Cadaver study using 9 fresh-frozen hands with external fixator–controlled metacarpal osteotomy models to quantify how progressive shaft shortening (0–10 mm in 2-mm steps) translates into MCP joint extensor lag at the index and small fingers.
When managing spiral or oblique metacarpal shaft fractures, expect roughly 7° of MCP extensor lag per 2 mm of shortening — but since most patients have ~20° of baseline MCP hyperextension and natural tethering limits real shortening to ~5 mm, clinical lag is often compensated; reserve surgical length restoration for cases where adequate active MCP extension cannot be demonstrated after correcting rotation and angulation.
Cadaver study using 9 fresh-frozen hands with external fixator–controlled metacarpal osteotomy models to quantify how progressive shaft shortening (0–10 mm in 2-mm steps) translates into MCP joint extensor lag at the index and small fingers.
When managing spiral or oblique metacarpal shaft fractures, expect roughly 7° of MCP extensor lag per 2 mm of shortening — but since most patients have ~20° of baseline MCP hyperextension and natural tethering limits real shortening to ~5 mm, clinical lag is often compensated; reserve surgical length restoration for cases where adequate active MCP extension cannot be demonstrated after correcting rotation and angulation.