Tactile Skill-Based Neurosurgical Simulators Are Effective and Inexpensive.

BACKGROUND: Regulations limit residency work hours and operating time, limiting the amount of hands-on surgical training. To develop alternative hands-on training, many programs teach surgical skills in laboratories and workshops with the use of simulators. The expense of computer simulators and lack of replication of the manual skills and tactile feedback of surgery limit their usefulness. We have developed 2 replicable simulators constructed from low-cost materials, which allow residents to practice the manual skills required in key portions of minimally invasive lumbar decompression and Chiari decompression surgeries. The objective was to review the efficacy of our lumbar and Chiari decompression simulators in improving resident and medical student surgical skills. METHODS: Resident and medical student participants completed one or both simulators 10 times. The lumbar decompression simulations were evaluated by the length of time participants blocked the field of view and by the number of times they lost control of the drill. Chiari decompression simulations were evaluated by the length of time to complete the simulation and by the regularity of their sutures. RESULTS: After 10 attempts, participants of the lumbar decompression simulator decreased the amount of time blocking the field of view by 52% and decreased the number of times they lost control of the drill by 69%. Participants of the Chiari decompression simulator decreased their suturing time by 56% and improved the regularity of their sutures. CONCLUSIONS: The simple and inexpensive simulators evaluated in this study were shown to improve the speed, quality of work, and comfort level of the participants.

Biomimetic 3-Dimensional-Printed Posterior Cervical Laminectomy and Fusion Simulation: Advancements in Education Tools for Trainee Instruction.

Surgical proficiency is classically acquired through live experience in the operating room. Trainee exposure to cases and complex pathologies is highly variable between training programs.1 Currently, there is no standard for neurosurgical skill assessment for specific operative techniques for trainees. Cadaveric simulation has been used to demonstrate surgical technique and assess resident skill but often presents a significant financial and facility burden.2-4 Three-dimensional (3D) printing is an alternative to cadaveric tissue in providing high-quality representation of surgical anatomy; however, this technology has significant limitations in replicating conductive soft tissue structures for the use of cauterization devices and haptic learning for proper tissue manipulation.5-7 Our team has combined novel synthesis methods of conductive thermoplastic polymerization and 3-dimensional-printed cervical spine models to produce a layered biomimetic simulation that provides cost-effective and anatomically accurate education for neurosurgical trainees (Video 1). This is accomplished through virtual modeling and layered simulator construction methods by placing the individual polymer layers according to anatomic location of the simulated in vivo structures. The consistency of the thermoplastics can be tailored according to the desired soft tissue structures (skin, fat, fascia, muscle) according to the degree of polymerization. This cost-effective simulation was designed to represent the material and biomechanical properties of the cervical spine cortico-cancellous interface, as well as individual soft tissue components with specific anatomic details of muscle tendinous and ligamentous insertion. These features allow for representative start-to-finish surgical simulation that has not yet been made widely available to neurosurgical training programs.

Design and Validation of a Cervical Laminectomy Simulator using 3D Printing and Hydrogel Phantoms.

BACKGROUND: The development of technical skills for a cervical laminectomy are traditionally acquired through intraoperative learning and cadaveric courses. These methods provide little objective assessment, involve financial and biohazard considerations, and may not incorporate desired pathology. OBJECTIVE: To develop an inexpensive cervical spine laminectomy simulator capable of measuring operative performance and to assess its face, content, and construct validity. METHODS: A virtual model was generated and 3D printed into negative molds. A multilayered surgical phantom was fabricating by filling molds with hydrogels, plaster, and fiberglass. A pressure transducer measured simulated spinal cord manipulation. Participants completed full-procedural laminectomy simulations. Post-simulation surveys assessed face and content validity. Construct validity was assessed by comparing expert and novice procedural metrics. RESULTS: Twelve surgeons participated. The simulator received median face and content validity ratings of 4/5. Differences between experts and novices were found in mean intrathecal pressure wave count (84 vs 153, P = .023), amplitude (4 vs 12% > 2SD above expert mean, P < .001), area under curve (4 vs 12% > 2SD above expert mean, P < .001), procedure time (35 vs 69 min P = .003), and complication rates (none vs 3 incorrect levels decompressed and 1 dural tear, P = .06). Insignificant differences were found in mean pressure wave slope and blood loss. CONCLUSION: This inexpensive cervical laminectomy simulator received favorable face and content validity ratings, and distinguished novice from expert participants. Further studies are needed to determine this simulator's role in the training and assessment of novice surgeons.

Artificial Intelligence Distinguishes Surgical Training Levels in a Virtual Reality Spinal Task.

BACKGROUND: With the emergence of competency-based training, the current evaluation scheme of surgical skills is evolving to include newer methods of assessment and training. Artificial intelligence through machine learning algorithms can utilize extensive data sets to analyze operator performance. This study aimed to address 3 questions: (1) Can artificial intelligence uncover novel metrics of surgical performance? (2) Can support vector machine algorithms be trained to differentiate "senior" and "junior" participants who are executing a virtual reality hemilaminectomy? (3) Can other algorithms achieve a good classification performance? METHODS: Participants from 4 Canadian universities were divided into 2 groups according to their training level (senior and junior) and were asked to perform a virtual reality hemilaminectomy. The position, angle, and force application of the simulated burr and suction instruments, along with tissue volumes that were removed, were recorded at 20-ms intervals. Raw data were manipulated to create metrics to train machine learning algorithms. Five algorithms, including a support vector machine, were trained to predict whether the task was performed by a senior or junior participant. The accuracy of each algorithm was assessed through leave-one-out cross-validation. RESULTS: Forty-one individuals were enrolled (22 senior and 19 junior participants). Twelve metrics related to safety of the procedure, efficiency, motion of the tools, and coordination were selected. Following cross-validation, the support vector machine achieved a 97.6% accuracy. The other algorithms achieved accuracy of 92.7%, 87.8%, 70.7%, and 65.9%, respectively. CONCLUSIONS: Artificial intelligence defined novel metrics of surgical performance and outlined training levels in a virtual reality spinal simulation procedure. CLINICAL RELEVANCE: The significance of these results lies in the potential of artificial intelligence to complement current educational paradigms and better prepare residents for surgical procedures.

Development of a Spine Surgical Skills and Written Assessment for Orthopaedic Surgery Residents.

OBJECTIVE: The objective of this study was to develop an assessment module for orthopaedic spine surgery residents which is cost-effective and can reliably test knowledge and surgical skills. DESIGN: A ten-question multiple choice question and hands-on spine sawbones combination assessment was prospectively administered to consenting PGY-3 and PGY-4 residents before and after their 8-week spine rotation. Pre- and postrotation scores were compared using the paired t-test. SETTING: The Department of Orthopaedics, The Ohio State University Wexner Medical Center, a large academic medical centre providing primary and tertiary care. PARTICIPANTS: Orthopaedic resident physicians. RESULTS: A total of 21 residents (15 PGY-3, 6 PGY-4) participated in the study. The mean pre- and postrotation written test score was 7.38 ± 1.53 and 9.24 ± 0.83, respectively (p < 0.001). Corresponding surgical skills assessment scores were 95.4% ± 4.7 and 97.1% ± 2.6, respectively (p = 0.10). Overall, the postrotation written and surgical scores improved and showed less variation about the mean. CONCLUSIONS: This combination assessment measured improvement in below-average scoring residents and maintenance or improvement in residents with average and above average prerotation scores.

Pre-education Enhances the Success of Manual Training for Orthopedic Surgery Residents.

INTRODUCTION: Surgical skill training is difficult due to limited resources and the associated risks in the clinical setting. There have been many studies that have looked at optimizing resident skill techniques out of the operating room to optimize intraoperative teaching. Specifically, as seen in spine surgery performing a laminectomy with a high-speed drill is difficult and requires many hours of training and guidance before a resident can feel comfortable to adequately complete the laminectomy with minimal risk of adverse effects. OBJECTIVE: The objective of this study is to assess if pre-education of residents prior to using the high-speed drill will significantly increase their comfort level, as well as increase the success of laminectomy. DESIGN, SETTING AND PARTICIPANTS: This was done by a prospective cohort study in evaluating 20 orthopedic surgical residents via the objective structured assessment of technical skills and global rating scale. RESULTS: Results showed that residents who had pre-education were in fact more successful in completing the laminectomy with the high-speed drill. CONCLUSIONS: Pre-education, whether via a didactic or simulator-based model are both beneficial to resident's knowledge and surgical skill attainment however the simulator based model did not deem the group more successful in completing the laminectomy with the high-speed drill. Certain technical skills still require unreplaceable hands-on practice to become proficient.

Learning Curve for Lumbar Decompressive Laminectomy in Biportal Endoscopic Spinal Surgery Using the Cumulative Summation Test for Learning Curve.

OBJECTIVE: The purpose of the present study was to determine the learning curve for biportal endoscopic spinal surgery (BESS) for decompressive laminectomy in lumbar spinal stenosis using a learning curve cumulative summation test (LC-CUSUM). METHODS: The surgeon was proficient in open and microscopic decompressive laminectomy in lumbar spinal stenosis but did not have any experience with BESS or other endoscopic surgery techniques. The learning curve of BESS was investigated using LC-CUSUM analysis. Procedure success was defined as an operative time <75 minutes, the mean operative time with microscopic decompression laminectomy. RESULTS: The present study included the first 60 patients who had undergone single-level decompressive laminectomy using BESS by a single orthopedic surgeon. The mean operative time for decompressive laminectomy by BESS was 83.8 ± 37.9 minutes. The mean operative time in the early learning period (≤30 cases) and late learning period (second 30 cases) was 105.3 ± 39.7 minutes and 62.4 ± 19.9 minutes, respectively. The overall complication rate was ∼10%. The LC-CUSUM signaled competency for surgery at the 58th operation, indicating that sufficient evidence had accumulated to prove that the surgeon was competent. Thus, a trainee with no experience with BESS had reached adequate performance at 58 cases. CONCLUSIONS: The results of the present study have demonstrated that a substantial learning period could be needed before adequate performance can be achieved with lumbar decompressive laminectomy using BESS.

Three-dimensionally printed vertebrae with different bone densities for surgical training.

PURPOSE: To evaluate whether 3D-printed vertebrae offer realistic haptic simulation of posterior pedicle screw placement and decompression surgery with normal to osteoporotic-like properties. METHODS: A parameterizable vertebra model was developed, adjustable in cortical and cancellous bone thicknesses. Based on this model, five different L3 vertebra types (α, ß, γ1, γ2, and γ3) were designed and fourfold 3D-printed. Four spine surgeons assessed each vertebra type and a purchasable L3 Sawbones vertebra. Haptic behavior of six common steps in posterior spine surgery was rated from 1 to 10: 1-2: too soft, 3-4: osteoporotic, 5-6: normal, 7-8: hard, and 9-10: too hard. Torques were measured during pedicle screw insertion. RESULTS: In total, 24 vertebrae (six vertebra types times four examiners) were evaluated. Mean surgical assessment scores were: α 3.2 ± 0.9 (osteoporotic), ß 1.9 ± 0.7 (too soft), γ1 4.7 ± 0.9 (osteoporotic-normal), γ2 6.3 ± 1.1 (normal), and γ3 7.5 ± 1.1 (hard). All surgeons considered the 3D-printed vertebrae α, γ1, and γ2 as more realistic than Sawbones vertebrae, which were rated with a mean score of 4.1 ± 1.7 (osteoporotic-normal). Mean pedicle screw insertion torques (Ncm) were: α 32 ± 4, ß 12 ± 3, γ1 74 ± 4, γ2 129 ± 13, γ3 196 ± 34 and Sawbones 90 ± 11. CONCLUSIONS: In this pilot study, 3D-printed vertebrae displayed haptically and biomechanically realistic simulation of posterior spinal procedures and outperformed Sawbones. This approach enables surgical training on bone density-specific vertebrae and provides an outlook toward future preoperative simulation on patient-specific spine replicas. These slides can be retrieved under Electronic Supplementary Material.

Neurosurgical training with a novel cervical spine simulator: posterior foraminotomy and laminectomy.

BACKGROUND: Neurosurgical residents have traditionally been instructed on surgical techniques and procedures through an apprenticeship model. Currently, there has been research and interest in expanding the neurosurgical education model. OBJECTIVE: To establish a posterior cervical decompression educational curriculum with a novel cervical simulation model. METHODS: The Congress of Neurological Surgeons developed a simulation committee to explore and develop simulation-based models. The educational curriculum was developed to have didactic and technical components with the incorporation of simulation models. Through numerous reiterations, a posterior cervical decompression model was developed and a 2-hour education curriculum was established. RESULTS: Individual's level of training varied, with 5 postgraduate year (PGY) 2 participants, 1 PGY-3 participant, 2 PGY-5 participants, and 1 attending, with the majority being international participants (6 of 9, 67%). Didactic scores overall improved (7 of 9, 78%). The technical scores of all participants improved from 11 to 24 (mean, 14.1) to 19 to 25 (mean, 22.4). Overall, in the posterior cervical decompression simulator, there was a significant improvement in the didactic scores (P = .005) and the technical scores (P = .02). CONCLUSION: The posterior cervical decompression simulation model appears to be a valuable tool in educating neurosurgery residents in the aspects of this procedure. The combination of a didactic and technical assessment is a useful teaching strategy in terms of educational development.

[Learning and teaching abilities of a newly inaugurated operation technique. Analysis of learning curves and transferability exemplified by Kypho-IORT]. / Lehrfähigkeit und Erlernbarkeit einer neu inaugurierten Operationsmethode. Analyse der eigenen Erfahrungskurve und des Weitergabeerfolgs am Beispiel der Kypho-IORT.

The Kypho-IORT procedure is a recently developed surgical technique to combine intraoperative radiotherapy with cement augmentation of the vertebra for spinal metastases. The technical feasibility and the operation principle of this new method have been described. In the following article the refinement of the standard operation procedure and the technical development of the method are described. Not only the procedural improvements but also the learning curves of the inaugurators are pointed out. Moreover, the article presents the measures which were necessary to educate trainees during surgical master classes in this new method and to transfer the method. The learning success was quantified by recording the accuracy reached by the trainees in the key procedure during hands-on cadaver exercises. Improvements of the standard operation procedure could be successfully transferred in a second master class. The method of Kypho-IORT and the demonstrated way of postgraduate education is feasible to instruct trainees. The Kypho-IORT procedure can be learnt and performed safely by running through the surgical master class.

Spine surgery training and competence of European neurosurgical trainees.

BACKGROUND: Little is known about the nature of spine surgery training received by European neurosurgical trainees during their residency and the level of competence they acquire in dealing with spinal disorders. METHODS: A three-part questionnaire entailing 32 questions was devised and distributed to the neurosurgical trainees attending the EANS (European Association of Neurosurgical Societies) training courses of 2004. RESULTS: Of 126 questionnaires, 32% were returned. The majority of trainees responding to the questionnaire were in their final (6(th)) year of training or had completed their training (60.3% of total). Spinal surgery training in European residency programs has clear strengths in the traditional areas of microsurgical decompression for spinal stenosis and disc herniation (77-90% competence in senior trainees). Deficits are revealed in the management of spinal trauma (34-48% competence in senior trainees) and spinal conditions requiring the use of implants and anterior approaches, with the exception of anterior cervical stabilisation. CONCLUSIONS: European neurosurgical trainees possess incomplete competence in dealing with spinal disorders. EANS trainees advocate the development of a postresidency spine subspecialty training program.

Operative results and learning curve: microscope-assisted tubular microsurgery for 1- and 2-level discectomies and laminectomies.

OBJECT: The authors present their clinical results and the learning curve associated with the use of tubular retractors for 1- and 2-level lumbar microscope-assisted discectomies and laminectomies. METHODS: The study involves a retrospective and prospective analysis of 230 patients who underwent noninstrumented minimally invasive procedures for degenerative lumbar spinal disease between 2004 and 2007. Data on patient demographic characteristics and operative results, including length of stay, blood loss, operative times, and surgical complications were collected. Clinical outcomes were assessed based on pre- and postoperative Visual Analog Scale scores, Oswestry Disability Index values, and the Macnab outcome scale scores. RESULTS: The results showed characteristic differences in blood loss and operating times between 1- and 2-level procedures and between discectomies and laminectomies. A significant learning curve was seen by a decrease in operating time for 1-level discectomies and 2-level laminectomies. Major complications were not observed. CONCLUSIONS: The use of tubular retractors for microsurgical decompression of degenerative spinal disease is a safe and effective treatment modality. As with other techniques, minimally invasive procedures are associated with a significant learning curve. As surgeons become more comfortable with the procedure, its applications can be expanded to include, for example, spinal instrumentation and deformity correction.