Long-term functional success and robust implant survival in lateral unicompartmental knee arthroplasty: A case series with a mean follow-up of twenty two and a half years.

PURPOSE: Lateral unicompartmental knee arthroplasty (UKA) is an accepted treatment option in cases of end-stage lateral osteoarthritis. While lateral UKA has many proposed advantages compared to total knee arthroplasty, its technical challenges and relatively small number of cases make this an uncommon procedure. The aim of this study was to report the survivorship and functional outcomes beyond 20 years of follow-up of isolated UKA. METHODS: Between January 1988 and October 2003, 54 lateral UKAs were performed in a single center. The fitted prosthesis was a fixed plate and cemented polyethylene (PE). All patients had isolated lateral tibiofemoral osteoarthritis, including five open meniscectomies, three arthroscopies, and three open reductions of lateral tibial plateau fractures. Patients with a minimum of 20 years of follow-up were included in the final analysis. RESULTS: Of the 54 UKA, 22 died before reaching the minimum follow-up period and four were lost to follow-up. Twenty-eight were included in the final analysis. Among them, 21 patients remained alive and an additional seven were deceased after 20 years. The mean age at the last follow-up was 84.8 ± 11.9 years with a mean follow-up duration of 22.5 ± 2.1 years. Of the 28 knees, eight underwent revision surgery (5 for the progression of osteoarthritis; 2 for aseptic loosening; 1 for PE wear). Kaplan-Meier survival analysis revealed a survival rate at 20 and 25 years of 72.3% (CI 59.1; 88.6). The average time to revision was 14.9 ± 4.9 years. At the last follow-up, the mean function Knee Society Score (KSS) was 41.5 ± 32.9 and the mean objective KSS score was 79.4 ± 9.7. In the unrevised population, 94.7% of patients (n = 18) reported being satisfied or very satisfied with the surgery. CONCLUSION: Lateral UKA remains a viable treatment option for patients with isolated lateral tibiofemoral osteoarthritis, providing satisfactory 20-year implant survivorship and high patient satisfaction.

Bone-anchored prostheses for lower limb amputation in a French cohort with 1-15 years of follow-up: implant survival rates, mechanical complications, and reported outcomes.

PURPOSE: To evaluate the implant survival rate, mechanical complications, and reported patient outcomes of bone-anchored prostheses for patients with lower limb amputation in France after 1-15 years of follow-up. METHODS: This retrospective cohort study included patients who underwent surgery at a single center in France between 2007 and 2021. The primary outcomes were the implant survival rate and functional scores assessed by the Questionnaire for Transfemoral Amputees (Q-TFA). Secondary outcomes were adverse events that occurred during follow-up. RESULTS: The cohort consisted of 20 bone-anchored prostheses in 17 patients. The main level of amputation was transfemoral (82%, n = 14). The main reason for amputation was trauma (n = 15). The mean age at amputation was 32 (range 15-54) years, and the mean age at the first stage of osseointegration was 41 (range 21-58) years. The Kaplan-Meier survival curve showed respective survival rates of 90%, 70%, and 60% at 2, 10, and 15 years. All Q-TFA scores were significantly improved at last the follow-up. Eleven patients (65%) experienced mechanical complications. In total, 37 infectious events occurred in 13 patients (76%), mainly comprising stage 1 infections (68%, n = 25). Only two cases of septic loosening occurred (12%), leading to implant removal. CONCLUSION: This is the first French cohort of bone-anchored prostheses and among the series with the longest follow-up periods. The findings indicate that bone-anchored prostheses are safe and reliable for amputee patients who have difficulties with classic prostheses.