Minimizing risk of iatrogenic nerve injury during peroneus longus tendon autograft harvest: a cadaveric study at different ankle or knee positions.

ABSTRACT

PURPOSE: To evaluate the distances using ultrasound between the superficial peroneal nerve (SPN) and sural nerve along the peroneus longus tendon (PLT) autograft harvest path at different ankle or knee positions in order to minimize risk of iatrogenic nerve injury during PLT autograft harvest. METHODS: Twenty-four fresh-frozen human cadaveric lower extremities were used to harvest a full-thickness PLT autograft with a tendon stripper. Four specimens were utilized to validate correct identification of nerves under ultrasound. Sonographically guided perineural injections were performed at the start point and end point of the PLT harvest path using coloured latex, followed by dissection with gross inspection. Using ultrasound, the distance from the peroneus brevis muscle to the sural nerve at different ankle positions (20° dorsiflexion, neutral, and 20° plantarflexion) was measured, and the distance from the end of the tendon stripper to the SPN at different knee positions (full extension and 90° flexion) was also measured. Measurements were performed by two separate observers using ImageJ software. RESULTS: Cadaveric dissection showed the presence of latex around nerves in all four specimens. The average distance from the brevis muscle to the sural nerve increased significantly from dorsiflexion to plantarflexion. The shortest distance from the tenodesis site to the sural nerve was 5.8 ± 1.7 mm. There was no significant difference from the end of the tendon stripper to the SPN between full extension or 90° flexion of the knee. CONCLUSION: When harvesting the PLT, it is recommended to place the ankle at plantarflexion. The knee at full extension or 90° flexion had no effect. Joint positions at the time of graft harvest should be monitored to reduce risks of iatrogenic nerve injury.