Review Question - QID 220835

This patient sustained an acute hamstring rupture at the myotendinous junction and underwent surgical repair. The sciatic nerve runs approximately 1.2 cm from the lateral aspect of the hamstring origin and is the most commonly injured nerve during surgical repair (Answer 4).

Hamstring injuries most commonly occur at the myotendinous junction in running adult athletes. These injuries are caused by sudden hip flexion and knee extension, and account for approximately 30% of new lower extremity injuries in athletes. They are most commonly seen in rapid acceleration sports like soccer, football, and track. These injuries are diagnosed clinically and with an MRI. Typically, an MRI is obtained to evaluate the number of tendons involved and the degree of retraction. Injuries with single tendon involvement, 2 tendon tears with <2 cm of retraction, rupture at the myotendinous junction, and less active patients with more comorbidities are treated with ice/rest, NSAIDs, and protected weight-bearing. Other treatment options include tendon repair and open reduction and internal fixation for avulsion injuries. Complications of operative intervention may include sciatic nerve injury, ischial tuberosity nonunion, or recurrence.

Arner et al. reviewed hamstring injuries in athletes and noted these may occur at the proximal origin, myotendinous junction/muscle belly, and distal insertion. The more proximal and distal injuries typically require surgical intervention. They report that the acute repair of proximal avulsions yields successful outcomes, whereas the repair of chronic complete tears is less reliable and more challenging. The authors conclude that the recurrence of hamstring injuries is common; therefore, continuation of preventive therapies after return to sport is essential.

Stephen et al. reviewed the anatomy, morphology, innervation, and function of the hamstring muscles. They note the semitendinosus, semimembranosus, and the long head of the biceps femoris originate on the ischial tuberosity and are innervated by the tibial division of the sciatic nerve. The peroneal division of the sciatic nerve innervates the short head of the biceps femoris distally in the thigh. They conclude that understanding hamstring anatomy is crucial, especially in athletes, as these injuries are common in the lower extremity and have a relatively high recurrence rate.

Figure A is a clinical image demonstrating the ecchymosis commonly seen on exam in hamstring injuries. Figure B is an axial MRI demonstrating a rupture of the biceps femoris (long head) and semitendinosus. Illustration A is an anatomical depiction of the neurovascular structures in the posterior pelvis and thigh. The arrow demonstrates the course of the sciatic nerve approximately 1.2 cm lateral to the hamstring origin on the ischial tuberosity.

Incorrect answer choices:
Answer 1: The pudendal nerve is 2-3 cm superior-medial to the ischial tuberosity and is less commonly injured during surgical repair.
Answer 2: The superior gluteal nerve travels proximal to the piriformis and is less commonly injured during surgical repair.
Answer 3: The inferior gluteal nerve travels 5 cm cephalad to the inferior border of the gluteus maximus and is less commonly injured during surgical repair.
Answer 5: The nerve to the obturator internus runs alongside the pudendal nerve, medial to the ischial tuberosity, and is less commonly encountered during surgical repair.