Oblique Metacarpal Shaft Fractures



- Frx Malrotation:
    - tend to shorten & rotate rather than angulate;
    - may telescope because of proximal pull of extrinsic muscles;
    - effect of malrotation:
         - if 5 deg of malrotation is accepted, then displacement will  override 10 mm;

- Frx Shortening:
    - long & ring metacarpals tend to shorten less because of tethering effect of deep transverse metacarpal ligament;
    - index and little metacarpals tend to have more shortening & rotation;
    - look for loss of normal contour of metacarpal head with MCP joint flexion;
    - shortening of up to 3 mm is well tolerated;

- Reduction:
    - malrotation is minimized by passive flexion of all fingers while stabilizing frx;

- Operative Treatment:
    - cross pinning
    - w/ unacceptaable shortening, length may be regained w/ closed reduction & cross pinning to adjacent metacarpal;
    - screw fixation:
           - single screw is not adequate to withstand rotational and shear stress, and therefore consider use of neturalization plate;
    - plate fixation:
           - seek to place 2 screws (4 cortices) distal & proximal to plate;
           - in midshaft one quarter tubular plate applied dorsally w/ 2.7 mm screws may be used in adults;
           - if frx is at proximal 1/3 of metacarpal, T or L plate may be used;
           - lag screw may be placed thru or independent of the plate



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, October 4, 2012 2:18 pm