Proximal Hamstring Tears
Hamstring muscle injuries occur frequently in athletes, particularly in those who engage in explosive activities such as sprinting or jumping. Injury may occur at the proximal origin (attachment of the tendon to the ischial tuberosity) or more distally in the muscle belly.
Anatomy and Pathophysiology
The hamstring muscles are located on the back of the thigh and include three muscles: Semitendinosus, Semimembranosus and Biceps femoris. The begin with a common tendon on the ischial tuberosity, course posteriorly, and attach distally just below the knee joint. The hamstrings are a powerful group, and both extend the leg back and flex the knee.
Injury to the hamstrings can include a muscle strain, a muscle tear, a tendonitis or a tendon tear.
Muscle Strain Grading
- Grade 1: mild, microscopic tearing
- Grade 2: moderate, partial tearing
- Grade 3: severe, complete tear of the muscle
Tendon injuries can be categorized as tendinitis/tendinopathy, partial tear and complete tear.
In the most severe hamstring injuries, the tendon tears completely and retracts away from its attachment point. A piece of bone may break off with the tendon, known as an avulsion injury.
Multiple risk factors exist including reduced mobility/lack of flexibility, muscle imbalances, training errors, and repetitive activities.
Pain is either in the back of the thigh or the buttocks at the ischial tuberosity. In the event of an acute tear, swelling, ecchymosis and weakness is often present.
Physical Examination and Work-up
On physical examination, the thigh is examined for tenderness and/or ecchymosis/bruising. Additionally, strength and neurovascular testing are conducted. In some, the sciatic nerve may be involved in hamstrings injury.
X-rays are assessed for hamstring tendon avulsion at the ischial tuberosity. An MRI better discerns for the presence and degree of severity of hamstrings tendon and muscle injuries.
Management of Hamstrings Injuries
The goal of treatment, both non-surgical and surgical, is to restore function and reduce pain. The majority of hamstring strains heal well with nonsurgical treatment of rest, activity modification, physical therapy, ice/compression and over the counter anti-inflammatories.
Surgery is most commonly performed for tendon avulsion injuries. Surgery may also be needed to repair a complete tear within the muscle. In the setting of an avulsion injury, the hamstrings tendon is reattached with the bone to the ischial tuberosity with the combination of strong suture material and an implant. A complete tear within the muscle is sewn back together using suture material. Following surgery, the repair is protected with bracing and crutch use. A specific rehab protocol is issued based on intra-operative findings and guided by desired activities and patient goals.