Endoscopic gastrocnemius recession: evaluation in a cadaver model.

The purpose of this study was to describe a new method of gastrocnemius recession using an endoscopic approach and to determine the accuracy of incision placement during gastrocnemius recession. Fifteen fresh-frozen cadaveric limbs underwent an endoscopic gastrocnemius recession utilizing a two-portal technique. All limbs were anatomically dissected after the procedure and each was examined for injury to the sural nerve. The ability to visualize the sural nerve intraoperatively, improvement in ankle dorsiflexion, time requirement for the procedure, incision size, and appropriateness of placement to facilitate recession were recorded for each specimen. An average of 83% of the gastrocnemius aponeurosis was transected in all 15 cadavers. After modifications of the technique, the final eight cadavers were noted to have had the entire (100%) gastrocnemius aponeurosis transected. Sural nerve injury occurred in one specimen (7%) in which the aponeurosis and the sural nerve were not well visualized. The sural nerve was definitively visualized during the procedure in 5 of 15 specimens (33%). No Achilles tendon injury was noted in any specimen. There was a mean improvement in ankle dorsiflexion of 20 degrees (range, 10 degrees-30 degrees) during full knee extension. The average length of time to perform the procedure was 20 minutes (range, 10-35 minutes). The average medial and lateral incision lengths used in the two-portal technique were 18 mm (range, 14-22 mm) and 17 mm (range, 12-19 mm), respectively, and the average distance from the midpoint of the medial incision to the level of the gastrocnemius-soleus junction was 26 mm (range, 5-60 mm). These results indicate that a complete gastrocnemius aponeurosis transection may be obtained utilizing a modified endoscopic gastrocnemius recession, but visualization of the sural nerve is poor with possible risk of iatrogenic nerve injury.