[Functional results of medio-carpal partial arthrodesis with excision of the scaphoid].

Midcarpal arthrodesis with excision of the scaphoid for the treatment of painful carpal collapse has been performed in our hospital since 1993. A clinical study was carried out to evaluate the results and determine special factors, which might influence the results. 26 out of 29 patients operated until 1999 were reexamined after an average follow-up of 27 months. The results were evaluated according to the Mayo-modified wrist score. The DASH score and the pain-disability index (PDI) were calculated postoperatively. Standard X-rays of the wrist were analyzed for alteration of the radio-lunate joint space, the position of the lunate with respect to the radius and the correction of the carpal height as calculated by the Youm index. Carpal collapse was due to scapholunate pathology (SLAC) in 12 cases, long-standing scaphoid nonunion (SNAC) in ten cases, perilunate dislocation, which was only simply reduced, in three cases, and calcium pyrophosphate deposition disease in two cases. The Mayo-modified wrist score improved significantly from an average of 46 points before to 76 points after surgery. The DASH score postoperatively was 22, the PDI 13. All patients reported improvement of their situation after the operation, eight were completely free of pain. The average range of motion from extension to flexion was 64 degrees, which was almost identical to the average preoperative value. The average grip strength before surgery was 24 kg, after surgery 34 kg. There was a correlation between the position of the lunate to the radius in the lateral X-ray and the range of extension. If the lunate was positioned correctly, wrist extension was significantly better. The radiolunate joint space was maintained during the period of observation with only two exceptions. Apparent subchondral sclerosis was seen in most of the cases. It was not possible to restore carpal height completely. Some results after perilunate luxations and one case of calcium pyrophosphate deposition disease were unsatisfactory. Midcarpal arthrodesis with scaphoid excision is a reliable method for treating radioscaphoid arthrosis caused by carpal collapse. Correction of the hyperextended position of the lunate is important to obtain optimum results. In our hospital, a wrist arthrodesis is only rarely performed nowadays, except in the rheumatoid patient.