並列摘要
We retrospectively analyzed the case records of 33 consecutive patients (36 knees) who received revision total knee arthroplasty (TKA). The average age of these patients at the time of revision surgery was 62.5 years. There were 17 right and 19 left knee arthroplasties. The indications for primary TKA included osteoarthritis in 31 knees, post-traumatic arthritis in 1, and rheumatoid arthritis in 4. The indications for revision TKA included aseptic loosening of prostheses in 28 (78%) knees, implant failure in 5 (14%), axial malalignment in 1 (3%), instability in 1 (3%), and patella fracture in 1 (3%). The duration from primary to revision TKA averaged 82 months. The mean follow-up duration was 45 months. The preoperative condition and postoperative results were evaluated with the Hospital for Special Surgery knee score and Knee Society radiographic evaluation system. The average knee score improved from 67.8 points preoperatively to 87.5 points postoperatively. Eighteen (50%) knees were painless on walking while 32 (89%) knees were painless at rest after revision TKA. The range of motion ranged from 2° to 104° preoperatively, and 0° to 114° at final follow-up. Radiographic assessment showed that the mechanical axis of the lower extremity was realigned from an average of 8.2° varus to an average of 3.1°varus at final follow-up. Postoperatively, 5 tibial components revealed a lucent line ＞=1 m in one or more zones, and two of them showed complete radiolucency. No femoral component showed radiolucency at the final followup. Fourteen (40%) patellas still had problems of lateral subluxation or tilting postoperatively. Superficial wound infection developed in 2 knees and was treated successfully by wound debridement and antibiotic therapy. No deep infection developed. Instability occurred in 4 knees, including 1 knee with severe anterioposterior instability requiring further revisison with a rotating hinge-type prosthesis. Overal,30 out of 36 patients (83.3%) achieved good to excellent knee functions. The alignment, stability, range of motion and functions of the knee were improved after revision surgery. With proper patient selection and improved surgical technique, revision TKA will be useful in treating failed TKA.