Quantification and Comparison of Talar Exposure Utilizing A Posteromedial Approach and Medial Malleolar Osteotomy

Abstract

Category:Ankle; Hindfoot; TraumaIntroduction/Purpose:Fractures of the talus contain a variety of morphologies including the head, neck, body, dome, lateral process, posterior process, and medial/lateral tubercles. Specifically, the posterior medial approach is useful for surgical fixation of posterior process fractures. The use of the medial malleolar osteotomy is beneficial in more extensive medial and distal exposure for neck or neck/body fractures. The purpose of this study was to quantify the area of osseous exposure afforded by a posteromedial approach to the talus and medial malleolar osteotomy. We believe this can be potentially useful for preoperative planning. To the authors' knowledge, a quantitative comparison of the talar access afforded by these two distinct approaches has yet to be described in the literature.Methods:Five fresh frozen cadaveric lower extremities were dissected using a posteromedial approach and medial malleolar osteotomy respectively. Following exposure, the talar surfaces directedly visualized and demarcated along its boarders using a 2.0 mm drill bit orthogonal to the talar surface. The surface visualized was labeled and captured using a calibrated digital image. The digital images were then analyzed using ImageJ software (National Institutes of Health, Bethesda, MD) to calculate the surface area of the exposure.Results:The average square area of talus exposed using the posteromedial approach was 9.70 (SD = 2.20, range 7.20 - 12.46) cm2. The average quantity of talar exposure expressed as a percentage was 9% (SD = 1.58, range 7.03 - 10.40). The average square area of talus exposed using a medial malleolar osteotomy was 14.32 (SD 2.00, range 11.26 - 16.66) cm2. The average quantity of talar exposure expressed as a percentage was 12.94% (SD = 1.79, range 9.97 - 14.73). The posteromedial approach provided superior visualization of the posterior talus, while the medial malleolar osteotomy offered greater access to the medial body.Conclusion:The posteromedial approach and medial malleolar osteotomy allow for significant exposure of the talus, yielding 9.70 cm2 and 14.32 cm2, respectively. Given the differing portions of the talus exposed, surgeons may prefer to utilize the posteromedial approach for surgical fixation of posterior process fractures and elect to use a medial malleolar osteotomy in cases requiring more extensive medial and distal exposure for neck or neck/body fractures.