Preoperative Oswestry Disability Index Cannot Reliably Predict Patient Satisfaction After Single and Double Level Lumbar Transforaminal Interbody Fusion Surgery.

Introduction: The role of patient-reported outcomes in preoperative assessment is not well studied. There is recent interest in studying whether Patient-reported outcomes scores can be used either independently, or in conjunction with clinical findings, in the assessment of patients for surgery.

Aims: To investigate if improvement in clinically significant scores correlate with post-operative patient satisfaction in 1-2 level transforaminal lumbar interbody fusion (TLIF) surgery. We also aim to define a threshold Oswestry Disability Index (ODI) which correlate with achieving post-operative MCID and patient satisfaction.

Methods: 1001 patients who underwent single or double level TLIF (Minimally invasive and Open) in our institution with at least 2 years follow up were included in this study. We studied self-reported measures including patient satisfaction and ODI score.

Results: At 2-year follow-up, the overall mean ODI score improved from 49.7 ± 18.3 to 13.9 ± 15.2 (P < 0.001) with 74.6% of patients meeting the MCID. Patient satisfaction was achieved in 95.3% of all patients. In the MIS group, the preoperative cut-off was determined to be 37.2 at maximal Youden index associated with AUC of 0.72 (95% CI 0.65-0.86). In the open group, the preoperative cut-off was determined to be 37.2 at maximal Youden index associated with AUC of 0.70 (95% CI 0.62-0.77). Using the preoperative cut-offs found, there was no significant difference in patient satisfaction in both MIS and open groups.

Conclusions: Overall, our patients undergoing TLIF had good 2-year ODI score improvement and patient satisfaction after surgery. While meeting the MCID for ODI score correlates with patients' satisfaction postoperatively, 75% of patients not meeting the MCID for ODI score remained satisfied with the surgery. We are unable to define a threshold pre-operative ODI which correlates with achieving post-operative MCID and patient satisfaction.