Higher Function Scores and Satisfaction in Patients with Anteromedial Osteoarthritis Compared with Other Wear Patterns of the Knee: 2 Years after Both Total and Unicondylar Knee Arthroplasties

Anteromedial osteoarthritis (AMOA) is a common wear pattern in primary osteoarthritic knees. In patients with bone-on-bone disease, the most appropriate surgical intervention is still a matter of debate. Knee arthroplasty is a well-accepted treatment to relieve symptoms and regain function. Unfortunately, satisfaction is limited, especially related to activities. A cross-sectional study was performed among patients treated with total knee arthroplasty (TKA) and unicondylar arthroplasty (UKA) to determine if the osteoarthritis wear pattern or type of prosthesis affects knee-specific function scores and satisfaction related to activities. All UKA patients ( N  = 100) were treated for AMOA. Based on radiological assessment of the wear pattern, TKA patients were divided into two groups: TKA for AMOA ( N  = 68) and true TKA ( N  = 99). The Knee injury and Osteoarthritis Outcomes Score (KOOS), new Knee Society score (KSS), anterior knee pain scale, visual analog scales (VASs) for satisfaction about activities, and net promoter score were collected. After 2 years' follow-up, the anterior knee pain scale and VAS satisfaction showed significantly better scores for patients treated with TKA for AMOA compared with the true TKA group. Also in the KOOS subscales, some differences were seen in favor of the TKA for AMOA group. The new KSS was not in favor of a specific wear pattern, but patients with AMOA treated with UKA performed better on the symptoms subscale compared with patients treated with TKA. In conclusion, patients treated with TKA for AMOA showed better knee-specific function scores and satisfaction scores compared with patients treated with TKA for other wear patterns, and only slight differences were found between both the AMOA groups (TKA for AMOA and UKA). Thus, the radiologic assessment of wear patterns might be useful to take into account the shared decision-making process, when discussing expectations, timing, and outcomes with knee osteoarthritis patients considering knee arthroplasty. When AMOA is present, it might be beneficial to choose UKA over TKA.