Total Ankle Arthroplasty Radiographic Alignment Comparison Between Patient-Specific Instrumentation and Standard Instrumentation

Abstract

BACKGROUND: Several benefits are published supporting patient-specific instrumentation (PSI) in total ankle arthroplasty (TAA). This study seeks to determine if TAA with PSI yields different radiographic outcomes vs standard instrumentation (SI). METHODS: Sixty-seven primary TAA patients having surgery using PSI or SI between 2013 and 2015 were retrospectively reviewed using weightbearing radiographs at 6-12 weeks postsurgery. Radiographic parameters analyzed were the medial distal tibia angle (MDTA), talar-tilt angle (TTA), anatomic sagittal distal tibia angle (aSDTA), lateral talar station (LTS), and talar component inclination angle (TCI). A comparison of the 2 groups for each radiologic parameter's distribution was performed using a nonparametric median test and Fisher exact test. Furthermore, TAAs with all radiographic measurements within acceptable limits were classified as "perfectly aligned." The rate of "perfectly aligned" TAAs between groups was compared using a Fisher exact test with a significance of .05. RESULTS: = .35). CONCLUSION: No significant radiographic alignment differences were found between PSI and SI implants. This study showed that both techniques achieve reproducible TAA radiographic coronal and sagittal alignment for the tibial component when performed by experienced surgeons. The talar component's sagittal alignment is similar whether or not PSI was used but is noticeably different from normal anatomic alignment by design. LEVEL OF EVIDENCE: Level III, retrospective cohort study using prospectively collected data.

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