End-stage ankle arthritis can involve malalignment of the ankle in both the coronal and sagittal planes. Up to 33% to 44% of patients who present for total ankle replacement (TAR) have greater than 10° of coronal plane deformity. Normalization of the sagittal and coronal alignment is key in improving survivorship and functional outcomes in TAR. In the present study, we analyzed how both the ankle and hindfoot alignment for both a fixed-bearing and mobile-bearing TAR system changed over time. Specifically, we measured coronal and sagittal alignment of both the ankle and hindfoot complex. A retrospective study was performed on 2 independent groups of patients undergoing 2 different systems for total ankle replacement: Zimmer (lateral approach, fixed-bearing) and Hintegra (anterior approach, mobile bearing). Specific demographic data and radiographic data were measured. Within-group comparisons were performed using 1-way repeated measures ANOVA, analyzing the temporal course of clinical data within the Hintegra and Zimmer groups. At the ankle joint, as measured by the α and β angles (P > .05), the position of the components remained relatively similar in both the fixed- and mobile-bearing TAR at 24-month follow-up. The sagittal alignment, as measured by the TT (tibiotalar) ratio, demonstrated a posterior shifting of the talus in the mobile bearing group (P = .036). Although the fixed- and mobile-bearing TAR had both significant hindfoot alignment improvement between the preoperative radiographs and at 24 months, over time, the fixed-bearing ankle had a significant increase in both the hindfoot alignment view angle and hindfoot alignment distance (P < .001), suggesting a possible dynamism of the hindfoot in the fixed-bearing TAR. The lateral-approach fixed and anterior approach mobile-bearing implants maintained coronal and sagittal alignment in the short term; the temporal course of the lateral approach fixed-bearing ankle showed an increase in the valgus positioning of the hindfoot. The anterior approach mobile-bearing implant maintained its hindfoot alignment over the course of the study. Level III, case-control study.

Category: Ankle Arthritis; Ankle Introduction/Purpose: Total ankle arthroplasty (TAA) is regarded as an increasingly accepted alternative to ankle arthrodesis in patients with ankle arthritis that have failed conservative management. While significant focus within orthopedic literature has been placed on determining various risk factors for particular outcomes, the stratification of outcomes based on sex has been insufficiently investigated. Moreover, as the number of TAAs performed continues to increase, there is a growing need to examine the effects of sex on outcomes after TAA. We sought to compare patient reported outcome measures (PROMs), ankle range of motion (ROM), and complications at multiple time points in the post-operative period after TAA as stratified by sex. Methods: undergoing TAA during the years 2013 to 2018 at a single academic institution who had minimum follow-up of two years. A total of 133 patients met inclusion criteria, comprising 55.6% males and 44.4% females. Patients were evaluated pre- operatively and at 6 months, 1-year, and 2-years post-operatively. PROMs, including the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot Score, Visual Analog Scale (VAS) score, and the Short Form - 12 (SF-12) were administered, and ROM was assessed at all time points. Post-operative complications were also recorded. Student t-test were used to determine differences between the outcome measures. Eighty-nine patients received the Zimmer total ankle (39 females), whereas 44 patients (20 females) received the mobile bearing Hintegra. Results: The average age was 53.6 in the male cohort as compared to 53.8 in the female cohort (p=0.93). Both pre-operatively and at 6-months post-operative, the cohorts did not differ statistically in any of the measured outcomes. At 1-year post-operative, females had a lower SF-12 PCS score (44.1 versus 47.1, p=0.019) and less plantarflexion (20.5 versus 23.5, p=0.029) as compared to males. While both cohorts saw a significant step-wise increase in AOFAS scores between pre-operative, 6-months, and 1-year post-operative (p<0.001), the AOFAS score of the female cohort plateaued at 1-year while the male cohort continued to improve significantly (<0.015). Ultimately by 2-years post-operative, females had a statistically significant lower AOFAS score as compared to males (80.3 versus 85.4, p=0.04). Conclusion: Our results show that while both cohorts experienced significant improvement in all measured outcomes, women have lower SF-12 PCS scores and AOFAS score at 1- and 2-years post-operative, respectively, as well as less plantarflexion at 1- year post-operative with a trend towards increased complication rate after TAA. While our results add to the growing body of literature supporting TAA as a reliable means of treating ankle arthritis, our results are novel in that they were stratified and analyzed based on sex. Understanding these differences in outcomes is critically important for effectively managing expectations and treating both male and female populations.