Longevity, Functional Status and Quality of Life of the Compress® Compliant Pre-Stress System

Study Overview
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Brief Summary
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In the treatment of malignant bone tumors, it may be necessary to remove large areas of the femur. To replace these large parts of missing bone, a prosthesis can be used. One innovative technology developed by Biomet is the Compress® Compliant Pre-Stress System (CPS; Zimmer-Biomet, Warsaw, USA). This fixation device uses compression, via a short traction bar, to stimulate osteointegration at the bone-prosthetic interface, promote hypertrophy of the loaded bone, and avoid stress bypass of the host bone around a stiff intramedullary stem. Young patients cured of tumors have a long life expectancy and a compelling need for prosthetic fixation that is equally durable. Good bone fixation is a prerequisite for implant longevity. Although the initial results are encouraging, there is a need for additional mid- to long-term survival data from larger patient series showing longevity of the system, as well as reporting of functional outcome. Furthermore, to the best of our knowledge, no study examining the survival of the device using prospective data already exists. In addition, no studies were found examining the quality of life of the patients with the CPS system.

Detailed Description
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In the treatment of malignant bone tumors, it may be necessary to remove large areas of the femur. To replace these large parts of missing bone, a prosthesis can be used. One innovative technology developed by Biomet is the Compress® Compliant Pre-Stress System (CPS; Zimmer-Biomet, Warsaw, USA). This fixation device uses compression, via a short traction bar, to stimulate osteointegration at the bone-prosthetic interface, promote hypertrophy of the loaded bone, and avoid stress bypass of the host bone around a stiff intramedullary stem. Young patients cured of tumors have a long life expectancy and a compelling need for prosthetic fixation that is equally durable. Good bone fixation is a prerequisite for implant longevity. Since 1999, the CPS has been routinely placed on the orthopedics - UZ Leuven service and, as a result, more than 100 patients have been treated in this way. However, there are only few studies reporting on long-term performance of this system. In addition, limited data reporting functional outcome were found. Although the initial results are encouraging, there is a need for additional mid- to long-term survival data from larger patient series showing longevity of the system, as well as reporting of functional outcome. Furthermore, to the best of our knowledge, no study examining the survival of the device using prospective data already exists. In addition, no studies were found examining the quality of life of the patients with the CPS system.

Official Title
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Longevity, Functional Status and Quality of Life of the Compress® Compliant Pre-Stress System: a Prospective Study

Conditions
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Compress Compliant Pre-Stress System, Malignant Bone Tumor

Intervention / Treatment
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* Device: Compress Compliant Pre-Stress System


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients are/will be operated from 26/08/1999 onwards in UZ Leuven Implantation of the Compress Compliant Pre-Stress Device Informed consent obtained Patients are able to complete the questionnaires Age: minimum 7 years old Exclusion Criteria: N/A

Ages Eligible for Study
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Minimum Age: 7 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Prospective group<br>Patients who have to undergone the implant surgery | Device: Compress Compliant Pre-Stress System<br>* Treatment of malignant femor tumors with the Compress Compliant Pre-Stress System<br>|
| Other: Retrospective group<br>Patients that have already undergone the implant surgery | Device: Compress Compliant Pre-Stress System<br>* Treatment of malignant femor tumors with the Compress Compliant Pre-Stress System<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compress device survival | Revision will be used to determine implant survival. Revision will be defined as the explantation of any fixation mechanism: anchor plug, traction bar, spindle, sleeve, fixation pin | 25 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative complications | Clinical assessment of postoperative complications. Complications will be classified acoording to Henderson classification. | 25 years | 
| Partial weight-bearing (crutches): duration | Clinical assessment to determine duration of partial weight-bearing | 25 years | 
| Radiography: signs of osseointegration | Radiographic assessment | 25 years | 
| EORTC Core Quality of Life questionnaire (QLQ-C30) | To assess the quality of life | 25 years | 
| Functional status | Musculoskeletal Tumor Society scoring system (MSTS) is used to determine the the physical and mental health | 25 years |