American Board of Internal Medicine (ABIM) Certification Practice Exam

Tarsal tunnel syndrome primarily involves compression of which nerve?

1. Common peroneal nerve

2. Posterior tibial nerve

3. Sural nerve

4. Femoral nerve

The correct answer is: Posterior tibial nerve

Tarsal tunnel syndrome involves the compression of the posterior tibial nerve as it passes through the tarsal tunnel, located behind the medial malleolus in the ankle. This condition typically arises due to various causes such as swelling from an injury, space-occupying lesions, or intrinsic changes that reduce the size of the tunnel. The posterior tibial nerve is responsible for innervating several muscles in the lower leg and foot, as well as providing sensory innervation to parts of the foot. As a result, when this nerve is compressed, patients may experience symptoms such as pain, burning sensations, numbness, or tingling in the area supplied by the nerve, particularly along the sole of the foot and in the toes. Understanding the specific role of the posterior tibial nerve in tarsal tunnel syndrome is essential for appropriate diagnosis and management. Other nerves mentioned, such as the common peroneal nerve, sural nerve, and femoral nerve, are not primarily involved in this syndrome, as they innervate different regions of the leg and foot and are not located within the tarsal tunnel.