Effect of distal metaphyseal ulnar shortening osteotomy on lunatum

Ulnocarpal abutment syndrome, also known as ulnar impaction syndrome, is one of the common causes of ulnar-sided wrist pain. The main pathology causing this condition is the presence of positive ulnar variance. Twenty patients aged 18-65 years who underwent distal ulnar metaphyseal shortening osteotomy for ulnar impaction syndrome were included in the study. The study patients were derived from the Orthopedics and Traumatology department of Dokuz Eylul University Medical Faculty Hospital between the dates January 2012 and January 2022. 70% of the patients were female, and the mean age was 45.55. The mean follow-up period of the patients was 12.3 months. There was no statistically significant difference between the operated side and the contralateral side in terms of wrist movements (p>0.05). Grip strength was measured to be significantly smaller on the operated side (p=0.007). According to PRWE and Quick DASH patient complaint questionnaires, scores decreased significantly after surgery (p<0.05). The ulnar variance was found to decrease following surgery (p<0.001). There was a significant positive correlation between union time and osteotomy level, with osteotomy levels below 13.5 mm healing more rapidly (p<0.05). A MCID cut-off value of 20.45 for Quick DASH and 22.25 for PRWE was determined, and their statistical significances were (p=0.004) (p=0.001), respectively. Patients who are diagnosed with ulnar impaction syndrome benefit from the distal metaphyseal shortening of the ulna with minimal damage and complications. A significant improvement in functional outcome scores can be observed after metaphyseal ulnar osteotomy. The utilization of the PRWE and Quick DASH questionnaires to evaluate these clinical outcomes show more subjective improvement results. The minimal clinically important difference levels of these two questionnaires are significant in distinguishing patients who benefit from surgery and those who do not. It has been demonstrated that an ulnar osteotomy carried out at 13.5 mm or less from the distal ulnar joint reduces the time required for bone union.