# Findings of preoperative patient risk factors to predict dislocation following total hip arthroplasty

## TL;DR

This study identifies preoperative risk factors that increase the chance of hip dislocation after hip replacement surgery.

## Contribution

The study reveals new independent risk factors, including rheumatoid arthritis and low serum calcium, for predicting hip dislocation after THA.

## Key findings

- Older age, rheumatoid arthritis, low serum calcium, and poor education are independent predictors of dislocation after THA.
- Targeted preoperative planning is needed for patients with these risk factors to prevent dislocation and revision surgeries.

## Abstract

Previous studies have identified some risk factors of dislocation after total hip arthroplasty (THA). However, there are many vital preoperative patient risk factors remaining unknown. This study aimed to investigate comprehensively patient risk factors to reduce the dislocation rate after THA.

We retrospectively reviewed patients who underwent primary THA in our department between January 2016 to December 2020. All readmissions related to postoperative dislocation were recorded, and each patient who dislocated was matched with three patients who did not dislocate according to date of operation, operative time and follow-up time. Patient risk factors were initially analyzed by univariate analyses, and independent risk factors for dislocation were identified by multivariate logistic regression.

A total of 5,133 patients were reviewed and 76 patients were readmitted with postoperative dislocations in follow-up time (1.5%). Age (odds ratio [OR], 1.027; 95% confidence interval [CI], 1.000–1.055; P = 0.049), rheumatoid arthritis (OR, 7.976; 95% CI, 1.419–44.827; P = 0.018), low serum calcium level (OR, 0.009; 95% CI, 0.000–0.211; P = 0.003) and poor education degree (OR, 0.847; 95% CI, 0.770–0.932; P = 0.001) were determined as independent predictors associated with dislocation after THA.

Patients with older age, rheumatoid arthritis, low serum calcium level, and poor education degree require targeted optimization of preoperative planning and should be performed by appropriate surgical techniques and hip prostheses to prevent dislocation after THA and revision surgeries.