Pathology: Loss of intrinsic muscle function leading to an overactive extrinsic muscle pull, resulting in hyperextension of the MCP joint and flexion of the IP joints.
Clinical Presentation: MCP hyperextension with flexed PIP and DIP joints.
Bouvier’s Test: MCP joint is passively brought out of hyperextension If PIP joint extension returns (positive) – simple claw hand If PIP joint extension does not return (negative) – complex claw hand
Treatment:
Conservative: Passive stretching and splinting for mild cases.
Surgical: Release of intrinsic muscles, tendon transfers, or contracture release.
5. Intrinsic Plus Hand (Functional hand)
Definition: A deformity characterized by MCP flexion and PIP & DIP extension due to imbalance between spastic intrinsics and weak extrinsics.
Etiology: Cerebral palsy, spasticity, or brain injury.
Pathology: Spasticity in the intrinsic muscles combined with weakness in extrinsic muscles.
Clinical Presentation: MCP flexion with extended PIP and DIP joints.
Bunnell test (intrinsic tightness test) differentiates intrinsic tightness and extrinsic tightness positive test when PIP flexion is less with MCP extension than with MCP flexion عملى مهم ❓️
Treatment: Surgical release of tight intrinsics or tendon transfers to restore balance.
Lumbrical Plus Finger is characterized by paradoxical extension of the IP joints while attempting to flex the fingers. شفوى ❓️ FDP avulsion,DIP amputation
Diagnosis is made clinically with extension of the IP joints of one digit with attempted flexion of all fingers (making a fist).
Treatment is observation if patient is minimally symptomatic. Operative tenodesis of FDP to terminal tendon or lumbrical release is indicated if symptoms affect patient’s activity demands.
Ortho-Mentor Course 