ULNAR STYLOID IMPACTION SYNDROME

A series of 8 patients each with an excessively long ulnar styloid tha t was impacting the triquetrum, causing chondromalacia, synovitis, and pain, is presented. Four patients developed symptoms as a result of a n injury and 4 had no definable acute precipitating injury. The averag e age at the time of surgery was 34 years. There were 3 male and 5 fem ale patients. The average follow-up period was 34 months. All patients were treated by open partial ulnar sty loidectomy. Outcome was evalua ted clinically and by means of patient questionnaire and radiographs. Pain decreased from a preoperative average score of 3.5 to a postopera tive average score of 1.3, which equates to mild pain requiring no med ication. All but 1 patient returned to their previous employment unres tricted. The average preoperative ulnar styloid length was 7.4 mm and the average ulnar styloid process index was 0.41, which is almost twic e normal. There were no complications. It is likely that an excessivel y long ulnar styloid has important implications for the kinematics of the lunatotriquetral interval. Details of the diagnosis of this condit ion, including a new provocative test and operative management are dis cussed.