and out details are in section 6. If the patient 
agrees to participate in the study and then declines further inclusion after surgery has been performed, then 
the patient’s follow-up care will be arranged as per routine TKA follow up at Perth Hip and Knee Clinic. 
Patients will be notified that once statistical analysis of the study has been performed, and all patient data 
has been de-identified for analysis, they will not be able to withdraw their clinical data.  Statistical analysis 
of patients that drop out is discussed in section 6. Following randomisation and informed consent at the 
preadmission visit, baseline information will be recorded and documented in the Perth Hip and Knee Clinic 
Socrates database. Data handling and management are recorded in more detail in section 9. 
 
3.7 Surgical Intervention: MA vs. FA TKA 
All patients undergoing TKA will undergo preoperative CT scan of the leg to establish the extent of the disease 
process, determine bone resection, and plan implant sizing and positioning. The preoperative CT scan will be 
used to create individualized plans for achieving mechanical and kinematic alignment and stored within the 
robotic program that is used during the operative procedure. This will ensure that all implants and equipment for 
achieving either mechanical alignment or functional alignment are ready and available for use in theatre. These 

plans will provide the initial point from which functional alignment will be achieved.  
 
Following informed consent and randomisation into one of the two treatment groups, patients will undergo 
robotic-arm assisted TKA by one of the participating surgeons. Surgery in both groups will be undertaken through 
the standard anteromedial arthrotomy with positioning of reference pins in the femur and tibia for registration of 
the hip centre, ankle position and limb alignment. The femur will be prepared first in all operations. Cruciate 
retaining technique will be used in both groups. Interoperative requirement for a more constrained implant will 
result in exclusion from the study.  
 
In MA TKA, tibial and femoral osteotomies in the coronal plane will be planned perpendicular to the tibial and 
femoral mechanical axes respectively to achieve neutral overall alignment. Soft tissue balance will be assessed 
and minor adjustments to bony alignment made to balance the knees with a maximal adjustment of two degrees 
valgus and two degrees varus of coronal alignment from neutral. Femoral rotation will be planned to surgical 
epicondylar axis and adjustments to rotation made to allow equal flexion and extension balance (to within 1mm). 
If balance can not be achieved within these boundaries then soft tissue release will be undertaken. 
In the sagittal plane, 0-3 degrees of posterior tibial slope and 0-5 degrees of femoral component flexion will be 
used to optimise implant sizing whilst preventing notching. In the axial plane, the tibial component aligned to 
Akagi’s line, which connects the medial border of the patellar tendon attachment to the middle of the posterior 
cruciate ligament.  
 
In kFA TKA, femoral and tibial osteotomies will be planned for equal bony resections from the femoral condyles 
to replicate the patients anatomy. In the coronal plane, the distal femoral resection will be 6.5mm from the 
subchondral bone of both medial and lateral condyles, with compensation for wear by adjusting the resection by 
1-3mm. In the proximal tibia, there will be 7mm of resection from the subchondral bone from both the medial and 
lateral tibial plateau. In the sagittal plane, resection angle will be determined intraoperatively to closely match the 
native femoral flexion and tibial slope. In the axial plane, posterior femoral resection will be 6.5mm from the 
subchondral bone of both medial and lateral posterior condyles. Tibial rotation will be aligned to Akagi’s line. 
Adjustments will be made to bony alignment to balance soft tissues within the boundaries of six degrees varus 
and three degrees valgus Hip-Knee-Ankle (HKA) alignment. Femoral component alignment will be limited to six 
degrees of valgus and three degrees of varus in the coronal plane. Tibial alignment will be limited to six degrees 
of varus and three degrees of valgus in the coronal plane. Combined flexion of the components will be limited to 
ten degrees of flexion. Only if balance can not be achieved within these boundaries will soft tissue release be 
undertaken. 
 
In both groups, polyethylene thickness will be selected to maximise range of motion whilst avoiding 
hyperextension and ligament laxity. Tibial depth will be adjusted to maintain insert thickness between 9 and 
14mm. Any TKA requiring a 16 mm or greater polyethylene insert thickness will be excluded from the study.  

 
Patients in both groups will undergo the same inpatient and outpatient postoperative rehabilitation programme. 
Intra-operative data will be recorded using the surgical data form (Appendix 19.7). The only difference between 
the two treatment groups is that the control group will undergo MA TKA and the investigation group will 
undergo FA TKA. 
 
  
3.8 Description of the device 
The Stryker Triathlon (Stryker Navigation, Mahwah, NJ) cruciate retaining knee system with patellar resurfacing 
will be used in both groups. The femoral component will be un-cemented, patella and tibial components will be 
cemented. This implant and its surgical instruments are already in routine use for TKA at St John of God Subiaco 
Hospital. The surgical team are fully trained and experienced with the use of the instruments and surgical 
equipment for these implants. 
 
All postoperative rehabilitation will follow Perth Hip and Knee Clinic standard practice at St John of God 
Subiaco Hospital for patients undergoing TKA. This will include a combination of inpatient and outpatient 
physiotherapy as required. Each patient will have standard radiographic and clinical follow-up. The required 
outcomes from these clinical and radiological assessments will be recorded in the follow-up investigator form at 
discharge. 
 
3.9 Post operative follow up 
All patients included in this study will undergo orthopaedic review at the PHK Clinic or Midland Orthopeadic 
Clinic at 2-3 weeks, 6 weeks, 3 months, 1 year and 2 years following surgery. These are the routine follow-up 
time intervals for non-study patients undergoing TKA at PHK. Clinical and radiological outcomes of interest will 
be recorded by blinded observers using case report forms during these follow-up times (Appendix 19.1). The RP 
and fellow will assist in this.  
 
3.10 
Clinical and radiological assessment  
The FJS, EQ5D-5L, OKS, VAS Pain, Likert scale , KOOS Jr and Kujala Anteior knee pain scores are validated 
tools for the clinical assessment of patients after knee arthroplasty (10,11,18,19). Each of these scores is 
completed preoperatively and then at regular intervals during follow-up (Appendix 19.1) This information is 
routinely discussed at each of these outpatient consultations but patients in this study will have the information 
recorded within these validates questionnaires to facilitate data analysis.  
 
Routine clinical measures of height, weight, range of movement and pain description will be taken. To test 
endurance and strength, a 30 sec Sit to stand test will be measured. This test asks the participant to stand up / sit 
down from a standardised chair height within 30 seconds (Appendix 19.6). To measure the AP stability of the 
knee (20), a lachmeter reading will also be recorded at the post operative intervals and to measure strength, a hand 

held dynamometer test will also be performed. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.  Study Schedule 
 
 
 4.1 Study Timeline 
Patients will be recruited from the private rooms at Perth Hip & Knee clinic. Based on the volume of TKAs 
performed and recruitment rates from previous studies within clinic, patients are expected to be recruited at a rate 
of 10 patients per month. The recruitment process will therefore take approximately 10-12 months from the start 
of the study. From the date of the operation, each patient will be followed-up for 24 months. A further six months 
will be required for data collection, analysis and dissemination of findings. The total duration of the study will 
therefore be 40 months.  
 
4.2 Patient withdrawal criteria and procedure  
Preoperative 
Discharge 
6 weeks 
3 months 
1 year 
2 years 
 
Patient demographics 
X 
Patient medical history 
X 
 
Operation details 
X 
Clinical history and PROMS (FJS, 
EQ5D-5L, OKS, VAS pain, 
KOOS Jr, Kujala Anterior Knee 
Pain, Likert scale) 
X 
 
 
 
X 
(FJS and 
VAS only) 
X 
X 
X 
Functional Examination ( 
Lachmeter testing, Range of 
Movement, Hand Held 
Dynamometer, 30s STS test) 
 
X 
 
 
X   
(range only) 
 
X 
(range only) 
 
X 
 
X 
 
X 
Adverse Events 
At occurrences through study period 
 
Table 1. Timelines for clinical data collection in all study patients.  
Preoperative 
Discharge 
6 weeks 
3 months 
1 year 
2 years 
 
Plain knee joint radiographs 
X 
X 
 
 
X 
 
X 
 
Plain long-leg radiographs 
X 
X 
 
CT Knee joint 
X 
 
Table 2.  Timelines for radiological data collection in all study patients. Assessment windows will be as followed; 6 
weeks review (± 1 week), 3 month review ((± 2 weeks), 12 month review ((±2 months), 2 year review ((± 2 months). 

All patients included into this study are free to withdraw from the study at any time without compromise to their 
future treatment. On withdrawal, patients will revert to the standard follow-up regimen for routine TKAs at the 
study site. The end of study form will be completed and the reason for withdrawal documented (Appendix 19.2). 
This form will also be completed if the patient is lost to follow-up or dies during the course of the study. 
 
Enrolled patients will be withdrawn from the study if: 
• 
The patient withdraws consent for participation in the study 
• 
The patient is no longer able to comply with study instructions, attend scheduled appointments or 
complete questionnaires 
• 
The patient undergoes implant revision 
 
Data to the point of withdrawal will be used for analysis. 
 
5.0 Consent  
Patients with symptomatic knee osteoarthritis requiring TKA will be recruited from the private rooms at Perth 
Hip & Knee Clinic. All patients will be screened for eligibility based on the predefined inclusion and exclusion 
criteria (section 5.1) by a member of the clinical team. This includes the Orthopaedic Consultant Surgeon, 
Clinical Fellow, or  Research Physio. If the patient meets the all of the inclusion criteria (section 5.1) and none of 
the exclusion criteria, and expresses an interest to participate in the study they will be provided with a patient 
information sheet (Appendix 19.7). This provides details about the study, treatment, follow-up and contact details 
for further information. All members of the clinical team are familiar with the study and will address any 
preliminary questions about the study. Details of those patients expressing an interest to participate in the study 
will be recorded in the patient contact sheet , which will be a password protected excel document that only Dr 
Clark, Dr Collopy and Beth Tippett will have access to.  
 
One week after this outpatient consultation, the Research Physiotherapist will telephone the patient to answer any 
additional queries and confirm whether or not the patient would like to participate in the study. If the patient 
agrees to participate in the study, the Research Physiotherapist will randomise the patient into one of the two 
treatment groups. Patients allocated to mFA TKA will form the ‘control group’ whilst those allocated to kFA 
TKA will form the ‘investigation group’. The method for randomisation is discussed in Section 3.6. Written 
informed consent for both the operative procedure and inclusion into the study will be signed at the preadmission 
appointment. 
 
The ideal length of time between initial consultation and obtaining informed consent for inclusion into the study 
is at least 1 week. This method provides time for potential participants to consider the trial and ask questions 
before written consent for participation is requested. This time may be shortened due to patient flow and clinic 
appointment availability, as long as the patient is agreeable. Consent will be taken by the study coordinator or by 

a designated member of the surgical team who is familiar with the study.  
 
If the patient initially agrees to participate in the study and then changes his/her mind at a later stage, they are free 
to do so without any compromise to their further care. If this occurs before obtaining informed consent then the 
patient’s decision will be relayed to the Operating Surgeon who will discuss suitable options directly with the 
patient, and organise postoperative follow-up care as per all routine (non-study) patients undergoing TKA at Perth 
Hip & Knee Clinic. If the patient agrees to participate in the study and then declines further inclusion after 
surgery has been performed then the patient’s follow-up care will be arranged as per routine TKA follow up. 
Statistical analysis of patients that drop out is discussed in section 6. Following randomisation and informed 
consent, baseline information will be recorded and documented in the baseline investigator form (Appendix 19.1). 
Data handling and management are recorded in more detail in section 9. 
  
Being able to provide informed consent to the study is of paramount importance. Therefore, patients who lack the 
capacity to provide this, for example patients with dementia, will not be considered for the study. It is also 
important to the data collection scheme that patients are able to follow commands, read and interpret questions 
via questionnaires. Those who cannot hear, read or understand English, will not be considered for the study.  
 
Participants will not receive any preferential treatment or payment for taking part in the study. 
 
5.1 Eligibility Criteria  
The inclusion and exclusion criteria for all patients included in this study is shown below:  
   Inclusion Criteria 
 Patient has symptomatic knee osteoarthritis requiring primary TKA 
 Patient and surgeon are in agreement that TKA is the most appropriate treatment 
 Patient is fit for surgical intervention following review by surgeon  
 Patient is between 45-75 years of age at time of surgery, computer literate, and able to complete 
patient reported outcome measures independently.  
 Patient must be capable of giving informed consent and agree to comply with the postoperative 
review program 
 Patient must be a permanent resident in an area accessible to the study site 
 Patient must have sufficient postoperative mobility to attend follow-up clinics and allow for 
radiographs to be taken 
 Patient has tried non-pharmacologic therapy’s including ; patient education, self-management 
programs, aerobic exercise, weight loss, physiotherapy and occupational therapy 
 Patient has tried appropriate pharmacologic therapies including ; regular paracetamol and NSAIDS if 
appropriate 

Exclusion Criteria  
 Patient is not suitable for routine primary TKA. E.g. patient has ligament deficiency that requires a 
constrained prosthesis 
 Interoperative requirement for a more constrained implant. 
 Intraoperative requirement for the PCL to be released. These patients will be still included in the 
study, but analyzed with an intention to treat principal.  
 Patient has bone loss that requires augmentation 
 Patient requires revision surgery following previously failed correctional osteotomy or ipsilateral 
TKA (eg. Post high tibial or distal femoral osteotomy) 
 Patient requires a polyethylene inset of 16mm or greater.  
 Patient is immobile or has another neurological condition affecting musculoskeletal function 
 Patient is less than 44 years of age or greater than 76 years of age 
 Patient is a compensable patient. I.e. Worker’s compensation claim or motor vehicle accident.  
 Patient is already enrolled on another concurrent clinical trial 
 Patient is unable or unwilling to sign the informed consent form specific to this study 
 Patient is unable to attend the follow-up program 
 Patient is non-resident in local area or expected to leave the catchment area postoperatively 
 Patients who lacks capacity to provide consent, or the ability to understand the study protocol due to 
a cognitive condition (eg. Dementia) 
 Patient is unable to communicate effectively in English.  
 
6.0 Statistical Methods 
 
6.1 Power / Sample size calculation 
Primary Outcome measure: Functional outcome as assessed using the FJS score at two years following 
Mako-arm assisted TKA. 
 
 Using data from our initial cohort recording functional outcomes, the mean FJS score at  1 year in the 
mFA TKA was 59 (SD 6) and in the kFA TKA was 75 (SD 8). It is assumed that MA results will be no 
better than mFA results. The study was powered to demonstrate a 12 point difference in the Forgotten 
Joint score, which is the minimal clinical important change in the score. Using a one tailed analysis 
(assuming superior results with the kFA), an alpha value of 0.05 and power of 0.80, and accounting for 
expected drop-out rate of 10%, this study will need 100 patients to answer the study question. 
 
 
6.2 Endpoint Analysis 
 
6.2.1 Primary Endpoint 
The analysis of the per-protocol population will be considered the primary analysis. The differences 

between the MA TKA and FA TKA groups will be analysed by calculating the difference from baseline, 
per patient, and a two-sided confidence interval for the difference between the changes from baseline will 
be calculated. This confidence interval will cover the true difference in the percentage change from 
baseline with a probability of 95%. 
 
 
6.2.2 Secondary Endpoints  
Standard statistical methods will be employed to analyse the data. It is anticipated that the following 
techniques may be used: descriptive statistics, t-test, paired t-test, analysis of variance, Fisher exact test, 
Chi-square test, and graphical displays. Assumptions of normality will be tested with the Shapiro-Wilk  
test. Assumptions of homogeneity of variance will be tested with Levene’s test. If the distributional 
assumptions are (severely) violated, non-parametric techniques, such as Mann-Whitney’s test will be 
employed. 
 
All tests will be declared statistically significant if the calculated p-value is less or equal to 0.05. All tests 
will appear as two-sided p-values. Summary statistics will consist of numbers and percentages of 
responses in each category for discrete measure, and of means, medians, standard deviation, 95% 
confidence interval, minimum, maximum for continuous measures, and will be presented per treatment 
group. 
 
6.3 Intention-to-treat population 
The intention-to-treat (ITT) population is defined as all randomised patients assigned to either the mFA 
TKA or kFA TKA group, regardless of adherence with the entry criteria, regardless of the treatment they 
actually received, and regardless of subsequent withdrawal from treatment or deviations from the 
protocol. In the event that MA is converted to FA or vice versa intraoperatively, analysis will be 
performed using the ITT population and the treatment actually received by the patients. Intra-operative 
conversion from one method to another will however, be documented and presented/ published as part of 
the study. 
 
In the event that there are errors in the randomization assignment, the analysis will be performed using 
the assigned treatment, not the treatment that the patient actually received. Any patient terminated early 
from the clinical trial will be included in the ITT population. All attempts will be made to collect 
complete follow-up evaluations for these patients despite study exit. These patients will be included in the 
analysis using univariate or multivariate-imputation methods. 
 
6.4 Per-protocol population 
The per-protocol population is defined as all patients who are randomised to MA TKA or FA TKA and 
complete the study according to the protocol. 

 
In the event that there are errors in the randomisation assignment, the analysis will be performed using the 
treatment that the patient actually received, not the assigned treatment. Patients will be considered 
protocol violators if they do not meet the eligibility criteria as outlined in the protocol. Other reasons to be 
considered a protocol violator include, but are not limited to, protocol violations, and any actions that 
compromise the effectiveness of the treatment, such as receiving a secondary treatment. Protocol violators 
will not be considered as part of the per-protocol population and will be listed separately with the reason 
for their exclusion from the per-protocol population. 
 
6.5 Baseline Data 
Baseline data will be recorded for each patient after completion of the consent form. This data will be 
recorded on Socrates, as detailed in the Data Management Plan (Section 9). 
 
7.0 Patient and Public Involvement 
This study will not actively include any patients or lay members of the public to assist in the study design, 
management, analysis of results or dissemination of findings. Patients will be provided with a lay summary of the 
research findings after completion of the study. 
 
8.0 Funding and Supply of Equipment 
Stryker Orthopaedics will be supplying the lachmeter and dynamometer for this study. St. John of God Healthcare 
currently fund a 1 FTE RP who will also assist in this project.  
 
9.0 Data Handling and Management 
 
9.1 Data Quality Assurance and Monitoring  
 The principle of Good Clinical Practice will be adhered to throughout with the research team 
responsible for its own regular internal audit for quality, recruitment goals and results targets. 
This will be in the form of monthly research meetings for those involved in the trial. The 
Investigator will designate one or more appropriately trained and qualified individuals to 
monitor the progress of the clinical study. As per section 2.1.1 of the NHMRC Code, all clinical 
trial research data will be retained for a minimum of 15 years from the date of publication or 5 years 
following the completion of the research. 
9.2 Onsite Monitoring  
On-site monitoring visits shall occur throughout the course of the clinical study by the Chief 
Investigator. The Chief Investigator shall permit and assist the IDSM (should they chose to monitor 
the study) to carry out verification of completed case report forms (CRFs) against data in the source 

documents, which shall occur as per the departmental policy for undertaking such activities. 
All personnel involved with the conduct of the study must undertake to maintain the confidentiality 
of patients in the study. The requirements of the current Good Clinical Practice guidelines will be 
adhered to for data processing. 
10.0 Consent and Case Report Form Storage  
All case report forms (CRFs) must be completed and signed by staff that are listed on the site staff delegation 
log and authorised by the CI/ PI to perform this duty. The CI/PI is responsible for the accuracy of all data 
reported in the CRF. 
Data required according to this protocol are to be recorded on the CRFs as soon as possible. Patients will be 
identifiable with a unique study number. Only the research physiotherapist will have the key to identify 
individual patients. All CRFs must be legible and completed in black ink. Any necessary corrections are to 
be made by drawing a single line through the incorrect entry and writing in the revision, and must be initialed 
and dated by the investigator or his or her representative. Data are not to be obliterated by blacking out, using 
correction fluid or by erasing the original entry. Any documents related to the study must be archived directly 
at the study site. These documents include listings that identify study subjects, research group allocated to 
each study subject, consent forms, and all completed CRFs. All consent forms and CRFs will be stored by 
the CI/PI investigator in a locked filing cabinet in a dedicated locked research office. This office has key 
access with monitored security. Patient data will be logged electronically using each patient’s unique 
identification number with Socrates computer software on an encrypted, password-protected research 
computer on the Perth Hip and knee clinic network. This computer is located within a dedicated lockable 
research office within Perth Hip and Knee Clinic Subiaco. 
11.0 Assessment and Management of Risks  
The trial will be conducted in full conformance with the principles of the Declaration of Helsinki and ICH 
Good Clinical Practice guidelines. All data will be stored securely and held in accordance with Data 
Protection Act 1998. The trial will be reported in line with the CONSORT statement. 
Written informed consent will be obtained from all patients participating in the study. Patient safety is of 
paramount importance and all participants will be treated with respect and dignity throughout. Inclusion or 
exclusion from the study will not impact the quality of the care they receive. Participants will not receive any 
preferential treatment or payment for taking part in the study, and are free to leave the study at any point 
without any compromise to their further treatment. 
There is no “safe” radiation dose but it is best clinical practice to limit radiation exposure as much as possible. 
Routine radiological follow-up of patients undergoing TKA at Perth Hip & knee Clinic includes 

anteroposterior and lateral knee radiographs at discharge, and anteroposterior skyline and lateral radiographs 
at 1 year, and 2 years postoperatively. Additional standard long-leg radiographs are performed at 3 months 
following TKA. In this study, the same protocol will be adhered to with no additional radiation dose. 
12.0 Recording and Reporting of adverse events 
12.1 Definitions of Adverse Events  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
13.2 Outcome of Adverse Events  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
13.3 Causality  
 
 
 
 
 
 
 
 
The assessment of relationship of adverse events to the procedure is a clinical decision based on all available 
information at the time of the completion of the case report form. It is of particular importance in this study to 
Term 
Definition 
Adverse Event (AE) 
Any untoward medical occurrence in a patient or study participant, which does 
not necessarily have a causal relationship with the procedure involved. 
Serious Adverse Event (SAE). 
Any adverse event that: 
 
results in death, 
 
is life-threatening*, 
 
requires hospitalisation or prolongation of existing hospitalisation**, 
 
results in persistent or significant disability or incapacity, or 
 
consists of a congenital anomaly or birth defect 
*A life- threatening event, this refers to an event in which the participant was at risk of death at the time of the event; it does not 
refer to an event which hypothetically might have caused death if it were more severe. 
** Hospitalisation is defined as an in-patient admission, regardless of length of stay. Hospitalisation for pre-existing 
Conditions or planned upcoming surgeries (ie. Other knee replaced), including elective procedures do not constitute an SAE. 
       Table 3. Definition of adverse events  
Category 
Definition 
Non-severe 
The adverse event does not interfere with the participant’s daily routine, and does not require 
further procedure; it causes slight discomfort 
Life threatening 
The adverse event interferes with some aspects of the participant’s routine, or requires further 
procedure, but is not damaging to health; it causes moderate discomfort 
Hospitilsation required / 
prolonged  
The adverse event results in alteration, discomfort or disability which is clearly damaging to health 
Permanent of significant 
disability/ incapacity  
 
Permanent of significant disability/ incapacity  
 
Table 4. Severity of SAE classification 
Category 
Definition 
Related  
There is clear evidence to suggest a causal relationship, and other possible contributing factors can be ruled out. 
Probably related  There is evidence to suggest a causal relationship, and the influence of other factors is unlikely 
Possibly related  
There is some evidence to suggest a causal relationship (e.g. the event occurred within a reasonable time after 
administration of the study procedure). However, the influence of other factors may have contributed to the 
event (e.g. the participant’s clinical condition, other concomitant events). 
Not related 
There is no evidence of any causal relationship. 
Not assessable 
Unable to assess on information available 
Table 5. Causality of SAE classification  

capture events related to the mFA TKA and kFA TKA. The assessment of relationship of an adverse event to 
these additional safety issue(s) will also be carried out as part of the study. 
 
14.0 Recording of Serious Adverse Events  
All serious adverse events will be recorded in the medical records and the CRF, and the sites AE log. 
All serious adverse events (SAEs) must be recorded on a serious adverse event form (appendix 19.4). The 
Principal Investigator will complete the SAE form and the form will be emailed to the SJOG HREC Committee 
within 5 working days of becoming aware of the event. The Chief Investigator will respond to any SAE queries 
raised by the primary HREC as soon as possible. Where the event is unexpected and thought to be related to the 
procedure this must be reported by the Investigator to the Therapeutic Goods Administration via the Incident 
Reporting and Investigation Scheme within 15 days.  
 
All SAE’s will be reported as per the flow diagram below.  
 
 
 
Diagram 1. Flow chart for reporting SAE’s. 
 
14.0 Reporting Incidents  
 
 
14.1 Protocol deviations and notification of protocol violations 
A deviation is usually an unintended departure from the expected conduct of the study protocol, which does 
not need to be reported to the TGA. The principal investigator will monitor protocol deviations. 
A protocol violation is a breach which is likely to effect to a significant degree – 
a) the safety or physical or mental integrity of the participants of the study; or 
b) the scientific value of the study. 
 
 

 
The Chief investigator and IDSM will be notified immediately of any case where the above definition applies 
during the study conduct phase. 
 
14.2 Reporting Incidents involving a medical device 
Adverse device effects (complications) are defined as any of the following: 
a) Any device component failure (e.g. excessive migration of the implant or failure otherwise). 
b) Local complications arising from use of the TKA implants to include osteolysis, inflammation, local 
tissue reaction, periprosthetic fracture. 
c) Bone fracture during implantation 
d) Nerve damage arising from implant placement (as evidenced immediate postoperative by motor and/or 
sensory deficit not present preoperatively). 
e) Large vessel damage arising during surgery (with large blood loss, i.e. > 1500 ml). 
f) Prosthetic joint infection 
g) Surgical site infection 
h) Loosening of prosthetic components 
i) Other adverse events that are deemed device related and serious. 
 
All serious adverse events, life-threatening problems, or deaths that occur during or following the use of the 
devices during the study should be fully documented in the research record by the Chief Investigator including the 
onset date, complete description of the event, severity, duration, action taken, and outcome. The event should be 
documented at the appropriate interval case report form. The Chief Investigator will be responsible for notifying 
the reviewing Research Ethics Committee, of any unanticipated adverse events according to local regulations. 
The Chief Investigator will record all non-serious adverse events on the appropriate case report form. 
 
Some adverse events may lead to subsequent surgical intervention. The surgical intervention should be reported 
separately from the presentation of the other adverse event. For example, if the adverse event is reported at the 3 
months visit and a revision subsequently occurs after the 3 months visit, the revision should be reported in the 
next follow-up visit. 
 
In the short term, revisions will usually occur due to acute/chronic infection, instability, and/or subject 
experiencing severe pain due to various causes. This data will be used in combination with clinical assessment, 
target history / examination and further investigation to determine likelihood of requiring revision. 
 
For all cases where revision was necessary, the investigator must record and forward a description of 
intraoperative findings including: presence of local reaction to implant, gross subsidence of implant, and any 
intraoperative findings relating to the device failure. This information will be recorded by the intra-operative 

product specialist, and information will be submitted to the TGA via the medical device incident reporting guide.  
Explant analysis will occur throughout the duration of this study.  
 
15.0 Training  
The Chief Investigator will review and provide assurances of the training and experience of all staff working on 
this study. Appropriate training records will be maintained in the study files. All personnel working on this study 
will have completed the Guideline for Good Clinical Practice ICH E6(R2) Qualification.   
 
16.0 Archiving 
Site files will be stored in the locked research room at Perth Hip and Knee Subiaco. As per the NHMRC code, 
data will be stored for 15 years.  Patient information will be located on Genie Medical Solutions software, and on 
research database Socrates. Both of this software programs are located on servers within Australia, and are 
automatically back up. These programs can only be accessed by login and password, and are located on 
computers at Perth Hip and Knee Clinic.  
 
17.0 Publication and Dissemination Policy 
The findings of this study will be published in peer-review journals. There are no terms or conditions to the 
funding that may impact upon publication and dissemination. Authorship will reflect the amount of time spent 
designing the study, collating the data and writing the manuscript. 
 
 
18.0 References 
 
1. 
Bourne RB, Chesworth BM, Davis AM, et al. Patient satisfaction after total knee arthroplasty: who 
is satisfied and who is not? Clin Orthop Relat Res 2010;468:57e63. 
2. 
Lingard EA, Katz JN, Sledge CB, et al. Predicting the outcome of total knee arthroplasty. Journal of 
Bone and Joint Surgery- America 2004.86(10)2179-86. 
3. 
Macdessi SJ, Gharaibeh MA, Harris IA. How accurately can soft tissue balance be determined in 
total knee arthroplasty? Journal of Arthoplasty 2019 34(2);290-294 
4. 
Cobb J, Henckel J, Gomes P, et al. Hands-on robotic unicompartmental knee replacement: a 
prospective, randomised controlled study of the Acrobot system. J Bone Joint Surg Br. 2006 
Feb;88 (2):188-97. 
5. 
Dunbar NJ, Roche MW, Park BH, et al. Accuracy of dynamic tactile-guided unicompartmental knee 
arthroplasty. J Arthroplasty. 2012 May;27(5):803-8.e1. 
6. 
Conditt MA, Roche MW. Minimally invasive robotic-arm-guided unicompartmental knee 
arthroplasty. J Bone Joint Surg Am. 2009 Feb;91(Suppl 1): 63-8. 
7. 
Matsumoto T, Takayama K, Ishida K, et al.Radiological and clinical comparison of kinematically 

versus mechanically aligned total knee arthroplasty. Bone Joint J. 2017 May;99-B(5):640-646. 
8. 
Waterson HB, Clement ND, Eyres KS, et al. The early outcome of kinematic versus mechanical 
alignment in total knee arthroplasty: a prospective randomised control trial. Bone Joint J. 2016 
Oct;98-B(10):1360-1368. 
9. 
Dossett HG, Estrada NA, Swartz GJ, et al. A randomised controlled trial of kinematically and 
mechanically aligned total knee re- placements: two-year clinical results. Bone Joint J 2014;96-
B:907e13. 
10. 
Garratt AM, Brealey S, Gillespie WJ, et al. Patient- assessed health instruments for the knee: a 
structured review. Rheumatology (Oxford) 2004;43(11):1414–1423. 
11. 
Haywood KL, Garratt AM, Fitzpatrick R. Quality of life in older people: a structured review of 
generic self- assessed health instruments. Qual Life Res 2005;14(7):1651–1668. 
12. 
Jones CJ, Rikli RE, Beam WC. A 30-s chair-stand test as a measure of lower body strength in 
community-residing older adults. Res Q Exerc Sport. 1999;70(2):113-9. 
13. 
 Kreibich DN, Vaz M, Bourne RB, Rorabeck CH, Kim P, Hardie R, et al. What is the best way of 
assessing outcome after total knee replacement? Clin Orthop Relat Res. 1996(331):221-5. Epub 
1996/10/01.  
14. 
Bohannon RW: The clinical measurement of strength. Clin Rehabilitation. 1987, 1: 05-16. 
10.1177/026921558700100103. 
15. 
Burns SP, Spanier DE: Break-technique handheld dynamometry: relation between angular 
velocity and strength measurements. Arch Phys Med Rehabil. 2005, 86: 1420-1426. 
10.1016/j.apmr.2004.12.041. 
16. 
Lu TW, Hsu HC, Chang LY, Chen HL: Enhancing the examiner's resisting force improves the 
reliability of manual muscle strength measurements: comparison of a new device with hand-held 
dynamometry. J Rehabilitation Med. 2007, 39: 679-684. 10.2340/16501977-0107. 
17. 
O'Shea SD, Taylor NF, Paratz JD: Measuring muscle strength for people with chronic 
obstructive pulmonary disease: retest reliability of hand-held dynamometry. Arch Phys Med 
Rehabilitation. 2007, 88: 32-36. 10.1016/j.apmr.2006.10.002. 
18. 
Jenkinson C, Chandola T, Coulter A, et al. An assessment of the constuct validity 
of the SF-12 summary  scores across ethnic groups. J Pub Health Med 
2005;23(3):187–194. 
19. 
Ware J Jr, Kosinski M, Keller SD. A 12-item short-form health survey: 
construction of scales and preliminary tests of reliability and validity. Med 
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the KT-1000. Knee Surg Sports Traumatol Arthrosc. 2000;8(1):36-9. 
 

 
 
 
 
19.0 Appendices 
Appendix 19.1 : Patient Case Report Forms  
 
 
Patient ID :    
 
 
Preop 
 
1. 
Relevant Past Medical History 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 
 
2. 
Previous Surgery to knee (including dates) 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 
 
3. Other relevant notes in history 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 
 
4. 
Additional future elective surgery planned  
________________________________________________________________________
Date Form Completed 
 
Height 
 
Date of Operation 
 
Weight 
 
Study Number 
 
BMI 
 
Date of Randomisation 
 
Side 
 
CT date 
 
Sex 
  F      M       
Plain film Xray  
(A/P, lat, Skyline) 
 
Age 
 

________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
__________________________________________ 
 
 
5. 
Current Medication and Analgesia Regime 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 
 
 PROMS 
o Oxford 
o Forgotten joint 
o Kujala 
o Eq5D-5L 
o Vas Pain 
o Koos JR 
 Functional 
o Range 
o Mobilisation Equipment 
o Lachmeter 
 90* 
 20* 
o Dynamometer 
 Knee flexion (achillies) 
 Knee extension (Anterior distal shin) 
o 30STS 
 Mods? 
 
 
 

Completed by : 
 
6 weeks 
 
1. Current Medication and Analgesia Regime 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
____________________________________________________________________ 
2. Hospital Admission since last visit - if need be, complete SAE. 
______________________________________________________________________________________________
______________________________________________________________________________________________
___________________________________________________________________ 
3. How satisfied are you with your knee replacement? 
0   Extremely satisfied      0  Satisfied       0 Neutral        0 Dissatisfied        0 Extremely Dissatisfied  
 
 
 
 PROMS 
o Forgotten joint 
o Vas Pain 
 Functional 
o Range 
o Mobilisation Equipment 
o Dynamometer 
 Knee Flexion (Achille’s) 
 Knee Extension (Anterior distal shin) 
Physio Observations and Treatment plan 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 
 
3. 
Protocol Deviation and reason why 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 

Completed by : 
 
3 Months 
 
1. Current Medication and Analgesia Regime 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
____________________________________________________________________ 
2. Hospital Admission since last visit - if need be, complete SAE. 
______________________________________________________________________________________________
______________________________________________________________________________________________
___________________________________________________________________ 
3. How satisfied are you with your knee replacement? 
0   Extremely satisfied      0  Satisfied       0 Neutral        0 Dissatisfied        0 Extremely Dissatisfied 
 
 PROMS 
o Oxford 
o Forgotten joint 
o Kujala 
o Eq5D-5L 
o Vas Pain 
o KOOS Jr. 
 Functional 
o Range 
o Mobilisation Equipment 
o Lachmeter 
 90* 
 20* 
o Dynamometer 
 Knee Flexion (Achillies) 
 Knee Extension (Distal anterior shin) 
o 30STS 
 Mods? 

o XRAY (A/P, lat, skyline and LLWB) 
 
 
3. 
Physio Observations and Treatment plan 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 
 
4. 
Protocol Deviation and reason why 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 
 
Completed by :  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
12 Months 
 
1. Current Medication and Analgesia Regime 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 
2. Hospital Admission since last visit - if need be, complete SAE. 
______________________________________________________________________________________________
______________________________________________________________________________________________
___________________________________________ 
3. How satisfied are you with your knee replacement? 
0   Extremely satisfied      0  Satisfied       0 Neutral        0 Dissatisfied        0 Extremely Dissatisfied 
 
 PROMS 
o Oxford 
o Forgotten joint 
o Kujala 
o Eq5D-5L 
o Vas Pain 
o KOOS Jr.  
 Functional 
o Range 
o Mobilisation Equipment 
o Lachmeter 
 90* 
 20* 
o Dynamometer 
 Knee Flexion (Achillies) 
 Knee Extension (Anterior distal shin) 
o 30STS 
 Mods? 

o XRAY (A/P, lat, skyline) 
 
 
3. Physio Observations and Treatment plan 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 
 
4. Protocol Deviation and reason why 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 
 
Completed by :  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
24Months 
 
1. Current Medication and Analgesia Regime 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_____________________________________________ 
 
2. Hospital Admission since last visit  - if need be, complete SAE. 
______________________________________________________________________________________________
______________________________________________________________________________________________
___________________________________________ 
3. How satisfied are you with your knee replacement? 
0   Extremely satisfied      0  Satisfied       0 Neutral        0 Dissatisfied        0 Extremely Dissatisfied 
 PROMS 
o Oxford 
o Forgotten joint 
o Kujala 
o Eq5D-5L 
o Vas Pain 
o KOOS Jr. 
 Functional 
o Range 
o Mobilisation Equipment 
o Lachmeter 
 90* 
 20* 
o Dynamometer 
 Knee Flexion (Achillies) 
 Knee Extension (Anterior distal shin) 
o 30STS 
 Mods? 
 

 
o XRAY (A/P, lat, skyline) 
 
3. 
Physio Observations and Treatment plan 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 
4. Protocol Deviation and reason why 
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
______________________________________ 
 
Completed by:  
Please complete end of study form.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
Appendix 19.2 – End of Study Form 
 

 
 
Appendix 19.3: Clinical Trial Letter to GP 
         
 
 
END OF STUDY FORM 
RCT: MAKO mFA TKA vs MAKO kFA TKA 
 
Name (Initials only) 
Study Number:  
□ M □  F 
DOB: 
Date of form completion 
Years since operation 
 
 
 
 
 
 
 
Classification 
□ Reached end of follow-up 
□ Complete withdrawal from study 
 
 
Reason (if given): 
 
 
□ Withdrawal from study apart from survivorship analysis  
 
Reason (if given): 
 
 
□ Lost to follow-up 
□ Death 
□ Implant removed 
 
If withdrawn from study, does patient agree to be contacted annually for survivorship analysis? 
 
 
 
Comments 
 
 
 
 
 
Signature of PI: 
 
 
 
 
 
Date:  

  Dr. Gavin Clark and Dr. Dermot Collopy 
St. John of God Hospital Subiaco  
Perth Hip and knee Clinic Subiaco 
1/1 Wexford Street, Subiaco 6008. (08) 6489 1777 
Dear Dr [XXX], 
 
 
Patient name: 
Patient DOB: 
Research Code No: 
Enrolment Date:  
 
  
 
I am writing to let you know that the above patient has consented to taking part in our research study at St John of God Subiaco 
Hospital. This study is a prospective randomised controlled trial comparing clinical and radiological outcomes in patients 
undergoing functionally aligned Mako robotic-arm assisted total knee arthroplasty comparing those with a mechanical axis aligned 
knee replacement to those with a functionally aligned knee replacement. This alteration in alignment has a minor effect on overall 
alignment but changes individual component position in three dimensions.. Both surgical approaches are established techniques 
with excellent outcomes in patients with knee osteoarthritis. The findings of this study will enable us to determine which of the 
two surgical treatment options provides better clinical outcomes following TKA. 
 
All patients included in this study will receive the same preoperative treatment and postoperative rehabilitation program. A 
computer will randomly allocate each patient to one of the two treatment groups. To preserve the double-blinded nature of this 
study, both patients and observers recording outcomes of interest will be blinded to the treatment group. All participants will 
complete a series of health- related questionnaires during their follow-up consultations. 
 
Patients will undergo clinical follow up at 2 weeks, 6 weeks, 3 months, 1 year and 2 years after operative intervention. The surgery 
will be undertaken at St John of God Subiaco Hospital and follow up will be at the Perth Hip and Knee Clinic or Midland 
Orthopaedics. Each patient will be followed for two years following surgery and the total study duration is three years. After this 
time, data relating to the clinical and radiological outcomes will be collated, analysed and findings published in peer reviewed 
journals. Participants will also receive a lay summary of the pertinent research findings. My standard ongoing follow up of joint 
replacement patients each five years will then resume. 
 
Please let me know if you would like any further information. Thank you. 
 
Yours Sincerely, 
 
 
 
 
 
Mr Gavin Clark                                   Mr Dermot Collopy 
 
 
 
Consultant Orthopaedic Surgeons  
St John of God Subiaco Hospital 
Perth Hip and Knee Clinic 
 
 

 
Appendix 19.4 Local Site SAE / AE Form 
 
 
 
 

Appendix 19.5 PROMS (10,11) 
  
EUROQOL EQ-5D 5L 
© 1990 EuroQol Group, Rotterdam, The Netherlands; www.euroqol.org; EQ-5D is a trademark of the EuroQol 
Group 
 
Patient Name______________________________      ID _____________________        Side  
Right  
Left  
Date of review:    _____/______/______  
Follow up period:     PreOp       OR         ______________ weeks/months/years (circle one) 
 
By placing a tick in one box in each group below, please indicate which statement best describes your own health 
state today. Do not tick more than one box in each group. 
 
Mobility 
1. 
I have no problems in walking about 
2. 
I have slight problems in walking about 
3. 
I have moderate problems in walking about 
4. 
I have severe problems in walking about 
5. 
I am unable to walk about 
 
Self-care 
1. 
I have no problems washing or dressing myself 
2. 
I have slight problems washing or dressing myself 
3. 
I have moderate problems washing or dressing myself 
4. 
I have severe problems washing or dressing myself 
5. 
I am unable to wash or dress myself 
 
Usual activities (e.g. work, study, housework, family or leisure activities) 
1. 
I have no problems doing my usual activities 
2. 
I have slight problems doing my usual activities 
3. 
I have moderate problems doing my usual activities 
4. 
I have severe problems doing my usual activities 
5. 
I am unable to do my usual activities 
 
Pain/Discomfort 
1. 
I have no pain or discomfort 
2. 
I have slight pain or discomfort 
3. 
I have moderate pain or discomfort 
4. 
I have severe pain or discomfort 
5. 
I have extreme pain or discomfort 
 
Anxiety/Depression 
1. 
I am not anxious or depressed 
2. 
I am slightly anxious or depressed 
3. 
I am moderately anxious or depressed 
4. 
I am severely anxious or depressed 
5. 
I am extremely anxious or depressed 
6. 
 
 
 
 
 

 
 
Your Health State Today 
To help people say how good or bad a health state is, we have drawn a scale on which the best state you can 
imagine is marked 100 and the worst state you can imagine is marked by 0. We would like you to indicate on this 
scale how good or bad your own health is today, in your opinion. Please do this by drawing a line on the scale 
below to whichever point on the scale indicates how good or bad your health state is.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Forgotten Joint Score FJS12 
Patient Name______________________________  ID _____________________   Side  
Right  
Left  
Date of review:  _____/______/______ OR Follow up period:  PreOp  OR  _____ weeks/months/years (circle 
one) 
 
Are you aware of your affected or artificial joint… 
 
1.  
… in bed at night? 
 
never 
almost never 
seldom 
sometimes 
mostly 
2.  
… when you are sitting on a chair for more than 1 hour? 
 
never 
almost never 
seldom 
sometimes 
mostly 
3.  
… when you are walking for more than 15 minutes? 
 
never 
almost never 
seldom 
sometimes 
mostly 
4.  
… when you are taking a bath/shower? 
 
never 
almost never 
seldom 
sometimes 
mostly 
5.  
… when you are traveling in a car? 
 
never 
almost never 
seldom 
sometimes 
mostly 
6.  
… when you are climbing stairs? 
 
never 
almost never 
seldom 
sometimes 
mostly 
7. 
… when you are walking on uneven ground? 
 
never 
almost never 
seldom 
sometimes 
mostly 
8. 
… when you are standing up from a low-sitting position? 
 
never 
almost never 
seldom 
sometimes 
mostly 
9.  
… when you are standing for long periods of time? 
 
never 
almost never 
seldom 
sometimes 
mostly 
10.  
… when you are doing housework or gardening? 
 
never 
almost never 
seldom 
sometimes 
mostly 
11.  
… when you are taking a walk/hiking? 
 
never 
almost never 
seldom 
sometimes 
mostly 
12.  
… when you are doing your favourite sport? 
 
never 
almost never 
seldom 
sometimes 
mostly 
 
 
 
 
 
 
 
 
 
 

Oxford Knee Score 
Patient Name______________________________      ID _____________________        Side  
Right  
Left  
Date of review:    _____/______/______  
Follow up period:     PreOp       OR         ______________ weeks/months/years (circle one) 
 
Please answer the 12 questions below.  
1. During the past 4 weeks… How would you describe the pain you usually have from your knee?  
None  
        
 Very mild                
Mild 
       
Moderate               
Severe   
____________________________________________________________________________________
__ 
2. During the past 4 weeks… Have you had any trouble washing and drying yourself (all over) because of 
your knee?  
No trouble at all 
Very little trouble  
 Moderate trouble 
Extreme difficulty 
Impossible to do  
____________________________________________________________________________________
___ 
3. During the past 4 weeks…Have you had any trouble getting in and out of a car or using public 
transport because of your knee (whichever you would tend to use)?  
 
No trouble at all 
Very little trouble  
 Moderate trouble 
Extreme difficulty 
Impossible to do  
___________________________________________________________________________________ 
 
4. During the past 4 weeks…   For how long are you able to walk before the pain from your knee 
becomes severe with or without a stick)?  
 
No pain – more than 30 minutes                  
16- 30 minutes                     
 5-15 minutes  
     
Around the house only                                  
Not at all - pain severe when walking   
  ____________________________________________________________________________________ 
5. During the past 4 weeks…    After a meal (sat at a table) how painful has it been for you to stand up 
from a chair because of your knee?  
 
Not at all painful      
Slightly painful        
  Moderately painful        
 Very painful       
Unbearable 
 
 
6. During the past 4 weeks…    Have you been limping when walking, because of your knee?   
   

    
Rarely/Never 
Sometimes or just at first 
Often, not just at first  
 Most of the time  
All of the 
time   
_____________________________________________________________________________________ 
7. During the past 4 weeks…   Could you kneel down and get up again afterwards  
 
    
Yes, easily  
With little difficulty  
 With moderate difficulty 
 With extreme difficulty 
No, 
impossible  
_____________________________________________________________________________________ 
8. During the past 4 weeks…  Have you been troubled by pain from your knee in bed at night?  
 
No nights         
 Only one or two nights       
 Some nights          
 Most nights           
Every 
night   
___________________________________________________________________________________ 
 
9. During the past 4 weeks… How much has pain from your knee interfered with your usual work? 
(including housework)  
 
Not at all                   
A little bit                 
Moderately                      
 Greatly                
Totally    
___________________________________________________________________________________ 
 
10. During the past 4 weeks… Have you felt that your knee might suddenly “give way” or let you down?  
 
Rarely/Never 
Sometimes or just at first 
Often, not just at first    
 Most of the time    
All of the 
time   
___________________________________________________________________________________ 
 
11. During the past 4 weeks… Could you do household shopping on your own?  
 
Yes, easily  
With little difficulty  
 With moderate difficulty 
 With extreme difficulty 
No, 
Impossible  
____________________________________________________________________________________
_______ 
 
12. During the past 4 weeks… Could you walk down one flight of stairs?   
 
Yes, easily  
With little difficulty  
 With moderate difficulty 
 With extreme difficulty 
No, 
Impossible  
 
 
 
 
 
 
 

Kuujala Anterior Knee Pain Score 
Patient Name______________________________      ID _____________________        Side  
Right  
Left  
Date of review:    _____/______/______  
Follow up period:     PreOp       OR         ______________ weeks/months/years (circle one) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

KOOS Jr. 
Patient Name______________________________      ID _____________________        Side  
Right  
Left  
Date of review:    _____/______/______  
Follow up period:     PreOp       OR         ______________ weeks/months/years (circle one) 
 
 
 

Patient Satisfaction and VAS Pain- Post op 
 
 

Patient satisfaction and pain - preop 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Appendix 19.6 Functional Testing protocols 
30-second Chair Stand Test (13,14) 
Participant  
 Comfortable walking footwear (e.g. tennis shoes/cross trainers) should be worn.  
 The participant sits in the chair in a position that allows them to place their feet flat on the floor, shoulder width 
apart, with knees flexed slightly more than 90 degrees so that their heels are somewhat closer to the chair than 
the back of their knees.  
 The arms are crossed at the wrists and held close to the chest (across chest).  
Tester  
The tester stands close to the side of the chair for safety and so as they can observe the technique, ensure that the 
participant comes to a full stand and full sit position during the test.  
Practice  
A practice trial of one or two slow paced repetitions is recommended before testing to check technique and 
understanding.  
Procedure  
  From the sitting position, the participant stands up completely up so hips and knees are fully extended, then 
completely back down, so that the bottom fully touches the seat. This is repeated for 30 seconds.  
  Same chair should be used for re-testing within site.  
 If the person cannot stand even once then allow the hands to be placed on their legs or use their regular mobility 
aid. This is then scored as an adapted test score.  
Equipment 
 Timer / stopwatch 
 Straight back chair with a 17 inch seat height, preferably without arms 
o The same chair should be used for re-testing between sites.  
Verbal instructions – to be followed exactly. 
“For this test, do the best you can by going as fast as you can but don’t push yourself to a point of overexertion or 
beyond what you think is safe for you.  
1. Place your hands on the opposite shoulder so that your arms are crossed at the wrists and held close 
across your chest. Keep your arms in this position for the test.  
2. Keep your feet flat on the floor and at shoulder width apart.  
3. On the signal to begin, stand up to a full stand position and then sit back down again so as your bottom 
fully touches the seat.  
4. Keep going for 30 seconds and until I say stop.  
5. Get ready and START”.  
Scoring  

 
On the signal to begin, start the stop watch. Count the total number of chair stands (up and down equals 
one stand) completed in 30 seconds. If a full stand has been completed at 30 seconds (i.e. standing fully 
erect or on the way down to the sitting position), then this final stand is counted in the total.  
 
The participant can stop and rest if they become tired. The time keeps going.  
 
If a person cannot stand even once then the score for the test is zero.  
 
Next, allow the hands to be placed on their legs or use their regular mobility aid. If the person can stand 
with adaptions, then record the number of stands as an adapted test score (see score sheet). Indicate the 
adaptations made to the test.  
Minimal reporting standards  
N.B. The individual should use the assistive device (if any) they would normally use to perform the activity at the 
time of testing, irrespective of how they performed it previously. However, if an assistive device/rail is used, then 
it should be recorded for that occasion. 
Dynamometer Testing (15-17) 
 
Before testing, subjects to be seated in the exercise chair or plinth with no back support. The patient to be 
instructed to remain seated in an upright position and place both hands on his or her upper legs to avoid 
compensation. The "make" method for strength testing to performed rather than the "break" method as it has been 
shown to have better reliability and provide more accurate measures. 
 
For knee flexion, Dynamometer to be placed on the posterior aspect of the calcaneus. For knee extension, the 
Dynamometer to be positioned perpendicular to the anterior aspect of the tibia, 5 cm proximal of the medial 
malleolus. Patient limb to be positioned at  90 degrees of flexion, measured with a goniometer, in an open chain 
postion. As previous studies have experienced patients being too strong for testers, the dynamometer will be 
fixated to the base of the plinth via a purpose-built cradle during testing (Figure 1).. The straps to be fixated 
to standardised attachment in the treatment rooms (figure 2). Patients may have one test attempt prior to the 
recording attempt. The patient to be instructed to gradually build up strength for two seconds to avoid explosive 
contraction, then to continue with a three-second maximal contraction as used in previous studies. 
 
Patient to be instructed identically each time, and encouraged to “go go go” during each attempt.  There is to be a 
30 second rest between each attempt to allow for muscle recovery. Knee extension is be performed first, followed 
by knee flexion. The initial measurement is to be performed on the unaffected leg, followed by the affected leg, 
and thereafter alternated in a similar fashion for both flexion and extension. This will be measured three times of 
each leg.  
 
 
Figure 1 – Note: arms to be placed on upper legs, not on plinth  
 

 
 
Figure 2 
 
 
Lachmeter Testing  
To be performed at 20* and 90* knee flexion. Plinth to be set up to correct angles. Appendix 19.7  

 
Appendix 19.7Patient Information and Consent Form  
Participant Informed Consent Form  
Prospective Randomized Control Trial Comparing Functionally Aligned Total Knee 
Arthroplasty Utlising Mechanical Axis aligned planning versus Kinematic Axis Planning 
Short Title: RCT: MAKO mFA TKA vs MAKO kFA TKA  
This information sheet explains the research project and describes what will be involved 
should you decide to participate. Please read the information carefully and ask Dr Gavin 
Clark, Dr Dermot Collopy or Beth Tippett any questions you might have.  
 
1. What is the purpose of the project? 
 
This project is being conducted by Perth Hip and Knee Clinic. The objective of this study is to compare clinical and 
radiological outcomes in robotic-arm assisted TKA using mechanical alignment (MA TKA) versus robotic-arm 
assisted TKA with functional alignment (FA TKA). Both FA TKA and MA TKA are performed through similar skin 
incisions, robotic-guidance, and use identical implants. In MA TKA, bone is prepared and implants positioned to 
ensure that that the overall alignment of the leg is in neutral. In FA TKA, the bone is prepared and implants 
positioned to restore the natural alignment of the patient’s leg. Both of these surgical techniques provide 
excellent outcomes in TKA but it is not known which of the two techniques is better for patient recovery. Mako 
robotic-assisted TKA is an established treatment for arthritis of the knee joint. The positions of the implants and 
overall alignment of the leg are important as they influence how quickly the implants wear out and need 
replacing. The aim of this study is to determine if patient recovery is better with functionally aligned Mako 
robotic-assisted total knee arthroplasty (FA TKA) or mechanically aligned Mako robotic-assisted total knee 
arthroplasty (MA TKA). 
 
2. Why have I been asked to participate? 
 
You have been asked to take part in this project because you will undergo a robotic-assisted Total Knee Replacement 
performed by Dr Clark. Patients who received/will receive a Total Knee Replacement implanted with the assistance 
of Mako at St John of God Hospital Subiaco will be invited to participate in this project.   
 
3. Which type of TKA will I receive? 
 
The surgeon will review your medical records and confirm that it is safe for you to receive either the KA TKA or FA 
TKA. An online computer programme will then be used to randomly assign you to one of the two treatment groups. 
Randomly assigning patients to a treatment is a scientific method used in many clinical studies to reduce bias. 
 
4. What is the information being collected? 
 
As per routine protocol all patients undergoing a total knee replacement will undergo preoperative CT scan of 
the knee joint to establish the extent of the disease process, determine bone resection, and plan implant sizing 
and positioning. Preoperative clinical data such as your demographics, medical history, and joint range/function 
will be taken along with 6 standardised questionnaires. Intraoperative data will also be recorded during your 
surgery, which will be retrieved from the MAKO robot along with your operation record.   Postoperative data, 
including joint range of movement/function, analgesia requirements, hospital length of stay, concurrent 
medical issues will be recorded, along with 6 standardised questionnaires. Functional testing of joint range, 
stability (using a Lachmeter: Image 1) and strength (using a hand held dynamometer : Image 2) will occur 
preoperatively, 3m, 12m and 2 years. Plain film x-rays will be taken preoperatively, on discharge, 3 months, 1 
year and 2 years as per standard of care. At 3 months, a plain long leg x-ray will also occur. All data will be de-

identified prior to analysis.  
 
5. Do I have to participate? 
 
Participation in this project is voluntary, and it is up to you to decide if you want to take part. Your surgeon can 
answer any questions you might have about the project before you decide to participate. If you do not wish to 
participate in this project and you wish to replace your knee joint with a Mako robotic arm assisted procedure, your 
surgeon will perform your surgery according to their standard clinical practice. Your surgeon can tell you detailed 
facts about this treatment and the benefits of other types of treatment you can have. You should feel free to talk 
with your surgeon about other options and/or inform your surgeon if you do not want to partake in this project. 
 
You have the right to refuse to sign this consent form, but if you do not sign it, you will not be able to participate in 
this project.  Your health care outside of this project, payment for your health care, and your health care benefits will 
not be affected if you choose not to sign this form. 
 
If you do decide to participate you will be asked to sign a consent form, and will be given a copy of this document for 
your own records. Your referring GP will also be sent a notice of clinical trial involvement. You are free to withdraw 
from the project at any time and do not need to provide a reason for doing so. If you choose to withdraw from the 
project, any of your data that has already been collected prior to the withdrawal of consent will be used and retained. 
If you decide not to take part, or withdraw from the project, your decision will not affect the relationship or treatment 
you receive from Dr Clark. 
 
6. What will happen to me if I participate? 
 
Your project participation begins once you sign this consent form. If deemed suitable, the surgeons will discuss the 
trial with you during your consultation. After your consultation, the research physiotherapist will contact you to 
discuss your involvement and to answer any questions. You may wish to discuss this trial with your GP, family and 
friends about your involvement.  If you choose to participate, you will sign the consent form at your pre-admission 
appointment as well as undergo the preoperative testing. The preoperative testing will include function, strength, 
range as well as 6 standardised questionnaires. Preoperative testing will take roughly 30 minutes to complete. Once 
you have completed the surgery, you will continue with the standard follow up care provided by your surgeon, as 
well as the same functional testing at 6 weeks, 3 months, 12 months and 2 years.  Please check with the surgeon if 
you are unsure of what this involves. All patients will not be required to return to the surgeon for any tests or visits 
beyond what would normally be required for follow-up care of knee replacement patients. 
 
If you choose to participate in this project, a de-identified version of your pre-operative CT , x-rays, intraoperative 
data, robotic session file, demographics and outcomes will be archived in the Perth Hip and Knee Registry for future 
research, training and medical education. 
 
7. What do I have to do? 
 
There are no lifestyle or dietary restrictions regarding this project. If you sign the consent form below, you will still 
follow the normal standard of care as described by Dr Clark and Dr Collopy.  
 
8. What will happen to the information being collected during the project? 
 
If you participate in this project, your medical records and identity will be protected as required by law and as 
explained in this consent. The research team will use the de-identified version of your pre-operative CT, x-rays, 
intraoperative data, demographics and outcomes collected as part of standard practice for your surgery to complete 
this project. The research team will use the information collected during this project for the purposes described in 
this consent, and for any future anticipated or unanticipated scientific uses as the research team may deem 

appropriate. The results will be written up as an educational project in a thesis and published in a recognised medical 
journal. This will be undertaken by a Dr Clark as part of his PhD studies. A lay report will also be sent to you within 
one year after completion of the study. You will not be identified in any report or publication released. Confidential 
information held about you will be stored on a password-encrypted computer file and destroyed at five fifteen years 
after completion of the study. 
 
9. What are the possible side effects or risks of participating? 
 
There are no side effects related to this project. In general, there are no additional risks for you because of 
participation in this project, as there will be no changes from standard clinical practice for this procedure. Your 
surgeon should have already informed you of risks/side-effects associated with knee replacement surgery, but to 
summarize, you may experience 
none, some or all the effects listed below to varying degrees during/ following your surgery, irrespective of whether 
you are involved in this research study: 
- Pain and symptoms of non-inflammatory degenerative joint disease may persist to a lesser or greater degree than 
before surgery. 
- Your ability to use your knee may be worse compared to before surgery. 
- Deep vein thrombosis (DVT) – a blood clot in the veins of your legs which can cause pain and swelling (occurs in 
approximately 26% of patients). Rarely (less than 2% of patients), parts of the clot may break off and go to the lungs 
which can be fatal. 
- Some blood loss occurs during surgery – you may need extra blood given to you if you lose a large volume of 
blood. 
- Infection in the joint or at the wound site which may require antibiotics or further surgery (occurs in approximately 
1% of patients). Bone fracture (occurs in less than 1% of patients). 
- Redness and scarring at the wound site. 
- Damage to nerves and blood vessels (rare). 
 
Other medical complications of surgery can occur, especially if you already have a pre-existing condition. Such 
complications include heart attack, stroke, kidney failure, pneumonia, bladder infection, or allergic reaction to 
medication 
 
See Question 14 for more information regarding the possible risks related to your personal information. Talk to your 
surgeon if you have any questions about the risks of robotic-arm assisted knee replacement surgery, or about any 
risks associated with participating in this project. 
 
10. What are the possible benefits of participating? 
 
There are no additional risks or benefits to you as a patient as part of this study. Routine Operative techniques and 
post-operative care are undertaken in both groups. The data collection undertaken as part of this study is also Dr 
Clark’s normal standard of care as part of the Perth Hip and Knee Clinic Registry. You might not receive any benefits 
from participating in this project but the results might help others that have joint replacement surgery in the future. 
 
11. What are my alternative treatment options? 
 
You have discussed alternative treatments with your surgeon which include but are not limited to: conservative non-
surgical treatment, robotic-arm assisted total knee replacement surgery, total knee replacement surgery without the 
assistance of the arm, or no treatment at all. 
 
12. What are the financial disclosures of this project? 
 
Mr Clark and Mr Collopy are a paid consultants for Stryker Orthopaedics whom manufacture both the Mako robot 

and the knee implant used in this study. Neither surgeon is receiving any financial benefits for undertaking this study. 
 
13. What if new information becomes available? 
 
Sometimes during the course of a project, new information becomes available about the technique being studied. If 
new information does become available, Dr Clark and Dr Collopy will discuss this with you. 
 
14. Will my participation in this project be kept confidential?  
 
If you participate in this Project, your medical records and identity will be kept confidential as required by law and as 
explained in this consent. In Australia these privacy laws and regulations comprise the Privacy Act 1988 (Cth) and the 
Australian Privacy Principles. 
 
Once you sign this consent form, you allow your surgeon, their staff (including the study co-ordinator) and the 
hospital to give information about your health, medical records or the procedure (including CT scan, pre-operative 
plan, x-rays, intraoperative data, robotic session file, demographics and outcomes) to the research team, and you 
allow the research team to see and use this Personal Information and other information collected during, or in 
connection with the project. Other people or groups that may see this Personal Information collected in this Project 
include: 
- The investigator (being the surgeon) who conducts this study and their research staff. 
- Government bodies or agencies, such as the United States Food and Drug Administration (FDA) or the Australian 
Therapeutic Goods Administration (TGA), that may inspect all records relating to the Project.  
- People who ensure that medical treatment and research studies are safe, such as the Ethics Committee that 
reviews the Project. 
 
Some of the persons and groups listed above may not be required by law to protect your health information to the 
same extent as your surgeon and the hospital. Once your health information has been released, it may be re-disclosed 
or used for other purposes. 
 
By signing this consent form, you also allow Perth Hip and Knee (or its related entities) to de-identify and/or store or 
your de-identified Personal Information in a Research and Development database for future research, product 
development, training and medical education. The data will be labelled with a unique code in place of your name, 
and will be stored in a password-protected database. Whilst you do not own your Personal Information, you have a 
right of access to your Personal Information upon your written request. 
 
The trial is registered on Australian New Zealand Clinical Trials Registry under ACTRN12621000060842 and 
clinicaltrials.org under NCT04748510. 
 
 
15. What are the costs involved to participate in this project? 
 
The cost of your treatment and surgery is not affected by participation in this product and costs will be determined 
by your surgeon with your out of pocket expense dependant on your insurer. You will not be paid for participating in 
this project. 
 
16. What if something goes wrong? 
 
Perth Hip & Knee will not provide compensation, reimbursement, or free medical treatment if you suffer an injury or 
other medical complications as a result of your medical treatment, including your participation in this project. The 
principal investigators, Dr Clark and Dr Collopy, should be contacted immediately at (08) 6489 1777 if such injury or 
complication occurs.  They have informed you of the hospital’s policy and their policy on such matters. Your insurer 

may or may not cover such injuries or complications, however, by signing this consent form, you are not waiving any 
legal rights that you would otherwise have.  
 
17. Who has reviewed the project? 
 
The St John of God Human Research and Ethics Committee (HREC) has given ethical approval for the conduct of this 
project HREC # 1626 . If you have any concerns or complaints, you can contact the Executive Officer of the Committee 
on (08) 9382 6940 on a confidential basis.  
 
18. Who should I contact for more information? 
 
This patient information leaflet has been provided in advance of your surgery to give you sufficient time to decide on 
your participation in the study. Should you require any further information then please do not hesitate to contact us 
using the details below: 
 
 
 
 
 
 
 
 
 
Image 1: Lachmeter  
Image 2: Hand Held Dynamometer  
Beth Tippett 
Research Physiotherapist 
Perth Hip and Knee Clinic 
1/1 Wexford St 
Subiaco WA 6008 
Tel: 08 6489 1777 
Dr Gavin Clark 
Chief Investigator 
Consultant Orthopaedic Surgeon 
Perth Hip and Knee Clinic 
1/1 Wexford St 
Subiaco WA 6008 
Tel: 08 6489 1777 
Dr Dermot Collopy 
Chief Investigator 
Consultant Orthopaedic Surgeon 
Perth Hip and Knee Clinic 
1/1 Wexford St 
Subiaco WA 6008 
Tel: 08 6489 1733 

Consent 
Prospective Randomized Control Trial Comparing Functionally Aligned Total Knee 
Arthroplasty Utlising Mechanical Axis aligned planning versus Kinematic Axis Planning.  
 
- Being part of this study is your choice.  If you decline to participate in the study, it will not prejudice your care.  
- By signing this form, you agree that Perth Hip & Knee Clinic) will be the sole owners of any and all intellectual 
property, including inventions, discoveries, materials, works of authorship and copyrighted materials, that is created, 
conceived, discovered or reduced to practice during or as a result of this project.   
- By signing and dating this form below, you are saying you have carefully read all the sections of this Participant 
Information Form and Informed Consent Form (Protocol 1.6.1, HREC approval date : 10/11/21) and wish to 
participate in the project. You are also saying someone has answered all of your questions and that you voluntarily 
consent to be in this project.  If you do not sign this form, you will not be able to take part in this project. 
 
______________________________________ 
 
Name of Participant/Legal Representative (Printed) 
 
 
______________________________________ 
  
 
 
__________________ 
Signature of Participant/Legal Representative 
 
 
 
Date Signed 
I, the undersigned have discussed the nature and purpose of the study and the possible risks and benefits of 
participation with the participant and/or legally authorised representative. I believe that the participant and/or their 
representative has been fully informed, using language which is understandable and appropriate, and has 
understood this explanation. 
 
______________________________________ 
  
 
 
__________________ 
Signature of Investigator   
 
 
 
 
Date Signed 
Withdrawal of Consent 
I hereby WITHDRAW my consent to participate in the study described above and understand that such withdrawal 
will not make any difference to my medical care or my relationship with my surgeon or other clinic staff. 
 
______________________________________ 
 
Name of Participant/Legal Representative (Printed) 
 
 
______________________________________ 
  
 
 
__________________ 
Signature of Participant/Legal Representative 
 
 
 
Date Signed 
 
This Withdrawal of Consent should be forwarded to:   
 
Dr Gavin Clark and Dr Dermot Collopy 
Perth Hip & Knee 
Suite 1/1 Wexford Street 
Subiaco WA 6008 
A signed and dated copy of this entire form must be given to the patient. All parties must sign and date this 
research consent form in their own handwriting, in black ink.  
 

 
 

19.8 Intraop Data Collection Form 
    Patient Details             
RCT Patient ID-
  Height: 
cm Weight: 
kg  BMI: 
                                   
Gender: 
 Male 
 Female    ASA Score _____   Total Knee Replacement: 
 Left 
 
Right  
Pre-Operative 
ACL Intact: 
 Yes  OR  
 No 
Pre-Operative Plan – Femur (Preplanning page after surgeon review)      Size:____ 
Femoral Coronal Alignment: _________˚ 
 Varus 
OR 
 Valgus  
Femoral Rotation to TEA: 
 _________˚ 
 Internal 
OR 
 External  
Femoral Rotation to PCA:  _________˚ 
 Internal 
OR 
 External  
Distal Femoral Resection:  Lateral ___________mm 
Medial ___________mm 
Post Femoral Resection:    Lateral ___________mm 
Medial ___________mm 
Femoral Flexion Angle: 
 _________˚ 
 Extension 
OR 
 Flexion  
Pre-Operative Plan – Tibia (Preplanning page after surgeon review)    Size:____ 
Tibial Alignment: _________˚ 
 Varus 
OR 
 Valgus  
Tibial Rotation: _________˚ 
 Internal 
OR 
 External 
 
Tibial Slope: 
 _________˚ 
 Anterior 
OR 
 Posterior  
Tibial Resection:   Lateral ___________mm Medial ___________mm 
Intra-Operative 
Surgical Times (Please record in 24-hour format) 
Surgery Start: 
:
        Implantation: 
:
      Surgery Finish: 
:
 
(Knife-to-skin)      (Hour) (Mins)              (Final implant placed)  (Hour) (Mins)  
(Wound Closure)  (Hour) (Mins)  
Surgical Theory (Select one) 
 Mechanical Alignment OR 
 Mechanical w/ Bony Release OR 
 Functional Alignment 
Initial Limb Alignment (Joint balancing page – ACL and osteophytes removed)  
ROM: _________˚  TO 
_________˚  
Knee Alignment - Extension Without Stress:  _________˚ 
 Varus 
OR 
 Valgus  
 
   Flexion Without Stress:       _________˚ 
 Varus 
OR 
 Valgus  
Maximum Gap Values:  Extension Pose (5-15˚ flexion) 
Maximal Varus:  _________˚ 
 Varus 
OR 
 Valgus  
Lateral Gap: ________mm 
Maximal Valgus:  _________˚ 
 Varus 
OR 
 Valgus  
Medial Gap: ________mm 
Note: Record hyperextension as a negative value. 

RCT Patient ID-
   
Maximum Gap Values:  Flexion Pose (85-95˚ flexion) 
Maximal Varus:  _________˚ 
 Varus 
OR 
 Valgus  
Lateral Gap: ________mm 
Maximal Valgus:  _________˚ 
 Varus 
OR 
 Valgus  
Medial Gap: ________mm 
Changes to Implant Position and order of changes: 
Femoral Coronal: Y/N 
 
 
Tibial Coronal: Y/N 
Femoral Rotation: Y/N 
 
 
Tibial Rotation: Y/N 
Femoral Sagittal: Y/N 
 
 
Tibial Slope: Y/N 
Femoral AP Position: Y/N  
 
Tibial Depth: Y/N 
Femoral Depth: Y/N 
Total number of changes: ____ 
Final Intra-Op Plan 
                                                                                                         
Final Plan – Femur          Size:____ 
Femoral Coronal Alignment: _________˚ 
 Varus 
OR 
 Valgus  
Femoral Rotation to TEA: 
 _________˚ 
 Internal 
OR 
 External  
Femoral Rotation to PCA:  _________˚ 
 Internal 
OR 
 External  
Distal Femoral Resection:  Lateral ___________mm 
Medial ___________mm 
Post Femoral Resection:    Lateral ___________mm 
Medial ___________mm 
Femoral Flexion Angle: 
 _________˚ 
 Extension 
OR 
 Flexion  
Final Plan – Tibia          Size:____ 
Tibial Alignment: _________˚ 
 Varus 
OR 
 Valgus  
Tibial Rotation: _________˚ 
 Internal 
OR 
 External 
 
Tibial Slope: 
 _________˚ 
 Anterior 
OR 
 Posterior  
Tibial Resection:   Lateral ___________mm Medial ___________mm 
 
 
Final Plan – Alignment & Maximal Gaps 
Knee Alignment - Extension Without Stress:  _________˚ 
 Varus 
OR 
 Valgus  
 
   Flexion Without Stress:       _________˚ 
 Varus 
OR 
 Valgus  
Maximum Gap Values:  Extension Pose (5-15˚ flexion) 
Maximal Varus:  _________˚ 
 Varus 
OR 
 Valgus  
Lateral Gap: ________mm 
Maximal Valgus:  _________˚ 
 Varus 
OR 
 Valgus  
Medial Gap: ________mm 
 
Maximum Gap Values:  Flexion Pose (85-95˚ flexion) 
Maximal Varus:  _________˚ 
 Varus 
OR 
 Valgus  
Lateral Gap: ________mm 
Maximal Valgus:  _________˚ 
 Varus 
OR 
 Valgus  
Medial Gap: ________ 
Details of changes: 

RCT Patient ID-
   
Soft Tissue Releases: 
 Yes OR  
 No 
If Yes: (Please circle applicable) 
 
MCL: 
None 
Microfenestration (minor) 
Surgical release (knife) 
 
LCL:  
None 
Microfenestration (minor) 
Surgical release (knife) 
 
PCL:  
None 
Partial 
Complete 
 
Other: (if major surgical release/knife was required, please include detail of what structures were 
released and in what order)______________________________________________________ 
 
________________________________________________________________
__ 
 
 
Post-Implantation 
Triathlon Type: CS / CR / PS (Circle one)                  Insert Thickness: ___________ 
 
Final Limb Alignment (Joint balancing page)     
ROM: _________˚  TO _________˚ 
 
Knee Alignment - Extension Without Stress:  _________˚ 
 Varus 
OR 
 Valgus  
 
   Flexion Without Stress:       _________˚ 
 Varus 
OR 
 Valgus  
Maximum Gap Values:  Extension Pose (5-15˚ flexion) 
Maximal Varus:  _________˚ 
 Varus 
OR 
 Valgus  
Lateral Gap: ________mm 
Maximal Valgus:  _________˚ 
 Varus 
OR 
 Valgus  
Medial Gap: ________mm 
 
Maximum Gap Values:  Flexion Pose (85-95˚ flexion) 
Maximal Varus:  _________˚ 
 Varus 
OR 
 Valgus  
Lateral Gap: ________mm 
Maximal Valgus:  _________˚ 
 Varus 
OR 
 Valgus  
Medial Gap: ________mm 
 
Patella Tracking (Select one) 
 Excellent OR 
 Acceptable OR 
 Poor (Requiring release) 
 
 
 Femoral Bone Loss  : 
 Yes OR  
 No 
  
 
 
Note: When capturing ‘maximum stressed gaps’ - if applying a valgus force to the knee and the ‘maximal valgus’ 
is still in varus, this should be recorded as varus (vice versa for max varus). 
Note: Record hyperextension as a negative value. 

19.9 Detailed Surgical Planning  
 
All Patients will have pre-operative CT scan for planning as per current standard technique.  
 
Prior to surgery Patient’s pre-operative plan will be formulated on the basis of their randomisation.  
 
The control group will be planned to mechanical axis alignment.  
 
To do this the tibia will be sized to best match with the tibial plateau size without more than 2mm overhang 
anterolaterally or posteriorly and no overhanging of cortices medial and laterally. The coronal angulation of the 
tibia will be 0° of varus/valgus and posterior slope will be 3°. Resection depth will be set to a depth of 7mm 
maximal resection. 
 
The femur will initially be planned with the same size as the tibia and 8mm resection depths posteriorly and 
distally. Coronal angulation will be zero degrees varus/valgus and flexion of 3° for males and 5° for females. Size 
is then adjusted to allow best match to condylar radius of curvature. Femoral rotation will be set to parallel to 
surgical epicondylar axis. Femoral flexion angle is then altered within the range of 0-7° to optimise the anterior 
cut exit point. If unable to accommodate size without notching anterior cortex or having the tip of the implant 
achieving bony contact, size will be altered to achieve this. Medial lateral width of component will not overhang 
distal femur or will be downsized.  
 
The investigation group will be planned with Kinematic Axis alignment. This will be changed to functional 
alignment intra-operatively once soft tissue balance assessed.  
 
To achieve this the tibia will be sized to best match with the tibial plateau size without more than 2mm overhang 
anterolaterally or posteriorly and no overhanging of cortices medial and laterally. The resection depths will be set 
to 7mm medially and laterally. (N.B. This may exceed 6° of varus angulation but this will be adjusted intra-
operatively).  
 
The same size femur is then used as starting size. 6.5mm resections are planned medially and laterally from the 
distal and posterior condyles.(N.B. this may result in excessive valgus but this will be adjusted intra-operatively). 
Femoral flexion angle is then altered within the range of 0-7° to optimise the anterior cut exit point. If unable to 
accommodate size without notching anterior cortex or having the tip of the implant achieving bony contact size 
will be altered to achieve this. Medial lateral width of component will not overhang distal femur or will be 
downsized.  
 
Tibial slope is then matched to native slope whilst not exceeding combined femoral flexion and tibial slope of 
more than 10°. If this value exceeds 10° then tibial slope is reduced. 
 
A standard anaesthetic approach involving Spinal anaesthetic involving 2.5mls of heavy bupivacaine and 30-
60mcg buprenorphine(dependant on patient size and comorbidities). An Adductor block is then performed with 
ultrasound guidance using bupivacaine. Sedation or GA is then undertaken as per patient preference for comfort 
and anxiety. If the anaesthetic is required to be altered for any reason it will be done so at the discretion of the 
Consultant Anaesthetist in the best interests of the patient and any variation will be recorded. 
 
Surgical approach is consistent for both groups. Following Anaesthetic and IDC insertion a pre-prep is 
undertaken with alcohol based skin prep. A tourniquet is then applied and inflated to 300mm Hg immediately 
prior to skin preparation and draping. The surgical area is then protected with an iodine occlusive dressing 
(Ioban). 
 
The incision is midline with a medial parapatellar approach. Trackers and checkpoints are inserted into the femur 
and tibia, The ACL is resected if present. 
 
Registration is then undertaken. Osteophytes are then removed from distal femur and medial tibia. A pre-resection 

balancing workflow is then undertaken with maximal soft tissue gaps measured at 10 degrees of flexion and 90 
degrees of flexion.  
 
This results in the following table which values are the used as per below treatment algorithms to balance TKA 
 
Medial maximal gap(mm) 
Lateral maximal gap(mm) 
Extension 
** 
** 
Flexion 
** 
** 
 
The aim is to balance the knee within the alignment principles of each treatment arm such that extension is 
balanced from medial to lateral to within 1mm (2mm acceptable) and balanced from extension to flexion on the 
medial side to within 1mm (2 mm acceptable). The lateral flexion gap is allowed to be lax with the resections 
described above. The lateral flexion gap should not be tighter than the medial flexion gap. 
 
For the Control Group (MA alignment) the following is undertaken to balance the TKA 
These steps are undertaken but will always observe limits in below table 
Parameter 
Limit 
HKA 
2 varus – 2 valgus 
Tibial coronal 
2 varus – 2 valgus 
Tibial slope 
0-3 posterior slope 
Femoral coronal  
2 varus – 2 valgus 
Femoral rotation 
0 IR to 3 ER to SEA 
Femoral flexion 
0-7 flexion 
Combined flexion (tibial slope + femoral 
flexion) 
Max 10 
 
STEP 1 
Alter tibial resection depth until maximal extension gap is 20mm 
 
STEP 2 
 
Balance the extension gap as per table below 
 
Gap measurements 
Action 
Lateral ext = 20mm 
Medial ext <20mm 
Increase Tibial varus up to two degrees with 
COR locked on LTP 
Lateral = 20mm 
Medial = 20mm 
Move on to Flexion balance 
Lateral < 20mm 
Medial = 20mm 
Increase Femoral valgus up to two degrees 
with COR locked on MFC 
 
The medial or lateral side may remain tight after these steps. This indicates the need for soft tissue release. These 
will be undertaken at the trial phase where the soft tissues will be under tension and release is easier to perform. 
 
 
 
 
 
 
 
 
 
 

STEP 3 
 
Balance Medial flexion gap as per table below. N.B. If medial extension gap remains tight aim to match medial 
flexion gap to equalise medial side 
 
Gap measurements 
Action 
Medial Flex = Medial Ext 
Lateral flex >=20mm 
Move on to check Femoral flexion 
Medial flex < Medial extension 
Lateral flex >= 20mm 
Externally rotate femur by up to 3 degrees 
with COR locked on posterior lateral 
femoral condyle 
Medial flex < Medial extension 
Lateral flex < 20mm 
Increase posterior resection depth until 
medial flexion depth equals medial 
extension gap. (N.B. need to check femoral 
rotation allows for sufficient bone contact 
anteriorly) 
Medial flex > Medial extension 
Lateral flex > 20mm 
Decrease posterior resection depth until 
medial flexion depth equals medial 
extension gap. (N.B. need to check femoral 
rotation prevents notching anteriorly) 
Medial Flex = Medial Ext 
Lateral flex < 20mm 
Requires internal rotation of femur with 
COR locked on posterior medial femoral 
condyle (N.B. Surgeon required to check 
stability of femoral tracker in flexion with 
the checkpoint as this may cause this rare 
combination) 
 
STEP 4 
 
Check Anterior cut on plan to ensure enough bone contact without notching. Anterior cut should exit within 1cm 
of tip of femoral prosthesis. Femoral flexion with COR locked at centre of femoral component radius of curvature 
should be adjusted within the range 0-7 degrees of flexion to finalise component position. 
 
STEP 5 
 
Execute bone cuts as planned and trial with 9mm insert. Perform soft tissue releases as necessary to balance gaps 
within 1mm. Utilise ligament balancing page on Mako software to assess soft tissue balance aim for equal gaps 
and accept differences of up to 2mm if best efforts to balance have been made. Assess sagittal stability clinically 
and upsize insert if positive drawer test. Partial PCL release can be performed for sagittal balance if tight. This 
can then be trialled and if adequate sagittal stability a CS insert utilised. IF PCL needs to be completely released 
for balance then conversion to a PS component will be required. 
 
STEP 6 
 
Insert definitive implants. Tibia and Patella are cemented. The femoral component is uncemented. Reassess 
balance for final measurements. 
 
STEP 7 
 
Lavage of joint with pulsatile lavage system. LA infiltration with 80-100ml(dependant on patient mass) of 0.2% 
Bupivicaine, 1g tranexamic acid and 1 ml 1:1000 Adrenaline throughout capsule and soft tissues. Closed in layers 
with either subcuticular sutures or staples dependant on patient skin quality. 

 
For the Investigation Group (Functional alignment) the following is undertaken to balance the TKA.  
These steps are undertaken but will always observe limits in below table 
Parameter 
Limit 
HKA 
6 varus – 3 valgus 
Tibial coronal 
6 varus – 3 valgus 
Tibial slope 
0-7 posterior slope 
Femoral coronal  
3 varus – 6 valgus 
Femoral rotation 
6 IR to 6 ER to SEA 
Femoral flexion 
0-7 flexion 
Combined flexion (tibial slope + femoral 
flexion) 
Max 10 
 
 
STEP 1 
Alter tibial resection depth until maximal extension gap is 20mm 
 
STEP 2 
 
Balance the extension gap as per table below 
 
Gap measurements 
Action 
Lateral ext = 20mm 
Medial ext <20mm 
Increase tibial varus up to 6 with COR 
locked on LTP. If reach Tibial limit of 6 
varus then decrease femoral valgus with 
COR locked on LFC until balanced or reach 
HKA limit.  
Lateral = 20mm 
Medial = 20mm 
Move on to Flexion balance 
Lateral < 20mm 
Medial = 20mm 
Decrease tibial varus with COR locked on 
MFC until reach HKA limit 
 
The medial or lateral side may remain tight after these steps. This indicates the need for soft tissue release. These 
will be undertaken at the trial phase where the soft tissues will be under tension and release is easier to perform. 
STEP 3 
 
Balance Medial flexion gap as per table below. N.B. If medial extension gap remains tight aim to match medial 
flexion gap to equalise medial side 
 
Gap measurements 
Action 
Medial Flex = Medial Ext 
Lateral flex >=20mm 
Move on to check Femoral flexion 
Medial flex < Medial extension 
Lateral flex >= 20mm 
Externally rotate femur with COR locked on 
posterior lateral femoral condyle until 
balance achieved 
Medial flex < Medial extension 
Lateral flex < 20mm 
Increase posterior resection depth until 
medial flexion depth equals medial 
extension gap. (N.B. need to check femoral 
flexion allows for sufficient bone contact 
anteriorly) 

Medial flex > Medial extension 
Lateral flex > 20mm 
Decrease posterior resection depth until 
medial flexion depth equals medial 
extension gap. (N.B. need to check femoral 
rotation prevents notching anteriorly) 
Medial Flex = Medial Ext 
Lateral flex < 20mm 
Requires internal rotation of femur with 
COR locked on posterior medial femoral 
condyle (N.B. Surgeon required to check 
stability of femoral tracker in flexion with 
the checkpoint as this may cause this rare 
combination) 
 
 
 
STEP 4 
 
Check Anterior cut on plan to ensure enough bone contact without notching. Anterior cut should exit within 1cm 
of tip of femoral prosthesis. Femoral flexion with COR locked at centre of femoral component radius of curvature 
should be adjusted within the range 0-7 degrees of flexion to finalise component position. 
 
STEP 5 
 
Execute bone cuts as planned and trial with 9mm insert. Utilise ligament balancing page on Mako software to 
assess soft tissue balance aim for equal gaps and accept differences of up to 1mm. For greater differences adjust 
plan of tibial cut to balance if possible within specified limits. Perform recut and reassess balance. If unable to 
achieve balance within limits of bony alignment perform soft tissue releases as necessary to balance gaps within 
1mm. Utilise ligament balancing page on Mako software to assess soft tissue balance aim for equal gaps and 
accept differences of up to 2mm if best efforts to balance have been made. Assess sagittal stability clinically and 
upsize insert if positive drawer test. Partial PCL release can be performed for sagittal balance if tight. This can 
then be trialled and if adequate sagittal stability a CS insert utilised. IF PCL needs to be completely released for 
balance then conversion to a PS component will be required. 
 
STEP 6 
 
Insert definitive implants. Tibia and Patella are cemented. The femoral component is uncemented. Reassess 
balance for final measurements. 
 
STEP 7 
 
Lavage of joint with pulsatile lavage system. LA infiltration with 80-100ml(dependant on patient mass) of 0.2% 
Bupivicaine, 1g tranexamic acid and 1 ml 1:1000 Adrenaline throughout capsule and soft tissues. Closed in layers 
with either subcuticular sutures or staples dependant on patient skin quality. 
 
Post-operative Management 
 
All patients will be transferred to recovery. There they will have standard pain protocol guidelines followed. 
When alert, comfortable and stable the patient will be transferred back to the orthopaedic ward. Intravenous fluids 
will continue until drinking oral fluids. 
 
Patients will be charted regular slow release narcotic analgesia and immediate release narcotic to be given as 
required. Oxycodone will be first choice narcotic with Tapentadol, Buprenorphine, and Tramadol as second line 
agents. 
 
Patients will also be charted regular Paracetamol, Celebrex (if<80 years and good renal function), Pregabalin 
(dose dependant on age and size). They will have regular aperients. 

All patients will have regular cryotherapy. 
 
IDC will be removed prior to 8am morning after surgery. IV cannula will be removed after last dose of IV Abs 
(24/24 post surgery). 
 
Patients will be stood and have their knee ranged on day of surgery. They will mobilise as able and no limits will 
be placed on flexion range. 
 
Patients will have daily Physiotherapy and undertake self-directed exercise three times per day consisting of 
seated flexion exercises and bed based extension exercises. 
 
Discharge criteria will be patient comfortable and safely mobile utilising oral analgesia, with a dry wound and 
greater than 80 degrees of flexion, having had a bowel motion.