Outcomes and O/D complex occupancy as a decision-making tool for surgical success in patients undergoing microendoscopic foraminotomy for lumbar foraminal stenosis.

OBJECTIVE: To determine the long-term outcomes of microendoscopic foraminotomy (MELF) in treating lumbar foraminal stenosis (LFS) and identify the optimal extent of decompression that yields improved results and fewer complications.

METHODS: A retrospective cohort study reviewed the medical records of 95 consecutive patients who underwent MELF for LFS. Clinical outcomes were assessed using the Japanese Orthopedic Association (JOA) scoring system and visual analog scale (VAS) for low back and leg pain. Surgical success was determined by meeting significant improvement thresholds for back and leg pain at 2 years postoperatively. Multiple regression analysis identified factors associated with improved pain scores. Receiver operating characteristic curve analysis determined the cut-off values for successful surgeries.

RESULTS: Significant improvements were observed in JOA and VAS scores for back and leg pain 2 years postoperatively compared with preoperative scores (P<0.0001) and sustained over a ≥5-year follow-up period. Reoperation rates were low and did not significantly increase over time. Multiple regression analysis identified occupancy of the vertebral osteophytes and bulging intervertebral discs (O/D complex) as surgical success predictors. A 45.0% O/D complex occupancy cut-off value was determined, displaying high sensitivity and specificity for predicting surgical success.

CONCLUSION: This study provides evidence supporting the long-term efficacy of MELF for LFS and predicting surgical success. The 45.0% O/D complex occupancy cut-off value can guide patient selection and outcome prediction. These insights contribute to informed surgical decision-making and underscore the importance of evaluating the O/D complex in preoperative planning and predicting outcomes.