Effect of Psychological Status on Outcome of Posterior Lumbar Interbody Fusion Surgery

STUDY DESIGN: Prospective longitudinal study. PURPOSE: To determine if preoperative psychological status affects outcome in spinal surgery. OVERVIEW OF LITERATURE: Low back pain is known to have a psychosomatic component. Increased bodily awareness (somatization) and depressive symptoms are two factors that may affect outcome. It is possible to measure these components using questionnaires. METHODS: Patients who underwent posterior interbody fusion (PLIF) surgery were assessed preoperatively and at follow-up using a self-administered questionnaire. The visual analogue scale (VAS) for back and leg pain severity and the Oswestry Disability Index (ODI) were used as outcome measures. The psychological status of patients was classified into one of four groups using the Distress and Risk Assessment Method (DRAM); normal, at-risk, depressed somatic and distressed depressive. RESULTS: Preoperative DRAM scores showed 14 had no psychological disturbance (normal), 39 were at-risk, 11 distressed somatic, and 10 distressed depressive. There was no significant difference between the 4 groups in the mean preoperative ODI (analysis of variance, p = 0.426). There was a statistically and clinically significant improvement in the ODI after surgery for all but distressed somatic patients (9.8; range, -5.2 to 24.8; p = 0.177). VAS scores for all groups apart from the distressed somatic showed a statistically and clinically significant improvement. Our results show that preoperative psychological state affects outcome in PLIF surgery. CONCLUSIONS: Patients who were classified as distressed somatic preoperatively had a less favorable outcome compared to other groups. This group of patients may benefit from formal psychological assessment before undergoing PLIF surgery.