Locking plates for fixation of extra-articular fractures of the first metacarpal base: a series of 15 cases.

Extra-articular fractures of the first metacarpal base may lead to retraction of the first web and weakness of the pinch. Conventional surgery (K-wire or non-locking plates) needs six weeks of immobilization. Our goal was to achieve the reduction of such fractures using locking mini-plates to allow early mobilization. Our series included 15 patients, with an average age of 35 years, operated on for an extra-articular fracture of the first metacarpal base. All patients underwent surgery with variable angle locking mini-plates. In 10 patients, we used a double-row plate and for the other five patients T-shaped plates. Fractures were immobilized for two weeks. Outcome evaluation consisted in the assessment of subjective criteria (pain, quick-DASH), objective criteria (Kapandji score, Jamar®, pinch®), screening for complications, time off work and radiological consolidation. Follow-up time was 10 months. Pain averaged 2.2/10 and quick-DASH 17.4. Kapandji score was 90%, grip strength 95.5% and pinch strength 88.6% of the contralateral hand. Three secondary displacements occurred with T-plates. Mean time off work was seven weeks. Radiological consolidation was detected at four to six weeks. Our results seem to indicate that locking T-plates do not provide sufficient strength to allow early mobilization. The direct cost of locking plates is high but this must be weighed against the reduced indirect costs when calculating the cost effectiveness of this type of management. Double-row locking plates offer a valuable therapeutic alternative since they allow stable fixation and early mobilization of the thumb, which may outweigh their high cost.