Summary Intrinsic Minus Hand is a hand deformity characterized by MCP joint hyperextension with PIP joint and DIP joint flexion caused by an imbalance between strong extrinsics and deficient intrinsics. Diagnosis is made by clinical exam which shows MCP hyperextension and IP joint flexion which corrects when the MCP joint is brought out from hyperextension. Treatment may be nonoperative or operative depending on the severity of the contracture and impact on quality of life. Etiology Pathophysiology ulnar nerve palsy cubital tunnel syndrome ulnar tunnel syndrome median nerve palsy Volkmann's ischemic contracture leprosy (Hansen's disease) failure to splint the hand in an intrinsic-plus posture following a crush injury Charcot-Marie-Tooth disease (hereditary motor-sensory neuropathy) compartment syndrome of the hand Pathoanatomy Pathoanatomic components loss of intrinsics leads to loss of baseline MCP flexion and loss of IP extension strong extrinsic EDC leads to unopposed extension of the MCP joint remember the EDC is not a significant extensor of the PIP joint most of the MCP extension forces on the terminal insertion of the central slip come from the interosseous muscles strong FDP and FDS leads to unopposed flexion of the PIP and DIP Presentation Symptoms decreased hand function Physical exam MCP hyperextension and IP joint flexion with an ulnar nerve palsy, the deformity will be worse in the 4th and 5th digits (lumbricals innervated by the ulnar nerve) not as severe in the 2nd and 3rd digits (lumbricals innervated by the median nerve) functional weakness unable to perform prehensile grasp diminished grip and pinch strength provocative tests 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 Operative contracture release and passive tenodesis vs. active tendon transfer indications progressive deformity that is affecting quality of life technique goal is to prevent MCP joint hyperextension