Background: Most extra-articular metacarpal fractures can be managed
nonoperatively. While the conventional wisdom is that the metacarpophalangeal
joint should be immobilized in a position of flexion, alternative methods for
cast immobilization have been described. The purpose of this study was to
retrospectively evaluate three methods of closed treatment; specifically, we
investigated whether the position of immobilization of the metacarpophalangeal
joint or the absence of a range of motion of the interphalangeal joints
affected the short-term outcome or fracture alignment.
Methods: Between November 2000 and April 2004, extra-articular
metacarpal fractures were immobilized for five weeks in one of three ways:
with the metacarpophalangeal joints in flexion and full interphalangeal joint
motion permitted (Group 1); with the metacarpophalangeal joints in extension
and full interphalangeal joint motion permitted (Group 2); and with the
metacarpophalangeal joints in flexion, the interphalangeal joints in
extension, and no interphalangeal joint motion permitted (Group 3).
Radiographs and the range of motion were evaluated at five weeks after
application of the cast, and the range of motion and grip strength were
assessed at nine weeks.
Results: Two hundred and sixty-three patients met the inclusion
criteria. At five weeks, there was no difference among the treatment methods
with regard to the range of motion or the maintenance of fracture reduction.
At nine weeks, there was no significant difference with regard to the range of
motion or grip strength.
Conclusions: When immobilization was discontinued by five weeks, the
position of the metacarpophalangeal joints and the absence or presence of
interphalangeal joint motion during the immobilization had little effect on
motion, grip strength, or fracture alignment. This finding contradicts the
conventional teaching that the metacarpophalangeal joint must be immobilized
in flexion to prevent long-term loss of joint extension. Patient comfort, ease
of application, and the surgeon's familiarity with the technique should
influence the choice of immobilization.
Level of Evidence: Therapeutic Level III. See
Instructions to Authors for a complete description of levels of evidence.