Abstract
Background
Total hip arthroplasty (THA) is increasingly used for active patients with displaced intracapsular hip fractures. Dislocation rates in this cohort remain high postoperatively compared to elective practice, yet it remains unclear which patients are most at risk. The aim of this study was to determine the dislocation rate for these patients and to evaluate the contributing patient and surgeon factors.
Methods
A five-year retrospective analysis of all patients receiving THA for displaced intracapsular hip fractures from 2013–18 was performed. Data was collected from the institutions' hip fracture database, including data submitted to the National Hip Fracture Database (NHFD). Cox regression analysis and log-rank tests were implemented to evaluate factors associated with THA dislocation. Patient age, sex, ASA grade, surgeon seniority, surgical approach, femoral head diameter and acetabular cup type were all investigated as independent factors.
Results
A total of 196 patients, with a mean age of 72 (range 49–90), received THA for hip fracture between 2013–18. A posterior approach, using standard cemented acetabular components and a 28mm femoral head, was used in 133 cases (72%).
Fourteen dislocations (7%) were observed during this period, with 5 patients requiring revision surgery. Of these dislocations, all were performed through posterior approaches with standard cemented cups. 28mm femoral heads were used in all cases except one, which used a 32mm femoral head.
In Cox regression analysis, ASA grade, but not age or sex, was significantly associated with dislocation (hazard ratio = 4.5; 95% confidence interval 2.0–10.0; p<0.001). On log rank testing no statistically, significant association was found between dislocation and surgeon grade (p=0.85), surgical approach (p=0.31), femoral head size (p=0.85) or cup type (p=0.30).
Discussion
This study demonstrates an increased risk of dislocation following THA for hip fracture with higher ASA grades. It may be appropriate to offer more stable implants to this cohort of patients.
