Hamstring Tear vs Avulsion
Hamstring tendon and muscle injuries are common in athletes and recreational sports such as football, rugby and athletics. Most can be appropriately graded with MRI and then rehabilitated by evidence based protocols and a comprehensive return to run/sport programme.
Hamstring avulsions on the other hand can cause significant disability.They commonly occur in adolescent athletes during sporting activities involving sudden, extreme, unbalanced and eccentric contracture of powerful muscles. They can however also occur in skeletally mature patients. Mechanism usually involves forceful flexion of the hip and simultaneous extension of the knee e.g. sprinting and hurdling. Patients often present with a history of acute pain at the buttock crease, a severely antalgic gait, loss of hip function and significantly reduced hamstring strength.
This newsletter describes an unusual case of complete hamstring tear, occurring just adjacent to the hamstring insertion, so shares characteristics of both hamstring tear and avulsion.
Clinical History
Clinical history;
- 34-year-old man presented to LBSM with an acute right hamstring injury during Christmas Rugby
- Mechanism – Leant over to retrieve ball with opposition player landing on his back, forcing a deep hip flexed position
- Felt tearing sensation in buttock immediately fell to ground
- Unable to stand up, had to be carried of pitch
- Able to partial weight bear in the following few days and attended clinic 3 days post injury
Past Medical history;
- BMI 28
- No previous hamstring injuries
- Otherwise fit and well
Exercise history;
- Plays Rugby once a week
- Sporadic gym goer
Social history;
- Works in accounting
- Non-smoker
- Good diet
Clinical examination (assessed day 3 post-injury);
- Antalgic pattern on load bearing through right leg
- Extension bruising all throughout posterior thigh, from glut to knee
- Very weak power on prone knee bend
- Mild Popeye deformity on hamstring activation
Next steps;
- Significant Hamstring tear/ Hamstring avulsion suspected so MRI pelvis and thigh organised
Diagnostic Imaging
Full thickness rupture of the right semi-tendinosus muscle and semi-membranosus component of the right proximal common hamstring tendon. Common tendon still attached to Ischial Tuberosity so therefore not true Hamstring Avulsion. Distal retraction of the muscle by 11.4 cm. The appearance is consistent with a BAMIC grade 4c injury unusual pattern (with most injuries occurring at the MTJ).
Management
Rehabilitation
- First 1 week
- Game ready and elevation
- Hamstring, quads and gluteal activation exercises e.g isometric prone knee bend
- Double Leg stance
- PWB with crutches
- 2-4 weeks
- Single Leg stance
- Concentric activation e.g. resisted prone knee bends
- Eccentric activation e.g. Double leg RDLs
- Restoration of normal gait patterns
- 4-8 weeks
- Weighted eccentric and concentric SL loading
- Commencement of Askling’s Hamstring protocol to regain length
- 8-12 weeks
- Gentle return to light jogging
- Walk/run programme
- Ongoing strength training
- 12+ weeks
- Graduated return to sport
- Back to rugby at 14 weeks
Medical
- Haematoma drainage performed at 2 weeks
- Hamstring repair considered at 3 weeks post injury
- Due to initial positive response to rehabilitation, decided against surgical intervention
Patient Self monitoring tools
- LBSM pain and symptom diary
- LBSM load monitoring diary
Key Summary – Hamstring injuries
- Hamstring avulsion must be considered in high hamstring injuries that occur from a high force mechanism, or external contributing force
- This is particularly true in adolescent athletes
- If diagnosis is delayed sciatica may develop as a result of irritation of the sciatic nerve, either through exuberant callus formation or when the avulsed fragment directly impinges
- Treatment of hamstring avulsions may involve non-operative or operative management with the majority of avulsions treated conservatively
- Indications for operative intervention may include significant displacement (greater than 1–3cm), fracture non-union or an inability to tolerate prolonged immobilisation
