Association of Preoperative Physical Function and Changes in Mental Health After Minimally Invasive Transforaminal Lumbar Interbody Fusion

Background: Few investigations have focused on the predictive value of Patient-Reported Outcomes Measurement Information System (PROMIS) scores, patient depression measured by the Patient Health Questionnaire-9 (PHQ-9), and their relationship in the setting of minimally invasive transforaminal lumbar interbody fusion (MIS TLIF). This study aims to detail the association between preoperative physical function with postoperative change in physical function and in depressive symptoms.

Methods: A prospectively maintained surgical registry was retrospectively reviewed from March 2016 to February 2019. Inclusion criteria were primary, single-level MIS TLIF procedures. Multilevel procedures and patients without PROMIS or PHQ-9 were excluded. Patients were grouped by preoperative PROMIS score (<35.0 and ≥35.0), with higher scores indicating greater physical function. A test analyzed differences between PROMIS subgroups for operative time (skin incision to closure), estimated blood loss, length of stay, and discharge day. A test also assessed the difference in PROMIS Physical Function (PF) and PHQ-9. Linear regression evaluated the relationship between pre- and postoperative PROMIS and PHQ-9.

Results: Of 119 patients, 53.8% were male and 47.9% were obese. The mean ± SD age was 52.2 ± 10.7 years. The PROMIS <35.0 group had a larger improvement of PROMIS scores compared to the PROMIS ≥35.0 group at 6 weeks, 12 weeks, and 6 months. There was a negative association between preoperative PROMIS and PROMIS score improvement at 6 weeks, 12 weeks, and 6 months. For all time points, improvement in PHQ-9 was not associated with preoperative PROMIS scores.

Conclusion: From 0 weeks to 6 months after MIS TLIF, patients with lower preoperative physical function had larger improvements in PROMIS PF scores. Preoperative function was not predictive of postoperative changes in PHQ-9. While relationships between mental and physical health cannot be discounted, the lack of PHQ-9 association with physical function demonstrates the impact that MIS TLIF can have, regardless of PROMIS PF score.

Clinical Relevance: Patients demonstrating lower levels of preoperative physical function may be in position for greater improvements in physical function following MIS TLIF surgery. In this study, there was no clear relationship between preoperative physical function levels and postoperative improvement in mental health, suggesting that all patients may achieve similar mental health improvement following MIS TLIF.

Level Of Evidence: 3.