Lateral unicompartmental knee arthroplasty: is really a good option?

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Reconstructive Surgery

Background:

• Lateral unicompartmental knee arthroplasty (LUKA) is infrequently performed, comprising less than 1% of all knee replacements.
• Limited literature exists for LUKA compared to medial UKA, suggesting less surgeon experience.
• This study addresses the need for more data on LUKA outcomes based on bearing surface type.

Purpose of the Study:

• To evaluate the implant survival and clinical-functional outcomes of LUKA.
• To compare outcomes between all-polyethylene and metal-backed bearing surfaces in LUKA.

Main Methods:

• Retrospective analysis of 42 LUKA procedures performed between 2009 and 2021.
• Utilized two fixed polyethylene-bearing models: all-polyethylene ACCURIS and metal-backed Triathlon PKR.
• Assessed demographic data, knee range of motion (ROM), tibiofemoral alignment, implant survival (Kaplan-Meier), and Knee Society Score (KSS).

Main Results:

• Mean follow-up was 8.2 years; 71.4% of patients were women, with osteoarthritis as the primary indication (88.1%).
• 100% LUKA survival at 1 and 5 years, with no post-surgical complications or re-operations.
• Significant improvements observed in KSS (clinical and functional), knee ROM, and tibiofemoral alignment post-surgery (p < 0.001). No significant differences between bearing types.

Conclusions:

• LUKA is a viable and definitive treatment for lateral tibiofemoral osteoarthritis.
• Achieved a survival rate exceeding 95% at 5 years.
• Clinical-functional outcomes and ROM are consistent regardless of the tibial component used.