Minimally Invasive Spine Surgery: The Learning Curve of a Single Surgeon

Integrating Augmented Reality in Spine Surgery: Redefining Precision with New Technologies

INTRODUCTION

The integration of augmented reality (AR) in spine surgery marks a significant advancement, enhancing surgical precision and patient outcomes. AR provides immersive, three-dimensional visualizations of anatomical structures, facilitating meticulous planning and execution of spine surgeries. This technology not only improves spatial understanding and real-time navigation during procedures but also aims to reduce surgical invasiveness and operative times. Despite its potential, challenges such as model accuracy, user interface design, and the learning curve for new technology must be addressed. AR's application extends beyond the operating room, offering valuable tools for medical education and improving patient communication and satisfaction.

MATERIAL AND METHODS

A literature review was conducted by searching PubMed and Scopus databases using keywords related to augmented reality in spine surgery, covering publications from January 2020 to January 2024.

RESULTS

In total, 319 articles were identified through the initial search of the databases. After screening titles and abstracts, 11 articles in total were included in the qualitative synthesis.

CONCLUSION

Augmented reality (AR) is becoming a transformative force in spine surgery, enhancing precision, education, and outcomes despite hurdles like technical limitations and integration challenges. AR's immersive visualizations and educational innovations, coupled with its potential synergy with AI and machine learning, indicate a bright future for surgical care. Despite the existing obstacles, AR's impact on improving surgical accuracy and safety marks a significant leap forward in patient treatment and care.

Learning curve analyses in spine surgery: a systematic simulation-based critique of methodologies

BACKGROUND CONTEXT

Various statistical approaches exist to delineate learning curves in spine surgery. Techniques range from dividing cases into intervals for metric comparison, to employing regression and cumulative summation (CUSUM) analyses. However, their inherent inconsistencies and methodological flaws limit their comparability and reliability.

PURPOSE

To critically evaluate the methodologies used in existing literature for studying learning curves in spine surgery and to provide recommendations for future research.

STUDY DESIGN

Systematic literature review.

METHODS

A comprehensive literature search was conducted using PubMed, Embase, and Scopus databases, covering articles from January 2010 to September 2023. For inclusion, articles had to evaluate the change in a metric of performance during human spine surgery across time/a case series. Results had to be reported in sufficient detail to allow for evaluation of individual performance rather than group/institutional performance. Articles were excluded if they included cadaveric/nonhuman subjects, aggregated performance data or no way to infer change across a number of cases. Risk of bias was assessed using the Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tool. Surgical data were simulated using Python 3 and then examined via multiple commonly used analytic approaches including division into consecutive intervals, regression and CUSUM techniques. Results were qualitatively assessed to determine the effectiveness and limitations of each approach in depicting a learning curve.

RESULTS

About 113 studies met inclusion criteria. The majority of the studies were retrospective and evaluated a single-surgeon's experience. Methods varied considerably, with 66 studies using a single proficiency metric and 47 using more than 1. Operating time was the most commonly used metric. Interval division was the simplest and most commonly used method yet inherent limitations prevent collective synthesis. Regression may accurately describe the learning curve but in practice is hampered by sample size and model choice. CUSUM analyses are of widely varying quality with some being fundamentally flawed and widely misinterpreted however, others provide a reliable view of the learning process.

CONCLUSION

There is considerable variation in the quality of existing studies on learning curves in spine surgery. CUSUM analyses, when correctly applied, offer the most reliable estimates. To improve the validity and comparability of future studies, adherence to methodological guidelines is crucial. Multiple or composite performance metrics are necessary for a holistic understanding of the learning process.

Adolescent Idiopathic Scoliosis: Is the Feasible Option of Minimally Invasive Surgery using Posterior Approach?

The purpose of this systematic review and meta-analysis is to perform a systematic review and meta-analysis of previous studies on minimally invasive scoliosis surgery (MISS) in adolescents with idiopathic scoliosis (AIS). Some data on MISS in AIS compared with conventional open scoliosis surgery (COSS) are conflicting. A systematic literature search was conducted in Medline, Embase, and Cochrane Library, including studies reporting outcomes for MISS in AIS. The meta-analysis compared the operative, radiological, and clinical outcomes and complications between MISS and COSS in patients with AIS. Of the 208 records identified, 15 nonrandomized studies with 1,369 patients (reviews and case reports are excluded) were included in this systematic review and meta-analysis. The mean scale was 6.1, and eight of the 15 included studies showed satisfactory quality using the Newcastle-Ottawa scale. For operative outcomes, MISS had significant benefits in terms of estimated blood loss (standard mean difference [SMD], -1.87; 95% confidence interval [CI], -2.94 to -0.91) and hospitalization days (SMD, -2.99; 95% CI, -4.45 to -1.53) compared with COSS. However, COSS showed significantly favorable outcomes for operative times (SMD, 1.71; 95% CI, 0.92-2.51). No significant differences were observed in radiological outcomes, including Cobb's angle of the main curve and thoracic kyphosis. For clinical outcomes, MISS showed significant benefits on the visual analog scale score (SMD, -0.91; 95% CI, -1.36 to -0.47). The overall complication rates of MISS were similar to those of COSS (SMD, 0.96; 95% CI, 0.61-1.52). MISS using the posterior approach provides equivalent radiological and clinical outcomes and complication rates compared with COSS. Considering the lower estimated blood loss, shorter hospitalization days, and longer operative times in MISS, COSS is still the mainstay of surgical treatment in AIS; however, MISS using the posterior approach is also one of the surgical options of choice in the case of moderate AIS.

A Tubular-Mounted Digital Camera Versus Optical Surgical Microscope for Minimally Invasive Lumbar Decompression Surgery: The Impact on Operative Times, Ergonomics, and Workflow

OBJECTIVE

Understanding ergonomic impact is foundational to critically evaluating value and safety of enabling technologies in minimally invasive spine surgeries. This study assessed the impact of a tubular-mounted digital camera (TMDC) versus an optical surgical microscope (OSM) in single-level minimally invasive spine surgeries on operative times, durotomy rate, surgeon ergonomics, safety, and operating room workflow.

METHODS

This retrospective study compared consecutive single-level minimally invasive lumbar decompression surgeries in a TMDC cohort (September 2021-June 2022) with an historical OSM cohort (January 2020-July 2021). Data included patient demographics, operative times, durotomy incidence, surgeon ergonomics (Rapid Entire Body Assessment scores), and equipment impact via staff surveys. Operative times were assessed by t test, while Pearson χ2 test compared sex. Age, body mass index, and Charlson Comorbidity Index comparisons were made by Wilcoxon rank sum tests, and survey results were analyzed with Wilcoxon signed rank tests.

RESULTS

TMDC and OSM groups included 74 and 82 patients, respectively. Age, sex, and Charlson Comorbidity Index did not significantly differ between groups. The TMDC group had a higher body mass index (29.6 ± 5.1) than the OSM group (29.0 ± 7.5) (P = 0.04). The TMDC group had significantly shorter operative times (57.3 ± 16.6 minutes) than the OSM group) (66.7 ± 22.5 minutes) (P = 0.004), with no difference in durotomy rates (P = 0.42). TMDC use yielded lower Rapid Entire Body Assessment scores compared with OSM (4.1 ± 0.77) (P < 0.001). Surveys indicated improved safety, setup time, and workflow with TMDC (P < 0.001).

CONCLUSIONS

TMDC in single-level minimally invasive lumbar decompression surgery improved surgeon ergonomics, reduced operative times, and maintained durotomy rates, enhancing operating room efficiency. Evaluating ergonomic impact of technology is vital for safety and value assessment.

Perspective: How can risks to patients be limited during spine surgeons' learning curves?

Background

Learning curves (LC) are typically defined by the number of different spinal procedures surgeons must perform before becoming "proficient," as demonstrated by reductions in operative times, estimated blood loss (EBL), length of hospital stay (LOS), adverse events (AE), fewer conversions to open procedures, along with improved outcomes. Reviewing 12 studies revealed LC varied widely from 10-44 cases for open vs. minimally invasive (MI) lumbar diskectomy, laminectomy, transforaminal lumbar interbody fusion (TLIF), anterior lumbar interbody fusion (ALIF), and oblique/extreme lateral interbody fusions (OLIF/XLIF). We asked whether the risks of harm occurring during these LC could be limited if surgeons routinely utilized in-person/intraoperative mentoring (i.e., via industry, academia, or well-trained colleagues).

Methods

We evaluated LC for multiple lumbar operations in 12 studies.

Results

These studies revealed no LC for open vs. MI lumbar diskectomy. LC required 29 cases for MI laminectomy, 10-44 cases for MI TLIF, 24-30 cases for MI OLIF, and 30 cases for XLIF. Additionally, the LC for MI ALIF was 30 cases; one study showed that 32% of major vascular injuries occurred in the first 25 vs. 0% for the next 25 cases. Shouldn't the risks of harm to patients occurring during these LC be limited if surgeons routinely utilized in-person/intraoperative mentoring?

Conclusions

Twelve studies showed that the LC for at different MI lumbar spine operations varied markedly (i.e., 10-44 cases). Wouldn't and shouldn't spine surgeons avail themselves of routine in-person/intraoperative mentoring to limit patients' risks of injury during their respective LC for these varied spine procedures ?

Extended-wavelength diffuse reflectance spectroscopy dataset of animal tissues for bone-related biomedical applications

Diffuse reflectance spectroscopy (DRS) has been extensively studied in both preclinical and clinical settings for multiple applications, notably as a minimally invasive diagnostic tool for tissue identification and disease delineation. In this study, extended-wavelength DRS (EWDRS) measurements of ex vivo tissues ranging from ultraviolet through visible to the short-wave infrared region (355-1919 nm) are presented in two datasets. The first dataset contains labelled EWDRS measurements collected from bone cement samples and ovine specimens including 10 tissue types commonly encountered in orthopedic surgeries for data curation purposes. The other dataset includes labelled EWDRS measurements of primarily bone structures at different depths during stepwise drilling into intact porcine skulls until plunging into the cranial cavity. The raw data with code for pre-processing and calibration is publicly available for reuse on figshare. The datasets can be utilized not only for exploratory purposes in machine learning model construction, but also for knowledge discovery in the orthopedic domain to identify important features for surgical guidance, extract physiological parameters and provide diagnostic insights.

Ten-step minimally invasive slalom unilateral laminotomy for bilateral decompression (sULBD) with navigation

BACKGROUND

Unilateral laminotomy for bilateral decompression (ULBD) is a MIS surgical technique that offers safe and effective decompression of lumbar spinal stenosis (LSS) with a long-term resolution of symptoms. Advantages over conventional open laminectomy include reduced expected blood loss, muscle damage, mechanical instability, and less postoperative pain. The slalom technique combined with navigation is used in multi-segmental LSS to improve the workflow and effectiveness of the procedure.

METHODS

We outline ten technical steps to achieve a slalom unilateral laminotomy for bilateral decompression (sULBD) with navigation. In a retrospective case series, we included patients with multi-segmental LSS operated in our institution using the sULBD between 2020 and 2022. The primary outcome was a reduction in pain measured by Visual Analogue Scale (VAS) for back pain and leg pain and Oswestry Disability Index (ODI).

RESULTS

In our case series (N = 7), all patients reported resolution of initial symptoms on an average follow-up of 20.71 ± 9 months. The average operative time and length of hospital stay were 196.14 min and 1.67 days, respectively. On average, VAS (back pain) was 4.71 pre-operatively and 1.50 on long-term follow-up of an average of 19.05 months. VAS (leg pain) decreased from 4.33 to 1.21. ODI was reported as 33% pre-operatively and 12% on long-term follow-up.

CONCLUSION

The sULBD with navigation is a safe and effective MIS surgical procedure and achieves the resolution of symptoms in patients presenting with multi-segmental LSS. Herein, we demonstrate the ten key steps required to perform the sULBD technique. Compared to the standard sULBD technique, the incorporation of navigation provides anatomic localization without exposure to radiation to staff for a higher safety profile along with a fast and efficient workflow.

Use of a High-Fidelity Training Simulator for Minimally Invasive Lumbar Decompression Increases Working Knowledge and Technical Skills Among Orthopedic and Neurosurgical Trainees

STUDY DESIGN

Prospective comparative study.

OBJECTIVE

To quantify the educational benefit to surgical trainees of using a high-fidelity simulator to perform minimally invasive (MIS) unilateral laminotomy for bilateral decompression (ULBD) for lumbar stenosis.

METHODS

Twelve orthopedic and neurologic surgery residents performed three MIS ULBD procedures over 2 weeks on a simulator guided by established AO Spine metrics. Video recording of each surgery was rated by three blinded, independent experts using a global rating scale. The learning curve was evaluated with attention to technical skills, skipped steps, occurrence of errors, and timing. A knowledge gap analysis evaluating participants' current vs desired ability was performed after each trial.

RESULTS

From trial 1 to 3, there was a decrease in average procedural time by 31.7 minutes. The cumulative number of skipped steps and surgical errors decreased from 25 to 6 and 24 to 6, respectively. Overall surgical proficiency improved as indicated by video rating of efficiency and smoothness of surgical maneuvers, most notably with knowledge and handling of instruments. The greatest changes were noted in junior rather than senior residents. Average knowledge gap analysis significantly decreased by 30% from the first to last trial (P = .001), signifying trainees performed closer to their desired technical goal.

CONCLUSION

Procedural metrics for minimally invasive ULBD in combination with a realistic surgical simulator can be used to improve the skills and confidence of trainees. Surgical simulation may offer an important educational complement to traditional methods of skill acquisition and should be explored further with other MIS techniques.

Learning Curve for Minimally Invasive Scoliosis Surgery in Adolescent Idiopathic Scoliosis

OBJECTIVE

To evaluate the learning curve of minimally invasive scoliosis surgery (MISS) in patients with adolescent idiopathic scoliosis (AIS).

METHODS

A total of 76 AIS patients who underwent MISS were included from March 2015 to February 2017. The cases were divided chronologically into early period group (Group A, March 2015-February 2016, n = 31) and late period group (Group B, March 2016-February 2017, n = 45). Radiological parameters, operative parameters, and clinical outcomes were included in this study. The selected criteria for receiver operating characteristic analysis used to assess learning curve were mean operative time (≤389 minutes) and estimated blood loss (EBL) (≤948 mL).

RESULTS

The mean operative time was 389 minutes, and the EBL was 948 mL. The mean operative time was significantly reduced in the late period group (360 minutes) compared to the early period group (431 minutes) (P < 0.005). The mean EBL was significantly reduced for the late period group (798 mL) compared to the early period group (1164 mL) (P < 0.001). Forty-six cases were required to achieve the preset criteria (area under the curve 0.858; P < 0.001; sensitivity 0.778; specificity 0.796).

CONCLUSIONS

A mild learning curve was demonstrated in MISS for AIS with significant improvement in operative times and EBL over time. Experience of more than 46 cases of MISS was required to obtain proficient surgical skills for a trained surgeon of conventional open scoliosis surgery.

Full endoscopic spine surgery

Background

With a dramatic increase in elderly population worldwide, the prevalence of degenerative spine disease is steadily rising. Even though the entire spinal column is affected the problem is more commonly seen in the lumbar, cervical spine and to some extent the thoracic spine. The treatment of symptomatic lumbar disc or stenosis is primarily conservative with analgesics, epidural steroids and physiotherapy. Surgery is advised only if conservative treatment is ineffective. Conventional open microscopic procedures even though are still a gold standard, have the disadvantages of excessive muscle damage and bone resection, epidural scarring along with prolonged hospital stay and increased need of postoperative analgesics. Minimal access spine surgeries minimize surgical access related injury by minimizing soft tissue and muscle damage and also bony resection thus preventing iatrogenic instability and unnecessary fusions. This leads to good functional preservation of the spine and enhances early postoperative recovery and early return to work. Full endoscopic spine surgeries are one of the more sophisticated and advanced form of MIS surgeries.

Purpose

Full endoscopy has definitive benefits over conventional microsurgical techniques. These include better and clear vision of the pathology due to presence of irrigation fluid channel, minimal soft tissue and bone trauma, better and relatively easy approach to deep seated pathologies like thoracic disc herniations and a possibility to avoid fusion surgeries. The purpose of this article is to describe these benefits, give an overview of the two main approaches - transforaminal and interlaminar, their indications, contraindications and their limitations. The article also describes about the challenges in overcoming the learning curve and its future prospectives.

Conclusion

Full endoscopic spine surgery is one of the fastest growing technique in the field of modern spine surgery. Better intraoperative visualization of the pathology, lesser incidence of complications, faster recovery time, less postoperative pain, better relief of symptoms and early return to activity are the main reasons behind this rapid growth. With better patient outcomes and reduced medical costs, the procedure is going to be more accepted, relevant and popular procedure in future.

Breast Reconstruction with DIEP Flap: The Learning Curve at a Breast Reconstruction Center and a Single-Surgeon Study

Although microsurgical breast reconstruction represents a very interesting and rewarding field of plastic surgery, appropriate microsurgical training is not possible in every plastic surgery department. In this retrospective study, we present the learning curve of our plastic surgery department as a whole and of a single microsurgeon assessing breast reconstruction procedures with a deep inferior epigastric artery perforator (DIEP) flap between July 2018 and June 2021. The present study included 115 patients and 161 flaps. Cases were stratified into single DIEP/double DIEP groups and into early and late groups based on the flap order. Surgery times and postoperative complications were analyzed. Regarding the institution, the length of hospital stay was lower in the late group than in the early group (single 7.1 ± 1.8 vs. 6.3 ± 1.5 days, p = 0.019; double 8.5 ± 3.8 vs. 6.6 ± 1.4 days, p = 0.043). Apart from that, no statistically significant differences were found between the start and end of our study. In terms of the single surgeon, there was a significant improvement in the total surgery time (single 296.0 ± 78.7 vs. 227.5 ± 54.7 min, p = 0.018; double 448.0 ± 85.6 vs. 341.2 ± 43.1 min, p = 0.008), flap ischemia time (53.6 ± 15.1 vs. 40.9 ± 9.5 min, p = 0.007) and length of stay among the compared groups. There was no significant difference in flap loss rate or other complications between the early and late groups. Further performance of surgeries seemed to improve the surgeon's skills as well as the overall experience of the medical institution.

Drivers of Cost in Primary Single-Level Lumbar Fusion Surgery

STUDY DESIGN

Retrospective cohort.

OBJECTIVES

Allocating cost is challenging with traditional hospital accounting. Time-driven activity-based costing (TDABC) is an efficient method to accurately assign cost. We sought to characterize the variation in direct total hospital cost (THC) among both lumbar fusion approaches and surgeons.

METHODS

Patients were treated with single-level anterior interbody (ALIF), lateral interbody (LLIF), transforaminal interbody (TLIF), instrumented posterolateral (PLF) or in-situ fusion (ISF) for degenerative disease. Process maps were developed for preoperative, intraoperative and postoperative care. THC was composed of implant, medication, other supply, and personnel costs. Linear regression and descriptive statistics were used to analyze THC variation.

RESULTS

A total of 696 patients underwent surgery by 8 surgeons. Approximately 50% of THC variation was associated with procedure choice while patient characteristics explained 10%. Implants (including biologics) accounted for 45% of cost. With reference to PLF, THC ranged from 0.6x (ISF) to 1.7x (LLIF). Implant cost ranged from 2.5x reference (LLIF) to 0.1x (ISF). There was a 1.7x difference between the highest THC surgeon and the lowest. The fusion type with the highest THC variation was TLIF. The surgeon with the highest TLIF THC was 1.5x more expensive than the surgeon with the lowest.

CONCLUSIONS

Surgeon-based choices have the greatest effect on THC variation and represent the largest opportunities for cost savings. Primary single-level lumbar fusion THC is driven primarily by fusion type. Implants, including biologics, account for nearly half this cost. Future work should incorporate outcomes data to characterize the differential value conferred by higher THC fusions.

Learning curve for minimally invasive transforaminal lumbar interbody fusion: a systematic review

PURPOSE

Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is commonly used to treat degenerative lumbar spinal disorders. It facilitates a full-scale spinal decompression and interbody fusion with minimal neural retraction using the tubular retractor system. Despite the benefits of surgical efficiency and minimalism, this technique requires a long learning curve. There is currently no consensus on the learning curve characteristics and proper training methods for MI-TLIF. Thus, this systematic review aimed to discuss the cutoff point at which technical proficiency is achieved and ways to enhance the learning process.

METHODS

Major databases, including PubMed, Embase, and Cochrane Library, were searched for learning curve studies that have evaluated the clinical outcome and learning progress of MI-TLIF using quantitative data. The qualities of the selected studies were assessed using the Newcastle‒Ottawa scale. The plateau points in the "learning curve" were analyzed according to various outcome measures.

RESULTS

Nine full-text articles, representing 753 cases, were included from 9743 screened studies. The most commonly used outcome measures were the operative time, followed by the complication rate. The mean cutoff point for the operative time was 31.33 ± 11.98 (range 13‒45) cases.

CONCLUSION

The plateau point in the learning curve for MI-TLIF may differ according to the outcome measures used. Most studies have demonstrated the learning progress based on simple task efficiency, rather than patient outcomes. Moreover, the learning rate may be affected by the patients' and technical conditions. Therefore, great care is required in interpreting the learning curve and cutoff point for MI-TLIF proficiency.

Full-endoscopic versus microscopic unilateral laminotomy for bilateral decompression of lumbar spinal stenosis at L4-L5: comparative study

PURPOSE

Full-endoscopic spine surgery for degenerative lumbar diseases is growing in popularity and has shown favourable outcomes. Lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) has been used to treat lumbar spinal stenosis (LSS). However, studies comparing LE-ULBD to microscopic ULBD are lacking. This study compared the clinical efficacy and radiological outcomes between the LE-ULBD and microscopic ULBD.

METHODS

The study retrospectively enrolled patients undergoing either LE-ULBD or microscopic ULBD for spinal stenosis at the L4-L5 level. The demographic data, operative details, radiological images, clinical outcomes, and complications of patients from the two groups were compared through matched-pairs analysis. The minimum follow-up duration was 24 months.

RESULTS

There were 93 patients undergoing either LE-ULBD (n = 42) or microscopic ULBD (n = 51). The patient demographics were similar between the two groups. The LE-ULBD group had significantly less estimated blood loss, less analgesic use, and shorter hospitalization duration (P < .05). The endoscopic group had a significantly lower visual analog scale for back pain at all follow-up intervals compared with the microscopic group (P < .05). There were no significant differences in leg pain or Oswestry Disability Index. The cross-section area of the spinal canal was significantly wider after microscopic ULBD. There were no significant differences in post-operative degenerative changes in disc height, translational motion, or facet preservation rate.

CONCLUSIONS

LE-ULBD is comparable in clinical and radiological outcomes with enhanced recovery for single-level LSS. The endoscopic approach might further minimize tissue injury and enhance post-operative recovery.

Impact of Surgeon Experience on Outcomes of Anterior Cervical Discectomy and Fusion

INTRODUCTION

The relationship between surgeon experience and cervical fusion outcomes has yet to be assessed. We investigate perioperative characteristics, patient-reported outcomes (PROMs), and minimal clinically important difference (MCID) achievement after anterior cervical diskectomy and fusion (ACDF) by the volume of cases done throughout an orthopaedic spine surgeon's career.

METHODS

ACDF procedures between 2005 and 2020 were identified. Group I included the first half of ACDF cases (#1-#321). PROMs were introduced in the second half of the ACDF cases; thus, the next 322 cases were subdivided to compare PROM and MCID between subgroups (cases #322 to #483 = group II and #484 to #645 = group III). PROMs, including VAS back/leg, Oswestry Disability Index (ODI), Short Form-12 Physical Composite Score, and PROMIS-PF, were collected preoperatively/postoperatively. Demographics, perioperative variables, mean PROMs, and MCID achievement were compared between groups and subgroups using the Student t-test and chi-square. Logistic regression evaluated MCID achievement using the established threshold values.

RESULTS

A total of 642 patients were included (320 in group I, 161 in group II, and 161 in group III). The latter cases had significantly decreased surgical time, blood loss, and postoperative length of stay in comparison of groups and subgroups (P ≤ 0.002, all). CT-confirmed 1-year arthrodesis rates were increased among the latter cases (P = 0.045). Group II had significantly higher arthrodesis rates than group III (P = 0.039). The postoperative complication rates were lower in the latter cases (P < 0.001, all), whereas subgroup analysis revealed lower incidence of urinary retention and other complications in group III (P ≤ 0.031, all). Mean PROMs were significantly inferior in group II versus group III for VAS neck at 6 months (P = 0.030), Neck Disability Index at 6 months preoperatively (P ≤ 0.022, both), Short Form-12 Physical Composite Score at 12 weeks/2 years (P ≤ 0.047, both), and PROMIS-PF at 12 weeks/6 months (P ≤ 0.036, both). The MCID attainment rates were higher among group III for VAS neck/Neck Disability Index at 2 years (P ≤ 0.005) and overall achievement across all PROMs (P ≤ 0.015, all).

DISCUSSION

Increased ACDF case volume may lead to markedly decreased surgical time, blood loss, and length of postoperative stay as well as improved clinical outcomes in pain, disability, and physical function.

Describing the spine surgery learning curve during the first two years of independent practice

Retrospective cohort studyTo characterize the learning curve of a spine surgeon during the first 2 years of independent practice by comparing to an experienced colleague. To stratify learning curves based on procedure to evaluate the effect of experience on surgical complexity.The learning curve for spine surgery is difficult to quantify, but is useful information for hospital administrators/surgical programs/new graduates, so appropriate expectations and accommodations are considered.Data from a retrospective cohort (2014-2016) were analyzed at a quaternary academic institution servicing a geographically-isolated, mostly rural area. Procedures included anterior cervical discectomy and fusion, posterior cervical decompression and stabilization, single and 2-level posterior lumbar interbody fusion, lumbar discectomy, and laminectomy. Data related to patient demographics, after-hours surgery, and revision surgery were collected. Operative time was the primary outcome measure, with secondary measures including cerebrospinal fluid leak and early re-operation. Time periods were stratified into 6 month quarters (quarter [Q] 1-Q4), with STATA software used for statistical analysis.There were 626 patients meeting inclusion criteria. The senior surgeon had similar operative times throughout the study. The new surgeon demonstrated a decrease in operative time from Q1 to Q4 (158 minutes-119 minutes, P < .05); however, the mean operative time was shorter for the senior surgeon at 2 years (91 minutes, P < .05). The senior surgeon performed more revision surgeries (odds ratio [OR] 2.5 [95% confidence interval [CI] 1.7-3.6]; P < .001). Posterior interbody fusion times remained longer for the new surgeon, while laminectomy surgery was similar to the senior surgeon by 2 years. There were no differences in rates of cerebrospinal fluid leak (OR 1.2 [95% CI 0.6-2.5]; P > .05), nor reoperation (OR 1.16 [95% CI 0.7-1.9]; P > .05) between surgeons.A significant learning curve exists starting spine practice and likely extends beyond the first 2 years for elective operations.

Magnetic Resonance Neurography for Evaluation of Dorsal Root Ganglion Morphology

BACKGROUND

In this study, the morphologic characteristics and anatomic position of the dorsal root ganglion (DRG) were measured and analyzed in healthy people using magnetic resonance neurography (MRN), which provided an anatomical reference for minimally invasive spinal surgery.

METHODS

From January 2018 to December 2019, 20 healthy adult volunteers (10 male and 10 female volunteers between 20 and 65 years old) were scanned and imaged by 3.0 T magnetic resonance imaging combined with neuroimaging technology. Here, the position of the DRG was located, and the shape and size of the DRG, as well as its distance to the upper pedicle, were measured.

RESULTS

All volunteers provided satisfactory MRN scans of the L1-S1 lumbar DRG. According to the spatial position of the DRG, the morphology of the DRG can be divided into the intervertebral foramen type (81.01%), intraspinal type (16.01%), extraforaminal type (0.8%), and mixed type (2.0%).

CONCLUSIONS

The intervertebral foramen type and Intraspinal type were observed to be the main distribution forms of lumbar DRG. Due to the downward movement of lumbar segments, the position of the DRG was noted to gradually move to the spinal canal while its volume gradually increased. In addition, the distance from the upper pedicle was found to decrease gradually. MRN imaging can clearly show the shape, location, and adjacent relationship of the DRG, providing effective imaging guidance for the minimally invasive lumbar techniques.