JOA - 2026-08-08 - Journal Article
Comparison of 90-Day Complications Between Direct Anterior and Postero-Lateral Total Hip Arthroplasty in Morbidly Obese Patients.
Bauer JA, Birbara B, Grosso MJ
Topics
Key Takeaway
In morbidly obese THA patients (BMI ≥40), the direct anterior approach produced significantly shorter operative times (71 vs. 92 minutes) and lower revision risk on sensitivity analysis (OR 0.31), but overall 90-day complication rates were statistically equivalent between DA and PL after multivariate adjustment.
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Summary
This retrospective study compared 90-day complications between DA and PL approaches in 365 morbidly obese (BMI ≥40) primary THA patients at a single institution from 2017–2022. Operative time was significantly shorter with DA (71 vs. 92 min, P<0.001), and penalized logistic regression showed reduced periprosthetic fracture risk with DA (OR 0.08, 95% CI 0.01–0.89), though higher cementation rates in the DA group confound this finding. On adjusted analysis, overall 90-day complication rates did not differ significantly between approaches, and MO patients had higher complication rates than non-MO patients regardless of approach.
Key Limitation
The significantly higher cementation rate in the DA group is an uncontrolled confounder that renders the periprosthetic fracture risk reduction (OR 0.08) uninterpretable as an approach effect, undermining the study's most clinically impactful secondary finding.
Original Abstract
BACKGROUND
Morbidly obese (MO) patients undergoing total hip arthroplasty (THA) are at increased risk of postoperative complications. The effect of surgical approach on outcomes in this population remains unclear. This study compared perioperative outcomes and 90-day complications between direct anterior (DA) and postero-lateral (PL) approaches in MO and non-MO patients.
METHODS
We retrospectively reviewed 5,933 primary THAs between January 2017 and March 2022. The surgeons included had performed at least 50 DA cases. Among 365 MO patients (body mass index [BMI] ≥ 40), 238 underwent DA and 127 underwent PL. Demographics, operative characteristics, and 90-day complications were analyzed. Multivariable logistic regressions adjusted for age, sex, BMI, American Society of Anesthesiology (ASA) class, and operative time; rare events were evaluated using penalized logistic regression. Propensity score-based sensitivity analyses were performed to account for confounders.
RESULTS
In MO patients, operative times were significantly shorter with DA (71 ± 18 versus 92 ± 26 minutes, P < 0.001). On penalized multivariable analysis, there was a reduced risk of periprosthetic fracture for the DA group (OR [odds ratio] 0.08, 95% CI [confidence interval] 0.01 to 0.89); however, interpretation is limited by higher rates of cementation in the DA group. In sensitivity analysis, the risk of revision surgery remained significantly lower with DA (OR 0.31, 95% CI 0.11 to 0.85). Complication rates were otherwise statistically similar between approaches on adjusted analysis. Compared to non-MO patients, MO patients had longer operative times and higher overall complication rates, regardless of approach.
CONCLUSION
In MO patients undergoing THA, the DA approach was associated with shorter operative times. After multivariate adjustment, overall complication risks were similar between approaches across two analytical frameworks. These findings suggest that both DA and PL can be safely utilized in MO patients undergoing THA, without an increased 90-day complication profile attributable to either approach.