Palm Laceration with Inability to Extend Third Digit
This patient has sustained an extensor tendon laceration requiring immediate surgical exploration, repair, and hand surgery consultation. Inability to extend the finger following a palm laceration indicates complete disruption of the extensor mechanism, which demands urgent operative intervention to prevent permanent functional impairment 1.
Initial Evaluation and Imaging
Obtain standard 3-view radiographs of the hand immediately to detect fracture fragments, as large bony avulsions may require open reduction and internal fixation 1. The radiographic examination should include:
- Posteroanterior (PA) view of the entire hand 1
- True lateral view 1
- Oblique projection (both internally and externally rotated for maximum diagnostic yield) 1
Radiographs are essential to assess for bone involvement and determine the need for operative fixation of any associated fractures 1.
Clinical Assessment Specifics
Examine for:
- Complete loss of active extension at the metacarpophalangeal (MCP) joint - indicates extensor digitorum communis laceration 1
- Tendon gap or visible tendon ends in the wound - confirms complete laceration requiring repair 1
- Associated nerve injury - test digital nerve sensation, as palmar lacerations can cause undiagnosed deep ulnar nerve paralysis that is easily missed acutely 2
- Vascular integrity - assess capillary refill and digital perfusion 1
Advanced Imaging if Radiographs Are Negative
If radiographs are negative but clinical suspicion remains high for associated injuries, MRI of the hand is ideal for evaluating tendon injuries and surgical planning 1. MRI demonstrates:
- Level of tendon retraction 1
- Quality of the tendon stump 1
- Associated pulley injuries 1
- Injury to the central slip or extensor hood (sensitivity 28-85% for extensor hood injuries) 1
Note that MRI of the extensor system has not been as well studied as the flexor system, but it remains the best modality for preoperative planning when soft tissue detail is needed 1.
Management Algorithm
Immediate Actions:
- Irrigate thoroughly with potable tap water (does not increase infection risk compared to sterile saline) 3
- Provide local anesthesia - epinephrine-containing anesthetic up to 1:100,000 concentration is safe for digits 3
- Explore the wound surgically to identify the extent of tendon injury 1
- Consult hand surgery emergently for operative repair 1, 4
Surgical Repair:
- Primary tendon repair should be performed with accurate anatomical restoration of all injured structures 4, 5
- Delayed closure may be appropriate if contamination is present 5
- Ensure meticulous repair to prevent permanent functional deficit 4, 5
Post-Operative Rehabilitation:
Immobilize the proximal interphalangeal (PIP) joint in a cylinder splint for 3 weeks, followed by 3 weeks of controlled mobilization with a Capener coil splint 4. This protocol achieves:
- Mean PIP flexion of 94° (range 70-110°) 4
- Minimal extension deficits (mean 6° in affected fingers) 4
- Excellent or good recovery in all cases 4
Critical Pitfalls to Avoid
- Do not miss associated deep ulnar nerve injury - stab wounds of the palm frequently cause undiagnosed deep motor nerve paralysis because sensation and major tendon function appear intact initially 2
- Do not delay repair - while there is no absolute "golden period," extensor tendon injuries require prompt surgical attention to optimize outcomes 3
- Do not rely on conservative management - complete tendon lacerations with loss of function require operative repair, unlike simple skin lacerations <2 cm which can heal conservatively 6
- Ensure tetanus prophylaxis is provided if indicated 3
Wound Closure Considerations
After tendon repair, use moist occlusive or semiocclusive dressings as wounds heal faster in a moist environment 3. Timing of suture removal depends on location and is typically 10-14 days for hand wounds 3.