Learning curve for biportal endoscopic transforaminal lumbar interbody fusion and 90-day postoperative complications during the learning phase: a multicenter retrospective cohort study.

PURPOSE: This study aimed to evaluate the learning curve for biportal endoscopic transforaminal lumbar interbody fusion (BE-TLIF) and assess 90-day postoperative complications during the learning phase.

METHODS

We retrospectively analyzed 188 consecutive patients who underwent single-level BE-TLIF performed by three surgeons at three institutions. Learning curve-cumulative summation (LC-CUSUM) analysis was used to determine the number of cases required to achieve proficiency, defined as an operative time of less than 160 min. Patients were divided into the early and late groups based on the learning curve. Clinical outcomes, including Oswestry Disability Index and Visual Analog Scale scores for back and leg pain, were assessed preoperatively and at 1 and 3 months postoperatively. Complications within 90 days were recorded and analyzed.

RESULTS

LC-CUSUM analysis showed that surgeons required an average of 39 cases (range: 29-51) to achieve proficiency. Operative time and estimated blood loss significantly decreased in the late group (p < 0.001 and p = 0.002, respectively). Clinical outcomes improved significantly in both groups over time, with no statistically significant differences between the groups. The overall complication rate was 6.9%, with a trend toward lower rates in the late group than in the early group, although this was not statistically significant. The 90-day reoperation rate decreased from 5.1% in the early group to 1.4% in the late group.

CONCLUSION

BE-TLIF demonstrated a learning curve comparable to other minimally invasive spine surgeries, with proficiency achieved after approximately 39 cases. Clinical outcomes were favorable and consistent across learning phases, indicating that BE-TLIF can provide significant benefits to patients even during the initial learning period. The trend toward lower complication rates in the late phase than those in the early phase underscores the importance of proper training and experience in maximizing the benefits of this technique.