What is the treatment for a puncture injury with tendon injury to the extensor digitorum?

Treatment for Puncture Injury with Extensor Digitorum Tendon Injury

Surgical repair is the definitive treatment for extensor digitorum tendon injuries caused by puncture wounds, with the specific technique determined by the zone of injury and tendon thickness. 1

Initial Assessment and Diagnosis

• Diagnosis should include thorough inspection for swelling, asymmetry, and erythema of the involved tendon, along with range-of-motion testing, palpation for tenderness, and examination maneuvers that simulate tendon loading and reproduce pain 2
• Loss of active extension in the injured digit is the primary clinical sign of extensor tendon injury 1
• The tenodesis effect can aid in diagnosis: wrist flexion should cause passive extension at the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints if the extensor tendon is intact 1
• Plain radiography, ultrasonography, and MRI can be helpful if the diagnosis remains unclear 2

Surgical Treatment Based on Zone of Injury

• For zone I and II injuries (distal finger):

  • Several "figure of 8" buried sutures or a running suture technique should be employed 1
  • When there is no remaining tendon on the distal end, suture anchors or bone tunnels may be utilized 1

• For zone III to VII injuries (middle finger to wrist):

  • One or two core sutures with a supplementary running suture is the recommended technique 1
  • The running interlocking horizontal mattress technique has been found to be stiffer, faster to accomplish, and produces good to excellent clinical results 1

• For zone VII injuries specifically:

  • The injured tendon may lie beneath the extensor retinaculum, requiring windowing of the retinaculum to decrease adhesion formation and facilitate repair 1

Post-Operative Management

• Most patients with tendon injuries (about 80%) fully recover within three to six months 2
• Relative rest of the affected area is essential to prevent further damage and promote healing and pain relief 2
• Cryotherapy (ice) should be applied through a wet towel for 10-minute periods to provide acute pain relief 2
• Eccentric strengthening exercises should be implemented as they are effective for treatment of tendinopathy and may reverse degenerative changes 2

Medication Management

• NSAIDs (topical or systemic) are effective for short-term pain relief but have no effect on long-term outcomes 2
• Topical NSAIDs may have fewer systemic side effects compared to oral NSAIDs 2
• Locally injected corticosteroids may provide acute pain relief but should be used with caution as they may inhibit healing and reduce the tensile strength of the tissue, potentially predisposing to spontaneous rupture 2

Rehabilitation Considerations

• Early passive motion techniques should be considered for complex injuries to reduce complications from increased fibroblastic response common to crushing injuries 3
• Proper management during the first 3 postoperative weeks is the major determinant for the final outcome in extensor tendon injuries 3
• Edema control is crucial to allow the patient to begin the mobilization phase with fewer problems 3

Potential Complications and Outcomes

• More fingers lose the ability to flex fully than lose the ability to extend after repair 1
• Distal zones (1 to 4) have significantly poorer results than more proximal zones (5 to 8) 4
• Patients without associated injuries (such as fractures, dislocations, joint capsule or flexor tendon damage) achieve better outcomes (64% good/excellent results) 4
• Loss of flexion may be a more significant complication from extensor tendon injury than previously thought 4

Alternative Treatments

• Nonoperative treatment is typically reserved for partial tendon injuries and for patients unable to tolerate surgery 1
• Therapeutic ultrasonography may decrease pain and increase the rate of collagen synthesis, but evidence for consistent benefit is weak 2
• Extracorporeal shock wave therapy appears to be a safe, noninvasive option for pain relief but requires further research to clarify mechanisms of action 2