Introduction

Percutaneous transforaminal endoscopic discectomy (PTED) is a minimally invasive surgical procedure employed in the treatment of lumbar disc herniation (LDH)1. This procedure involves the removal of disc fragments to decompress the nerve root and therefore relieve pain radiating from the lower back to the legs2,3. Compared to open microdiscectomy, PTED offers advantages in reducing iatrogenic injury and surgical complications, attributable to its minimal muscle dissection, reduced soft tissue trauma, and preservation of bony structures4,5. Patients undergoing PTED experience reduced postoperative pain, accelerated recovery, and shorter hospital stays6. Owing to its clinical benefits, PTED has gained preference among both surgeons and patients.

PTED demands a high level of surgical skill due to the challenge of manipulating instruments within confined anatomical corridors. The procedure is characterized by a steep learning curve7. Inexperienced surgeons often face prolonged operative times and increased radiation exposure8, which can lead to a higher risk of complications such as neurovascular injury, incomplete decompression, and instrument failure9,10,11. Previous studies indicate that surgeons require approximately 72 procedures to achieve competence in PTED and ensure optimal outcomes12, this steep learning curve presents a significant challenge for novice surgeons in developing essential skills while maintaining patient safety.

Fortunately, surgical simulation provides a safe environment for effective training, enabling surgeons to ascend the learning curve more rapidly13,14,15. Numerous studies have highlighted various technologies for enhancing clinical training16,17,18,19, with evidence confirming that skills acquired through simulation are transferable to the operating room. Earlier studies indicate that simulated PTED training improves preoperative planning20,21 and the application of clinical skills21. Nevertheless, the efficacy of simulated training is often hampered by obstacles related to local scenarios and the extent of organizational support22.

While previous studies have established a foundation for spinal surgery training23,24,25, including its general features, the integration of simulation in residency programs, and the learning curves for various techniques, the specific competencies and optimal training pathways for PTED remain poorly defined. To address this gap, we conducted a survey to identify the surgical skills deemed most essential for PTED by practicing surgeons and to evaluate the current landscape of simulated training for this technique.

Methods

The survey employed in this study comprised 38 items, organized into four sections: background information, general surgical knowledge and skills, PTED-specific skills, and simulation training (Supplemental Table). The framework of the survey instrument, along with questions concerning background information, general knowledge and skills, and simulation methods, was adapted from a prior study26 and refined with input from two expert surgeons (each having performed over 300 PTED procedures). While these surgeons also designed the PTED-specific skill questions based on the standard surgical protocol, the subsequent development of items investigating prior simulation exposure further tailored the survey to our research objectives. The online survey, hosted on www.wenjuan.com, was disseminated via links shared in five social media groups dedicated to spine surgeons and was also administered at two orthopaedic surgery conferences.

Upon agreeing to the informed consent form, which outlined the study’s purpose, participants proceeded to the survey. The first section collected demographic information and PTED experience. Subsequently, participants rated the importance of general and specific PTED skills on a 5-point Likert scale (1 = least important, 5 = most important). The final section gathered perceptions on simulated training, including preferences, prior exposure, and practice duration. Additionally, open-ended comment fields were provided following the specific skills and simulation training sections.

As this study involved no collection of personally identifiable information and was conducted in accordance with the Declaration of Helsinki, it was granted a waiver of ethical approval by the research ethics committee of Nanchuan Hospital of Chongqing Medical University.

Analysis and statistics

To identify the key skills for PTED training, the specific skills (21 skills) were further divided into three categories on the basis of their features26,27,28: (a) preparation of the patient and instruments; (b) identification of anatomical structures; and (c) surgical procedure. The internal consistency of the survey items was assessed using Cronbach’s alpha. Prior to analysis, the normality of all continuous variables was examined. The ratings for three specific skills (identifying the superior articular process using an intervertebral endoscope, selecting tools to shape the articular process, and decompressing the traversing nerve roots) were found to be severely skewed. Accordingly, a Box-Cox transformation was applied for data correction, resulting in transformed variables that met parametric assumptions. For group comparisons, one-way ANOVA with LSD post-hoc tests was used when assumptions of normality and homogeneity of variances were satisfied; otherwise, Welch’s ANOVA with Tamhane’s T2 tests was employed. The Bonferroni correction was applied to control the family-wise error rate. To ensure robustness, a sensitivity analysis was conducted using the non-parametric Kruskal-Wallis H test. All analyses were performed using the SPSSAU data science platform (https://spssau.com).

Results

A total of 194 specialist surgeons completed the survey. Following a rigorous manual screening process against three validity criteria—(a) full completion, (b) self-reported experience in performing or assisting PTED, and (c) absence of implausible responses—154 valid responses from 111 hospitals across 22 provincial-level regions in China were retained for analysis. The survey instrument demonstrated excellent internal consistency, with Cronbach’s alpha values of 0.943 overall, 0.873 for general skills, 0.905 for specific skills, and 0.846 for simulation methods. The cohort comprised 8 postgraduates/residents/fellows, 46 junior specialists, 64 consultants, and 36 senior consultants. Detailed demographic characteristics are presented in Table 1.

Table 1 Participants demographics.
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A one-way ANOVA was conducted to examine the effect of experience level. Post hoc LSD tests revealed a statistically significant difference in the average years of PTED experience between junior specialists and senior consultants. Although no significant inter-group differences were found in the annual or total number of PTED procedures performed, senior consultants demonstrated a non-significant trend toward higher procedural volumes.

General skills

Surgeons’ ratings of the five general skills are presented in Table 2. Welch ANOVA revealed significant differences in the perceived importance of these skills collectively. Subsequent analyses, corrected with the Bonferroni method, identified specific disparities in two skills: knowledge of imaging anatomy (F = 2.858, P = 0.039) and spatial perception (F = 3.339, P = 0.021). Post-hoc tests indicated that both junior specialists and consultants rated knowledge of imaging anatomy significantly higher than postgraduates/residents/fellows. For spatial perception, senior consultants, junior specialists, and consultants all assigned significantly higher ratings than the postgraduate/resident/fellow group. The Kruskal-Wallis test showed no significant differences in the ratings of any general skills across training levels.

Table 2 Five general surgical skills trainees should possess prior to performing in operating room.
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Specific skills

Specific surgical skills were categorized into three domains for analysis. Welch ANOVA and Tamhane T2 test indicated that skills pertaining to the identification of important anatomical structures were rated as the most critical. There were no significant differences in the ratings of these skill categories based on surgeon experience level. Detailed results are presented in Table 3.

Table 3 Categories of specific surgical skills important for trainees to possess prior to performing in operating room.
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The analysis of specific PTED skills revealed distinct patterns in their perceived importance (shown in Table 4). The first 11 skills received uniformly high ratings, whereas the last five skills were rated significantly lower. ANOVA with Bonferroni correction identified significant inter-group differences for three skills. While a significant main effect was found for operating room setup (F = 3.038, P = 0.031), post-hoc pairwise comparisons did not reach significance. For connecting various surgical instruments (F = 3.905, P = 0.010) and expanding the intervertebral foramen (F = 3.478, P = 0.018), consultants rated these skills significantly higher than senior consultants. In a complementary non-parametric analysis, the Kruskal-Wallis test showed significant differences only for operating room setup and puncture under fluoroscopy (P < 0.05).

Table 4 Specific surgical skills trainees should possess prior to performing in operating room.
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Preferred types of simulation

As presented in Table 5, surgeons’ ratings of four simulation modalities revealed a consistent descriptive trend: cadaveric specimens were perceived as the most beneficial for skill development, while low-fidelity bench-top models were considered the least useful. The Welch ANOVA found no significant overall differences in the ratings of these modalities among surgeons with different experience levels.

Table 5 Usefulness of the different types of simulations.
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Simulation training received

Surgeons reported their prior exposure to the four simulation modalities using a binary scale (1 = experienced, 0 = not experienced). As summarized in Table 6, training with cadaveric specimens was the most commonly reported. The Tamhane T2 test further indicated that younger surgeons (e.g. postgraduates, residents, and fellows) had undergone significantly more VR simulation training than their senior counterparts. Conversely, a one-way ANOVA on logarithmically transformed training hours revealed no statistically significant difference in the total duration of simulation training across experience levels. Despite this, descriptive data showed a trend wherein junior surgeons tended to report longer overall training durations than senior surgeons.

Table 6 The simulated training that previously received.
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Discussion

This study elucidated the current PTED training by synthesizing input from medical professionals. It identified the surgical skills deemed most critical for operative quality and ascertained preferred training methodologies. These findings offer an evidence-based foundation for designing structured PTED training curricula and informing the development of targeted simulation technologies.

Although PTED is a recognized treatment for sciatica, its adoption is hindered by a demanding learning curve. Our research sought to identify the essential skills to address this challenge. Specifically, surgeons across all career stages emphasized that profound anatomical knowledge and the capacity for accurate anatomical identification are the most vital competencies for trainees. This reinforces that mastering anatomy is central to navigating the PTED learning curve, a principle well-supported in studies of analogous endoscopic skills26,27.

Similarly, for the three categories of specific skills, the identification of anatomical structures was uniformly rated as the most critical by surgeons across all experience levels. This consensus likely stems from the indispensable need for advanced visuospatial skills in endoscopic surgery29,30. The PTED procedure presents a particular challenge in accurate puncture and localization, requiring surgeons to mentally reconstruct three-dimensional anatomy from two-dimensional fluoroscopic images, a capability that hinges on considerable cognitive effort31. Inaccurate mental mapping, common among novices, can lead to multiple puncture attempts and excessive reliance on fluoroscopy, thereby elevating the risks of tissue damage and radiation exposure for both patients and surgical staff32. In contrast, the other two categories are more readily honed through routine practice and may be transferred from other surgical domains, which likely accounts for their comparatively lower perceived importance.

The fact that a substantial number of specific skills received similarly high importance ratings indicates the comprehensive skill set demanded by PTED, which directly correlates with its characteristically steep and protracted learning curve. Notably, junior surgeons (postgraduates, residents, and fellows) assigned lower ratings to the top three skills, including identifying the superior articular process using an intervertebral endoscope, traversing nerve root decompression, and selecting tools for shaping the articular process, compared to their experienced counterparts. As these skills are pivotal for clinical efficacy and surgical quality, the rating disparity likely reflects a lack of operative experience and a consequent underappreciation of their nuanced complexity. Therefore, targeted training that explicitly emphasizes and deconstructs these high-stakes skills is essential to accelerate the learning curve and enhance the operative performance of novice surgeons.

For simulated training, cadaveric specimens emerged as the most preferred and frequently utilized modality. The fidelity of visual and haptic feedback they provide is instrumental in developing spatial orientation and practical skills, benefits extensively documented in the literature33,34,35,36. Nonetheless, the routine application of cadaveric training is significantly constrained by cultural, ethical, legal, and financial hurdles37,38. These limitations likely explain the observed differences in its access across generations. Consequently, junior surgeons now report substantially fewer opportunities for cadaver-based training during their training period.

As viable alternatives, high-fidelity physical models and VR simulators are favorable for PTED practice. VR simulators offer adaptable training scenarios, immersive visual feedback, real-time performance assessment, and support self-directed learning39. Recent evidence confirms that VR environments enhance the acquisition of anatomical knowledge and procedural skills among medical students40 and can significantly boost trainee engagement in learning spine surgery techniques41. In contrast, high-fidelity physical models address concerns regarding cost and the need for precise haptic feedback42,43,44, allowing trainees to rehearse invasive steps and spatial techniques. Although low-fidelity benchtop models were rated least favorable, they remain beneficial for practicing foundational clinical steps and familiarizing trainees with essential surgical instruments45,46,47. Consequently, in an educational context, the selection of simulation modality should be driven by the key learning objectives of the training program rather than by technological sophistication alone.

Simulated training is widely recognized as an essential component of surgical preparation in many countries48, and its ability to transfer skills to the operating room has been well documented49. However, our findings reveal a substantial implementation gap in the context of PTED: the average time dedicated to such training is only 22 h, with significant disparities in access across different training levels. This limited and uneven integration suggests simulation has not yet become a routine educational component, leading to suboptimal training efficiency.

To bridge this gap, a dual-pathway approach could be considered. First, developing a structured, blended training model to strategically integrate simulation with traditional apprenticeship. The higher simulation usage among younger surgeons, as observed in our study, signals a growing acceptance of this technology and provides a fertile ground for its systematic implementation. Second, and equally important, this blended model should be guided by a competency-based framework. Given the considerable variability in clinical experience among PTED surgeons, a time-based training approach may be insufficient. Progression could therefore be determined by the achievement of predefined skill milestones, which would help ensure uniform proficiency outcomes. This combined approach could modernize the clinical training paradigm and optimize the PTED learning curve.

This study has several limitations. Firstly, the survey instrument used in this study lacked formal validation. The absence of established construct validity means some uncertainty remains regarding whether the survey accurately measured the intended theoretical constructs. This limitation should be considered when interpreting the findings. Future research would benefit from a rigorous pilot study to validate the instrument. Secondly, the limited sample size among postgraduates/ residents/fellows subgroup may introduce selection bias and constrain the generalizability of the findings. Future research should aim to recruit a larger and more diverse cohort of novice trainees to enhance the representativeness of the data and to better elucidate the distinct challenges faced at different stages of the PTED learning curve. Finally, while this study identified preferred simulation modalities, it did not delve into the specifics of their implementation. Subsequent investigations should focus on how different simulation types quantitatively influence learning efficiency and skill acquisition, thereby informing the development of more targeted and effective training programs and simulators.

Conclusion

Our findings confirm the critical role of anatomical proficiency in PTED training, indicating a need for focused educational strategies. Despite a currently modest average of 22 h of simulated training, usage is rising among younger surgeons. Although cadaveric specimens are the preferred method, younger surgeons are increasingly embracing alternatives like high-fidelity physical models and VR simulators, translating to a broader and more accessible training landscape.