A distal hamstring rupture is a tear of the hamstring tendons at or near their insertion on the tibia, most commonly the semitendinosus and semimembranosus on the medial side or the biceps femoris on the lateral side. These injuries are uncommon but can produce significant weakness and altered knee mechanics. Treatment depends on the specific tendon, completeness of the tear, and patient demand.
What Is a Distal Hamstring Rupture?
The hamstring muscle group consists of three muscles: the semitendinosus and semimembranosus medially, and the biceps femoris laterally. These muscles flex the knee, extend the hip, and contribute to rotational stability. Their tendons insert at multiple sites around the posterior and medial proximal tibia and fibular head.
Distal hamstring injuries are less common than proximal hamstring injuries (at the hip) but can occur from:
- Eccentric contraction during running or kicking
- Forced knee hyperextension with hip flexion
- Direct blow to the back of the knee
- Water skiing injuries, which have a specific mechanism of forced hip flexion with knee extension
The most common distal hamstring injury is a partial or complete tear of the biceps femoris tendon from the fibular head, sometimes associated with lateral collateral ligament or posterolateral corner injury.
Causes and Risk Factors
- Sprinting and kicking sports
- Water skiing
- Inadequate warm-up before explosive activity
- Prior hamstring injury, which predisposes to recurrent injury
- Age 25 to 45 is the most common demographic
- Male sex
- Associated ligament injury raises the index of suspicion
Symptoms
- Sharp pain at the back or outside of the knee during activity
- Audible or palpable pop in some cases
- Bruising and swelling that develops over hours to days
- Weakness with resisted knee flexion
- Difficulty walking without limp
- Palpable defect or gap at the tendon insertion in complete tears
- Associated ligament symptoms in cases with combined injury
Diagnosis
Dr. Chudik’s evaluation includes the mechanism, the specific timing, and a physical examination assessing knee flexion strength, tendon integrity, and any associated ligament injury. The lateral hamstring (biceps femoris) is palpated at the fibular head. MRI confirms the diagnosis, characterizes the tear (partial versus complete, location, retraction), and identifies any associated ligament injury. The Westmont office has on-site high-field MRI.
Treatment
Non-surgical treatment is appropriate for partial tears and for complete tears in lower-demand patients. It involves rest, ice, compression, a hinged knee brace for comfort, and a targeted physical therapy program emphasizing progressive strengthening and range of motion.
Surgical repair is recommended for complete tears in active patients, particularly biceps femoris ruptures at the fibular head in athletes and in cases with associated ligament injury. Dr. Chudik performs distal hamstring repair, reattaching the torn tendon to the bone with suture anchors. Acute repair within three to four weeks produces better outcomes than delayed repair because the tendon has not yet scarred in a retracted position. Chronic tears may require tendon graft augmentation.
Recovery and Outcomes
Non-surgical recovery for partial tears typically allows return to sport in four to eight weeks with appropriate rehabilitation. Recovery after surgical repair typically includes four to six weeks of protected weight-bearing in a hinged knee brace, progressive range of motion over two to three months, strengthening at three months, and return to sport at five to six months.
Outcomes after acute repair are good, with restoration of most strength and function. Chronic tears and combined injuries have more variable outcomes.
When to See Dr. Chudik
Schedule an evaluation after any injury that produces sharp pain at the back of the knee, weakness with knee flexion, or difficulty walking, particularly if associated with a water skiing injury or contact sport mechanism. Call 630-324-0402 or request an appointment online.