Concurrent Triple-class Psychotropic Use and Postoperative Morbidity Following Single-Level Lumbar Fusion: A Propensity Score-matched Cohort Study.

OBJECTIVE: To determine whether triple-class psychotropic exposure before single-level lumbar fusion is associated with different postoperative outcomes than selective serotonin reuptake inhibitor (SSRI) monotherapy in patients carrying a psychiatric diagnosis.

SUMMARY OF BACKGROUND DATA: Psychiatric illness is common before spine surgery and associated with inferior outcomes, but is usually analyzed as a single categorical variable. Whether regimen complexity carries independent prognostic information is unclear.

METHODS: Adults with a psychotic-spectrum or mood disorder (ICD-10-CM, F20-F39) undergoing primary single-level posterior lumbar arthrodesis were identified in TriNetX. Exposure was ascertained 365 to 1 day preoperatively; postoperative prescriptions did not contribute. Patients receiving an SSRI, benzodiazepine and antipsychotic were matched 1:1 on 75 preoperative characteristics to SSRI monotherapy. Pseudarthrosis and surgical site infection were co-primary outcomes; revision, readmission, emergency department visits and opioid use were secondary, assessed at 3 and 6 months and 1, 3 and 5 years (Bonferroni P<0.025).

RESULTS: Among 638 matched pairs, all but one characteristic achieved a standardized mean difference <0.10. Surgical site infection was more frequent at every interval (5 y, 14.73% vs 8.31%; RR 1.77, 95% CI 1.29-2.44; P=0.0003), as was readmission (5 y, 67.40% vs 57.99%; RR 1.16, 1.07-1.27; P=0.0005). Revision was approximately twofold higher from 1 year onward (5 y, 8.62% vs 4.39%; RR 1.96, 1.26-3.06; P=0.0022). Pseudarthrosis was more frequent at every interval but met the corrected threshold only at 1 year (16.87% vs 12.38%; RR 1.36, 1.04-1.78; P=0.0224). The proportion receiving any opioid was identical (97.49%).

CONCLUSION: Triple-class exposure was associated with higher infection, readmission and revision than SSRI monotherapy. These associations do not establish causation and may reflect illness severity, unmeasured surgical factors or detection bias. The regimen is a risk marker warranting closer perioperative surveillance, not a treatment target.

STUDY DESIGN: Retrospective propensity score-matched cohort study.