Unusual Presentation: Foot Drop, Fabella Bone, Squatting Position - What Relationship?

The combination of a squatting position and the presence of a fabella bone, which can cause common peroneal nerve palsy, is an extremely rare condition; this rarity often leads to late presentation due to diagnostic challenges.

We report the case of a 42-year-old sheet metal worker who gradually experienced a snapping sensation along the posterolateral aspect of his right knee and numbness along the dorsum of his right foot, evolving into a steppage gait due to foot drop. Given the clinical and radiological findings, as well as the patient's discussion, we elected to proceed with surgical management. We performed neurolysis of the common peroneal nerve until it reached the fibular neck, as well as excision of the fabella sesamoid. After 3 days, the patient was discharged with a prescription for an ankle-foot orthosis and a gradual full range of motion exercise for his right foot. At the 6-month follow-up, the patient had regained full range of motion in the foot with no deficit and had returned to his daily activities.

The combination of the squatting position and the presence of a fabella bone can lead to the development of a foot drop.