Accuracy assessment of measuring component position after total ankle arthroplasty using a conventional method.

BACKGROUND: This study was to assess the accuracy of measuring the tibial and talar components position and to investigate the outlier rate of each component and predisposing factors related to component malalignment after total ankle arthroplasty (TAA) using a conventional method. METHODS: One hundred fifty consecutive primary total ankle arthroplasty were performed using the three-component HINTEGRA prosthesis for ankle end-stage osteoarthritis. Radiographic analysis for the accuracy of component position in coronal and sagittal plane was conducted at postoperative 6 months. Additionally, the accuracy of component position was evaluated according to presence of preoperative deformity or joint incongruency. RESULTS: The mean postoperative coronal angles of the tibial and talar components (α and γ) were 91.9° and 91.3°. The mean postoperative sagittal angles of the tibial and talar components (ß and δ angle) were 84.6° and 91.7°. In the coronal plane, 16 (10.7%) tibial components and 15 (10.0%) talar components showed outliers greater than 5°. In sagittal plane, 15 (10.0%) tibial components and 29 (19.3%) talar components showed outliers greater than 5°. There was no meaningful increase of the outlier rate regarding presence of preoperative deformity or joint incongruency. CONCLUSIONS: In conventional method of TAA, the outlier rate of the tibial and talar components was about 10 to 20%, especially, the outlier rate of talar component in sagittal plane was up to 20%. Therefore, careful attention should be paid to implant the talar component in conventional TAA.

Minimum Two-year Results of Revision Total Knee Arthroplasty Following Infectious or Non-infectious Causes.

PURPOSE: To compare clinical outcome of revision total knee arthroplasty (TKA) between the infected and non-infected groups. MATERIALS AND METHODS: This study compared the clinical and radiographic results of 21 infected and 15 non-infected revision TKAs at a minimum 2-years follow-up. Clinical evaluations were assessed using the range of motion (ROM), Hospital for Special Surgery (HSS) score, Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS), and Western Ontario and McMaster Universities (WOMAC) score. Radiologic evaluations were assessed using the radiographic results of the American Knee Society and joint line change. RESULTS: Patients operated for non-infectious causes had significantly better postoperative ROM than the infected group (infected group, 101.7°; non-infected group, 117.8°). The infected group achieved significantly poor HSS (79.2 vs. 85.5), KSKS (75.5 vs. 86.6), KSFS (76.9 vs. 85.5), WOMAC (30.3 vs. 21.2) scores than the non-infected group. Postoperative joint line elevation was lower in the infected versus non-infected group (0.5 mm vs. 2.1 mm), but there was no significant difference. CONCLUSIONS: Revision TKA is an effective treatment that can provide successful results in the infected as well as non-infected patients. The overall results of non-infected revision were more satisfactory than infected revision.