Survivorship of the fixed-bearing medial unicompartmental knee arthroplasty: mean 14-year follow-up in a single medical center

• Published in: BMC musculoskeletal disorders Vol. 25; no. 1; p. 283
• Main Authors: Hung, Kung-Tseng, Chen, Chun-Chieh, Lin, Yu-Chih, Lee, Sheng-Hsun, Hu, Chih-Chien, Chang, Yu-Han, Hsieh, Pang-Hsin, Shih, Hsin-Nung, Chang, Chih-Hsiang
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 12.04.2024; BioMed Central; BMC
• Subjects: Arthritis; Arthroplasty (knee); Arthroplasty, Replacement, Knee - adverse effects; Bone implants; Care and treatment; Complications and side effects; Decision-making; Diagnosis; Failure; Fixed-bearing; Follow-Up Studies; Fractures; Health aspects; Humans; Hypertension; Joint replacement surgery; Knee; Multivariate analysis; Osteoarthritis; Patients; Periprosthetic Fractures; Prostheses; Regression analysis; Retrospective Studies; Risk factors; Statistical analysis; Surgical techniques; Survival; Survival analysis; Survivorship; Unicompartmental knee arthroplasty; Taiwan; United States > US; Fixed-bearing; Survival; Unicompartmental knee arthroplasty; Risk factors
• ISSN: 1471-2474; 1471-2474
• DOI: 10.1186/s12891-024-07378-1

This study aimed to report the long-term survival of fixed-bearing medial unicompartmental knee arthroplasty (UKA) with a mean of 14-year follow-up, and to determine possible risk factors of failure. We retrospectively evaluated 337 fixed-bearing medial UKAs implanted between 2003 and 2014. Demographic and radiographic parameters were measured, including pre-operative and post-operative anatomical femorotibial angle (aFTA), posterior tibial slope (PTS), and anatomical medial proximal tibial angle (aMPTA). Multivariate logistic regression analysis was applied to figure out risk factors. The mean follow-up time was 14.0 years. There were 32 failures categorized into implant loosening (n = 11), osteoarthritis progression (n = 7), insert wear (n = 7), infection (n = 4), and periprosthetic fracture (n = 3). Cumulative survival was 91.6% at 10 years and 90.0% at 15 years. No statistically significant parameters were found between the overall survival and failure groups. Age and hypertension were significant factors of implant loosening with odds ratio (OR) 0.909 (p = 0.02) and 0.179 (p = 0.04) respectively. In the insert wear group, post-operative aFTA and correction of PTS showed significance with OR 0.363 (p = 0.02) and 0.415 (p = 0.03) respectively. Post-operative aMPTA was a significant factor of periprosthetic fracture with OR 0.680 (p < 0.05). The fixed-bearing medial UKA provides successful long-term survivorship. Tibial component loosening is the major cause of failure. Older age and hypertension were factors with decreased risk of implant loosening.