Total Hip Arthroplasty in Patients With Previous Lumbar Fusion Surgery: Are There More Dislocations and Revisions?

ABSTRACT

BACKGROUND: The purpose of this study was to determine whether the risk of dislocation and/or revision following THA is increased in patients with a history of prior lumbar fusion given the alterations in dynamic pelvic motion following LSF. METHODS: A total of 62,387 patients (5% Medicare part B claims database) were identified from 1997 to 2014 with primary THA. From this group, 1809 patients (2.9%) were stratified to identify those with prior lumbar fusion within 5 years of primary THA to compare risk of dislocation and revision with those without lumbar fusion. Multivariate cox regression analysis was performed adjusting for age, socioeconomic status, race, census, region, gender, Charlson score, preexisting conditions, and type of fusion. RESULTS: Between years 2002 and 2014, there was a 293% increase in the number of patients with prior lumbar fusion undergoing THA. Prevalence of hip dislocation in patients with lumbar fusion before THA was 7.4% compared to 4.8% without fusion, P < .001. There was an 80% increase in dislocation in the fusion group at 6 months, 71% at 1 year, and 60% at 2 years. There was a 48% increased risk of failure leading to revision hip surgery in patients with fusion at 6 months, 41% at 1 year, and 47% at 2 years. Dislocation was the most common mode of failure leading to revision in both the fusion group (20.8%) and the nonfusion group (16%). CONCLUSION: Results of this study demonstrate that lumbar fusion before THA is an independent risk factor for dislocation leading to increased risk of revision THA.