Background: Sural nerve injuries are an evident risk especially of minimal-invasive surgical Achilles tendon repair. However, detailed anatomical studies focussing the relationship of the sural nerve to the Achilles tendon at varies levels are scarce, in two planes even pending.
Methods: In 10 cadavers (55.3yrs, 19-89yrs), the exact course of the sural nerve was determined using a computer-assisted method in two planes (transversal/sagittal).
Results: The sural nerve crossed the Achilles tendon at 11 (8.7-12.4) cm proximal to the tuber calcaneii. The distance between the lateral crossing and the proximal musculotendineus junction was 35mm (20- 58mm). Starting from the tuber calcanei, the distance was 2/2mm (transversal/sagittal plane) 11cm proximal to the tuber calcanei, 4/4mm at 10cm proximal, 5/6mm at 9cm, 8/10mm at 5cm, and 11/18mm at the tuber calcanei.
Conclusion: Especially in the lateral crossing region of the sural nerve and the lateral proximal Achilles tendon 9-12cm proximal to the tuber calcanei, a close relationship of both anatomical structures can be visualised using computer-assisted measurement where caution is suggested to prevent sural nerve entrapment in either open or percutaneous Achilles tendon repair.