Cross-Sectional Analysis of the Distal Fibular Intramedullary Canal: A Cadaveric Evaluation.

Fractures of the distal fibula secondary to rotational ankle injuries are one of the most common injuries requiring surgical intervention. The aim of this study was to describe the anatomy of the distal fibular medullary canal as a means of aiding in surgical management with an intramedullary device. Twenty fresh cadaveric below-knee specimens (group 1, 10 in 2015, group 2, 10 in 2016) were dissected to expose the distal fibular. Fifteen (10 mm each) segments were sectioned with a sagittal saw from the distal tip proximally and measured with a digital caliper. In group I, the widest and narrowest fibular diameter was at the 20-mm interval (mean 15.02 mm) and 90-mm interval (mean 3.51 mm), respectively. From 70 to 120 mm, the mean diameter was less than 4.0 mm. In group 2, the widest and narrowest diameter was at the 20-mm interval (mean 15.05 mm) and 100-mm interval (mean 4.33 mm), respectively. From 70 to 140 mm, the mean diameter was less than 5.0 mm. The combined mean diameter at the 60- to 80-mm intervals were 4.99 ± 1.70, 4.35 ± 1.63, and 4.02 ± 1.35 mm, respectively. Based on our investigation, we propose an intramedullary device diameter of 4.5 to 5.0 mm in diameter with a length of 60 to 80 mm may provide most appropriate bony purchase to achieve acceptable cortical contact for expected osseous compression.

LEVELS OF EVIDENCE: Level IV: Cadaveric case series.