Demographics and Outcomes of Unicondylar Knee Arthroplasty in Türkiye: A Nationwide Retrospective Database Study of 8590 Cases

Background Favorable long-term clinical and radiological outcomes with low revision and reoperation rates have been reported for unicondylar knee arthroplasty (UKA) in the treatment of end-stage unicompartmental knee osteoarthritis. However, no information on these data is available for the Turkish population. Our aim was to analyze the demographics, indications, outcomes, and revision rates of UKA in Türkiye using a nationwide database. Methods The electronic medical records of 8,590 patients undergoing UKA for unicompartmental osteoarthritis between 2016 and 2022 were retrospectively analyzed. Demographic data of the study population including sex, age, body mass index (BMI), and institution were assessed. The primary outcome measures were complication and revision rates. Results Of the 8,590 analyzed patients, 85.2% were women with an average age of 59 ± 8 years. The primary indication was osteoarthritis in 7,205 (94.1%) cases. Most patients received cemented implants (78% vs. 22%) and the use of fixed insert designs increased from 18% to 74% between 2018 and 2022. The overall complication rate for the study population was 5.5% (475/8,590). The rate of complications did not differ according to fixation type. However, it was statistically significantly higher in patients who received mobile UKA than the fixed design (3.8% vs. 1.8% for mechanical complications and 1.7% vs. 0.6% for other complications, respectively; P  < 0.001). The overall revision rate was 4.4% (234/5,377), with rates being similar for cemented and cementless designs ( P  = 0.832). However, the revision rate of mobile UKA was significantly higher than that of fixed designs ( P  < 0.001). Conclusion The majority of UKAs in Türkiye were cemented implants with an increased usage of fixed bearings over time. Mobile-bearing designs had significantly greater complication and revision rates compared to fixed-bearing implants.