Conditions that can result in a clawhand:
(1) Dejerine-Klumpke palsy affecting the C7, C8 and T1 roots of the brachial plexus
(2) lesion of the inner cord of the brachial plexus
(2) acute poliomyelitis
(3) syringomyelia
(4) damage to the ulnar nerve below the elbow and to the median nerve
(5) Volkmann's ischemic contracture
(6) progressive muscular atrophy
(7) amyotrophic lateral sclerosis
(8) leprosy
(9) suppurative tenosynovitis of the ulnar bursa
(10) advanced rheumatoid arthritis
Features of the clawhand:
(1) atrophy or weakness of the interosseous muscles, lumbrical muscles and adductor pollicis
(2) hyperextension of the metacarpophalangeal joints
(3) flexion of the distal interphalangeal joints
The clawhand occurs when there is no or little muscle opposition to the flexor digitorum and extensor communis digitorum.
