Influence of Preoperative 12-Item Short Form Mental Composite Score on Clinical Outcomes in an Isthmic Spondylolisthesis Population Undergoing Minimally Invasive Transforaminal Lumbar Interbody Fusion.

Objective: To determine preoperative 12-Item Short Form Health Survey (SF-12) Mental Component Summary (MCS) influence on minimally important clinical difference (MCID) and patient-reported outcome measures in patients with isthmic spondylolisthesis receiving minimally invasive transforaminal lumbar interbody fusion.
Methods: Patients with isthmic spondylolisthesis undergoing primary, single-level minimally invasive transforaminal lumbar interbody fusion at L5-S1 were retrospectively identified and divided into preoperative SF-12 MCS <50 and SF-12 MCS ≥50 groups. Visual analog scale (VAS) back/leg, Oswestry Disability Index (ODI), SF-12 Physical Composite Score (PCS), and Patient-Reported Outcome Measurement Information System physical function (PROMIS-PF) were assessed. Improvements from preoperative score were analyzed via paired samples t test. Patient-reported outcome measures and MCID attainment between groups were evaluated using linear regression and χ ² , respectively.
Results: SF-12 MCS <50 and SF-12 MCS ≥50 groups included 35 and 26 patients, respectively. SF-12 MCS < 50 group had inferior scores for all VAS back time points except 6 weeks, all VAS leg time points except 6 weeks/1 year, all ODI time points, SF-12 PCS at 6 months/2 years, and PROMIS-PF at preoperative/6 months (all P ≤ 0.049). SF-12 MCS <50 group improved for VAS back/leg to 1 year, ODI and SF-12 PCS from 12 weeks to 1 year, and PROMIS-PF at 1 year only (all P ≤ 0.047). SF-12 MCS ≥50 group improved for VAS back from 12 weeks to 1 year, SF-12 PCS 6 months to 2 years, and VAS leg, ODI, and PROMIS-PF 12 weeks to 2 years (all P ≤ 0.018). MCID attainment differed for ODI at 6 weeks and PROMIS-PF at 12 weeks only (both P ≤ 0.035).
Conclusions: Patients with SF-12 MCS <50 demonstrated fewer long-term improvements from preoperative to 2 years and inferior patient-reported outcome measures at most time points for pain and disability following minimally invasive transforaminal lumbar interbody fusion. MCID attainment largely did not differ by preoperative mental functioning.
(Published by Elsevier Inc.)