Transverse Metacarpal Fractures   



- Discussion:
    - usually result from direct blow;
    - presents w/ dorsal angulation & increased palmar displacement of metacarpal heads because of deforming force of interosseous muscles and long flexor muscles, which are volar to the fracture plane;
    - more proximal frxs (ie, shaft frx) are more likely to produce noticable dorsal angulation & clawing, and therefore less angulation can be accepted in midshaft fractures than in neck frx;

- Clinical Effects: (of dorsal angulation);
    - weakened grip;
    - hyperextension at MP joint;
    - reduced extension at the PIP joint;

- Closed Reduction:
    - easy to reduce by difficult to maintain;
    - MCP & PIP joints are both flexed 90 deg to gain control of distal fragment & then exert dorsally directed force on metacarpal to push metacarpal head dorsally (& metacarpal shaft volarly) to achieve reduction;
           - immobilization in this position is not allowed, however, as flexion contracture will develop;
    - more proximal frxs (ie, shaft frx) are more likely to produce noticable dorsal angulation & clawing, and therefore less angulation can be accepted in midshaft fractures than in neck frx;

- Acceptable Reduction:
    - index and long metacarpals:
           - minimal angulation can be accepted because there is no compensatory motion at the CMC joints;
           - do not tolerate > 10 deg;
    - ring & little metacarpals:
           - little finger CMC articulation allows flexion extension arc of 20-30 deg;
           - slight rotatory arc motion assists little finger in contacting thumb;
           - ring metacarpal has 10-15 deg of mobility;
           - will tolerate some dorsal angulation < 20 deg;
           - more angulation is accepted for more distal fractures;

- Operative Treatment of Shaft Frx



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

Last updated by Data Trace Staff on Thursday, October 4, 2012 2:17 pm