Intrinsic tightness following a severe crush injury to the hand or unrecognized compartment syndrome or trauma or distal joint malalignment due to RA
Physical examination:limited PIP flexion while the MP joints are fully extended, with greater PIP flexion with the MP joints flexed.
Bunnell test=MCP hyperextension puts intrinsics on stretch and causes decreased IP flexion with intrinsic tightness. This is due to the displacement of the lateral bands which occurs due to many reasons.
MCP joint flexion and IP extension resting posture.
RX passive stretching
surgery=loosening intrinsics by distal release or proximal muscle slide resection of the lateral bands and oblique fibers.
References:
Smith RJ: Non-ischemic contractures of the intrinsic muscles of the hand. JBJS 1971;53:1313-1331
BUNNELL S. Ischaemic contracture, local, in the hand. J Bone Joint Surg Am. 1953 Jan;35-A(1):88-101.
HARRIS C Jr, RIORDAN DC. Intrinsic contracture in the hand and its surgical treatment. J Bone Joint Surg Am. 1954 Jan;36-A(1):10-20.
