Background: Ulnar nerve entrapment at the elbow (UNE) is overrepresented in patients with diabetes, but the outcome of surgery is unknown. We aimed to evaluate patient-reported outcome in patients with and without diabetes, and to assess potential sex differences and compare surgical treatment methods. Methods: Data on patients operated for UNE (2010-2016, n = 1354) from the Swedish National Registry for Hand Surgery were linked to the Swedish National Diabetes Register. Symptoms were assessed preoperatively (n = 389), and 3 (n = 283), and at 12 months postoperatively (n = 267) by QuickDASH and HQ-8 (specific hand surgery questionnaire - 8 questions). Only simple decompressions were included when comparing groups. Results: Men with diabetes reported higher postoperative QuickDASH scores than men without diabetes. Women scored their disability higher than men on all time-points in QuickDASH, but showed larger improvement between preoperative and 12 months postoperative values. Patients operated with transposition scored 10.8 points higher on QuickDASH than patients who had simple decompression at 12 months (95% confidence interval 1.98-19.6). Conclusions: Women with diabetes benefit from simple decompression for UNE to the same extent as women without diabetes. Men with diabetes risk not to benefit from simple decompression as much as women do. Ulnar nerve transposition had a higher risk of residual symptoms compared to simple decompression.
