Prospective Clinical Study Evaluating Tibiofemoral Rotational Alignment Using Intraoperative Sensing During Total Knee Arthroplasty
Phase: NA
Conditions: Osteoarthritis
Sponsor: Orthosensor, Inc.

Prospective Clinical Study Evaluating Tibiofemoral Rotational Alignment using Intraoperative Sensing during TKA 
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PROTOCOL 
 
 
Prospective Clinical Study Evaluating Tibiofemoral Rotational 
Alignment using Intraoperative Sensing during Total Knee 
Arthroplasty 

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Clinical Investigation Approval/Agreement 
 
 
I, _________________________ (name of Principal Investigator), as Principal Investigator 
for this Clinical Research Study have read and agree with the study design described 
within this clinical research protocol. I agree to follow the protocol as described above 
and abide by the rules and regulations set forth within it and the Code of Federal 
Regulations. 
 
 
___________________________________________________ 
____________________ 
Signature of Principal Investigator 
Date 
 
 
 
 
Statement of Confidentiality and Sponsor Address 
 
 
This document may contain confidential and proprietary information belonging to 
OrthoSensor, Inc. Access to this document is restricted to the following persons: 
 
A. The Principal Investigator/surgeon for whom it was prepared; 
 
B. Associates involved with the study under the direct supervision of the Principal 
Investigator; and 
 
C. Members of the Institutional Review Board. 
 
Those persons with authorized access to this document shall not photocopy, reproduce 
by any means or reveal the contents of this document to any other person without the 
expressed written consent of OrthoSensor, Inc. 

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1. INTRODUCTION 
The success of total knee arthroplasty (TKA) depends on a multitude of surgical 
factors, including appropriate rotational alignment of the prosthetic components [11]. 
Despite the high success rate of TKA, early post-operative complications can occur 
as a result of poor rotational positioning of one or both components [5, 8, 18], which 
may ultimately require revision surgery [11, 13]. Complications indicative of 
tibiofemoral rotational incongruency may present early in the post-operative period 
with patient complaints of anterior knee pain, joint stiffness, the sensation of 
instability, and difficulty navigating stairs and inclined planes. It has been reported 
that the incidence of anterior knee pain may be as high as 20% after a TKA [1, 10, 
14]. Clinical examinations of these incongruent patients can reveal restricted range 
of motion, patellar crepitus, patellar maltracking (tilt - dislocation), and significant 
rotational mismatch displayed by rotational gait disturbances (foot progression angle) 
[3, 4, 6, 14, 16-18]. Suboptimal outcomes due to incongruency, which have been well 
documented in literature, may be associated with only small rotational deviations of 
the tibial and femoral components. For instance, Barrack, et al. reported that as little 
as 6.2° of internal rotation (IR) of the tibial component is associated with 
postoperative anterior knee pain [1]. Berger, et al. showed that combined IR of the 
tibial and femoral components from 3° to 8° was correlated with patellar subluxation, 
and 7° to 17° of combined IR correlated with observed patellar dislocation or patellar 
prosthesis failure [2]. 
 
While there are advocated methods for establishing optimal rotation of the femoral 
component, no such reliable method currently exists for positioning the tibial tray 
[12]. Thus, surgeons must rely upon anatomic landmarks to guide proper tibial 
component orientation. These landmarks include: the projected femoral 
transepicondylar axis, medial third of the tibia, posterior condylar line of the tibia, 
mid-sulcus of the tibia spine, malleolar axis, patellar tendon, and axis of the second 
metatarsal [12]. However, difficulty may exist in identifying these landmarks during 
surgery. Poor intraoperative visibility, coupled with variations in patient anatomy, can 
contribute to unfavorable positioning. It has been suggested that aligning the tibial 
tray to the mid-third of the tibial tubercle may reduce positioning outliers with more 
consistency than referencing other anatomic landmarks [15]. Yet, reliance on these 
landmarks is still subject to variability [12, 19] and may not provide the precision 
necessary to avoid complications, such as those described by studies conducted by 
Barrack, et al. and Berger, et al. As such, an obvious need exists to refine clinical 
technique, and to explore new methods to optimize tibiofemoral implant congruency. 
 
Recently, technology has made it possible to embed microelectronics into the 
standard tibial trial [9] (VERASENSE™ Knee System, OrthoSensor, Dania FL). This 
array of sensors provides dynamic intraoperative feedback regarding tibiofemoral 
position and quantitative pressure at peak contact points in the medial and lateral 

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compartments during TKA trailing. Utilizing sensor-derived data, the surgeon can 
now evaluate intercompartmental loading throughout the range of motion and correct 
for soft-tissue abnormalities while receiving real-time feedback regarding joint 
position and the tibiofemoral relationship defined by the contact point location. 
 
2. STUDY DESIGN 
The study is designed as a prospective, randomized (two-cohort) double-blinded 
clinical evaluation and will be conducted at multiple centers throughout the United 
States. Approximately 500 patients will be included and followed for a period of 2 
years. Clinical Assessments will be performed at baseline, 6 weeks, 6 months, 1 and 
2 years after surgery. 
 
3. OBJECTIVES 
The objectives of the study are twofold: 1) Evaluate how intra-operative sensing may 
assist the surgeon with tibiofemoral rotational alignment by testing the precision and 
variability of setting tray rotation to the mid-third of the tibial tubercle. 2) Understand if 
patients with a combined axial rotation couple at the tibiofemoral joint and 
quantitative intercompartmental balance, achieved with the use of VERASENSE, 
exhibit less post-operative knee pain and improved clinical outcomes. Radiographic 
outcomes will also be assessed to measure post-operative alignment and to evaluate 
the prevalence and location of radiolucency and/or osteolysis. 
 
Hypothesis: TKA with VERASENSE results in a more reliable and precise option for 
establishing implant-to-implant congruency and joint balance leading to less knee 
pain, faster return to normal activities and higher patient satisfaction compared to 
TKA without VERASENSE. 
 
The secondary objectives of the study are to establish correlations between the 
intraoperative VERASENSE data, the surgeon’s perception of balance and patient 
outcomes in addition to understanding any learning curve associated with using new 
technology. 
 
4. TREATMENT AND DEVICE 
The intervention involves the use of VERASENSE by the surgeon during Total Knee 
Replacement Surgery. VERASENSE is available for use with the Stryker Triathlon 
Total Knee System. VERASENSE replaces the standard tibial trial inserts and is 
embedded with microelectronics and sensors to provide surgeons with real-time 
knee kinetic data. The data is wirelessly transmitted to a graphic display 
(VERASENSE Knee Application), allowing surgeons to quantify and assess soft 
tissue intercompartmental loads throughout the range of motion. The VERASENSE 
sensor is not an investigational device. OrthoSensor, Inc., received FDA 510K 
clearance in 2009. The indication for use is a tool for adjustment of the femoral knee 

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implant to reduce instability from flexion gap asymmetry. The VERASENSE sensor is 
sterile and single patient use. 
 
4.1 – Description of VERASENSE 
• One articulation (Figure 1): Cruciate Retaining (CR); However can be utilized with 
Posterior stabilizing implant designs 
• Six Sizes: 2, 3, 4, 5, 6, 7 
• Four attachable shim thicknesses: 9, 11, 13, and 16mm 
Figure 1 – CR VERASENSE Inserts 
 
4.2 – VERASENSE Knee Application (Figure 2) 
• Graphic display is a 27” iMac with keyboard, mouse, bar-code reader, activation 
magnet, receiver (Antenna) 
• Software application provides femoral contact point location and load values for 
medial and lateral condyles; kinematic tracking; tray rotation, tibia varus/valgus axis; 
mechanical axis 
Figure 2 – Graphic Display 
 

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5. METHODS / PROCEDURES 
Patients indicated for TKA and who meet all study eligibility criteria will be asked to 
participate in the study. Eligible patients will receive a primary unilateral PCL- 
retaining or – sacrificing TKA using the Stryker Triathlon Total Knee System with or 
without the use of the VERASENSE™ Knee System. Patients will be enrolled in a 
consecutive series consisting of two cohorts (Groups A and B). Both groups are 
described below: 
 
Group A – Control (Surgeon-Guided) will consist of 250 consecutive patients who 
will undergo primary unilateral PCL-retaining or – sacrificing TKA using the Stryker 
Triathlon Total Knee System without the use of VERASENSE to guide rotational 
alignment and balance. Prior to closing the arthrotomy, VERASENSE will be 
utilized in a surgeon-blinded fashion to record rotational alignment and 
intercompartmental pressures through a range of motion. 
 
Group B (Sensor-Guided) will consist of 250 consecutive patients who will undergo 
primary unilateral PCL-retaining or – sacrificing TKA using the Stryker Triathlon Total 
Knee System with the use of VERASENSE to guide rotational alignment and 
balance. The sensor data will be used for balancing per the VERASENSE protocol 
below. 
 
Each patient will be given a unique study number once informed consent has been 
obtained. The investigator will be blinded to the patient study number and the patient 
will be blinded to his/her assigned group. It will be important that all patients remain 
blinded to their assigned group. The patient will be informed during the consent 
process that they may or may not receive their knee replacement procedure using 
the VERASENSE Knee System. 
Radiographic outcomes will be assessed on all patients within the first 12 weeks and 
at the annual visits. Any postop complications will also be monitored. 
 
Surgical Protocol – Using VERASENSE 
 
All knees will be prepared using standard instrumentation and a measured resection 
or gap balancing technique. The following steps will be performed when using 
VERASENSE: 
 
Step 1: Establish Tibial Tray Rotation: 
 
Select and position appropriate sized trial tibial tray. Align the tray 
to the anatomy (mid-medial third of the tubercle) as 
recommended by the manufacture’s surgical technique. Insert a 
single anterior or posterior pin (medially or laterally) into the trial 
tray to allow for internal / external rotational adjustment while 
maintaining optimal medial / lateral coverage. 
 
Figure 2 - view of proximal tibia referencing the mid-medial third 
of tibial tubercle 

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Step 2: Sensor Insertion 
 
 
Insert the VERASENSE Sensor with appropriate sized shim 
attached to replicate thickness of standard trial insert. In a tight 
knee capsule, it may be necessary to insert the VERASENSE 
Sensor prior to insertion of the femoral trial. DO NOT utilize 
excessive force or impact the sensor directly with a mallet. 
 
Figure 3 - VERASENSE™ Sensor activated and inserted into 
knee 
 
 
 
Step 3: Establish Tibial Tray Rotation Utilizing Contact Points 
With the leg supported in 10° flexion, rotate the tibial tray to the most posterior contact 
point (internally or externally) as needed to horizontally align the medial and lateral 
contact points within 5° of each other. Reference protocol found in Appendix I on how to 
hold the leg using VERASENSE. A positive (+) value in the Contact Point Rotation (CP 
Rotation box) indicates internal rotation (IR); a negative (-) value indicates external 
rotation (ER). Figures 4-6. 
 
When preferred tray rotation is achieved (within 5° Contact Point Rotation): 
• 
Add additional Pin to stabilize tray 
• 
Flex knee and confirm patellar tracking 
• 
Record the final value 
 
 
 
Figure 4 - VERASENSE™ Sensor as displayed on graphical user interface. CP (Contact Point) 
Rotation degree [in red box] references the degree of tibiofemoral incongruity. Yellow circles 
correspond to femoral contact points. The number 8 represents total pounds of pressure in the 
medial and lateral compartments 

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Figure 5 - Left: Medial and lateral femoral contact points (indicated by arrows) demonstrate tibiofemoral 
rotational incongruency, due to excessive IR of the tibial tray. Right: After correcting for IR, the femoral 
contact points demonstrate symmetry (indicated by arrows). 
 
 
 
 
Figure 6 - Left: Example of excessive ER (indicated by arrows), as a result of referencing the mid-third 
of the tibial tubercle, shown by the sensor interface. Middle: Trial tibial/femoral components in place with 
the sensor; tibial tray visually and digitally exhibiting external rotation. Right: The tibial tray is rotated to 
improve congruency, as seen by the parallel contact points (indicated by arrows) on the sensor 
interface. 
 
Step 4: Balance Soft-Tissue Sleeve 
 
Once tibial tray rotation has been assessed, the medial and lateral compartment 
pressures will be evaluated in the coronal and sagittal planes. The soft tissue gaps will 
be evaluated and recorded at 10°, 45°, and 90° of flexion, with the hip in neutral rotation 
and the femur supported just proximal of to the knee. The capsule must be closed 
provisionally during assessment at each pose using a towel clip placed above and below 
the patella in the medial retinaculum. Incremental balancing using a pie-crusting 
technique with an 18-guage needle or #11blade scalpel is recommended to address 
ligamentous tension when necessary. Additional bony resections may be necessary for 
excessive loading (refer to surgical reference guide). Previous research evaluating the 
use of VERASENSE during TKA suggests a load differential of up to 15 lbs or less 
between the medial and lateral condyles is indicative of soft-tissue balance [7] (Figure 
7). These balancing parameters will be the target in the sensor-guided group. 

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Figure 7 – Left: The mediolateral intercompartmental difference, pre-release, is 42 lbs. This value 
exceeds the 15 lb. limit, thus classifying this joint as “unbalanced.” Right: The mediolateral 
intercompartmental difference, post-release, is 1 lb. and was classified as “balanced” upon closing. 
 
6. CLINICAL SITES 
This study will be conducted at multiple centers by experienced, high-volume surgeons in 
the United States 
 
7. PATIENT SELECTION 
Enrollment: Approximately 500 patients will be enrolled and followed for a period of 24 
months in order to assess patient outcomes. Each center is expected to enroll 
approximately 100 patients (50 in each group). The investigator is responsible for 
evaluating each patient against the following criteria and assuring that the patient meets 
the following requirements in order to be enrolled in the study. Each patient must meet all 
the inclusion criteria and none of the exclusion criteria to be considered for enrollment. 
 
7.1 Patient Eligibility 
a. Inclusion Criteria 
• Patients who meet the indications for use for primary PCL-retaining TKA using 
the Triathlon® Total Knee System using VERASENSE™ 
• Subject must be diagnosed with one or more of the following conditions 
■ osteoarthritis 
■ rheumatoid or other inflammatory arthritis 
■ post-traumatic arthritis 
• Subject is likely to be available for all study visits 
• Subject is able and willing to sign the informed consent and follow study 
procedures 
 
b. Exclusion Criteria 
• Prior Total Knee Arthroplasty 
• Avascular Necrosis 
• Any knee surgery other than meniscectomy (can be arthroscopic or open) 
• Ligament insufficiencies, prior surgeries such as ACL or PCL reconstructions, 
posterolateral reconstructions, osteotomies, tibia plateau fractures 
• Ipsilateral foot/ankle and hip arthritis 

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• Range of motion less than 90°, flexion contracture greater than 20° 
• Subject has a mental condition that may interfere with the subject’s ability to 
give an informed consent or willingness to fulfill the study requirements (i.e., 
severe mental retardation such that the Subject cannot understand the 
informed consent process, global dementia, prior strokes that interfere with the 
Subject’s cognitive abilities, senile dementia, and Alzheimer’s Disease) 
• Any subjects meeting any contraindication criteria as identified in the locally 
approved labeling for the device should be excluded from this study. 
 
7.2 Contraindications for the Triathlon™ Knee are: 
1. Any active infection or suspected latent infection in or about the knee joint 
2. Distant foci of infection which may cause hematogenous spread to the implant 
site 
3. Any mental or neuromuscular disorder which would create an unacceptable risk 
of prosthesis instability, prosthesis fixation failure, or complications in post- 
operative care 
4. Bone stock compromised by disease, infection or prior implantation that cannot 
provide adequate support and/or fixation to the prosthesis 
5. Skeletal immaturity 
6. Severe instability of the knee joint secondary to the absence of collateral 
ligament integrity and function 
7. Obesity. An overweight or obese patient can produce loads on the prosthesis 
that can lead to failure of fixation of the device or to failure of the device itself 
 
7.3 Patient Failure / Withdrawals 
Removal or revision of any implant or malfunction of VERASENSE™ intra- 
operatively will be considered endpoints, with the patient being withdrawn from 
continued follow-up in the study. Every attempt must be made to ensure that all 
patients return for all of the post-operative assessments. However, patients are 
free to withdraw from the trial at any time and are under no obligation to provide a 
reason for doing so. All attempts should be made to ascertain whether a patient is 
lost to follow up, chosen not to return for follow-up or is deceased. 
 
8. Medical Device Adverse Clinical Event Reporting 
This study is not intended to prospectively assess the absolute product safety; 
however any device or procedure related safety issues will be documented as 
follows. The site will be required to transcribe onto the Safety Data CRF only those 
adverse clinical events that have been determined by the physician investigator to 
be attributable (even remotely) to 1) the knee arthroplasty procedure and/or 2) the 
use of the VERASENSE™ device. 
The information to be captured on the CRF include the severity, relationship to 
knee arthroplasty procedure and the VERASENSE™ Device, outcome and 
treatment (when applicable). 

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a. 
 Expeditious Reporting - Medical Device Reportable Events (21 CFR §803.3) 
 
Expeditious reporting to OrthoSensor is required for any fatal or serious injury (as 
defined below) that in the judgment of the physician investigator may have be 
attributed to the use of the VERASENSE™ device (only), or that the device was 
or may have been a factor in a death or serious injury, including events occurring 
as a result of: (1) failure; (2) malfunction; (3) improper or inadequate design; (4) 
manufacture; (5) labeling; or (6) user error. 
The term “Serious injury” is defined per 21 CFR 803 as an injury or illness that: 
 
1. Is life-threatening 
2. Results in permanent impairment of a body function or permanent damage to 
a body structure; 
3. Necessitates medical or surgical intervention to preclude permanent 
impairment of a body function or permanent damage to a body structure 
The clinical site must notify the OrthoSensor by email or telephone immediately 
but no later than 2 business days of any fatal or serious injury directly attributed 
to the use of the VERASENSE™ device. Notification to the IRB of record will be 
done according to the IRB’s specific procedures. OrthoSensor will be responsible 
for reporting the event to the FDA according to the timelines put forth in 21 CFR 
803. 
8.1 Risk Benefit Analysis: 
As in any surgical procedure, certain risks are associated with total joint 
arthroplasty. These risks include but are not limited to: anaesthetic and post- 
anaesthetic reactions (such as hyperaemia), allergic reactions to prophylactic 
antibiotics or blood transfusions, damage to blood vessels or nerves or death. 
Post-operatively, a patient may experience thrombophlebitis, pulmonary 
embolus, dislocation, pain, limp, component loosening, osteolysis due to wear 
debris or the need for additional surgery. Fracture of the prosthesis is a potential 
complication. 
As all patients recruited for this study are indicated for primary total knee 
arthroplasty with the device described in the protocol anyway, there is no known 
risk associated with participating in this study. 
 
8.2 Protocol Departures: 
Any departure from the current, approved protocol is considered to be a deviation 
or violation. Depending on severity of the departure, the reporting timeframe for 
the deviation/violation will change. 
The following definitions apply: 

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• 
Violation: protocol deviation that is IRB/FDA reportable. For example, but not 
limited to, Informed Consent Documents not signed before surgery, a missing 
or lapsed IRB approval or an ineligible subject enrolled 
• 
Deviation: protocol is not being followed exactly. For example, but not limited 
to, visits out of window, some data not collected for that visit or source 
documentation not available for a visit (CRFs used as source document). 
 
8.3 Informed consent violation: 
No patient will be enrolled in the study and have any study-related procedures 
performed, including completing subject clinical assessments, before an 
approved Informed Consent Document is signed. If this occurs, this is a 
VIOLATION and must be reported to OrthoSensor. 
 
9. DATA COLLECTION 
All data collection will be prospective and will be collected after the patient has 
voluntarily agreed to participate in the study by signing and dating an IRB-approved 
informed Consent and HIPAA document (as required by the local IRB). Data will be 
collected according to the scheme outlined in Table 1. 
 
 
a. Methods: 
i. Data can be collected via paper form, or entered directly to an online 
database, if applicable. 
 
ii. If the site has an existing database, data may be sent to OrthoSensor via raw 
data format in an excel spreadsheet. If using a local database, it must be 
ensured that the data in the spreadsheet is compliant with the methods 
presented in the case report forms, as all data must be available for statistical 
analysis. 
 
b. Data and Clinical Assessments: 
• 
Patient Demographics: Age at surgery, gender, surgical side, height, weight, 
primary diagnosis. This data is collected from the medical record. 
• 
Operative Data: Part Numbers (if able) or Femoral Component Type & size, 
Tibial Tray Type & Size, Tibial Bearing Type & Size, Patella Type & Size, OR 
Time, Surgical Technique, Surgical Approach, Operative Complications, Length 
of stay. This data is collected from the medical record. 
• 
Length of stay, Discharge Destination: Based on the operation day and day of 
discharge, the length of hospital stay is determined. 
• 
Patient Reported Outcome Measures – Perceived functioning, including pain, 
satisfaction and function will be measured using three patient reported outcome 
measures (PROMs). 

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o 
EQ-5D 
A standardized instrument for use as a measure of health outcome 
 
o 
Knee Society Score (2011 Version) 
The latest version of the KSS was developed in 2011 and introduced by 
the Knee Society. The latest version of the KSS originates from the 
popular KSS (from 1989); both physician and patient derived. It includes 
versions administered preoperatively and postoperatively. It has an initial 
assessment of demographic details, including an expanded Charnley 
functional classification. The objective knee score, completed by the 
surgeon, includes a VAS score of pain, walking on level ground and on 
stairs or inclines, as well as an assessment of alignment, ligament 
stability and ROM, along with deductions for flexion contracture or 
extension lag. Patients then record their satisfaction, functional activities, 
and expectations. Given the diverse activity profiles of many 
contemporary patients, the functional component of the score was 
improved to include a patient-specific survey, which evaluates features 
such as standard activities of daily living, patient-specific sports and 
recreational activities, patient satisfaction, and patient expectations. The 
new Knee Society Knee Scoring System has been developed and 
validated, in part, to better characterize the expectations, satisfaction, and 
physical activities of the younger and more diverse population of current 
patients undergoing TKA. The score was validated in a thoughtful and 
methodical fashion confirming internal reliability and analyzed for 
differential item functioning. The new Knee Society Scoring System is 
broadly applicable across sex, age, activity level, and implant type. 
Completing the questionnaire takes 10 to 30 minutes. 
 
o 
Forgotten Joint Score (FJS) 
The FJS is a patient reported outcome measure, consisting of 12 
questions (e.g. awareness traveling in a car or climbing stairs?). It uses a 
5-point Likert response format and the raw score is transformed to range 
from 0-100 points. High score indicates good outcome, e.g. a high degree 
of forgetting the joint in everyday life (forgotten joint phenomenon). The 
FJS has a low ceiling effect and was designed to discriminate between 
good, very good and excellent outcomes after TKA. 
 
o 
Knee Pain Evaluation Form 
The knee pain evaluation will be used to assess the prevalence and 
location site of knee pain when applicable. This evaluation will be 
completed by the investigator post total knee surgery during the intervals 
defined in Table 1 “Schedule of study assessments”. 
 
• 
Radiographic evaluation via Mediolateral and anteroposterior x-rays as is 
standard of care. The prevalence and location of radiolucency and/or osteolysis 
is evaluated on both AP and lateral views at each patient’s routine postoperative 

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follow-up visits. These evaluations are performed by each patient’s operating 
surgeon. 
• 
Complications, adverse events, and survivorship data will be collected and 
reported. This information will be gathered at each of the study follow-up visits. 
 
c. Data Collection Periods: 
Data will be collected pre-operatively, intra-operatively, and post-operatively at 6 
weeks, 6 months, and 1 year. All time point windows are determined using the 
date of surgery (DOS) as day 0, including all annual visits. The visit windows are 
as follows: 
 
 
Pre-operative: within 3 months prior to the date of the surgery excluding 
*Pre-operative radiographs. Pre-operative radiographs taken within 12 
months of scheduled knee replacement surgery are sufficient. 
Intra-operative: within 2 weeks after the date of surgery 
6 weeks: DOS + 6 weeks ± 4 weeks 
6 months: DOS + 6 months ± 45 days 
1 year: DOS + 1 year ± 90 days 
2 year: DOS + 2 year ± 90 days 
 
 
 
Table 1. Schedule of study assessments 
 
Data Collected 
Pre-op 
Baseline 
Operative 
Discharge 
6 Weeks 
6 Months 
1 Year 
2 Years 
Obtain Written 
Informed Consent 
X 
Demographics 
X 
Intra Operative 
X 
EQ-5D 
X 
X 
X 
X 
X 
New-KSS 
X 
X 
X 
X 
X 
FJS 
X 
X 
X 
X 
Knee Pain 
Evaluation Form 
X 
X 
X 
Radiographic 
Alignment 
X 
X 
X 
X 
X 
Adverse Event 
Reporting 
(When Present) 
(X) 
(X) 
(X) 
(X) 
(X) 

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10. Analysis to be Performed on Data (e.g. Statistical Analysis) 
Analysis of the data will be performed using SPSS version 21. Comparative Statistics 
will be run between outcomes data stratified by both groups: Analysis of variance 
(AVOVA) will be used to assess the difference between each group, with post-hoc t- 
tests to demonstrate significance. Separate analyses will be performed to evaluate 
power of sample sizes and any correlative affect that demographic/clinical variables 
may have on patient outcomes. 
 
11. Monitoring of data collection 
The Sponsor will monitor all data collected for accuracy and completion. The site will 
be monitored at least once per calendar year following the initial/first-monitoring visit. 
 
12. Patient Identification 
Each patient who signs an informed consent document will be given a unique, 
sequential 3-digit number. The three initials of each patient will be used (first, middle, 
last). In the case where the subject does not have a middle initial, that placeholder 
will be held by a dashed line (-). This unique patient identifier will be used on all 
study-related documentation for each subject enrolled in the study. The patient’s 
initials will be used to further identify the subject; no names will be used. 
 
13. Screening Enrollment Logs 
A record of all patients consented for the study, with their consecutively assigned 
study numbers, will be maintained in the site’s Regulatory Binder. This log will be 
identified as the Screening/Enrollment Log. Patients who sign a consent form but 
who do not continue into the study for whatever reason (i.e., cancel surgery) will be 
assigned a unique subject identifier which WILL NOT BE REASSIGNED to anyone 
else. 
 
14. Patient Identification 
Each patient who signs an informed consent document will be given a unique, 
sequential 3-digit number. The three initials of each patient will be used (first, middle, 
last). In the case where the subject does not have a middle initial, that placeholder 
will be held by a dashed line (-). This unique patient identifier will be used on all 
study-related documentation for each subject enrolled in the study. The patient’s 
initials will be used to further identify the subject; no names will be used. 
 
Example: Subject number: 001. 
Subject initials: FML where F = first initial, M = middle initial, L = last initial. This 
subject’s unique identifier would be 001 and uniquely associated with the initials 
FML. 

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15. Institutional Review Board Approval and the Informed Consent Document. 
It is the responsibility of the Principal Investigator to ensure that an Institutional 
Review Board (IRB) reviews the study and that the IRB acts in accordance with the 
requirements set forth in 21CFR56 – Institutional Review Boards. The Principal 
Investigator will forward copies of the protocol and all required documents to the IRB 
for review. Further, it is the Principal Investigator’s responsibility to promptly inform 
the IRB of any revisions to the Clinical Study Protocol, to promptly report any serious 
medical device adverse events and/or unexpected events and to provide a periodic 
report of the study’s progress to the IRB at intervals not to exceed 1 year. Any 
proposed amendment to the protocol that involves increased risk to the subject will 
require IRB approval prior to its enactment. 
The investigator must forward written verification of the initial IRB review and 
approval to OrthoSensor before beginning the clinical study. The Principal 
Investigator must immediately forward copies of all subsequent correspondence 
between the Principal Investigator and the IRB concerning the continued approval of 
this clinical study, or withdrawal of such approval, to OrthoSensor. 
 
16. Administrative Considerations 
• 
Ethics: The Declaration of Helsinki 
In any research on human subjects, each potential subject must be adequately 
informed of the aims, methods, anticipated benefits and potential hazards of the 
study and the discomfort it may entail. He or she should be informed that he or 
she is at liberty to abstain from participation in the study and that he or she is free 
to withdraw his or her consent to participation at any time. (21CFR312.120(3)I.9. 
• 
Changes to the protocol 
OrthoSensor and the Investigator must approve any changes made to this 
Protocol and/or any of the appendices and are subject to the approval of the 
relevant Institutional Review Board(s). 
• 
Clinical Investigator Agreement 
The Clinical Investigator Agreement is a written agreement to be signed by the 
Investigator that defines his/her responsibilities and willingness to follow the 
study protocol. This agreement must be signed by the Investigator and submitted 
to OrthoSensor before the initiation of the study. 
• 
Completion of the Study 
OrthoSensor will notify the Investigator when adequate data have been collected 
or when the clinical evaluation is terminated for any reason. 
• 
Reporting of Results 
The data collected in this study will be analyzed and compiled into a report for 
review by the Investigator per the contracted agreement between the Investigator 
and OrthoSensor. The results will be published in a scientific medical journal and 
will be presented at National and International congresses and symposia. 

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17. Contact Information 
 
For assistance or questions regarding this evaluation, please contact the Department 
of Clinical and Bioengineering Research at OrthoSensor, Inc as indicated below: 
 
Sr. Director, Clinical Research 
Chris Anderson 
Phone: 813-352-9887 
E-mail: canderson@orthosensor.com 
Clinical Research Associate 
Leah Elson 
Phone: 951-577-7343 
E-mail: lelson@orthosensor.com 
 
 
 
 
1855 Griffin Road, Suite A-310 | Dania Beach, FL 33004 | 888-75-ORTHO (888-756-7846) 
www.OrthoSensor.com 

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18. References 
 
1) Barrack RL, Schrader T, Bertot AJ, Wolfe MW, Myers L. Component rotation and 
anterior knee pain after total knee arthroplasty. Clin Orthop Rel Res 2001;392:46-55. 
2) Berger RA, Crossett LS, Jacobs JJ, Rubash HE. Malrotation causing patellofemoral 
complications after total knee arthroplasty. Clin Orthop Rel Res 1998;356:144-153. 
3) Boldt JG, Stiehl JB, Hodler J, et al. Femoral component rotation and arthrofibrosis 
following mobile-bearing total knee arthroplasty. Int Orthop 2006;30(5):420. 
4) Bong MR, Di Cesare PE. Stiffness after total knee arthroplasty. J Am Acad Orthop 
Surg 2004;12:164-171. 
5) Bozic KJ, Kurtz SM, Lau E, Ong K. The epidemiology of revision total knee 
arthroplasty in the United States. Clin Orthop Relat Res 2010;468;45-51. 
6) Byrne JM, Gage WH, Prentice SD. Bilateral lower limb strategies using a step-up 
task in individuals who have undergone unilateral total knee arthroplasty. Clin Biomech 
(Bristol, Avon) 2002;17:580-585. 
7) Gustke KA, Golladay GJ, Roche MW, Elson LC, Anderson CR. A New Method for 
Defining Balance: Promising Short-term outcomes of Sensor-Guided TKA. J 
Arthroplasty. 2013. [Epub ahead of print]. 
8) Fehring TK, Odum S, Griffin WL, Mason B, Nadaud M. Early Failures in Total Knee 
Arthroplasty. Clin Orthop Rel Res 2001;392:315-318. 
9) Gustke, K. Use of smart trials for soft-tissue balancing in total knee replacement 
surgery. J Bone Joint Surg Br. 94B, Supple A: No. 11 November 2012 
10) Healy WL, Wasilewski SA, Takei R, Oberlander M. Patellofemoral complications 
following total knee arthroplasty. Correlation with implant design and patient risk 
factors. J Arthroplasty 1995;10(2):197-201. 
11) Hofmann S, Romero J, Roth-Schiffl E, Albrecht T. [Rotational malalignment of the 
components may cause chronic pain or early failure in total knee arthroplasty]. 
Orthopade. 2003;32(6)469-473. 
12) Hutter EE, Granger JF, Beal MD, Siston RA. Is there a gold standard for TKA tibial 
component rotational alignment? Clin Orthop Relat Res 2013;471:1646-1653. 
13) Incavo SJ, Wild JJ, Coughlin KM, et al. Early revision for component malrotation in 
total knee arthroplasty. Clin Ortho Relat Res 2007; 458:131-136. 
14) Kim BS, Reitman RD, Schai PA, Scott RD. Selective patellar nonresurfacing in 
total knee arthroplasty: 10-year results. Clin Orthop Rel Res 1999;367:81-88. 
15) Lützner J, Krummenauer F, Günther K, Kirschner S. Rotational alignment of the 
tibial component in total knee arthroplasty is better at the medial third of the tibial 
tuberosity than at the medial border. BMC Musculoskel Disord 2010;11(57):1-7. 
16) Mulhall KJ, Ghomrawi HM, Scully S, Callaghan JJ, Saleh. Current etiologies and 
modes of failure in total knee arthroplasty. Clin Orthop Rel Res 2006;446:45-50. 
17) Ritter MA, Lutgring JD, Davis KE, Berend ME. The effect of postoperative range of 
motion on functional activities after posterior cruciate-retaining total knee arthroplasty. 
J Bone J Surg Am 2008;90:777-784. 
18) Sharkey PF, Hozack WJ, Rothman RH, Shastri S, Jacoby SM. Insall Award Paper: 
Why are total knee arthroplasties failing today? Clin Orthop Rel Res 2002;404:7-13. 
19) Uehara K, Kadoya Y, Kobayashi A, et al. Bone anatomy and rotational alignment 
in total knee arthroplasty. Clin Orthop Relat Res 2002. 402:196-201. 

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Appendix I 
 
Holding the Leg using Verasense 
 
 
 

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Appendix II 
Surgical Reference Guide 

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