ABSTRACT
Background: The purpose was to compare the clinical and radiographic outcomes between preoperative mild and severe varus deformity after total knee arthroplasty (TKA) with medial stabilizing technique (MST). Methods: We retrospectively analyzed 158 knees of 125 female patients with a 2-year follow-up who underwent mechanically aligned TKA with MST between April 2018 and February 2021. Patients were divided into two groups; the severe varus group was defined as one with preoperative hip-knee ankle (HKA) angle ≥ 15° and the mild varus group with HKA angle < 15°. Pre- and post-operative clinical outcomes (Western Ontario and McMaster University Osteoarthritis Index, Knee Society Knee Score) and radiographic outcomes (medial proximal tibial angle (MPTA), HKA angle, lateral distal femoral angle (LDFA), joint line distance, and femoral component rotation angle) were compared between the groups. Results: Among the 158 knees analyzed, 131 and 27 were allocated to the mild and severe varus groups, respectively. Preoperative data showed that the MPTA (84.7° ± 2.8° vs. 80.7° ± 3.2°, p < 0.001) was significantly less in the severe varus group. In postoperative data, clinical outcomes were not different between the groups. Joint line distance (18.4 mm ± 2.8 mm vs. 18.6 mm ± 2.7 mm, p = 0.676) was also not significantly different. Femoral component rotation angle (-1.7° ± 1.0° vs. -1.0° ± 1.3°, p = 0.018) was more externally rotated in the severe varus group. Conclusions: Severe varus group showed comparable clinical and radiographic outcomes to that of mild varus group after mechanically aligned TKA with MST.
ABSTRACT
BACKGROUND: Although the modular sleeve concept for femoral implants has several advantages, studies reporting on greater than 20-year outcomes are limited. This study aimed to report the mean 23-year results of total hip arthroplasty (THA) using a modular stem with metaphyseal fixation sleeve. METHODS: This study reviewed primary THAs performed using a modular stem between October 1994 and April 1998. Of the 272 hips (221 patients) identified, 220 hips (177 patients) satisfying the minimum 20-year follow-up were included. The Harris Hip Score was used for clinical evaluation. Final hip radiographs were analyzed to evaluate the implant stability and the extent of femoral osteolysis. The mean follow-up duration was 23 years (range, 20 to 28). RESULTS: The mean Harris Hip Score improved from 38 points (range, 26 to 67) preoperatively to 90 points (range, 71 to 100) at the final follow-up (P < .001). Femoral osteolysis was observed in 146 hips (67.1%), but 145 were located proximal to the osseo-integrated sleeve. Overall, 4 femoral revisions were performed; 2 for chronic infection, one for aseptic loosening, and one for periprosthetic femoral fracture. Of the 19 (8.6%) periprosthetic femoral fractures, the most common type was Vancouver AG (13 hips). One (0.5%) asymptomatic distal stem fracture occurred, while no complications were identified at the stem-sleeve junction. Implant survivorship free of any femoral revision was 98.3% at 23 years. CONCLUSIONS: A THA using a modular stem with metaphyseal fixation sleeve demonstrated 98.3% stem survivorship with excellent clinical outcomes at a mean follow-up of 23 years in non-obese patients.
