Following closed reduction of a posterior dislocation of the hip, a 32-year-old man notices he cannot dorsiflex his left great toe and has diminished sensation on the dorsum of the foot. Knee flexion strength is normal. Which component of which nerve is most commonly injured in this complication?

• A Tibial division of the sciatic nerve
• B Common peroneal division of the sciatic nerve ✓
• C Superior gluteal nerve
• D Obturator nerve

Explanation

Sciatic nerve injury occurs in about 10 percent of posterior hip dislocations, and the common peroneal division is affected far more often than the tibial division because its fibres lie posterolaterally, directly against the posterior rim of the acetabulum against which the nerve is stretched. Foot drop and dorsal sensory loss match this division. Superior gluteal injury weakens hip abduction, and obturator injury affects thigh adduction, neither of which is present here.

Reference: Rockwood and Green's Fractures in Adults, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.