Surgical Anatomy of the Endoscopic Gastrocnemius Recession

Abstract

The objective of this investigation was to analyze the surgical anatomy of the endoscopic gastrocnemius recession procedure with reference to the curved nature of the aponeurosis. A consecutive series of 34 magnetic resonance imaging scans were evaluated under the direction of a musculoskeletal radiologist. An angular calculation of the effective curvature of the aponeurosis was measured 2 cm distal to the musculotendinous junction based on the maximal posterior excursion and terminal medial and lateral edges. A frequency count was additionally performed of the number of deep intramuscular septa extending from the aponeurosis, as well as a description of the location of the neurovascular bundle in this location. The mean effective curvature was 126.5 degrees (standard deviation [SD]=6.3 degrees, range 115-143 degrees, 95% confidence interval 124.3-128.7 degrees). We observed an average of 1.2 (SD=0.5, range=0-2) deep intramuscular septa extending from the aponeurosis, and that 20.6% of neurovascular bundles were located superficial to the aponeurosis in this location. In conclusion, we found that a straight cannula needs to be navigated around an approximate 125-degree angle during performance of the EGR procedure. We think that this information provides evidence of potentially unrecognized complications of this procedure and leads to future investigations demonstrating anatomic and procedural outcomes.