Three weeks after open reduction of a posterior wall acetabular fracture through a Kocher-Langenbeck approach, a 29-year-old woman has weakness of ankle dorsiflexion and eversion with preserved plantarflexion and inversion. Sensation is reduced over the dorsum of the foot. Which structure has been injured?

• A Tibial division of the sciatic nerve
• B Common peroneal nerve at the fibular neck
• C Superior gluteal nerve
• D Peroneal division of the sciatic nerve ✓

Explanation

Sciatic nerve palsy occurs in roughly 10 to 20 percent of acetabular fractures, particularly those involving the posterior wall and column. The peroneal division is injured far more often than the tibial division because its fibers lie more posterolaterally and are tethered near the piriformis and the fibular neck, so isolated foot drop with sensory loss on the dorsum is typical. The superior gluteal nerve causes abductor weakness, not foot drop.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.