Exposure of the Calcaneus via the Sinus Tarsi Approach versus the Lateral Extensile Approach: A Cadaveric Study

Abstract

Category: Hindfoot; Trauma Introduction/Purpose: The lateral extensile approach (LEA) to the calcaneus has long been a popular surgical approach to treat calcaneal fractures. However, high rates of wound complications have led surgeons to investigate alternative approaches. As a result, the sinus tarsi approach has grown in popularity. The lateral extensile approach affords substantial visualization of the calcaneus. However, this visualization has never been compared in a quantitative manner to the sinus tarsi approach (STA). The objective of this cadaveric study is to compare calcaneal visualization afforded by a sinus tarsi approach and a lateral extensile approach. Methods: Seven pair-matched, fresh-frozen, below-knee cadaver specimens were obtained. For each pair, one side received an LEA and the other side received a STA. To identify areas of the calcaneus accessible by instrument, a curette was used to mark the visualized calcaneal surfaces. The calcaneus was then disarticulated and cleared of all soft tissue. The curette markings were then identified and marked with blue surgical marker. Photos were taken of each calcaneus, and visualized surface areas were calculated using Image J software. Results: There were no statistically significant differences in the articular surfaces accessible between the two approaches (831.99 mm2 for LEA vs. 903.41 mm2 for STA, p=0.53) including the anterior, middle, and posterior facets. The total calcaneal surface area accessible was 3107.08 mm2 for LEA and 1444.19 mm2 for STA (p=0.02). The LEA allowed better exposure to the lateral wall (p<0.01) and superior greater tuberosity of the calcaneus (p=0.05). Conclusion: In comparison to the LEA, the STA allows for equivalent exposure to articular surfaces. While the LEA allows for greater exposure of the lateral wall and posterior tuberosity, direct visualization of these structures may not warrant the higher risk of wound complications. Surgeons should be mindful of these differences when choosing a surgical approach in the treatment of calcaneal fractures.