Macroscopic changes in sural nerve after gastrocnemius recession: a cadaver study.

BACKGROUND

Gastrocnemius recession is a common foot and ankle procedure and various techniques that have been utilized are mainly delineated by the anatomic position of the gastrocnemius transection; the 2 common ones are the Baumann and Strayer procedure. Both can adversely affect the sural nerve. The objective of this study was to evaluate the macroscopic changes in the sural nerve following gastrocnemius recession, and to compare the efficacy of the two procedures, regarding the improvement of maximal ankle dorsiflexion.

METHODS

Ten fresh-frozen, above knee cadaveric legs were assigned to one of two gastrocnemius recession techniques: Baumann (n = 5) or Strayer (n = 5). A goniometer was used to measure degree of ankle dorsiflexion before and after the surgery. The sural nerve was meticulously dissected and marked with two suture knots, 2 cm apart. The ankle was passively dorsiflexed from 90° to maximal dorsiflexion in 5° degree increments, and the distance between two suture knots was measured at each increment. The distance between the two cut ends of gastrocnemius muscle was measured with the ankle at 90° and at maximal dorsiflexion.

RESULTS

Overall, a mean increase in length between the suture knots on the sural nerve was 0.2 cm, from 90° to maximum ankle dorsiflexion (130°); both the Baumann and Strayer techniques resulted in 0.2 cm increase. The mean improvement in maximal ankle dorsiflexion in the Baumann and Strayer group was 22.6° and 22°, respectively. The mean change in distance between the two cut ends of the gastrocnemius muscle in the Baumann and Strayer group was 1.0 cm and 0.9 cm, respectively.

CONCLUSION

Increased dorsiflexion of the ankle following Strayer or Baumann gastrocnemius recession resulted in similar macroscopic change in the sural nerve, which may contribute to the development of sural neuritis. Further clinical studies are warranted to assess clinical implications of these findings.