Radiographic appearance and patient outcome after ulnar shortening osteotomy for idiopathic ulnar impaction syndrome.

PURPOSE: Radiographic carpal chondromalacia (RCC) was defined as the presence of cortical sclerosis or subchondral changes, such as a lucent defect or cystic changes in a carpal on plain radiographs. The purpose of this study was to investigate the factors associated with the occurrence of RCC in idiopathic ulnar impaction syndrome and to determine the efficacy of ulnar shortening osteotomy on patient outcome and RCC.

METHODS: Thirty-nine patients (42 wrists) with idiopathic ulnar impaction syndrome were treated with either ulnar shortening osteotomy or arthroscopic wafer resection. Patients were divided into 2 groups according to the presence (RCC group; 17 patients, 19 wrists) or absence (non-RCC group: 22 patients, 23 wrists) of RCC on preoperative radiographs. To determine the factors associated with RCC, a comparative analysis of these 2 groups was performed with respect to sex, age, duration of symptoms, positive ulnar variance, pain scores, and Chun and Palmer grading system. The RCC area was measured on serial radiographs taken during follow-up. Progressive changes of RCC area and clinical outcomes were evaluated.

RESULTS: Patients in the RCC group were older, exhibited greater positive ulnar variance, and demonstrated a significantly higher mean pain score before surgery. The RCC was found to reverse over the year following ulnar shortening osteotomy and did not recur up to 2 years after surgery. In 3 wrists, RCC had completely disappeared at the last follow-up. All patients showed improved clinical outcomes.

CONCLUSIONS: The RCC changes correlated with older age, a positive ulnar variance, and preoperative pain severity. The RCC progressively reversed after ulnar shortening osteotomy, and this reversal of radiographic changes correlated with clinical improvements.

TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.