What is the treatment for a hamstring injury with a full thickness tear and retraction of the semimembranosus tendon?

Treatment for Hamstring Injury with Full Thickness Tear and Retraction of Semimembranosus Tendon

Surgical repair is recommended for a full thickness tear with retraction of the semimembranosus tendon, especially when retraction exceeds 2 cm, as this approach leads to better functional outcomes and more reliable return to sports compared to nonoperative management. 1

Diagnostic Assessment

• MRI is the gold standard for diagnosis of hamstring injuries 2
  • Look for the "dropped ice cream sign" which indicates full-thickness tendon discontinuity (high interrater reliability) 3
  • Measure tendon retraction using direct measurement method (shortest distance between hamstring origin and tendon stump) 3
  • Quantify extent of retraction in millimeters (>2 cm retraction is a key surgical indicator) 1

Treatment Algorithm

Surgical Indications

• Full thickness tear with >2 cm of retraction 1, 4
• Complete 3-tendon tears 1
• Isolated semimembranosus tears with significant retraction 1
• Injuries that fail to improve after 6 months of nonoperative management 2

Surgical Approach

1. Timing: Acute surgical repair (within first few weeks) provides better outcomes than delayed repair 4
2. Technique options:
   • Open repair: Through transverse incision in gluteal crease, which can be extended in a "T" configuration for chronic retracted tears 4
   • Endoscopic repair: Both endoscopic and open approaches show favorable outcomes at 5-year follow-up 1
3. Special considerations:
   • Sciatic nerve neurolysis may be required in chronic cases due to scarring 4
   • Male patients with isolated semimembranosus injuries may experience earlier return to sports 1

Nonoperative Management

If surgical criteria are not met or surgery is delayed:

• Activity modification and relative rest initially 2
• Progressive physical therapy focusing on:
  • Eccentric hamstring strengthening exercises 1
  • Range of motion exercises 2
• Adjunct treatments:
  • NSAIDs for pain and inflammation management
  • Platelet-rich plasma injections may be considered, though evidence is still being investigated 2

Rehabilitation Protocol

Post-Surgical Rehabilitation

1. Early phase (0-6 weeks):

   • Protected weight-bearing
   • Limited range of motion to protect repair
   • Pain management

2. Intermediate phase (6-12 weeks):

   • Progressive strengthening
   • Gradual return to functional activities
   • Sport-specific exercises

3. Advanced phase (12+ weeks):

   • Return to sport testing
   • On- and off-pitch injury-specific reconditioning 5
   • Global athletic development 5

Expected Outcomes

• Full return to unrestricted activities by 6 months post-surgery 4
• Elite athletes may require 18+ weeks before returning to team training 5
• Use of Parisian Hamstring Avulsion Score (PHAS) to predict return to sports 1

Important Caveats

• Delayed surgical repair of chronic tears results in poorer functional outcomes and higher re-tear rates compared to acute repairs 4
• Sciatic nerve is at risk during surgery due to proximity to the injury site, particularly in chronic cases 4
• Careful monitoring for re-injury is essential, especially when returning to high-speed running activities 5
• Isolated semimembranosus injuries may have better prognosis for earlier return to sports compared to multi-tendon injuries 1

The evidence strongly supports surgical intervention for full thickness tears with significant retraction of the semimembranosus tendon to optimize functional outcomes and successful return to activities.