Innovative Technologies for Cost-Effective Healthcare Delivery for Salvage Procedures of Failed Treatments of Osteoarthritis: Specific Biomimetics Solutions to Reduce a Growing Problem With a High Social and Economic Impact.(CustomPN)
Conditions: Bone Loss, Hip Prosthesis Infection, Arthroplasty Complications
Sponsor: Istituto Ortopedico Rizzoli

 
TITLE:  INNOVATIVE TECHNOLOGIES FOR COST-EFFECTIVE HEALTHCARE 
DELIVERY FOR SALVAGE PROCEDURES OF FAILED TREATMENTS OF 
OSTEOARTHRITIS: SPECIFIC BIOMIMETICS SOLUTIONS TO REDUCE A 
GROWING PROBLEM WITH A HIGH SOCIAL AND ECONOMIC 
IMPACT.(CUSTOMPN) 
NCT Number: not provided yet 
Document date: 23/07/2024 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

BRIEF SUMMARY 
In this prospective multicenter study, a population of adult individuals consecutively treated for 
revision hips, requiring a custom-made acetabular implant for non-oncological reasons, will be 
included. The custom-made implant is a personalized implant produced using additive 
manufacturing, based on the pre-operative CT scan that details the bone damage. Patients eligible 
for this implant are those with severe acetabular bone damage Paprosky 3 (loss of the superolateral 
part and one of the two ventro-caudal walls). 
Preoperatively, the patient will undergo a clinical evaluation. Data will be collected on the patient's 
general health status with the Charlson score, the reason for revision, number of revisions, type of 
implant in place, and the time elapsed between the failed implant and the revision in question. The 
bone deficit will be studied through CT measurements according to qualitative and quantitative 
scales. During the surgery, information on intraoperative complications will be collected. In the 
postoperative period, perioperative complications will be collected according to the Clavien Dindo 
classification. The clinical radiographic evaluations will be carried out during outpatient follow-up 
visits at 1, 3, 12, 24, and 36 months after revision. They include the Harris Hip Score clinical score, 
the EQ-5D, and the patient's satisfaction level (qualitative assessment in 4 grades: unsatisfied, 
slightly satisfied, moderately satisfied, fully satisfied). The positional parameters of the implant will 
be evaluated, as compared to the immediate post-operative X-ray: acetabular abduction, acetabular 
anteversion, center of rotation height, center of rotation medialization, and inclination of the 
custom-made component. From 12 months onwards, the osteointegration characteristics of the 
component will be assessed: presence of radial trabeculae at the interface, superolateral and inferior 
reinforcements, stress shielding, absence of radiolucent lines. Re-revision rates will be determined 
using the Kaplan-Meier method. The reasons for re-revision will be noted. 
 
 
 

DETAILED DESCRIPTION 
Osteoarthritis (OA) increased from 247.51 million people in 1990 to 527,81 million in 2019. OA 
places a huge burden on healthcare services accounting for 1-2,5% of the gross national products 
and the cost is expected to quadruple by 2030. Total joint replacement (TJR) represents the standard 
of care of end-stage OA. TJR is projected to nearly double by 2026. Unfortunately, TJR are subject 
to failure, thus the number of revision procedures is also growing, accounting for 5-6% of all TJR. 
Failure of TJR represents a dramatic event for patients and National Health Systems. Patients suffer 
enormous disability, with impact on function, emotional sphere, and loss of autonomy. The average 
cost of treatment is almost doubled compared to TJR, and in case of periprosthetic joint infections 
almost tripled. In patients under 65 years (with a failure rate of 9%-12%), the full return to work is 
reported only in 7%-33% of the cases, and not earlier then 1 year after the surgery, while around 
50% retired or remained on welfare benefits. Current technology is not enough to overcome this set 
of problems, while actual projections predict a 43%-70% increase in revisions by 2030. In 
particular, revision hips involve various diagnoses and settings: in some cases, the severe bone loss 
makes the reconstruction very complex. In these cases, acetabular reconstruction can be performed 
with off-the-shelf implants, but outcomes are not always consistent and reproducible. Thus, in cases 
of severe acetabular bone loss, it may be very useful to proceed with a customized implant, 
designed according to the patient's needs. Implants produced in this way are designed based on the 
patient's pre-operative CT scan using additive manufacturing technology. The purpose is to offer a 
personalized bone filling of the defect with a highly porous interface that promotes osteointegration. 
Currently, most of the custom-made implants are performed for oncological cases. On the contrary, 
there are few indications on the clinical and radiological outcomes of custom-made acetabular 
reconstructions in revision hips with severe bone loss in non-oncological cases. The purpose of this 
project is to validate an innovative and reliable technology (custom-made acetabular component 
produced using additive manufacturing) for managing non-oncological revisions, assessing short 
term outcomes. 

The aims are:  
Description of demographic characteristics and bone defect in candidates for acetabular 
reconstruction with custom-made implants 
Perioperative complications and implant survival 
Clinical evaluation of custom-made implants in custom-made acetabular reconstructions in hip 
prosthesis revisions with severe bone loss (clinical score Harris Hip Score; subjective score PROM 
EQ-5D; post-operative patient satisfaction level) 
Radiographic evaluation (positioning and osteointegration) of custom-made implants in custom-
made acetabular reconstructions in hip prosthesis revisions with severe bone loss 
This is a prospective multicenter study. The study population will consist of adult individuals 
consecutively treated for revision hips, requiring a custom-made acetabular implant. Patients with a 
diagnosis leading to an oncological revision will not be included. The custom-made implant is a 
personalized implant created by an external company based on the pre-operative CT scan that 
details the bone damage. Patients eligible for this implant are those with severe acetabular bone 
damage Paprosky 3 (loss of the superolateral part and one of the two ventro-caudal walls). In these 
cases, off-the-shelf therapeutic options are limited and achieve uncertain outcomes: therefore, a 
custom-made component with ultra-porous anchoring surfaces can represent a highly advantageous 
therapeutic choice. After identifying the suitable patient and obtaining their consent for the study, a 
pre-operative CT scan will be performed as per normal clinical practice for every revision. After 
uploading it to the dedicated website or app of the company, this CT scan will be used for the 
manufacturing of the custom-made implant by a third-party company. The company will also 
provide plastic phantoms for preliminary study of the implant. Upon approval of the implant 
production, the company will manufacture the implant according to current regulations and 
production techniques, following previous and established clinical practice. The device will be 
accompanied by personalized instrumentation, such as cutting guides, positioners, calipers, and 
plastic simulation phantoms, to facilitate the surgical procedure. The implant and the produced 

instrumentation will be delivered to the reference center after performing the patient's surgical 
planning.  
Preoperatively, the patient will undergo an evaluation with the Harris Hip score clinical score. 
Additionally, data will be collected on the patient's general health status with the Charlson score, 
the reason for revision, number of revisions, type of implant in place, and the time elapsed between 
the failed implant and the revision in question. The bone deficit will be studied through CT 
measurements according to qualitative and quantitative scales.  
During the surgery, information on intraoperative complications will be collected. In the 
postoperative period, perioperative complications will be collected according to the Clavien Dindo 
classification. The clinical radiographic evaluations will be carried out during outpatient follow-up 
visits at 1, 3, 12, 24, and 36 months after revision. They include the Harris Hip Score clinical score, 
the EQ-5D PROM, and the patient's satisfaction level (qualitative assessment in 4 grades: 
unsatisfied, slightly satisfied, moderately satisfied, fully satisfied). The positional parameters of the 
implant will be evaluated, as compared to the immediate post-operative X-ray: acetabular 
abduction, acetabular anteversion, center of rotation height, center of rotation medialization, and 
inclination of the custom-made component. From 12 months onwards, the osteointegration 
characteristics of the component will be assessed: presence of radial trabeculae at the interface, 
superolateral and inferior reinforcements, stress shielding, absence of radiolucent lines. Re-revision 
rates will be determined using the Kaplan-Meier method. The reasons for re-revision will be noted. 
TYPE OF STUDY 
Prospective multicenter study 
Study population  
The study population will consist of adult individuals (minimum age: 18 years) consecutively 
treated for revision hips (non-oncological reasons) requiring a custom-made acetabular implant. 
Patients will be enrolled in 4 tertiary centers (multicenter prospective study). Patients eligible for 

this implant are those with severe acetabular bone damage Paprosky 3 (loss of the superolateral part 
and one of the two ventro-caudal walls). 
INCLUSION and EXCLUSION criteria:  
Inclusion Criteria: 
• 
need of custom-made acetabular implant on the basis of CT and X-ray evaluation () 
• 
pre-operative CT scan 
• 
adults patients (minimum age: 18 years) 
• 
complete medical charts 
• 
patients' availability 
Exclusion Criteria: 
• 
oncological reasons for revision 
• 
other types of revision implant (non custom) 
• 
inadequate medical chart 
• 
lack of pre-operative CT scan 
 
Primary aims: assessing the clinical and radiographic short-term outcomes of custom-made 
implants for acetabular component revisions due to non-oncological revisions, produced using 
additive manufacturing. 
Primary Outcome Measures: 
1.Perioperative complications (Clavien-Dindo classification). 
2.Objective clinical outcomes (Harris Hip Score) 
3.Subjective clinical outcomes (EQ-5D-5L) 
4.Subjective clinical outcomes (satisfaction) 
5.Survival rates (Kaplan Meier curve) 
Secondary Outcome Measures: 

1. Osseointegration of the acetabular component (percentages of cases with good 
osseointegration of the acetabular component according to Moore's criteria. At least three 
criteria among: presence of radial trabeculae at the interface, presence of superolateral 
buttress, presence of inferior buttress, presence of medial stress shielding, absence of 
radiolucent lines. Range: 0-100%. Best outcome: 100%) 
Baseline variables: 
1) Sex. 
2) Age at first implant. 
3) Age at revision 
4) Side 
5) Weight (kg) 
6) Height (cm) 
7) Body mass index (Kg/m2) 
8) Charlson score 
9) ASA score 
10) Type of revision (complete, isolated component, etc) 
11) Pre-operative bone stock damage (classification and mm3) 
Statistics 
Quantitative data will be reported as mean values, standard deviations, and minimum and maximum 
ranges. Qualitative data will be expressed as frequencies and percentages and will be tested using 
the chi-square test. The t-test will be used for correlation between two quantitative variables 
(means). A Kaplan-Meier curve will be performed with corresponding 95% confidence intervals to 
estimate implant survival. Significance threshold: p=0.05. 

REFERENCES 
1 - Pandey AK, Zuke WA, Surace P, Kamath AF. Management of acetabular bone loss in revision 
total hip replacement: a narrative literature review. Ann Jt. 2023 Oct 5;9:21. doi: 10.21037/aoj-23-
23. 
2 - Jones SA, Parker J, Horner M. Can a reconstruction algorithm in major acetabular bone loss be 
successful in revision hip arthroplasty? Bone Joint J. 2024 May 1;106-B(5 Supple B):47-53. doi: 
10.1302/0301-620X.106B5.BJJ-2023-0809.R1. 
3 - Stauffer TP, Purcell KF, Pean C, DeBaun M, Bolognesi M, Ryan S, Chun D, Seyler T. 
Management of Intraoperative Acetabular Fractures During Total Hip Arthroplasty. Orthop Clin 
North Am. 2024 Jan;55(1):9-17. doi: 10.1016/j.ocl.2023.06.009. 
4 - Romagnoli M, Zaffagnini M, Carillo E, Raggi F, Casali M, Leardini A, Marcheggiani Muccioli 
GM, Grassi A, Zaffagnini S. Custom-made implants for massive acetabular bone loss: accuracy 
with CT assessment. J Orthop Surg Res. 2023 Sep 30;18(1):742. doi: 10.1186/s13018-023-04230-5. 
5 - Kim K, Sandiford NA. The Role of Three-Dimensional Custom Printing in Revision Total Hip 
Arthroplasty. Surg Technol Int. 2023 Sep 6;42:sti42/1698. doi: 10.52198/23.STI.42.OS1698.