Branching patterns and anatomical course of the common fibular nerve

Objective To present the branching patterns and anatomical course of the common fibular nerve (CFN) and its relationship with fibular head (FH). Methods A total of 21 limbs from 12 fresh cadavers were dissected. The FH width (FH_width), distance between the FH and CFN (FH_CFN), and thickness of the nerve were measured. The ratio of the FH_CFN to FH_width was calculated as follows: <1, cross type and ≥1, posterior type. Angle between the CFN and vertical line of the lower limb 5 cm proximal to the tip of the FH was measured. Branching patterns of the lateral cutaneous nerve of the calf (LCNC) were classified into four types according to its origin and direction as follows: type 1a, lateral margin of the CFN; type 1b, medial margin of the CFN; type 2, lateral sural cutaneous nerve (LSCN); and type 3, CFN and LSCN. Results In the cross type (15 cases, 71.4%), the ratio of FH_CFN/FH_width was 0.83 and the angle was 13.0°. In the posterior type (6 cases, 28.6%), the ratio was 1.04 and the angle was 11.0°. In the branching patterns of LCNC, type 2 was the most common (10 cases), followed by types 1a and 1b (both, 5 cases). Conclusion Location of the CFN around the FH might be related to the development of its neuropathy, especially in the cross type of CFN. The LCNC showed various branching patterns and direction, which could be associated with difficulties of electrophysiologic testing.