Does delay from injury to surgery increase the risk of dislocation of a hip hemiarthroplasty?

Dislocation of a hip hemiarthroplasty used to treat a hip fracture is a serious complication. The aim of this study was to identify whether a delay in the time from fracture to surgery causes an increase in the rate of post-operative hip dislocation. From a single center, data from intracapsular neck of femur patients treated with hip hemiarthroplasty was collected between October 1986 to August 2021. The time from both fall to surgery and admission to surgery was recorded. Surviving patients were followed up for one year. The overall dislocation rate was 51 out of 4155 patients (1.2%). The 3019 patients who had surgery within two days of the injury had a lowest dislocation rate (29 dislocations, 0.96%). For the 197 patients with no history of a fall, there were 5 (2.5%) dislocations (p=0.036, 95% confidence interval of difference 0.15 to 0.97 for comparison with surgery within two days). For the 399 patients with a delay of more than four days from injury till surgery, there were nine dislocations (2.3%) (p=0.045, 95% confidence intervals of difference 0.20 to 0.89 for comparison with surgery within two days). This study demonstrates an increase in the risk of dislocation for those patients with no history of a fall and those with a delay of more than four days from injury to surgery.