Question
A 30 year old man had a laceration to the front of his elbow six months ago. He now cannot bend his index finger when he tries to make a fist.
- What is the deformity?
- What is the cause?
- What is the classification?
- What is the management?
Answer
Deformity
- Pointing index finger, the benediction posture on attempted fist
- Loss of index finger flexion at the PIP and DIP joints and weak thumb IP flexion
- Positive Ochsner clasp test
Cause
- High median nerve palsy proximal to the origin of the anterior interosseous nerve
- Loss of FDS, FDP to the index and middle fingers, FPL and the thenar muscles, with pronator weakness
- Middle finger flexion may be partly preserved through FDP interconnections with the ring finger
- Causes include penetrating injury, supracondylar and forearm fractures, and compression at the ligament of Struthers or lacertus fibrosus
Classification
- Seddon, neurapraxia, axonotmesis and neurotmesis
- Sunderland grades I to V, with Mackinnon grade VI for a mixed injury
Management
- Open injuries are explored early, with direct repair or nerve grafting
- Closed injuries are observed with serial examination, Tinel progression and nerve conduction studies at 6 to 12 weeks
- Explore if there is no recovery by about 3 months
- Nerve transfers can shorten the distance to reinnervation in high injuries
- Late reconstruction with side to side suture of index and middle FDP to ring and little FDP, brachioradialis to FPL and an opponensplasty
- Hand therapy and splinting to prevent contracture
Related pages
Author Contributions
Orthofracs team
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.