Causes:
Tears of collateral ligaments or volar plate
Impingement by osteophytes, irregular articular surfaces, loose bodies, soft tissue bands
Entrapment of radial collateral ligament, sesamoid bone, exostosis
Epidemiology:
Index and middle fingers
Equal in men and women
Types:
Spontaneous
Degenerative: >50 years, middle finger prediliction
Treatment:
Closed manipulation - rarely successful
Usually requires surgery - resection of prominence on metacarpal head
Reference:
Thomas RJ et al. Locked Metacarpophalangeal Joint in a 20-Year-Old Football Player. The American Journal of Sports Medicine 34:29-31 (2006)
