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

Meta-Analysis of Learning Curve in Endoscopic Spinal Surgery: Impact on Surgical Outcomes

Study DesignSystematic review and meta-analysis.ObjectiveThis meta-analysis aimed to evaluate the learning curve in endoscopic spinal surgery, including the time to mastery and challenges faced by novice surgeons, to improve learning and surgical outcomes.MethodsData extraction included the learning curve period and a comparison of surgeons with more experience or late period of the learning curve (late) and surgeons with less experience and in the early period of the learning curve (early) with respect to demographic, surgical, hospitalization, functional, and complication variables. Statistical analysis was performed using Review Manager 5.4.1 software.ResultsThis meta-analysis included 16 studies (n = 1902). The average number of cases required to reach the learning curve was 32.5 ± 10.5. The uniportal technique required fewer cases (30.1 ± 10.2) than biportal technique (38.7 ± 10.3). There were no significant differences in demographic variables, operation level, or duration of symptoms between the advanced and novice surgeons. Advanced surgeons showed better outcomes in VAS leg pain at less than 6 months (SMD 0.18, 95% CI 0.01-0.34) and >6 months (SMD 0.14, 95% CI 0.02-0.27), as well as VAS back pain at > 6 months (SMD 0.16, 95% CI 0.04-0.29). The incidence of total complications was significantly higher in the novice surgeon group. The specific complications did not differ significantly between the 2 groups.ConclusionsThe average number of cases required to reach the learning curve was 32.5 ± 10.5. Experienced surgeons had shorter surgery and fluoroscopy times, better outcomes in leg and back pain, and a lower incidence of complications than novice surgeons.

A retrospective study on safety and clinical outcomes of unilateral biportal endoscopic technique for spinal degenerative diseases

Background and Objective

Unilateral biportal endoscopy (UBE) has been developing rapidly in coincidence with the popularization of minimally invasive spine surgery (MISS). However, the clinical outcome and invasiveness of UBE-assisted spinal surgery (UBESS) are undefined. The aim of the present study was to summarize the clinical outcome and surgical invasiveness of UBE for the treatment of various spinal degenerative diseases in a single center to validate the safety and application value of UBESS.

Methods

Included in this study were 105 patients who received UBESS from November 2021 to June 2022 in our center. All patients were followed up postoperatively for at least 12 months. All basic information was recorded to depict the demographic and surgical variables. Clinical outcomes were assessed in terms of the operation time, complications, days of hospital stay, total blood loss, intraoperative blood loss, postoperative drainage volume, hidden blood loss, biochemical changes associated with surgical injury, comparison of the visual analogue scale (VAS) for back and leg pain, Japanese Orthopedic Association (JOA) scores for cervical diseases at preoperative and postoperative stage, as well as Oswetry Disability Index (ODI), and modified MacNab scores one year after treatment.

Results

Of the 105 included patients, 68 patients were with single-level lumbar degenerative diseases, 22 with two-level diseases, two with three-level diseases, 10 with single-level isthmic spondylolisthesis, and three with single-level cervical spondylotic radiculopathy. UBE was performed by using five surgical approaches. The operation time, days of hospital stay, blood loss, postoperative immobilization time and prognosis were all estimated in consideration of the surgical approaches and the number of operated segments. The mean operation time ranged from 80 min to 214 min for single-level spinal diseases, and 112 min to 330 min for two-level ones. Total blood loss was higher in multilevel spinal surgery and single-level UBE-assisted lumbar interbody fusion+discectomy (ULIFD). The postoperative immobilization duration was between 0.5 and 2 days for single level spinal diseases, 1 and 3 days for 2-level diseases, fewer than 2 days for three-level diseases, and 1.5-12 days for isthmic spondylolisthesis (IS). The VAS and ODI for lumbar diseases decreased significantly and the JOA scores for cervical diseases improved after operation. The satisfaction rate was 89.70%, 85.71%, 90.00%, 66.67%, and 90.00% for the five surgical approaches respectively.

Conclusions

UBESS has proved to be a safe, reliable and minimally invasive option for spinal degenerative diseases, with significant benefits of pain control, rapid functional recovery, short hospitalization, and early rehabilitation. However, postoperative hidden blood loss should be put under the careful management when performing UBESS.

Practice and application of learning curve theory in improving prescription review skills in standardized training for pharmacists in medical institutions

To explore the practice and application of learning curve theory in improving prescription review skills in standardized training for pharmacists in medical institutions, and to provide reference for enhancing the effectiveness of standardized training for pharmacists in medical institutions. A retrospective analysis was conducted on the relevant data of 20 students who participated in our hospital's standardized pharmacist training in 2022 and 2023 during their prescription review practice learning process. The prescription review practice learning process is divided into 10 stages, with 100 prescriptions in each stage. Three indicators, namely the time spent on the review operation (A1), the accuracy of the review result judgment (A2), and the proficiency of the review system operation (A3), are quantified. The cumulative sum control chart method of binary variables (CUSUM) is used to establish the benchmark target value of the evaluation indicators and the success rate standard of the evaluation indicators. Through accumulation and analysis, the scatter plot was fitted with curves. The stages where the slope of the learning curve began to decrease for different indicators are stage 7, stage 6, and stage 5, respectively. The overall learning curve reaches its peak crossing point in the sixth stage, and prescription review learning transitions from the improvement stage to the proficiency stage. The slope of the individual learning curve began to decrease from stages 4-8. Through further analysis of the correlation between students crossing the learning curve and possible influencing factors, Spearman analysis results shown that students' theoretical exam scores are highly negatively correlated with the number of times they cross the learning curve in practice. By applying the learning curve theory, we can scientifically define the developmental stages of pharmacists' auditing abilities. As the number of prescription reviews accumulates, the prescription review ability and proficiency of the trainees gradually improve, and the accuracy of prescription review significantly increases. The time spent on prescription review is significantly shortened compared to the learning stage, and the system operation proficiency meets the standard. Through the practice and application of learning curve theory, regulatory training institutions provide scientific basis for teaching and training, which can serve as an evaluation standard for the standardized training effect of pharmacist prescription review, and also provide valuable reference for the scientific design of teaching practice for future students.

Unilateral biportal endoscopic spine surgery: a meta-analysis unveiling the learning curve and clinical benefits

Objective

To provide insights into the learning curve of unilateral biportal endoscopic (UBE) spine surgery by synthesizing available evidence on critical points and associated clinical outcomes.

Methods

A comprehensive literature search was conducted across multiple databases, yielding a pool of relevant studies. Inclusion criteria encompassed studies reporting on UBE learning curves and quantitative data related to clinical outcomes (operative time, hospital stay, and complications).

Results

A total of five studies were included in the analysis, providing six datasets to elucidate the UBE learning curve. Three of the five studies analyzed learning curves using the Cumulative Sum method and identified cutoff points. One study plotted learning curves and determined cutoff points based on surgical time analysis, while the remaining one study (providing two datasets) plotted learning curves using the phased analysis method. The mean value of the cutoff point in terms of the number of cases required to reach proficiency in time to surgery was calculated at 37.5 cases, with a range spanning from 14 to 58 cases. Notably, there was a statistically significant difference in time to surgery between the late group and the early group, with the late group demonstrating a significantly reduced time to surgery (P < 0.0001). Additionally, the determined cutoff points exhibited significant variations when applied to patient outcome parameters, including postoperative hospitalization, postoperative drainage, and surgical complications (P < 0.05).

Conclusion

While the analysis indicates that UBE surgery's learning curve is associated with surgical time, the limited focus on this metric and potential discrepancies in cutoff point determination highlight the need for a more comprehensive understanding.

Evaluating robotic assistance on the learning curve and efficiency of mandibular angle ostectomy: an animal model study

Introduction

This study evaluated the efficacy and learning curve of a maxillofacial surgical robotic system (MSRS) guided by electromagnetic navigation for mandibular angle ostectomy (MAO), compared to traditional surgical methods.

Methods

The study utilized a controlled experiment involving thirty rabbits, paired divided into experimental and control groups. The experimental group underwent MAO using the MSRS, while the control group was treated with conventional surgical techniques. The surgeons performing the procedures were inexperienced in robotic surgery and MAO to assess the learning curve and the impact of robotic assistance. Key parameters measured included the accuracy of ostectomy, setup time, and ostectomy efficiency, with data analyzed through a paired-t test to compare the performance between the two groups.

Results

The study indicated a significant reduction in ostectomy time for the experimental group, with improved accuracy and efficiency in ostectomy. The study found that robotic assistance could decrease the risk of complications and enhance surgical outcomes. It also highlighted the presence of an initial learning curve when adopting new robotic technologies, which could be mitigated through adequate training and simulation practices.

Discussion

Using MSRS for MAO could lead to faster early learning curves and increased ostectomy efficiency compared to traditional surgical methods. It demonstrated the potential benefits of integrating robotic systems into craniofacial surgery, suggesting a promising direction for future surgical practices.

Trans-Pars Interarticularis Approach for Lumbar Interbody Fusion: An Efficient, Straightforward, and Minimally Invasive Surgery for Lumbar Spondylolisthesis and Stenosis

BACKGROUND

 Lumbar interbody fusion is a commonly applied surgical treatment for spondylolisthesis. For this procedure, various minimally invasive (MIS) approaches have been developed, including posterior lumbar interbody fusion, transforaminal lumbar interbody fusion (TLIF), oblique lumbar interbody fusion, and anterior lumbar interbody fusion. In this study, we characterized the features of an MIS trans-pars interarticularis lumbar interbody fusion (TPLIF) and compared its surgical outcomes with those of MIS-TLIF.

METHODS

 This study included 89 and 44 patients who had undergone MIS-TPLIF and MIS-TLIF, respectively, between September 2016 and December 2022. The following clinical outcomes were analyzed: operative time, blood loss, and hospitalization duration.

RESULTS

 The average operative time, blood loss, and hospitalization duration for the MIS-TPLIF and MIS-TLIF groups were, respectively, 98.28 and 191.15 minutes, 41.97 and 101.85 mL, and 5.8 and 6.9 days.

CONCLUSION

 The MIS-TPLIF approach for lumbar spondylolisthesis or other degenerative diseases involves the use of the commonly available and cost-effective instrument Taylor retractor, thus enabling posterior lumbar interbody fusion to be performed with minimal invasion. This approach also confers the benefits of a short learning curve and an intuitive approach. Our results suggest that although MIS-TPLIF is noninferior to MIS-TLIF, it is easier to learn and perform than MIS-TLIF.

Comparison of midline lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion for treatment of lumbar degeneration disease

Midline lumbar interbody fusion (MIDLIF) and minimally invasive transforaminal interbody fusion (MIS-TLIF) are two minimally invasive lumbar fusion methods that have gained popularity in the past two decades. MIDLIF involves the use of cortical bone trajectory screws, whereas MIS-TLIF uses traditional pedicle screws. However, there is a significant lack of research directly examining the clinical efficacy of these two methods in treating single-segment lumbar degenerative diseases. Hence, the objective of our retrospective study is to assess and contrast the surgical and clinical results of MIDLIF and MIS-TLIF. The study population comprised 133 patients diagnosed with single-segment lumbar degenerative disease that received treatment using either MIDLIF (n = 65) or MIS-TLIF (n = 68) in our department from January 2017 to January 2019. The fusion rates for MIDLIF were consistently lower than MID-TLIF at all post-operative time periods of follow-up, however, the differences between the two groups were not statistically significant. The 1-year fusion rates were 81.5% (MIDLIF) and 83.8% (MIS-TLIF) (P = 0.728), and the 2-year fusion rates were 87.7% (MIDLIF) and 91.2% (MIS-TLIF) (P = 0.513). The final follow-up fusion rates were 93.8% (MIDLIF) and 95.6% (MIS-TLIF) (P = 0.653). MIDLIF had several advantages over MIS-TLIF, including a shorter operative time (135.2 ± 15.70 vs. 160.1 ± 17.2 min, P < 0.001), decreased intraoperative blood loss (147.9 ± 36.4 vs. 169.5 ± 24.7 mL, P < 0.001), and a shorter length of hospital stay (10.8 ± 3.1 vs. 12.4 ± 4.1d; P = 0.014). No significant differences were seen between the groups in terms of the postoperative day of ambulation, Oswestry dysfunction index (ODI) scores, and visual analog scale (VAS) scores for leg and lower back pain (P > 0.05). Although not significant (P = 0.707), MIDLIF (13.8%) had fewer overall complications than MIS-TLIF (16.2%). Therefore, compared to MIS-TLIF, MIDLIF provides perioperative benefits while achieving the same outcomes as MIS-TLIF in terms of fusion rate, pain relief, functional improvement, and complication rate.

The Learning Curve and Clinical Outcomes With 250 Laser Ablations for Brain Tumors: A Pathway to Experience

BACKGROUND AND OBJECTIVES

Laser interstitial thermal therapy (LITT) has gained popularity as a minimally invasive technique for treating brain tumors. Despite its proven safety profile, LITT is not yet widely available, and there is a lack of data on the learning curve required to achieve proficiency. This study analyzes a 250-patient cohort of laser-ablated tumors to describe changes in patient selection and clinical outcomes over time and experience, with the aim of providing insight into the learning curve for incorporating LITT into a neuro-oncology program and identifying a cutoff point that distinguishes novice from expert performance.

METHODS

We retrospectively reviewed 250 patients with brain tumor who underwent LITT between 2013 and 2022. Demographic and clinical data were analyzed. Kaplan Meier curves were used for survival analysis. Operative time was evaluated using exponential curve-fit regression analysis to identify when consistent improvement began.

RESULTS

The patients were divided into quartiles (Q) based on their date of surgery. Mean tumor volume increased over time (Q1 = 5.7 and Q4 = 11.9 cm 3 , P = .004), and newly diagnosed lesions were more frequently ablated ( P = .0001). Mean operative time (Q1 v Q4 = 322.3 v 204.6 min, P < .0001) and neurosurgical readmission rate (Q1 v Q4 = 7.8% v 0%, P = .03) were reduced over time. The exponential curve-fit analysis showed a sustained decay in operative time after case #74. The extent of ablation ( P = .69), the recurrence ( P = .11), and the postoperative complication rate ( P = .78) did not vary over time.

CONCLUSION

After treating 74 patients, a downward trend in the operative time is observed. Patient selection is broadened as experience increases.

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 ?

The Surgical Learning Curve for Cervical Disk Replacement

STUDY DESIGN

Retrospective study.

OBJECTIVE

To characterize an experienced single surgeon learning curve for cervical disk replacement (CDR).

SUMMARY OF BACKGROUND DATA

A single surgeon learning curve has not been established for CDR.

METHODS

Patients undergoing CDR were included. The cumulative sum of operative time was utilized to separate cases into 3 phases: learning, practicing, and mastery. Demographics, perioperative characteristics, complications, patient-reported outcomes (PROs), and radiographic outcomes were collected preoperatively and up to 1 year postoperatively. PROs included Patient-reported Outcomes Measurement Information System Physical Function, 12-item Short Form-12 Physical Component Score, 12-item Short Form-12 Mental Component Score, visual analog scale (VAS) arm, VAS neck, Neck Disability Index. Radiographic outcomes included segmental angle/segmental range of motion/C2-C7 range of motion. Minimum clinically important difference achievement was determined through a comparison of previously established values.

RESULTS

A total of 173 patients were identified, with 14 patients in the learning phase, 42 patients in the practicing phase, and 117 patients in the mastery phase. Mean operative time and mean postoperative day 0 narcotic consumption were significantly higher in the learning phase. The preoperative segmental angle was significantly lower for the learning phase, though these differences were eliminated at the final postoperative time point. Patients in the learning phase reported worse improvement to 6-week postoperative, final postoperative, and worse overall final postoperative VAS Arm scores compared with practicing and mastery phases.

CONCLUSIONS

For an experienced spine surgeon, the learning phase for CDR was estimated to span 14 patients. During this phase, patients demonstrated longer operative times, higher postoperative narcotic consumption, and worse postoperative VAS Arm scores. Radiographically, no postoperative differences were noted between different phases of mastery. This single surgeon learning curve demonstrates that CDR may be performed safely and with comparable outcomes by experienced spine surgeons despite decreased operative efficiency in the learning phase.

Comparison of minimally invasive transforaminal lumbar interbody fusion (Mis-TLIF) with bilateral decompression via unilateral approach and open-TLIF with bilateral decompression for degenerative lumbar diseases: a retrospective cohort study

OBJECTIVE

Presently, no study has compared the clinical outcomes of minimally invasive transforaminal lumbar interbody fusion (Mis-TLIF) with bilateral decompression via the unilateral approach (BDUA) and Open-TLIF with bilateral decompression for degenerative lumbar diseases (DLD). We aimed to compare the clinical outcomes of through Mis-TLIF combined with BDUA and Open-TLIF with bilateral decompression for the treatment of DLD, and reported the learning curve of the procedure of MIS-TLIF with BDUA.

METHODS

We retrospectively analyzed the prospectively collected data of consecutive DLD patients in the two groups from January 2016 to January 2020.

RESULTS

The operative time (OT) was significantly longer in the Mis-TLIF group (n = 113) than in the Open-TLIF group (n = 135). The postoperative drainage volume (PDV) and length of stay (LOS) were significantly higher in the Open-TLIF group than in the Mis-TLIF group. Additionally, the complication rate was significantly higher in the Open-TLIF group than in the Mis-TLIF group (14.8% vs. 6.2%, P = 0.030), while there was no significant difference in the reoperation and adjacent segment disease rates between the two groups. There were no significant differences in back pain and leg pain Numerical Rating Scale (NRS) scores and Oswestry Disability Index (ODI) between the two groups preoperatively, at discharge, and 2 years postoperatively. Patients in both groups showed significant improvements in NRS scores and ODI scores after surgery. OT was negatively correlated with the number of surgeries performed (P < 0.001, r =  -0.43). The learning curve of Mis-TLIF with BDUA was steep, with OT tapered to steady state in 43 cases.

CONCLUSION

Compared with Open-TLIF with bilateral decompression, Mis-TLIF with BDUA can achieve equivalent clinical outcomes, lower PDV and LOS, and lower complication rates. Although this procedure took longer, it could be a viable alternative for the treatment of DLD after a steep learning curve.

Learning Curve for Endoscopic Transsphenoidal Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Endoscopic transsphenoidal surgery (ETSS) is emerging as an effective, minimally invasive surgery technique for brain tumors of the pituitary fossa. Using a surgical endoscope, surgeons can obtain a broader, nearer, and more apparent visual field with minimal keyhole entrance. However, ETSS may require a steep learning curve to achieve technical competence and relevant outcomes. Moreover, there is no consensus on the learning process of ETSS. We aimed to review and determine the technical proficiency points of ETSS and discuss how to accelerate the learning curve.

METHODS

Core databases, including PubMed, Embase, and the Cochrane Library, were systematically searched for learning curve studies that demonstrated the clinical outcomes and learning status of ETSS for pituitary adenomas using numerical data. Quality assessments of the included articles were performed using the Newcastle-Ottawa scale. The cutoff points were evaluated based on various outcome measures.

RESULTS

Eleven full-text articles, representing 2780 cases, were selected from 317 screened studies. The outcome measures were operative time, tumor removal, endocrinological results, visual field, and surgical complications. The plateaus or cutoff points in the learning curve varied with a mean of 103 ± 139.43 (range, 9-500) cases.

CONCLUSIONS

ETSS is an efficient and minimally invasive alternative surgical option for pituitary tumors. Plateau points may differ according to outcome measures, patient selection, training status, and surgical conditions. Therefore, great care should be taken when interpreting the learning curve. A systematic training program is essential to improve the learning process of endoscopic neurosurgical procedures.

Minimally invasive fusion surgery for patients with degenerative spondylolisthesis and severe lumbar spinal stenosis: a comparative study between MIDLIF and TLIF

PURPOSE

This study aims to compare midline lumbar interbody fusion (MIDLIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for treatment of patients with severe stenosis and lumbar degenerative spondylolisthesis (DS), focusing on dural tears rates, other complications, clinical and radiological outcomes.

METHODS

This cohort study included patients with severe lumbar spinal stenosis (Shizas C or D) and lumbar DS who underwent MIDLIF or MIS-TLIF. Propensity score matching was done and the groups were compared regarding surgery time, length of stay, perioperative complications, clinical results and radiological outcomes, at 1 year of follow-up.

RESULTS

The study included initially 80 patients, and 72 patients after matching, 36 in each group. Six patients had dural tears, four in the MIDLIF group and two in the MIS-TLIF group (p = 0.67). General complication rates and reoperations were not significantly different between the groups. Good or excellent clinical was achieved in 75% of the MIDLIF patients and 72% of the MIS-TLIF patients (p = 0.91). Radiological parameters showed small but statistically significant (p < 0.01) improvements after surgery, particularly in segmental lordosis and lumbar lordosis (2.0° and 1.7°), while pelvic tilt and global tilt decreased (1.6° and 2.6°). These findings were similar for both groups.

CONCLUSION

Our study confirms that MIDLIF is a safe and reliable minimally invasive alternative for lumbar interbody fusion in DS, even in patients with severe stenosis and previous spine surgery. It seems to offer similar results to MIS-TLIF regarding clinical results, radiological outcomes and complications.