Effect of baseline veterans RAND-12 physical composite score on postoperative patient-reported outcome measures following lateral lumbar interbody fusion.

Purpose: To determine the prognostic value of preoperative Veterans RAND-12 (VR-12) Physical Composite Score (PCS) scores on postoperative clinical outcomes in patients undergoing lateral lumbar interbody fusion (LLIF).

Methods: LLIF patients were separated into 2 cohorts based on preoperative VR-12 PCS scores: VR-12 PCS < 30 (lesser physical function) and VR-12 PCS ≥ 30 (greater physical function). Patient-reported outcome measures (PROMs) of VR-12 PCS, VR-12 Mental Composite Score (MCS), Short Form-12 (SF-12) PCS, SF-12 MCS, Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), Patient Health Questionnaire-9 (PHQ-9), Visual Analog Scale (VAS) Back Pain (VAS-BP), VAS Leg Pain (VAS-LP), and Oswestry Disability Index (ODI) were collected at preoperative and up to 2-year postoperative time points. Mean postoperative follow-up time was 16.69 ± 8.53 months. Minimum clinically important difference (MCID) achievement was determined by comparing ∆PROM to previously established thresholds.

Results: Seventy-eight patients were included, with 38 patients with lesser preoperative physical function scores. Patients with lesser physical function reported significantly inferior preoperative PROM scores in all domains, except for SF-12 MCS and VAS-LP. At the 6-week postoperative time point, patients with lesser physical function reported significantly inferior VR-12 PCS, VR-12 MCS, SF-12 PCS, PROMIS-PF, and PHQ-9. At the final postoperative time point, patients with lesser physical function reported significantly inferior VR-12 PCS, VR-12 MCS, PROMIS-PF, PHQ-9, and ODI. Magnitude of 6-week postoperative improvement was significantly higher in the lesser physical function cohort for VR-12 PCS.

Conclusion: Patients undergoing LLIF with worse baseline VR-12 PCS scores reported inferior postoperative physical function, mental health, and disability outcomes. At the final postoperative follow-up, magnitude of postoperative improvement and MCID achievement did not significantly differ. Baseline VR-12 PCS scores may indicate inferior postoperative clinical outcomes in physical function, mental health, and disability in patients undergoing LLIF; however, baseline VR-12 PCS does not limit the magnitude of postoperative improvement.