Purpose: 1/ To compare patients treated with both ankle arthroplasty or ankle fusion using validated functional outcome measures and a computerized motion analysis system that measures three-dimensional kinematics and temporal data. 2/ To compare the functional outcome and gait mechanics of ankle arthroplasty and ankle arthrodesis to a healthy control group.

Methods: Fifteen patients underwent seventeen ankle arthroplasties with the Scandinavian Total Ankle Replacement (STAR), twenty-three patients underwent ankle arthrodesis, and twenty-three healthy control patients were enrolled in this study. Assessment included: 1/ Ankle Osteoarthritis Scale (AOS) and general health status (SF-36). 2/ Gait data, including temporal-spatial, kinematic, and kinetic parameters using a seven-camera VICON 370 system (Oxford Metrics, UK). Comparison between groups was done using one-way ANOVA post hoc Bonferroni (p< 0.05).

Results: Kinematic gait parameters for post-op arthrodesis, post-op arthroplasty and a control group are summarized in Table 1. Postoperative arthrodesis patients had significantly reduced ankle range of motion in the sagittal and frontal plane when compared to both postoperative arthroplasty patients and a control group (p< 0.05). Forefoot range of motion was also significantly reduced in the sagittal and frontal planes for arthrodesis patients when compared to the control group, however there were no significant differences between patient groups or between arthroplasty patients and controls (p< 0.05).|Functional questionnaire (AOS) data for the three groups is summarized in Table 2. There were no significant differences in patient perception of pain and disability, however AOS scores compared between arthrodesis patients and a control group were significant (p< 0.05). No difference was noted in AOS scores between ankle arthroplasty and control patients at one year post operative.

Conclusions: Functional outcome analysis of treatment methods of end-stage ankle arthritis clearly shows the advantage of ankle arthroplasty over arthrodesis when comparing kinematic and outcome questionnaire data against controls. The results of this study will help determine the best surgical treatment for patients with end-stage ankle arthritis failing non-operative treatment.