Chapter 10: Lower Limb
A 48-year-old male dropped a kitchen knife that pierced his canvas shoe and cut the skin on the dorsum of his foot, near the third and fourth toes. He did not seek immediate medical attention, but the next day became aware of numbness in the area of the cut. A branch of what nerve is most likely injured?
Answer D. The superficial fibular nerve provides sensory innervation to most of the dorsum of the foot. A small area of skin between the 1st and 2nd metatarsals and the adjacent sides of those same toes is supplied by deep fibular nerve.
A 16-year-old soccer player "rolled" her ankle when she stepped on another player's foot. Physical examination reveals swelling and pain over the lateral aspect of the ankle joint. Imaging does not reveal a fracture. The physician assistant diagnoses an inversion sprain. Which ligament is most likely injured?
E. Plantar calcaneonavicular ("spring")
Answer A. Forced inversion of the foot places increased stress on the calcaneofibular ligament as the lateral malleolus and calcaneus are forced apart.
A 45-year-old jockey presents in the orthopedic clinic with a painful right knee. He reports that the pain has become progressively worse. He walks with a conspicuous limp, favoring the right limb. A CT scan reveals a popliteal artery aneurysm that is compressing the adjacent nerve. Which nerve is being compressed?
Answer E. When the popliteal artery enters the popliteal fossa, it courses parallel with, and adjacent to, the tibial nerve.
A 38-year-old female bicyclist was struck by a motorist and suffered a comminuted fracture of the proximal one-third of her left tibia. During repair, the surgeon notes that a nerve on the anterior surface of the interosseous membrane had been partially severed by bone fragments. Which movement would be compromised in this patient?