LOWER EXTREMITY - BASEBALL/RUNNING

Abstract

HISTORY A 21-year-old male university student had an inversion-type injury to his right ankle while playing softball. The injury occured as he rolled his ankle into a position of inversion, while rounding first base on his way to second base. He felt sharp pain associated with a “pull and ripping sensation” in the lateral aspect of his right leg, but continued to play the remainder of the inning. There was no direct trauma to the right leg or ankle. Six hours after the injury, he noted pain, tightness and swelling of his right lateral leg and was not able to extend his right big toe. That night, the pain in his leg prevented him from sleeping. He saw a doctor the next morning that suspected a compartment syndrome and referred him to a second doctor who recommended observation and did not treat him. No compartment pressure measurements were performed, and his pain gradually improved with pain medication. Over the next month he had persistent numbness in his right lateral leg, dorsal foot and big toe, with the inability to extend his big toe. Although improved, he continued to have right lateral leg muscle pain with activities involving running, turning or cutting, and foot eversion. At this time, six weeks after the initial injury, he presented to an orthopedic surgeon. PHYSICAL EXAMINATION The patient was found to have decreased sensation in the right lateral leg, dorsal foot, hallux and first web space. He had a mild steppage gate with 4+/5 strength in the right peroneal muscles, 5−/5 in the right tibialis anterior and extensor digitorum, and paralysis of the right extensor hallucis longus. There was a Tinel sign to percussion just below the right fibular head and numbness and tingling felt in the leg and dorsum of the foot. DIFFERENTIAL DIAGNOSIS Ankle sprain, ankle fracture, muscle strain, compartment syndrome. TESTS AND RESULTS Radiographs revealed no calcifications, no abnormalities, and no fractures. MRI showed a 14–16 cm hematoma in the lateral compartment of the right leg, with associated edema of the lateral compartment muscles and hemosiderin within the hematoma. The other compartments of the right leg were not involved. EMG studies demonstrated a right peroneal neuropathy, involving the superficial and deep peroneal nerves, at the level of the knee or fibular head. Compartment pressures under anesthesia and prior to decompression by fasciotomy were, 25mm Hg in the lateral compartment and 11mm Hg in the anterior compartment. FINAL WORKING DIAGNOSIS Isolated lateral or peroneal compartment syndrome of the leg secondary to inversion injury to the ankle. TREATMENT The patient underwent lateral compartment decompression by fasciotomy with exploration of the peroneal nerve and evacuation of the hematoma. The common peroneal nerve was found to enter the lateral compartment, then trifurcate with one branch to the peroneal muscles, another branch traveling down the lateral compartment, and one branch going to the anterior compartment. No contusions or other injuries were noted to the nerve. OUTCOME At one week post-op, the patient was found to have (3+ to 4−)/5 strength of his right extensor hallucis longus and by six months he had regained full strength in all the muscles of his right leg and foot. By two years follow-up, he had normal strength and sensation in the leg, foot, and ankle. Repeat EMG was normal, and he had returned to full athletic activity.