The effect of malunion on functional outcome after plate fixation of fractures of both bones of the forearm in adults.

Fifty-five adults who had a fracture of both bones of the forearm were managed with plating and were followed for a mean of six years (range, one year to sixteen years and two months) with functional and radiographic assessment. Malunion was quantified by measurement of the amount and location of the maximum radial bow in relation to the contralateral, normal forearm. Fifty-four of the radial and fifty-four of the ulnar fractures united. Eighty-four per cent of the patients had an excellent, good, or acceptable functional result, according to the criteria of Grace and Eversmann. Bone-grafting did not affect the rate of union. Restoration of the normal radial bow was related to the functional outcome. A good functional result (more than 80 per cent of normal rotation of the forearm) was associated with restoration of the normal amount and location of the radial bow (p less than 0.05 and p less than 0.005). Similarly, the recovery of grip strength was associated with restoration of the location of the radial bow toward normal (p less than 0.005).