Association Between Leg Length Discrepancy and Posterior Tibial Tendon Dysfunction

Abstract

Background. Leg length discrepancy (LLD) is associated with a variety of orthopaedic disorders and biomechanical gait changes that involve possible overload of the posterior tibial tendon (PTT). In view of the biomechanical disturbances induced by LLD, an association may exist between LLD and PTT dysfunction (PTTD). Purpose. To compare the frequency and magnitude of LLD between subjects with and without PTTD and ascertain whether associations exist between clinical features and presence of dysfunction. Study Design. Case–control study. Methods. A total of 118 patients with a diagnosis of PTTD were seen between January 2009 and September 2012 and compared with 118 gender-matched and race-matched volunteers. The frequency of LLD, the mean absolute LLD, and the mean relative LLD were measured by conventional (radiographic) or computed tomography scanography and compared between cases and controls. Results. The prevalence of LLD and mean absolute and relative LLD values were significantly greater in the case group (94.9%, 5.64 mm and 7.36%, respectively) than in the control group (79.7%, 3.28 mm and 4.18%, respectively) (P < .001). Conclusion. The findings of this study demonstrate a relationship between LLD and PTTD. In light of the major biomechanical changes it induces, LLD may be a predisposing factor for development of PTTD. Level of Evidence: Prognostic, Level III: Case–control series, retrospective