Study Design.: Retrospective review of prospectively collected data. Objective.: To describe the learning curve for percutaneous transforaminal endoscopic discectomy (PTED) and demonstrate its efficacy in treating lumbar disc herniation. Summary of Background Data.: The learning curve for PTED has not yet been standardized in the literature. Patients and Methods.: Consecutive patients who underwent lumbar PTED by a single surgeon between December 2020 and 2022 were included. Cumulative sum analysis was applied to operative and fluoroscopy time to assess the learning curve. Inflection points were used to divide cases into early and late phases. The 2 phases were analyzed for differences in operative and fluoroscopy time, length of stay, complications, and patient-reported outcome measures (PROMs). Patient characteristics and operative levels were also compared. PROMs entailed the Oswestry Disability Index, Patient-Reported Outcomes Measurement Information System, Visual Analog Scale Back/Leg, and 12-item Short Form Survey at preoperative, early postoperative (<6 mo), and late postoperative (≥6 mo) time points. PROMs between PTED cases and a comparable cohort of tubular microdiscectomy cases, performed by the same surgeon, were compared. Results.: Fifty-five patients were included. Cumulative sum analysis indicated that both operative and fluoroscopy time diminished rapidly after case 31, suggesting a learning curve of 31 cases (early phase: n = 31; late phase: n = 24). Late-phase cases exhibited significantly lower operative times (85.7 vs. 62.2 min, P = 0.001) and fluoroscopy times (131.0 vs. 97.2 s, P = 0.001) compared with the early-phase cases. Both early and late-phase cases showed significant improvement in all PROMs. There were no differences in PROMs between the patients who underwent PTED and tubular microdiscectomy. Conclusion.: The PTED learning curve was found to be 31 cases and did not impact PROMs or complication rates. Although this learning curve reflects the experiences of a single surgeon and may not be broadly applicable, PTED can serve as an effective modality for the treatment of lumbar disc herniation.

Study Design.: Retrospective review of prospectively collected data. Objective.: To analyze the learning curves of three spine surgeons for robotic minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Summary of Background Data.: Although the learning curve for robotic MI-TLIF has been described, the current evidence is of low quality with most studies being single-surgeon series. Materials and Methods.: Patients who underwent single-level MI-TLIF with three spine surgeons (years in practice: surgeon 1: 4, surgeon 2: 16, and surgeon 3: two) using a floor-mounted robot were included. Outcome measures were operative time, fluoroscopy time, intraoperative complications, screw revision, and patient-reported outcome measures. Each surgeon’s cases were divided into successive groups of 10 patients and compared for differences. Linear regression and cumulative sum (CuSum) analyses were performed to analyze the trend and learning curve, respectively. Results.: A total of 187 patients were included (surgeon 1: 45, surgeon 2: 122, and surgeon 3: 20). For surgeon 1, CuSum analysis showed a learning curve of 21 cases with the attainment of mastery at case 31. Linear regression plots showed negative slopes for operative and fluoroscopy time. Both learning phase and postlearning phase groups showed significant improvement in patient-reported outcome measures. For surgeon 2, CuSum analysis demonstrated no discernible learning curve. There was no significant difference between successive patient groups in either operative time or fluoroscopy time. For surgeon 3, CuSum analysis demonstrated no discernible learning curve. Even though the difference between successive patient groups was not significant, cases 11 to 20 had an average operative time of 26 minutes less than cases 1–10), suggesting an ongoing learning curve. Conclusions.: Surgeons who are well-experienced can be expected to have no or minimal learning curve for robotic MI-TLIF. Early attendings are likely to have a learning curve of around 21 cases with the attainment of mastery at case 31. Learning curve does not seem to impact clinical outcomes after surgery. Level of Evidence.: Level 3.

Study Design.: Retrospective cohort. Objective.: To compare navigation and robotics in terms of clinical outcomes after minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Summary of Background Data.: Although robotics has been shown to have advantages like reduced radiation exposure, greater screw size, and slightly better accuracy over navigation, none of the studies has compared these two modalities in terms of clinical outcomes. Methods.: Patients who underwent single-level MI-TLIF using robotics or navigation and had a minimum of 1-year follow-up were included. The robotics and navigation groups were compared for improvement in patient-reported outcome measures (PROMs), minimal clinically important difference, patient-acceptable symptom state, response on the global rating change scale, and screw-related complication and reoperation rates. Results.: A total of 278 patients (143 robotics, 135 navigation) were included. There was no significant difference between the robotics and navigation groups in the baseline demographics, operative variables, and preoperative PROMs. Both groups showed significant improvement in PROMs at below six and six months or above, with no significant difference in the magnitude of improvement between the two groups. Most patients achieved minimal clinically important difference and patient-acceptable symptom state and reported feeling better on the global rating change scale, with no significant difference in the proportions between the robotics and navigation groups. The screw-related complication and reoperation rates also showed no significant difference between the two groups. Conclusions.: Robotics did not seem to lead to significantly better clinical outcomes compared with navigation following MI-TLIF. Although the clinical outcomes may be similar, robotics offers the advantages of reduced radiation exposure, greater screw size, and slightly better accuracy over navigation. These advantages should be considered when determining the utility and cost-effectiveness of robotics in spine surgery. Larger multicenter prospective studies are required in the future to further investigate this subject.