Risk factors for bipolar hemiarthroplasty dislocation: a retrospective cohort study

Area of Science:

• Orthopedic surgery
• Trauma surgery
• Geriatric orthopedics

Background:

• Bipolar hemiarthroplasty (BHA) is a common procedure for displaced femoral-neck fractures.
• Postoperative dislocation is a significant complication following BHA, impacting patient outcomes.
• Identifying risk factors for dislocation is crucial for improving surgical safety and patient care.

Purpose of the Study:

• To investigate clinical, surgical, and radiographic parameters associated with dislocation after BHA for femoral-neck fractures.
• To identify predictive factors for postoperative dislocation in patients undergoing BHA.
• To inform strategies for reducing dislocation rates in BHA procedures.

Main Methods:

• Retrospective single-center cohort study of 434 patients undergoing BHA for femoral-neck fractures.
• Analysis of demographics, comorbidities, surgical approach (timing, duration), and postoperative radiographs.
• Univariate analyses, ROC analysis, and logistic regression, including a nested case-control subanalysis.

Main Results:

• Dislocation occurred in 2.5% of patients; nighttime surgery was more frequent in dislocated cases (45% vs. 20%).
• Smaller center-edge angle (CEA ≤ 25°), larger femoral neck-shaft angle (FNSA), reduced contralateral offset, and higher bipolar head extrusion index were associated with dislocation.
• Logistic regression identified nighttime surgery as a potential predictor, while age, sex, comorbidities, time to surgery, and operative duration were not significant.

Conclusions:

• Pre-operative evaluation of CEA and consideration of operative timing may help identify patients at increased risk of dislocation.
• Nighttime surgery may be an additional predictor for dislocation following BHA.
• Prospective trials are needed to confirm these findings and develop preventive strategies.