Forgotten Joint Score: Comparison between total and unicondylar knee arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Rehabilitation Medicine

Background:

• The Forgotten Joint Score (FJS) is a key metric for assessing patient satisfaction after knee arthroplasty.
• Evaluating FJS in total knee arthroplasty (TKA) and unicondylar knee arthroplasty (UKA) is crucial for understanding long-term outcomes.
• This study investigates FJS across different follow-up durations and implant types.

Purpose of the Study:

• To assess the efficacy of the Forgotten Joint Score (FJS) in patients who underwent total knee arthroplasty (TKA) and unicondylar knee arthroplasty (UKA).
• To compare FJS between TKA and UKA at various follow-up intervals (1, 5, and 10 years).
• To evaluate FJS differences between specific TKA and UKA prosthesis models.

Main Methods:

• A consecutive cohort of patients undergoing primary TKA or UKA were surveyed using the FJS.
• Data collection included patient demographics, operative details, and prosthesis type (3 TKA, 2 UKA).
• The study analyzed 588 completed FJS questionnaires from patients with 1, 5, or 10 years of follow-up.

Main Results:

• UKA demonstrated significantly higher mean FJS (65.4) compared to TKA (50.2).
• Fixed-bearing UKA (ZUK, 73.1) showed superior FJS compared to mobile-bearing UKA (Oxford, 60.1).
• For TKA, mean FJS improved significantly from 1 year (44.8) to 5 years (53.8); UKA showed highest scores at 10 years (69.0).

Conclusions:

• UKA generally yields superior patient-reported outcomes (FJS) compared to TKA.
• Fixed-bearing UKA designs are associated with better FJS than mobile-bearing UKA.
• For TKA, functional outcomes measured by FJS improve substantially between 1 and 5 years post-surgery.