[Surgically treated intraarticular fractures of the trapeziometacarpal joint -- a clinical and radiological outcome study].

BACKGROUND: Fractures of the thumb metacarpal occur quite frequently at the base. Intra-articular metacarpal base fractures (such as Bennett or Rolando fractures) present treatment challenges and surgical therapy remains controversial. Malunion of these fractures may lead to the development of painful osteoarthrosis at the trapeziometacarpal joint which can seriously impair overall hand function.

PATIENTS AND METHODS: In a retrospective analysis, 30 intra-articular fractures (24 Bennett's, three Rolando's and three comminuted fractures) treated between 1994 and 1999 in the Department of Hand, Plastic and Reconstructive Surgery in Ludwigshafen have been reviewed. A total of 25 patients (83%) could be examined clinically and radiologically at an average follow-up of 39 months. The subjective outcome was measured using the DASH-questionnaire. Clinical examination included grip strength and range of motion measurements.

RESULTS: Four cases were treated with percutaneous pinning, in 26 cases open reduction with internal fixation was performed. Radiological analysis demonstrated good reduction in 90% of all cases (metacarpal base gap/step-off in articular surface: <1 mm in 63%, between 1-2 mm in 27%, >2 mm in 10%). Twelve patients (48%) were free of symptoms at follow-up. Slight restricted flexion was noted in 11 (44%) patients (75-90% of healthy collateral values), including one patient with moderate opposition deficit (<75% of uninjured value). Three patients (12%) demonstrated weakness in tip pinch and one patient had decreased key pinch compared to the uninjured hand. Overall, good functional results for radial abduction, flexion and opposition as well as good grip strength compared to their uninjured side were found. At follow-up a total of 64% radiological features of trapeziometacarpal arthrosis have been documented. Very low impairment rates in the DASH-scores of all three parts (below 9 points) were measured. There was no correlation between the quality of thumb base restoration and radiological or subjective outcome.

CONCLUSION: Exact anatomical restoration of the articular surface may not be essential for obtaining satisfactory functional results.