The Analysis Of Short-term Clinical Outcome Of Treating Forearm Deformity Due To Hereditary Multiple Exostoses At The Distal End Of The Ulna By Ulna Lengthening With Inlaied External Fixator

Objective:To analysis the short-term clinical outcome of treating forearm deformity due to Hereditary Multiple Exostoses at the distal end of the ulna by ulna lengthening with inlaied external fixator, and to provide evidence for clinical reasonable selected therapy.Method:A retrospective study was carried out in 26 patients(28 arms) who were treated forearm deformity due to Hereditary Multiple Exostoses at the distal end of the ulna by operations from January 2005 to September 2009.9 patients(9 arms) including 5 male and 4 female in the unlengthen group that the average age at operation was 8.5 years (from 6 to 13 years) were treated only by excision of exostoses.17 patients(19 arms) including 9 male and 8 female in the lengthen group that the average age at operation was 8.7 years (from 2 to 19 years) were treated by excision of exostoses and lengthening the ulna with inlaied external fixator.The follow-up visit included X-ray evaluation and functional evaluation before the operation and at the end of follow-up.①X-ray evaluation:Relative ulnar shortening (RUS); Radial articular angle (RAA); Carpal slip(CS).②Functional evaluation:the ranges of active elbow flexion/extension, forearm pronation/supination, wrist flexion/extension, wrist radial-deviation/ulnar-deviation and the evaluated score of Krimmer. Result:All of the patients were followed-up for 7～15 months (average 10.3±2.2 months) after operation.①X-ray evaluation results of patients:RUS,RAA and CS all decreased notablely after operation in the lengthen group. In the unlengthen group there was only RUS which decreased little. The correction of the shortening of the ulna, bowing of the radius, ulnar tilt of the distal radial epiphysis and ulnar translocation of the carpus in the lengthen group was much better than which in the unlengthen group by comparison of the end of follow-up in two groups.And dislocation of the head of the radius in 6 arms were also corrected except one arm in the unlengthen group.②Functional evaluation results of patients:There was not obvious improvement of articular function after operation in the unlengthen group. In the lengthen group, only function of forearm rotation and wrist radial-deviation had been improved and it was much better than which in the unlengthen group. Comparing the results of the evaluated score of Krimmer before the operation and at the end of follow-up in each group and at the two ends of follow-up in the two groups, we found that the total function of wrist had been improved obviously in the lengthen group, which not happened in the unlengthen group.Conclusion:Using ulna lengthening by inlaied external fixator for treatment of forearm deformity due to Hereditary Multiple Exostoses at the distal end of the ulna can correct the shortening of the ulna, bowing of the radius, ulnar tilt of the distal radial epiphysis, ulnar translocation of the carpus and dislocation of the head of the radius obviously. At the same time, the forearm rotation function and partial wrist function can also be improved remarkably. It has a satisfactory short-term therapeutic effects.