Operative Treatment of Metacarpal Shaft Frx 



- Treatment Options:
    - percutaneous pinning w/ 1.6 mm or 2.00 m K wires in small fragments;

           
            - ref:
                   Complications of smooth pin fixation of fractures and dislocations in the hand and wrist.
                   Absorbable intramedullary implants for hand fractures. Animal experiments and clinical trial.
    - screw fixation:
            - 2.0 mm or 2.7 mm cortex screws as lag screws in spiral frx;
            - 2.0 mm screws are applied to the cortex and the 2.7 mm screws are applied to the metaphysis;
            - screws should be countersunk to remove prominent head and to improve loading characteristics;
            - generally two screws are required for metacarpal shaft fractures;
            - note: the drilling into small bones does have an effect of torsional rigidity;
                   - drilling a hole more than 30% of the shaft diameter, leads to a 90% reduction in torsional rigidity;
    - plate fixation:
            - indicated for multiple metacarpal shaft frx, or other unstable shaft fractures that cannot be help reduced w/ K wires or screws;
                   - overlying soft tissues must be intact for plate fixation;
            - in absence of comminution & intact palmar cortex, one quarter tubular plate w/ 2.7 mm screws is adequate;
                   - this will allow plate to function as a tension band plate;
            - w/ comminution, use stronger implant such as 2.7 mm DCP & consider bone grafting;
            - plates must be placed on the dorsal surface inorder to function as a tension band;
            - quater tubular plate or 2.7 mm DCP as neutralization plate, especially in lag screw fixation of second to fifth metacarpals, esp w/ spiral fractures with rotational displacement;
                   - w/ segmental defects or comminution a 2.7 mm DCP is required;
            - prebending of the plate slightly beyond the normal metacarpal bow allows restoration of the anterior cortical butress;

                   

            - references:
                   Unstable metacarpal and phalangeal fracture treatment with screws and plates.
                   Rigid internal fixation in the hand: 104 cases.
                   Rigid fixation of phalangeal and metacarpal fractures.
                   Use of a minicondylar plate for metacarpal and phalangeal periarticular injuries.
                   Complications of plate fixation in the hand skeleton.

    - surgical approach: (plate fixation)
            - see: extensor anatomy;
            - longitudinal incision made either between on the outer border of the metacarpals;
            - border metacarpals are approached thru longitudinal incisions between 2nd and thrid or fourth and fifth metacarpals;
            - juncturae tendinum interconnecting the common extensor tendons can be split to enhance exposure (tag for later repair);
            - proximally the incision may be curved to expose the CMC joints;
            - if the metacarpal head needs to be exposed the extensor mechanism may be split down the middle or may be entered thru the radial saggital band;
                    - the radial side offers better exposure to the joint than the ulnar side;
            - carefully incise thru the intrisic fascia inorder to preserve an optimal gluiding mechanism;
    - external fixation of metacarpal fractures:
            - indicated for crush, mangling, or burn injuries which occur along w/ metacarpal fractures;
            - often used in conjunction w/ soft tissue reconstructive procedures;
            - references:
                    Manipulation and external fixation of metacarpal fractures.
                    External fixation of unstable metacarpal and phalangeal fractures.
                    External fixation of metacarpal and phalangeal fractures.
                    Treatment of hand injuries by external fixation.



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

Last updated by Data Trace Staff on Thursday, October 4, 2012 2:07 pm