Factors influencing shoulder stiffness after open reduction and internal fixation of proximal humeral fractures.

Abstract

The study aimed to investigate the factors associated with shoulder stiffness following open reduction and internal fixation (ORIF) of proximal humeral fractures. The retrospective study included a total of 151 patients who underwent ORIF of proximal humeral fractures between January 2016 and May 2021. Based on their shoulder joint motion at the latest follow-up, the patients were divided into two groups. The stiffness group (n=32; 8 males, 24 females; mean age: 62.4±9.3 years; range, 31 to 79 years), exhibited restricted shoulder forward flexion (<120°), limited arm lateral external rotation (<30°), and reduced back internal rotation below the L3 level. The remaining patients were included in the non-stiffness group (n=119; 52 males, 67 females; mean age: 56.4±13.4 years; range, 18 to 90 years). Various factors were examined to evaluate the association with shoulder stiffness following ORIF of proximal humeral fractures by multivariate unconditional logistic regression models. The mean follow-up duration was 31.8±12.6 (range, 12 to 68) months. Based on the results of the multivariate regression analysis, it was found that high-energy injuries [compared to low-energy injuries; adjusted odds ratio (aOR)=7.706, 95% confidence interval (CI): 3.564-15.579, p<0.001], a time from injury to surgery longer than one week (compared to a time from injury to surgery equal to or less than one week; aOR=5.275, 95% CI: 1.7321-9.472, p=0.031), and a body mass index (BMI) >24.0 kg/m2 (compared to a BMI between 18.5 and 24.0 kg/m2 ; aOR=4.427, 95% CI: 1.671-11.722, p=0.023) were identified as risk factors for shoulder stiffness following ORIF of proximal humeral fractures. High-energy injury, time from injury to surgery longer than one week, and BMI >24.0 kg/m2 were identified as independent risk factors for shoulder stiffness after proximal humeral fracture surgery, which should be treated with caution in clinical treatment.