Etiology of total knee arthroplasty failure and functional outcome of revision knee arthroplasty

BACKGROUND Total knee arthroplasty (TKA) is a widely used treatment for advanced knee osteoarthritis; however, the incidence of failures requiring revision surgery is increasing. Identifying the causes of TKA failure and assessing the outcomes of revision procedures are essential for improving patient care. We hypothesized that infection and aseptic loosening are the primary causes of TKA failure and that revision TKA (rTKA) significantly enhances functional outcomes. AIM To examine the primary causes of TKA failure and evaluate the functional outcomes following rTKA. METHODS This descriptive study was conducted at the Department of Orthopedic Surgery, Civil Hospital, Bahawalpur, from April to September 2024. A total of 118 patients undergoing rTKA for failed primary TKA were included. Data on demographics, causes of failure, and surgical details were collected. Functional outcomes were evaluated using the Knee Society Score and Visual Analog Scale before and six months after surgery. Statistical analysis was performed using SPSS version 25.0, with statistical significance set at P < 0.05. RESULTS The leading causes of TKA failure were infection (45.8%), aseptic loosening (44.1%), and periprosthetic fractures (10.2%). The rTKA significantly improved knee function, with the mean Knee Society Score increasing from 39.43 ± 6.18 to 78.91 ± 6.17 (P < 0.001). Pain levels decreased substantially, with the mean Visual Analog Scale scores reducing from 7.99 ± 1.37 to 1.42 ± 1.17 (P < 0.001). No significant differences in outcomes were observed between single-stage and two-stage revision procedures. CONCLUSION Infection and aseptic loosening are the predominant causes of TKA failure. The rTKA effectively enhances knee function and alleviates pain, offering significant benefits to patients.