Anatomical patterns of the sural nerve: a meta-analysis with clinical and surgical considerations.

BACKGROUND: The sural nerve (SN) supplies the posterolateral aspect of the leg and the lateral aspects of the ankle and foot and descends through the gastrocnemius muscle along the lower third of leg. Because in-depth knowledge about SN anatomy is essential for clinical and surgical approaches, our study aims to review SN anatomical patterns.

METHODS: We searched the PubMed, Lilacs, Web of Science, and SpringerLink databases to find relevant articles for meta-analysis. We assessed the quality of the studies using the Anatomical Quality Assessment tool. We used proportion meta-analysis to analyze the SN morphological variables and simple mean meta-analysis to analyze the SN morphometric variables (nerve length and distance to anatomical landmarks).

RESULTS: Thirty-six studies comprised this meta-analysis. Overall, Type 2A (63.68% [95% CI 42.36-82.64]), Type 1A (51.17% [95% CI 33.16-69.04]) and Type 1B (32.19% [95% CI 17.83-48.38]) were the most common SN formation patterns. The lower third of leg (42.40% [95% CI 32.24-52.86]) and middle third of leg (40.00% [95% CI 25.21-53.48]) were the most common SN formation sites. The pooled SN length from nerve formation to the lateral malleolus was 144.54 mm (95% CI 123.23-169.53) in adults, whereas the SN length was 25.10 mm (95% CI 23.20-27.16) in fetuses in the second trimester of gestation and 34.88 mm (95% CI 32.86-37.02) in fetuses in the third trimester of gestation.

CONCLUSIONS: The most prevalent SN formation pattern was the union of the medial sural cutaneous nerve with the lateral sural cutaneous nerve. We found differences regarding geographical subgroup and subject age. The most common SN formation sites were the lower and middle thirds of the leg.