From 2010 to 2018, the PearlDiver Humana research database contained a retrospective cohort analysis of consecutive individuals receiving lumbar spinal fusion (LSF). For a study, investigators sought to determine if the timing of total hip arthroplasty (THA) impacts LSF results. Patients undergoing lumbar fusion were separated into 4 groups: those who had LSF without THA (No THA); those who had THA at least 2 years before LSF (>2 Prior THA); those who had THA in the 2 years before LSF (0–2 Prior THA); and those who had THA after LSF (THA After). The study group looked at lumbar-specific outcomes such as pseudarthrosis, revision, mechanical failure, and ASD, as well as systemic problems. Complication rates were compared between all groups using univariate and multivariate logistic regression analysis, controlling for age, gender, and the Charlson comorbidity index. Post hoc comparisons were performed using the Fisher exact test with Bonferroni correction to account for repeated pairwise comparisons, resulting in an adjusted statistical significance threshold of P<0.007. On multivariate analysis, individuals in the THA After the group had a greater rate of ASD than those in the no THA group [adjusted odds ratio: 1.53, 95% CI: 1.20–1.94, P<0.001]. Patients who had THA after LSF had a higher risk of ASD (adjusted odds ratio: 3.80, 95% CI: 2.21–6.98, P<0.001) compared to all patients who had THA before LSF. Patients who have THA after LSF have a greater lumbar-related problem than those who did not have THA and patients who got THA before LSF.
