Metacarpal #’s cont.
They prefer open reduction because it is difficult to determine the quality of the closed reduction on image intensifier in the OR.
– tend to shorten and rotate rather than angulate
– the 3rd and 4th shorten less because of the tethering of the deep transverse metacarpal ligament and the interossei. Shortening is more pronounced in the border 2nd and 5th metacarpals.
– if, after closed reduction, the angulation is acceptable, the rotation is correct, and there is less than 5 mm of shortening, treat with a volar/dorsal slab with the MCPï¿½s held in about 60-70o of flexion.
– if not acceptable, or if the spiral tip appears that it might impinge on proximal phalangeal flexion, ORIF with K-wires, plates, AO lag screws, cerclage wires. Consider K-wiring to an adjacent metacarpal. They prefer open reduction because it is difficult to determine the quality of the closed reduction on image intensifier in the OR.
– frequently need a combination of internal and external fixation, with delayed primary bone grafting
Metacarpal Base Fractures
– usually stable injuries, requiring little more than a cast or splint immobilization
– note that ANY rotational deformity is greatly magnified at the tip
– neither Rockwood and Green or Jupiter indicate what unacceptable alignment would be. Probably best again to remember that the 2nd and 3rd are stable and move very little, while the 4th and 5th are more mobile and thus tolerate deformity better.
Note that soft tissue damage is common. Concomitant extensor tendon damage is common, with adhesions being likely. The interossei may be damaged, and scarring may lead to an intrinsic contractures of the hand.