Background:

Patients who have prior lumbar spine fusion (LSF) have an increased risk for dislocation after total hip arthroplasty (THA). These patients also have elevated rates of opioid use. We aimed to evaluate the associated risk of dislocation after THA in patients who have prior LSF comparing those who have opioid use to those who do not.

Methods:

This was a retrospective review utilizing a large national database of 246,617 primary and 34,083 revision THA cases from 2012 to 2019. There were 1,903 primary THA and 288 revision THA cases identified with LSF prior to THA. Post-operative hip dislocation was our primary outcome variable and patients were stratified to use or non-use of opioid at THA. Demographic data including age, sex and obesity were collected. Multivariate analyses evaluated association of opioid use and dislocation after adjusting for demographics.

Results:

There was increased odds of dislocation for opioid use at THA for both primary, adjusted Odds Ratio (aOR)=2.29, 95% Confidence Interval (CI) 1.46 to 3.57, p<0.0003 and revision THA, aOR=1.92, 95% CI 1.62 to 3.08, p<0.0003, in patients who have prior LSF. Prior LSF without opioid use was associated with increased odds of dislocation, aOR=1.38, 95% CI 1.01 to 1.88, p=0.04, but this was lower than the associated risk of opioid use without LSF, aOR 1.72, 95% CI 1.63 to 1.81, p<0.001.

Conclusion:

Increased odds of dislocation were noted with opioid use at time of THA in patients who have prior LSF. Associated risk of dislocation was higher for opioid use than prior LSF. This suggests that dislocation risk is multifactorial and we should look to strategies to reduce opioid use prior to THA.