The communicating branch of the lateral plantar nerve: a descriptive anatomic study.

Since the communicating branch of the lateral plantar nerve has been implicated as a factor in the etiology of Morton's neuroma, a painful perineurofibrosis of a common plantar digital nerve, this project was designed to investigate the anatomy of this communicating branch. Both feet of 40 embalmed human cadavers were dissected to show the frequency of occurrence and anatomical variation of the communicating branch. The communicating branch was present in 66.2% of the feet we studied with no large gender-based differences. Branches occurred bilaterally in 52.5% of cadavers, while 27.5% had branches unilaterally. The occurrence of this branch does not correlate well with the likelihood of development of Morton's neuroma. Differences in diameter of the communicating branch ranged from less than 0.5 mm to as large as the common plantar digital nerves themselves, about 2 mm. The presence or absence of the communicating branch made no qualitative difference in the diameters of the common plantar digital nerves. There were 60.4% of the communicating branches in this study that had a typically-described orientation, arising more proximally in the foot from the fourth common plantar digital nerve, while 39.6% of the branches had a reversed orientation, arising more proximally from the third common plantar digital nerve. These reversed branches had a more oblique orientation when compared to the classic branches. Other anatomical variations were noted, including accessory branches that attached to deeper structures in the foot. These data form a basis for further research into the etiology of Morton's neuroma and improved surgical techniques for correcting this condition.