Abstract and Introduction
Abstract
Hamstring injuries are common in athletes and can cause notable disability. They can be separated based on proximal, muscle belly, and distal injuries, with proximal and distal injuries more commonly requiring surgical intervention. Most injuries do not require acute MRI; however, MRI is useful in proximal and distal injuries as well as muscle belly tears that fail to respond to nonsurgical treatment. Acute repair of proximal avulsions, both partial and complete, result in successful outcomes, whereas chronic complete repairs are more difficult and less reliable. Muscle belly injuries have predictable outcomes but recurrence is common. Nonsurgical treatments focus on eccentric strengthening with the possible addition of low WBC platelet-rich plasma, which may have the potential to hasten recovery and decrease re-rupture. Distal injuries are relatively rare but may require surgical intervention. Hamstring reinjury is common, making continuation of preventive therapies after return to sport essential. Future research with larger sample sizes are required to determine how to decrease injury and reinjury rates, to evaluate the efficacy of platelet-rich plasma and to determine other treatments that may accelerate recovery after injury.
Introduction
Hamstring injuries are common and can account for notable disability in athletic patients, with male athletes being more commonly affected. Hamstring injuries makes up nearly 30% of new lower extremity pathology, and are at a notable risk of becoming chronic issues, with reinjury rates between 12% and 31%.[1] Typically, rapid acceleration sports produce the highest injury rates. Particularly high injury rates are seen in hurdling, soccer, American football speed positions, as well as other running, jumping, and kicking sports. Professional soccer players are among the athletes at greatest risk for this injury, and a 20% rate of hamstring injury per season has been reported, with 20% of injuries becoming chronic. Hamstring injuries are most commonly muscular, with severity ranging from mild disruptions to complete loss of fiber organization. Although less frequent than muscle and myotendinous injuries, proximal hamstring tendinous avulsions are commonly encountered in waterskiing, skating, and weight lifting patients.[2] Proximal injuries can more severely affect activities of daily living and have prolonged recoveries.
Despite the increase in attention and knowledge of these injuries, rates and recurrences have not improved. In fact, one cohort of elite soccer players reported a 4% annual increase in hamstring injuries over a 13-year period and 33% of National Collegiate Athletic Assocaition (NCAA) hamstring tears are recurrences.[3] Timely and appropriate diagnosis and treatment are essential, with physical therapy, biologic treatments, and surgical repairs offering promise.
J Am Acad Orthop Surg. 2019;27(23):868-877. © 2019 American Academy of Orthopaedic Surgeons
