2025 ISAKOS Congress in Munich, Germany

2025 ISAKOS Biennial Congress ePoster


Mid-Term Outcomes Of Lateral Fixed-Bearing Unicompartmental Knee Arthroplasty

Sumin Lim, MD, Gyeonggi-Do KOREA, REPUBLIC OF
Jun-Young Chung, MD, Suwon, Gyeonggi-do KOREA, REPUBLIC OF
Tae Hun Kim, MD, Suwon, Kyounggi-do KOREA, REPUBLIC OF
Myung-Sub Lee, MD, Suwon, Gyeonggi-do KOREA, REPUBLIC OF
Jeong-Hyun Koh, MD, Suwon, Gyeonggi-do KOREA, REPUBLIC OF
Jeong Sunwoo, MD, Suwon, Gyeonggi-do KOREA, REPUBLIC OF

Ajou university hospital, Suwon, Gyeonggi-do, KOREA, REPUBLIC OF

FDA Status Not Applicable

Summary

The mid-term results of lateral fixed-bearing UKA showed significant correction of valgus alignment; satisfactory clinical results were observed. It is recommended that the HKA be maintained within 3 degrees of neutral alignment following the lateral UKA.

ePosters will be available shortly before Congress

Abstract

Purpose

The study aimed to analyze the mid-term outcomes of lateral fixed-bearing unicompartmental knee arthroplasty (UKA).

Methods

A retrospective review was conducted on 39 consecutive patients who underwent lateral UKA and had at least 2 years of follow-up. Clinical outcomes were assessed using the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) score and knee range of motion (ROM). Radiologic parameters were evaluated using the hip-knee-ankle axis angle (HKA), medial joint space width, and osteoarthritis (OA) grade according to the Kellgren-Lawrence (K-L) grading system. Implant survivorship was assessed using Kaplan-Meier survival analysis.

Results

The average age at the time of surgery was 54.5 years, with a mean follow-up period of 83.0 months. HKA showed significant correction of valgus alignment after UKA (from 181.0° to 178.7°, p<0.001). The WOMAC score significantly improved after surgery (from 37.3 to 20.9, p=0.019). Patients with a postoperative HKA within 3° of neutral had better WOMAC score compared to those outside this range (16.2 vs. 29.4, p=0.049). 10-year survivorship was 100%, and 13-year survivorship was 80% when considering failure as conversion only. When considering failure as conversion or polyethylene change, 10-year survivorship was 97%, and 13-year survivorship was 78%.

Conclusion

The mid-term results of lateral fixed-bearing UKA showed significant correction of valgus alignment; satisfactory clinical results were observed. It is recommended that the HKA be maintained within 3 degrees of neutral alignment following the lateral UKA.