Intrinsic contracture: diagnosis and management

Purpose of review: Intrinsic muscle contracture disrupts the fine balance between intrinsic and extrinsic muscles of the fingers and compromises the hand's strength and versatility. This condition may occur secondary to inflammation, tumor, central nervous system disease, joint destruction, and trauma. Other causes are muscle spasticity, pathologic change within the intrinsic muscles, lateral band displacement, or tendon transfers to the lateral bands. Presentation ranges from finger stiffness or difficulty with grasp to loss of flexion occurring at the proximal and distal interphalangeal joints accompanied by loss of extension at the metacarpophalangeal joints. Its present incidence is lower than historical publications have indicated due to prevention of hand compartment syndrome. Treatment has received considerable attention and ranges from stretching exercises to oblique fiber releases, muscle slide procedures, and lateral band tenotomy. A management algorithm is presented. Recent findings: This review highlights recent investigations focusing on intrinsic muscle anatomy demonstrating anatomic variation that was not previously appreciated. Recent biomechanical research offers guidelines for intrinsic contracture correction in pathology limited to the proximal interphalangeal joints when the interosseous muscles are functional. Summary: Early recognition of hand compartment syndrome and appropriate intervention are of paramount importance to prevent the most common cause of intrinsic contracture. Treatment is initiated with splinting and stretching exercises; surgery is indicated once nonoperative measures have failed. Surgical options depend on muscle function and the pathologic etiology.