Objective Full-endoscopic spine surgery is gaining interest as a less-invasive alternative to treat sciatica caused by a lumbar disc herniation. Concerns, however, exist with the learning curve as percutaneous transforaminal endoscopic discectomy (PTED) appears to be more difficult to be performed compared to other techniques. In this study, the clinical outcomes during and after the learning curve are presented of 3 surgeons naïve to PTED.
Methods In the first phase of a randomized controlled, noninferiority trial comparing PTED with microdiscectomy, 3 surgeons were trained in the PTED-procedure by a senior surgeon. After performing up to 20 cases under supervision, they started performing PTED on their own. Results of the early cases were compared to the later cases (>20). Furthermore, complications and reoperations were compared. Finally, differences in clinical outcomes between surgeons were compared.
Results At 12 months of follow-up, 87% of the patients had follow-up data available. In general, there were no significant differences in patient-reported outcomes between the early and later PTED cases. Furthermore, outcomes of the early PTED cases were comparable to the outcomes of microdiscectomy, while the later PTED cases had small, but more favorable outcomes compared to microdiscectomy. Two learning curve surgeons had substantially higher rates of reoperations within 1 year, compared to the senior surgeon or the microdiscectomy group. Duration of surgery was also longer for all learning curve surgeons. Finally, when comparing clinical outcomes of patients undergoing PTED versus microdiscectomy, there appears to be some statistically significant differences in outcomes compared between the senior and 3 learning curve surgeons.
Conclusion PTED appears to be safe to be adopted by surgeons naïve to the procedure when they are initially supervised by an experienced senior surgeon. Duration of surgery and risk of repeated surgery are increased during the learning curve, but patient-reported outcomes of the early PTED cases are similar to the outcomes of later PTED cases, and similar to the outcomes of microdiscectomy cases. This study underlines the need for an experienced mentor for surgeons to safely adopt PTED.
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Objective Percutaneous transforaminal endoscopic discectomy (PTED) is gaining popularity by both surgeons and patients as a less invasive treatment option for sciatica. Concerns, however, exist for its learning curve. No previous study has assessed the learning process of PTED. Hereby we present the learning process of 3 surgeons learning PTED.
Methods This analysis was conducted alongside a multicenter randomized controlled trial. After attending a cadaveric workshop, 3 spine-dedicated surgeons started performing PTED, initially under the supervision of a senior surgeon. After each 5 cases, and up to case 20, the learning process was evaluated using the validated questionnaires (objective structured assessment of technical skills [OSATS], global operative assessment of laparoscopic skills [GOALS]) and a 10-step checklist specifically developed for PTED.
Results In total, 3 learning curve surgeons performed a total of 161 cases. Based on self-assessment, surgeons improved mostly in the domains “time and motion,” “respect for tissue,” and “knowledge and handling of instruments.” Learning curve surgeons were more able to detect differences in performances on the OSATS than the senior surgeon. Based on the GOALS, the biggest improvements could be seen in “depth-perception” and “autonomy.” Based on the 10-item specific checklist, all surgeons performed all 10 steps by case 10, while only 1 surgeon performed all steps adequately by case 15.
Conclusion Based on these study results, PTED appears to be successfully adopted stepwise by 3 spine-dedicated surgeons. From 15 cases on, most steps are performed adequately. However, more cases might be necessary to achieve good clinical results. Validated tools are needed to determine the cutoff when a surgeon should be able to perform PTED independently.
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Operative time, recurrence, and complications throughout the initial learning curve in transforaminal endoscopic lumbar discectomy Michelle D. Poelman, Annegien Boeykens, Biswadjiet S. Harhangi, Marc L. Schröder, Victor E. Staartjes Acta Neurochirurgica.2026;[Epub] CrossRef
Integrated Optical and Magnetic Navigation for Simplified Percutaneous Transforaminal Endoscopic Lumbar Discectomy: A Novel Approach Xing-Chen Yao, Jun-Peng Liu, Xin-Ru Du, Li Guan, Yong Hai, Jincai Yang, Aixing Pan Neurospine.2025; 22(1): 297. CrossRef
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Validity Evidence for Procedure-specific Competence Assessment Tools in Orthopaedic Surgery: A Scoping Review Yibo Li, Robert Chan, Matthew R.G. Menon, Joanna F. Ryan, Brett Mador, Sandra M. Campbell, Simon R. Turner JAAOS: Global Research and Reviews.2024;[Epub] CrossRef
Outcome of Percutaneous Endoscopic Lumbar Discectomy in Relation to the Surgeon’s Experience: Propensity Score Matching Seong Son, Michael Y. Oh, Han Byeol Park, Alexander M. Lopez Bioengineering.2024; 11(4): 312. CrossRef
Letter to the editor regarding, “Biportal endoscopic versus microscopic discectomy for lumbar herniated disc: A randomized controlled trial” by Park et al. Concepts, analyses and interpretation of noninferiority randomized controlled trials Pravesh S. Gadjradj, Fabian Sommer, Rodrigo Navarro-Ramirez, Judith D. de Rooij The Spine Journal.2023; 23(3): 467. CrossRef
Reply to letter to the editor regarding, “Biportal endoscopic versus microscopic discectomy for lumbar herniated disc: a randomized controlled trial” Sang-Min Park, Ho-Joong Kim The Spine Journal.2023; 23(3): 469. CrossRef
Objective To perform the psychometric validation of the Dutch version of the Core Outcome Measures Index (COMI) for the neck.
Methods A total of 178 patients, who had an indication for surgery due to degenerative cervical spinal disease, were enrolled in the study. They filled in a baseline booklet containing the Dutch version of the COMI-neck, Likert-scales for neck and arm/shoulder pain, the Neck Disability Index (NDI), the EuroQol-5 dimensions (EQ-5D) and the 12-item Short Form health survey (SF-12). Aside from analyzing construct validity using the Spearman correlation test, test-retest reliability, and responsiveness at 3 months were assessed using the intraclass correlation coefficient (ICC) and the receiver-operating characteristic (ROC) curve, respectively.
Results The COMI-neck showed good acceptability with missing data ranging from 0% to 4.5% and some floor/ceiling effects for 3 of the domains at baseline. The COMI-summary score showed good to very good correlation with the EQ5D (ρ = -0.43), the physical component summary of the SF-12 (ρ = -0.47) and the NDI (ρ = 0.73). Individual domains showed correlations of -0.28 to 0.85 with the reference questionnaires. Test-retest reliability analysis showed an ICC of 0.91 with a minimal detectable change of 1.7. Responsiveness analysis of the COMI-neck showed an area under 0.79 under the ROC-curve. The standardized response mean for a good outcome was 1.24 and for a poor outcome 0.37.
Conclusion The current study shows that the Dutch version of the COMI-neck is a valid, reliable and responsive Patient-Reported Outcome Measure, among patients undergoing surgery for degenerative cervical spinal disorders.
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