Pedobarographic analysis of body weight distribution on the lower limbs and balance after ankle arthrodesis with Ilizarov fixation and internal fixation

BACKGROUND: A number of various techniques were proposed to stabilized ankle arthrodesis, among them external and internal fixation. Appropriate balance and adequate distribution of lower limb loads determine normal biomechanics of the locomotor system. We hypothesized that various techniques used to stabilize ankle arthrodesis may exert different effects on (1) balance and (2) distribution of lower limb loads. METHODS: Retrospective analysis included 47 patients who underwent ankle arthrodesis with external stabilization with Ilizarov fixator (group 1, n = 21) or internal stabilization with screws (group 2, n = 26) between 2007 and 2015. Balance and distribution of lower limb loads were determined with a pedobarographic platform. RESULTS: In group 1, average load of the operated and non-operated limb amounted to 48.8% and 51.2%, respectively, and in group subjected to internal stabilization to 48.4% and 51.6%, respectively. Neither the intragroup nor the intergroup differences in the distribution of lower limb loads were statistically significant. Mean length of the center of gravity (COG) path was 137.9 cm for group 1 and 134 cm for group 2, and mean COG area amounted to 7.41 cm(2) and 6.16 cm(2), respectively. The latter intergroup difference was statistically significant. CONCLUSIONS: Balance after ankle arthrodesis with Ilizarov fixation is worse than after the same procedure with internal stabilization. Despite correction of ankle deformity, musculoskeletal biomechanics still remains impaired. While ankle fusion with either Ilizarov or internal fixation provide appropriate distribution of lower limb loads, none of these procedures normalize patients’ balance.