Impact of gender on outcomes following single-level anterior lumbar interbody fusion

Background: There have been a multitude of studies attempting to identify the relationship between gender and postoperative outcomes; however, few studies have examined how this relationship may affect outcomes after anterior lumbar interbody fusion (ALIF) surgery. We aim to better characterize the impact that self-reported gender may have on patient reported outcome measures (PROMs) and achievement rates of minimum clinically important difference (MCID) after ALIF.

Methods: A retrospective database of a single spine surgeon was searched for patients who had undergone single-level ALIF. Indications for surgery including acute trauma, infection, or malignancy were excluded. The population was separated into cohorts by self-reported gender, female or male. PROMs were recorded and compared within groups to their preoperative baselines and between groups. MCID achievement rate was compared between groups.

Results: 140 patients were identified for this study, with 68 patients self-identifying as female gender. The male gender cohort was found to have a significantly greater prevalence of hypertension (p = 0.018). Both cohorts showed significant improvement during at least one or more postoperative time points for each evaluated outcome measure (p ≤ 0.048, all). No significant difference in mean PROM scores was noted between cohorts at any time point for any measured outcome. The female gender cohort had significantly greater MCID achievement rates for visual acuity scale (VAS) back pain overall and at the 6-month time point (p ≤ 0.043, both). The female gender cohort also had significantly greater achievement of MCID at the 1-year time point for VAS leg pain (p = 0.017).

Conclusion: Both female and male gender cohorts demonstrated significant improvement in all outcomes measured at one or more postoperative time points. Postoperative outcomes did not differ by gender. MCID achievement was more common in female patients. Female patients may experience more tangible clinical improvement after ALIF compared to male patients.