Determinants of Complex Regional Pain Syndrome Type I among Radial Head Fracture Patients with Unilateral Arthroplasty

OBJECTIVE: This study aims to assess the proportions of complex regional pain syndrome type I (CRPS I) in radial head fracture patients undergoing unilateral arthroplasty and to explore associated factors. METHODS: This is a prospective observational study. From March 2016 to May 2019, a total of 221 adult patients with radial head fracture patients were included in consecutive studies and completed the 1‐year follow‐up. All patients were treated by unilateral arthroplasty. At each follow‐up visit, the visual analogue scale was used to measure patients' pain level. Occurrence of CRPS I, which was diagnosed by Budapest criteria, was the main outcome collected at baseline and the 1‐, 3‐, 6‐, and 9‐month follow‐ups. The baseline data were collected before surgery and included demographic and clinical data. Independent t‐tests and χ (2) tests were used as univariate analyses to compare the baseline data of patients with and without CRPS I. Multivariate analysis (Backword‐Wald) was used to identify factors independently associated with CRPS I. RESULTS: The proportion of CRPS I cases among radial head fracture patients undergoing unilateral arthroplasty was 11% (n = 24). A total of 19 (79%) patients were diagnosed with CRPS I within 1 month after surgery. Multivariable logistic regression analysis revealed that female gender (odds ratios [OR]: 1.537; 95% confidence interval [CI]: 1.138–2.072), age younger than 60 years (OR: 1.682; 95% CI: 1.246–2.267), moderate and severe Mayo Elbow Performance Score (MEPS) pain (OR: 3.229; 95% CI: 2.392–4.351) and anxiety (OR: 83.346; 95% CI: 61.752–112.320) were independently associated with CRPS I. CONCLUSIONS: This exploratory study reported that the incidence of CRPS I developing after radial head arthroplasty was 11%. Female sex, younger age, moderate and severe MEPS pain and anxiety patients seems more likely to develop CRPS I.