Tme diagnosis and treatment of nontrauatic ulnocarpal impaction syndrome

Objective To explore the characteristics of non-traumatic ulnocrpal impaction syndrome without typical X-ray features and discuss the diagnosis criteria and treatment methods.Methods Fifty-five cases of definite diagnosis of ulnocarpal impaction syndrome treated from October 2003 to October 2010 were retrospectively reviewed.25 cases were identified as with no definite trauma history and no typical X-ray features.Based on the diagnostic criteria described by Kostas,ulnocarpal stress test,dynamic positive ulnar variance and early MRI and wrist arthroscopty findings of these 25 cases were analyzed.All the cases underwent ulnar shortening osteotomy with compression plate fixation,among which 16 with transverse osteotomy (Darrow procedure) and 9 with oblique osteotomy (Rayhack procedure).Results were scored using the criteria described by Darrow.Results Among the 25 cases,ulnocarpal stress test was positive in 84％ of the cases,dynamic positive ulnar variance was present in 52％ of the cases,and abnormal changes in signal intensity occurred in theMRI findings of 82％ cases.These changes were always located at the ulnar side of the lunate and (or) at the waist or bottom of the triquetrum.TFCC degeneration and cartilage degeneration on ulnar head and lunate were present in wrist arthroscopy of all the cases.Follow-up period ranged from 4 to 48 months with an average of 26months.Bone union was achieved in all 25 cases.Union time averaged 4.5 months after transverse osteotomy and 2.5 menthe after oblique osteotomy.Function evaluation revealed excellent results in 7 cases,good results in 15 cases,fair results in 2 cases and poor results in 1 case.The overall good-excellent rate was 88％.There were no complications.The clinical outcomes were satisfactory.Conclusion It is difficult to differentiate non-traumatic ulnocarpal impaction syndrome from other etiologies of ulnar side wrist pain due to its lack of a traumatic history and typical X-ray features.Ulnocarpal stress test,dynamic positive ulnar variance and early MRI imaging studies can improve the early diagnosis rate.Wrist arthroscopy can allow assessment of pathology and be used as a diagnostic tool for differential diagnosis.Ulnar shortening osteotomy is an effective method and oblique osteotomy is recommended. Key words: Carpal joints;  Diagnosis;  Ulna;  Osteotomy;  Nontraumatic;  Ulnocarpal impaction