Clinical trial NCT04358601: All-poly Versus Metal-backed
Official title: Migration and Survival of All-polyethylene Tibial Components Compared to the Metal-backed Modular Components of the Triathlon PS Total Knee System. A RSA Study
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Osteoarthritis
Lead sponsor: Region Skane
Sponsor class: OTHER
First posted: 2020-04-24
Enrollment: 60
Sex: ALL
Minimum age (years): 40
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The primary objective is the assessment of prosthetic migration results after two years of the Triathlon PS Knee System with all-polyethylene tibial components compared to the Triathlon PS Knee System with metal-backed modular components by means of Roentgen Stereophotogrammetry.

Detailed description: The secondary objective will be the prediction of the long-term survival based on the two-year migration patterns combined with clinical factors and radiographic aspects. In order to identify other clinical parameters besides the fixation of the prosthesis components, clinical scores and radiographic aspects will be correlated with the RSA outcome.

Eligibility criteria: 1. The subject is morbidly obese, defined as Body Mass Index (BMI) of \> 40. 2. Patient has a flexion contracture of 15° and more. 3. Patient has a varus/valgus contracture of 15° and more. 4. Patients with a pre-operative knee score of \>70. 5. The subject has a history of total or unicompartmental reconstruction of the affected joint. 6. The subject will be operated bilaterally. 7. Patients who had a Total Hip Arthroplasty (THA) on contralateral and/or ipsilateral side within the last year that is considered to have an unsatisfactory outcome (Patients with contralateral and/or ipsilateral THA \> 1 year ago with good outcome can be included in the study). 8. Patients who had a Total Knee Arthroplasty (TKA) on contralateral side within the last 6 months that is considered to have an unsatisfactory outcome. (Patients with contralateral TKA \> 6 months ago with good outcome can be included in the study). 9. The subject has an active or suspected latent infection in or about the knee joint. 10. Osteomyelitis 11. Sepsis 12. Patient who is expected to need lower limb joint replacement for another joint within one year. 13. The subject has a neuromuscular or neurosensory deficiency, which would limit the ability to assess the performance of the device. 14. The subject has a systemic or metabolic disorder leading to progressive bone deterioration. 15. The subject is immunologically suppressed or receiving steroids in excess of normal physiological requirements. 16. The subject's bone stock in compromised by disease or infection which cannot provide adequate support and/or fixation to the prosthesis. 17. The subject has had a knee fusion to the affected joint. 18. Female patients planning a pregnancy during the course of the study. 19. The patient is unable or unwilling to sign the Informed Consent specific to this study

Primary outcomes:
measure: Migration, measured by means of RSA
timeFrame: 2 years
Secondary outcomes:
measure: Migration, measured by means of RSA
timeFrame: 10 years
measure: Investigation of clinical performance and patient outcome with the Knee Society Score (KSS)
timeFrame: pre-operative, 3 months, 1, 2, 5, 7 and 10 years
measure: Investigation of clinical performance and patient outcome with the Knee Injury and Osteoarthritis Outcome Score (KOOS) patient questionnaire
timeFrame: pre-operative, 3 months, 1, 2, 5, 7 and 10 years
measure: Investigation of clinical performance and patient outcome with EuroQuol-5 dimension (EQ-5D) patient questionnaire
timeFrame: pre-operative, 3 months, 1, 2, 5, 7 and 10 years
measure: Investigation of clinical performance and patient outcome with the Forgotten Joint Score (FJS) patient questionnaire.
timeFrame: pre-operative, 3 months, 1, 2, 5, 7 and 10 years
measure: Investigation of patient outcome with radiographic analysis
timeFrame: pre-operative, 3 months, 1, 2, 5, 7 and 10 years
Other outcomes:
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