The learning curve associated with thoracoscopic spinal instrumentation

Preoperative Radiographic Predictors of Subsequent Fusion After Lumbar Decompression Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The purpose of this study is to determine which demographic, surgical, and radiographic preoperative characteristics are most associated with the need for subsequent fusion after decompression lumbar spinal surgery.

SUMMARY OF BACKGROUND DATA

There is a relatively high rate of the need for repeat decompression or fusion after an index decompression procedure for degenerative spine disease. Nevertheless, there is a dearth of literature identifying risk factors for lumbar fusion following decompression surgery.

METHODS

Patients 18 years or older receiving a primary lumbar decompression surgery within the levels of L3-S1 between 2011 and 2020 were identified. All patients had preoperative radiographs and 2 years of follow-up data. Chart review was performed for surgical characteristics and demographics. The sagittal parameters included lumbar lordosis (LL), segmental lordosis (SL), anterior disk height (aDH), posterior disk height (pDH), sacral slope (SS), and pelvic tilt (PT). Pelvic incidence (PI=PT+SS) and pelvic incidence minus lumbar lordosis (PI-LL) were calculated. In addition, the Roussouly classification was determined for each patient. Bivariant and multivariant analyses were performed.

RESULTS

Of the 363 patients identified in this study, 96 patients had a fusion after their index decompression surgery. Multivariable analysis identified involvement of L4-L5 level in the decompression [odds ratio (OR)=1.83 (1.09-3.14), P =0.026], increased L5-S1 segmental lordosis [OR=1.08 (1.03-1.13), P =0.001], decreased SS [OR=0.96 (0.93-0.99), P =0.023], and decreased endplate obliquity [OR=0.88 (0.77-0.99), P =0.040] as significant independent predictors of fusion after decompression surgery.

CONCLUSIONS

This is one of the first studies to assess preoperative sagittal parameters in conjunction with demographic variables to determine predictors of the need for fusion after index decompression. We demonstrated that decompression at L4-L5, greater L5-S1 segmental lordosis, decreased sacral slope, and decreased endplate obliquity were associated with higher rates of fusion after decompression surgery.

Challenges in Contemporary Spine Surgery: A Comprehensive Review of Surgical, Technological, and Patient-Specific Issues

Spine surgery has significantly progressed due to innovations in surgical techniques, technology, and a deeper understanding of spinal pathology. However, numerous challenges persist, complicating successful outcomes. Anatomical intricacies at transitional junctions demand precise surgical expertise to avoid complications. Technical challenges, such as underestimation of the density of fixed vertebrae, individual vertebral characteristics, and the angle of pedicle inclination, pose additional risks during surgery. Patient anatomical variability and prior surgeries add layers of difficulty, often necessitating thorough pre- and intraoperative planning. Technological challenges involve the integration of artificial intelligence (AI) and advanced visualization systems. AI offers predictive capabilities but is limited by the need for large, high-quality datasets and the "black box" nature of machine learning models, which complicates clinical decision making. Visualization technologies like augmented reality and robotic surgery enhance precision but come with operational and cost-related hurdles. Patient-specific challenges include managing postoperative complications such as adjacent segment disease, hardware failure, and neurological deficits. Effective patient outcome measurement is critical, yet existing metrics often fail to capture the full scope of patient experiences. Proper patient selection for procedures is essential to minimize risks and improve outcomes, but criteria can be inconsistent and complex. There is the need for continued technological innovation, improved patient-specific outcome measures, and enhanced surgical education through simulation-based training. Integrating AI in preoperative planning and developing comprehensive databases for spinal pathologies can aid in creating more accurate, generalizable models. A holistic approach that combines technological advancements with personalized patient care and ongoing education is essential for addressing these challenges and improving spine surgery outcomes.

Comparison Between Resident and Attending Surgeons as Assistants on Adolescent Idiopathic Scoliosis Surgery: No Differences in Outcomes, Complications Rate, or Pedicle Screw Placement Accuracy

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of the present study was to determine if the level of training of the first assistant (resident or attending surgeon) has an influence on the radiographic outcome of AIS surgery and on the accuracy rate of the pedicle screws placement.

SUMMARY OF BACKGROUND DATA

Adolescent idiopathic scoliosis (AIS) surgery is a challenging procedure that requires a dedicated team of skilled professionals. Therefore, understanding the learning curve is of outstanding importance to guarantee the best outcomes and the highest safety to the patients.

METHODS

A retrospective analysis of patients who underwent surgery for AIS with a minimum follow-up of 2 years was conducted. All patients were operated by an experienced spine surgeon, assisted by and attending surgeon (group A) or a senior resident (group B). Radiographic outcomes were assessed. Through postoperative CT scan, accuracy of pedicle screw placement was measured (using Gertzbein-Robbins classification). Groups were then statistically compared.

RESULTS

A total of 120 patients were included (mean age 15.3±3.39 y, major curve Cobb 60.7±11.9 degrees). No difference was found between groups in terms of preoperative characteristics and postoperative radiographic (correction rate, thoracic kyphosis, screw density) outcomes or complications. Operative time and estimated blood loss were significantly higher in Group B (P=0.045 and P=0.024, respectively). Of the 2746 pedicle screws inserted (1319 group A and 1427 group B), 2452 had a perfect intrapedicular trajectory (absolute accuracy of 89.29%) and 2697 had a breach <2 mm (relative accuracy of 97.56%). No difference was found among groups in terms of absolute or relative accuracy (P=0.06 and P=0.23, respectively).

CONCLUSIONS

AIS cases assisted by senior residents have longer operative time and higher blood loss, but this does not negatively affect the overall radiographic outcome and does not place the patient at increased risk of complications.

LEVEL OF EVIDENCE

III.

Minimally Invasive Surgery for Adolescent Idiopathic Scoliosis: A Systematic Review

Background: Minimally invasive surgical (MIS) techniques have gained popularity as a safe and effective alternative to open surgery for degenerative, traumatic, and metastatic spinal pathologies. In adolescent idiopathic scoliosis, MIS techniques comprise anterior thoracoscopic surgery (ATS), posterior minimally invasive surgery (PMIS), and vertebral body tethering (VBT). In the current systematic review, the authors collected and analyzed data from the available literature on MIS techniques in AIS. Methods: The articles were shortlisted after a thorough electronic and manual database search through PubMed, EMBASE, and Google Scholar. Results: The authors included 43 studies for the review; 14 described the outcomes with ATS, 13 with PMIS, and 16 with VBT. Conclusions: While the efficacy of the ATS approach is well-established in terms of comparable coronal and sagittal correction to posterior spinal fusion, the current use of ATS for instrumented fusion has become less popular due to a steep learning curve, high pulmonary and vascular complication rates, implant failures, and increased non-union rates. PMIS is an effective alternative to the standard open posterior spinal fusion, with a steep learning curve and longer surgical time being potential disadvantages. The current evidence, albeit limited, suggests that VBT is an attractive procedure that merits consideration in terms of radiological correction and clinical outcomes, but it has a high complication and re-operation rate, while the most appropriate indications and long-term outcomes of this technique remain unclear.

A thoracoscopic anterior approach to the spine for adolescent idiopathic scoliosis does not have a detrimental effect on pulmonary function at 2 years compared to posterior-only surgery

PURPOSE

This study aims to examine pulmonary function outcomes in patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal fusion (PSF) with an anterior thoracoscopic release compared to those undergoing PSF alone.

METHODS

A retrospective review of patients with AIS over a 9-year period at a single institution compared 2 groups: PSF with video-assisted thoracoscopic surgery (PSF/VATS) and patients undergoing a posterior spinal fusion (PSF) alone. Standard radiographs and Forced Expiratory Volume (FEV1) and Forced Vital Capacity (FVC) were obtained preoperatively and at regular follow up periods up to 2-year post-operatively. Within group and between-group comparisons were performed.

RESULTS

There were 110 patients in the study: 12 in the PSF/VATS cohort and 98 in the PSF only cohort. The PSF/VATS group were younger (12.6 vs. 14.6, p = 0.003) and had larger coronal curves (80.8° vs. 60.7°, p = 0.001), and worse preoperative FVC (64.7% vs. 79.6%, p = 0.018) and FEV1 (62.3% vs. 77.6%, p = 0.003). At 2 years, the percent coronal Cobb correction was greater in the PSF/VATS group (67.9% vs. 48.4%, p < 0.001) with greater improvement in thoracic height (32.8 mm vs. 20.7 mm, p = 0.028). While the 2-year PFTs were the same for FEV1% (75.8% vs. 81.8%, p = 0.368) and FVC% (77.3% vs. 83.7%, p = 0.562), there was greater percent improvement over the 2 years in the PSF/VATS cohort: FEV1% (13.5% vs. 4.2%, p = 0.082) and FVC% (12.7% vs. 4.1%, p = 0.112).

CONCLUSION

AIS patients who have a VATS approach in addition to PSF have greater coronal plane correction and improved pulmonary function compared to PSF alone despite more severe spinal deformity and worse baseline pulmonary function.

Benefits of Best Practice Guidelines in Spine Fusion: Comparable Correction in AIS with Higher Density and Fewer Complications

BACKGROUND

There is significant variability in surgeons' instrumentation patterns for adolescent idiopathic scoliosis surgery. Implant density and costs are difficult to correlate with deformity correction, safety, and quality of life measures.

MATERIALS AND METHODS

Two groups of postoperative adolescents were compared based on exposure to a best practice guidelines program (BPGP) introduced to decrease complications. Hybrid and stainless steel constructs were dropped, and posterior-based osteotomies, screws, and implant density were increased to 66.8 ± 12.03 vs. 57.5 ± 16.7% (p < 0.001). The evaluated outcomes were: initial and final correction, rate of correction loss, complications, OR returns, and SRS-22 scores (minimum two-year follow-up).

RESULTS

34 patients were operated on before BPGP and 48 after. The samples were comparable, with the exceptions of a higher density and longer operative times after BPGP. Initial and final corrections before BPGP were 67.9° ± 22.9 and 64.6° ± 23.7; after BPGP, the corrections were 70.6° ± 17.4 and 66.5° ± 14.9 (sd). A regression analysis did not show a relation between the number of implants and postoperative correction (beta = -0.116, p = 0.307), final correction (beta = -0.065, p = 0.578), or loss of correction (beta= -0.137, p = 0.246). Considering screw constructs only (n = 63), a regression model controlled for flexibility continued to show a slight negative effect of density on initial correction (b = -0.274; p = 0.019). Only with major curve concavity was density relevant in initial correction (b = 0.293; p = 0.038), with significance at 95% not being achieved for final correction despite a similar beta (b = 0.263; p = 0.069). Complications and OR returns dropped from 25.6% to 4.2%. Despite this, no difference was found in SRS-22 (4.30 ± 0.432 vs. 4.42 ± 0.39; sd) or subdomain scores pre- and post-program.

FINDINGS

Although it appears counterintuitive that higher density, osteotomies, and operative time may lead to fewer complications, the study shows the value of best practice guidelines in spinal fusions. It also shows that a 66% implant density leads to better safety and efficacy, avoiding higher costs.

Effect of Fellow Involvement and Experience on Patient Outcomes in Spine Surgery

INTRODUCTION

Investigations in spine surgery have demonstrated that trainee involvement correlates with increased surgical time, readmissions, and revision surgeries; however, the specific effects of spine fellow involvement remain unelucidated. This study aims to investigate the isolated effect of fellow involvement on surgical timing and patient-reported outcomes measures (PROMs) after spine surgery and evaluate how surgical outcomes differ by fellow experience.

METHODS

All patients aged 18 years or older who underwent primary or revision decompression or fusion for degenerative diseases and/or spinal deformity between 2017 and 2019 at a single academic institution were retrospectively identified. Patient demographics, surgical factors, intraoperative timing, transfusion status, length of stay (LOS), readmissions, revision rate, and preoperative and postoperative PROMs were recorded. Surgeries were divided based on spine fellow participation status and occurrence in the start or end of fellowship training. Univariate and multivariate analyses compared outcomes across fellow involvement and fellow experience groups.

RESULTS

A total of 1,108 patients were included. Age, preoperative diagnoses, number of fusion levels, and surgical approach differed markedly by fellow involvement. Fellow training experience groups differed by patient smoking status, preoperative diagnosis, and surgical approach. On univariate analysis, spine fellow involvement was associated with extended total theater time, induction start to cut time, cut to close time, and LOS. Increased spine fellow training was associated with reduced cut to close time and LOS. On regression, fellow involvement predicted cut to close extension while increased fellow training experience predicted reduction in cut to close time, both independent of surgical factors and assisting residents or physician assistants. Transfusions, readmissions, revision rate, and PROMs did not differ markedly by fellow involvement or experience.

CONCLUSION

Spine fellow participation predicted extended procedural duration. However, the presence of a spine fellow did not affect long-term postoperative outcomes. Furthermore, increased fellow training experience predicted decreased procedural time, underscoring a learning effect.

AVAILABILITY OF DATA AND MATERIAL

The data sets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

LEVEL OF EVIDENCE

Level 3.

Selective Thoracic Fusion for Idiopathic Scoliosis: A Comparison of Three Surgical Techniques with Minimum 5-year Follow-up

STUDY DESIGN

Single-center retrospective review of outcomes among three surgical techniques in the treatment of thoracic idiopathic scoliosis (T-AIS) with a follow-up of at least 5 years.

OBJECTIVE

To investigate how outcomes compare in video-assisted anterior thoracic instrumentation (VATS), all hooks/hook-pedicle screw hybrid instrumentation (HHF), and all pedicle screw instrumentation (PSF) techniques for T-AIS.

SUMMARY OF BACKGROUND DATA

Studies comparing outcomes for anterior versus posterior fusion for T-AIS are few and with short follow-up.

METHODS

Three groups of patients with T-AIS who underwent thoracic fusion were included in this study: 98 patients with mean curve of 49.0° ± 9.5° underwent VATS (Group 1); 44 patients with mean curve of 51.1° ± 7.4° underwent HHF (Group 2); and 47 patients with mean curve of 47.6° ± 9.9° underwent PSF (Group 3). Radiological outcomes were compared at preoperative, and up to 5 years. Surgical outcomes were noted until latest follow-up.

RESULTS

Group 1 had less blood loss, less fusion levels, longer surgical time, and longer hospital stay compared with the other groups (P < 0.01). Groups 1 and 3 were comparable in all time periods with 78.8% and 78.2% immediate curve correction, and 72.9% and 72.1% at 5 years, respectively. Group 2 had lower correction in all time periods (P < 0.0001). Thoracic kyphosis and lumbar lordosis decreased in Group 3, but improved in both Groups 1 and 2 (P < 0.0001). Group 1 had more respiratory complications. The posterior groups had more deep wound infections. Two patients in Group 1 and one patient in Group 2 required revision surgery for implant-related complications. Reoperations for deep wound infections were noted only in the posterior groups.

CONCLUSION

This is the first report comparing 5 year outcomes between anterior and posterior surgery for T-AIS. All three surgical methods resulted in significant and durable scoliosis correction; however, curve correction using HHF was inferior to both VATS and PSF with the latter two groups achieving similar coronal correction. However, VATS involved fewer segments, kyphosis improvement, and no deep wound infection, whereas PSF has less surgical time, shorter hospital stays, and no revision surgery from implant-related complications.Level of Evidence: 3.

Defining the learning curve in CT-guided navigated thoracoscopic vertebral body tethering

Estimated blood loss (EBL), anesthesia time, operative time, and length of stay decreased over 67 navigated vertebral body tethering (VBT) surgeries performed in a 5-year period, indicating a steep learning curve.

DESIGN

Retrospective review of prospectively collected data.

HYPOTHESIS

There would be a significant improvement in the performance of VBT procedures over time at a single tertiary center in terms of perioperative and postoperative outcomes.

PURPOSE

Learning a new procedure for surgeons takes time, and previous studies have described improved efficiency as experience grows. VBT procedures are increasingly being performed in the US, but there is limited data regarding the learning curve specifically regarding the use of CT-guided navigation. We sought to assess the learning curve of VBT with respect to estimated blood loss, anesthesia time, operative time, length of stay, percent correction of the major curve at first follow-up. We further sought to characterize change in rates of 90-day complications.

METHODS

Pediatric scoliosis patients who underwent thoracic or lumbar CT-guided navigated VBT with a consistent surgical team at a single tertiary referral center between 2015 and 2020 were included. Student t-test was used to assess change in perioperative parameters over time, and also results between first and latest group of 20 patients were compared.

RESULTS

67 patients met inclusion criteria. Estimated blood loss (EBL), operative time, anesthesia time and length of stay significantly decreased over the 5-year study period. Specifically, on comparison of our first 20 patients with our last 20, the former had greater EBL (282 vs 116 ml, p = 0.0005; 8.5% vs 3.6%, p = 0.0024), operative time (4.8 h vs. 3.3 h, p < 0.001), anesthesia time (7.4 h vs. 5.7 h, p = 0.0001), and length of stay (3.7 days vs. 3.2 days, p = 0.019). We also found significant reduction in EBL, operative time, anesthesia time and LOS in patients who underwent VBT surgery after 2019. There was no significant change in the percent correction of the major Cobb angle at first erect imaging or 90-day complications over the 5-year study period or between the various cohorts.

CONCLUSION

This series has demonstrated improvements in surgical efficiency for VBT including reduced EBL, operative time, anesthesia time and hospital stay over a 5-year period. This indicates improved surgical technique and outlines the significant learning curve for surgeons who wish to perform this procedure. Improved surgeon training programs and newer instrumentation may reduce this learning curve.

TAKE HOME POINT

67 cases in a 5-year period, VBT procedures performed at a single center had significantly decreased EBL, anesthesia time, operative time, and length of stay, indicating a steep learning curve.

A Two-Surgeon Approach Improves Performance for Young Surgeons in Adolescent Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) is a complex 3-dimensional deformity. Previous studies have suggested a learning curve in the successful execution of this technically demanding procedure. A 2-surgeon model may be helpful for less experienced surgeons by facilitating greater consistency in surgical metrics. The objective of this study was to show no significant difference in the parameters examined for surgeries done by inexperienced primary surgeons with a 2-surgeon model compared with those done by their more experienced cohorts. All surgeries with a primary diagnosis of AIS that were performed from January 2012 to December 2015 and had a minimum of 2-year follow-up were included for analysis. Three groups were created based on surgeon experience: inexperienced surgeons (IS) group, experienced surgeons (ES) group, and a third group where the primary surgeon was in the experienced group and the assistant surgeon was in the inexperienced group (EIS). Variables included for analysis were age, Lenke classification, number of levels fused, length of surgery, length of stay, percent curve correction, ratio of estimated blood loss to levels fused, surgical blood loss, and complications. There were no significant differences between the groups in terms of operative time, blood loss, number of levels fused, lower estimated blood loss ratio to the number of levels fused, or percent curve correction (P>.05). The IS group was found to have a significant shorter length of stay (P=.004). The 2-surgeon model is an effective tool for inexperienced surgeons to achieve consistent and reproducible operative performance that is comparable with their more experienced peers. [Orthopedics. 2021;44(3):e347-e352.].

Warm Weather and Surgical Site Infections: A Meta-analysis

Seasonal variability, in terms of warm weather, has been demonstrated to be a significant risk factor for surgical site infections (SSIs). However, this remains an underexposed risk factor for SSIs, and many clinicians are not aware of this. Therefore, a systematic review and meta-analysis has been conducted to investigate and quantify this matter.

METHODS

Articles were searched in Embase, Medline Ovid, Web of Science, Cochrane Central, and Google Scholar, and data were extracted from relevant studies. Meta-analysis used random effects models to estimate and compare the pooled odds ratios (OR) and corresponding confidence intervals (CIs) of surgery performed during the warmest period of the year and the colder period of the year.

RESULTS

The systematic review included 20 studies (58,599,475 patients), of which 14 studies (58,441,420 patients) were included for meta-analysis. Various types of surgical procedures across different geographic regions were included. The warmest period of the year was associated with a statistically significant increase in the risk of SSIs (OR 1.39, 95%CI: [1.34-1.45], P < 0.0001). Selection of specific types of surgical procedures (eg, orthopedic or spinal surgery) significantly altered this increased risk.

CONCLUSIONS

The current meta-analysis showed that warm weather seasons are associated with a statistically significant risk increasement of 39% in developing SSIs. This significant risk factor might aid clinicians in preoperative patient information, possible surgical planning adjustment for high risk patients, and potentially specific antibiotic treatments during the warmer weather seasons that could result in decrease of SSIs.

The Transverse Process Trajectory Technique: An Alternative for Thoracic Pedicle Screw Implantation-Radiographic and Biomechanical Analysis

BACKGROUND

This study evaluates the accuracy, biomechanical profile, and learning curve of the transverse process trajectory technique (TPT) compared to the straightforward (SF) and in-out-in (IOI) techniques. SF and IOI have been used for fixation in the thoracic spine. Although widely used, there are associated learning curves and symptomatic pedicular breaches. We have found the transverse process to be a reproducible pathway into the pedicle.

METHODS

Three surgeons with varying experience (experienced [E] with 20 years in practice, surgeon [S] with less than 10 years in practice, and senior resident trainee [T] with no experience with TPT) operated on 8 cadavers. In phase 1, each surgeon instrumented 2 cadavers, alternating between TPT and SF from T1 to T12 (n = 48 total levels). In phase 2, the E and T surgeons instrumented 1 cadaver each, alternating between TPT and IOI. Computed tomography scans were analyzed for accuracy of screw placement, defined as the percentage of placements without critical breaches. Axial pullout and derotational force testing were performed. Statistical analyses include paired t test and analysis of variance with Tukey correction.

RESULTS

Overall accuracy of screw placement was comparable between techniques (TPT: 92.7%; SF: 97.2%; IOI: 95.8%; P = .4151). Accuracy by technique did not differ for each individual surgeon (E: P = .7733; S: P = .3475; T: P = .4191) or by experience level by technique (TPT: P = .1127; FH: P = .5979; IOI: P = .5935). Pullout strength was comparable between TPT and SF (571 vs 442 N, P = .3164) but was greater for TPT versus IOI (454 vs 215 N, P = .0156). There was a trend toward improved derotational force for TPT versus SF (1.06 vs 0.93 Nm/degrees, P = .0728) but not for TPT versus IOI (1.36 vs 1.16 Nm/degrees, P = .74). Screw placement time was shortest for E and longest for T for TPT and SF and not different for IOI (TPT: P = .0349; SF: P < .0001; IOI: P = .1787) but did not vary by technique.

CONCLUSIONS

We describe the TPT, which uses the transverse process as a corridor through the pedicle. TPT is an accurate method of thoracic pedicle screw placement with potential biomechanical advantages and with acceptable learning curve characteristics.

CLINICAL RELEVANCE

This study provides the surgeon with a new trajectory for pedicle screw placement that can be used in clinical practice.

Outcome and negative events in thoracic disc herniation surgery: a Danish registry study

BACKGROUND

Thoracic disc herniation (TDH) is a surgically demanding entity. Various surgical approaches have been developed and advanced in an attempt to achieve sufficient outcomes and reduce consecutive complication rates. Still, controversy exists regarding selecting the best surgical approach. This retrospective study aims to support decision-making regarding surgical approach.

METHODS

We performed a retrospective analysis of 71 patients who underwent thoracic discectomy at Aarhus University Hospital, Denmark, between 1996 and 2015. Patients were divided into two groups depending on whether a lateral approach or a posterior approach was used. Data on demographics, symptomatology, peri- and post-operative events, length of hospitalization and discharge disposition were assembled from medical records.

RESULTS

Lateral and posterior approach had an approximately equal peri-operative event rate (39% versus 36%), whereas the lateral approach was associated with a higher post-operative event rate in-hospital and post-discharge than the posterior approach (50% versus 18%; 45% versus 40%). The overall probability of improvement in clinical outcome regardless approach at follow-up was 77% in the short-term and 80% in the long-term. Odds of clinical improvement at any time point was 29% higher with the lateral approach than with the posterior approach (OR = 1.29, 95% CI: 0.52-3.21, p = .76). Adjusting for time, the odds of clinical improvement at short-term follow-up was twice as high for the lateral than for the posterior approach (OR = 2.16, 95% CI: 0.16-30.11); however, the trend seems to fade away over time (OR = 1.10, 95% CI: 0.07-17.55).

CONCLUSIONS

The probability of improving after TDH surgery is good. However, a clear conclusion regarding the best surgical approach cannot be established; thus, surgeons should consider pros and cons of each approach when allocating a patient to surgery.

Analyzing the Correlation Between Surgeon Experience and Patient Length of Hospital Stay

Introduction  Many clinical, social, and even economic factors have been extensively analyzed in the literature and shown to influence the length of stay (LOS) after spinal procedures. However, surgeon's experience was mostly examined relative to a learning curve and not regarding the time in practice. The primary objective of this study was to determine the effect of one surgeon's experience on the LOS in patients undergoing one- to two-level transforaminal lumbar interbody fusions (TLIFs). Materials and Methods  The study design was a retrospective cohort study of hospital discharge data. The cohort was comprised of 240 consecutive patients who had undergone open one- or two-level elective TLIF procedures for lumbar degenerative disc disease. The primary predictor was the surgeon's experience based upon the years of practice. The primary outcome was LOS, which was controlled by the discharge criteria that remained consistent throughout the study. Results  Based on the Poisson regression model, it can be inferred that the LOS is not significantly associated with a surgeon's experience (Pr(>|t|) = 0.8985, CI: -0.5825 to 0.5114) while controlling for all other variables. Other independent factors did seem to significantly influence patients' LOS, including the admission type (Pr(>|t|) = 9.637^-08, CI: -0.8186 to -0.3786), the number of TLIF levels (Pr(>|t|) = 1.721^-06, CI: 0.0606 to 0.1446), the Clavien-Dindo ( Pr(>|t|) = 0, CI: 0.1489 to 0.1494), the American Society of Anesthesiologists (ASA) physical status classification scores (Pr(>|t|) = 4.878^-3, CI: 0.0336 to 0.1880), and being discharged to skilled nursing facility (Pr(>|t|) = 3.44^-2, CI: 0.0127 to 0.3339). Conclusions Based upon the years in practice, surgeon experience was not associated with length of hospitalization and estimated blood loss during surgery in patients undergoing one- and two-level TLIF surgeries. However, while controlling for all other variables, the surgeon's experience and surgical time had a highly significant correlation. The study results clearly demonstrated efficiency, but we did not identify a clear correlation between LOS and surgeon experience overtime suggesting that other factors are likely contributing to such outcome. The average LOS is a complex measure of healthcare resource use and hospital discharge policy or other variables are likely having more effect on LOS than individual surgeons' preferences.

Minimal invasive surgery techniques for patients with adolescent idiopathic and early onset scoliosis

OBJECTIVE

Provide an update on minimal invasive surgery (MIS) techniques for surgical management of pediatric spine.

METHODS

Minimal Invasive surgery for pediatric spine deformity has evolved significantly over the past decade. We include updated information about the surgical management of patients with adolescent idiopathic and Early Onset Scoliosis through MIS techniques. We take into consideration the implementation of this technique in Low-to-Middle Income Countries (LMICs).

RESULTS

Although MIS began as a technique in adult and degenerative spine, recent publications on MIS in pediatric spine cases report benefits of decreased blood loss and infection incidence, and cosmetic advantages from fewer incision numbers. Adoption of MIS techniques in pediatric spine can be facilitated with pre- and intraoperative use of pertinent medical systems.

CONCLUSION

With appropriate considerations and training, MIS is a safe procedure for pediatric spine correction surgery and can be applicable in LMICs.

The Adolescent Idiopathic Scoliosis International Disease Severity Study: Do Operative Curve Magnitude and Complications Vary by Country?

BACKGROUND

The prevalence of adolescent idiopathic scoliosis (AIS) in diverse regions of the world has been studied. Access to care varies widely, and differences in disease severity and operative treatment outcomes are not well understood. This study aimed to determine variation in disease presentation and operative complications for AIS patients from an international cohort.

METHODS

This is a retrospective study carried out at seven surgical centers in the United States (Manhattan and Miami), Ghana, Pakistan, Spain, Egypt, and China. A total of 541 consecutive patients with AIS were evaluated. Preoperative major curve magnitude, operative parameters, and complications were compared among sites using analysis of variance with post hoc tests and Pearson correlation coefficients. Univariate and multivariate forward stepwise binary logistic regressions determined the variables most predictive of complications.

RESULTS

Countries with lowest-access to care (Ghana, Egypt, and Pakistan) displayed larger curves, more levels fused, longer operative time (OT), and greater estimated blood loss (EBL) than the other countries (p ≤ .001). Increasing curve magnitude was correlated with greater levels fused, longer OT, and greater EBL in all groups (p = .01). In the univariate regression analysis, Cobb magnitude, levels fused, EBL, and OT were associated with complication occurrence. Only OT remained significantly associated with complication occurrence after adjusting for Cobb magnitude, levels fused, and site (odds ratio [OR] = 1.005, 95% confidence interval 1.001-1.007, p = .003). Complications were greatest in Pakistan and Ghana (21.7% and 13.5%, respectively) and lowest in Miami (6.5%).

CONCLUSIONS

Larger curve magnitudes in the least-access countries correlated with more levels fused, longer OT, and greater EBL, indicating that increased curve magnitude at surgery could explain the difference in operative morbidity between low- and high-access countries. With OT as the prevailing predictive factor of complications, we suggest that increased curve magnitude leads to longer OTs and more complications. A lack of access to orthopedic care may be the largest contributor to the postponement of treatment.

LEVEL OF EVIDENCE

Level II.

Early-term postoperative thoracic outcomes of videothoracoscopic vertebral body tethering surgery

Background

This study aims to discuss the early-term postoperative thoracic complications in videothoracoscopic anterior vertebral body tethering surgery.

Methods

The study included 56 patients (3 males, 53 females; mean age 12.6 years; range, 10 to 16 years) operated with a total of 65 videothoracoscopic anterior vertebral body tethering surgeries between April 2014 and November 2018. Surgical indications were adolescents with different growth potentials, who had thoracic, thoracolumbar or double curves less than 70°. Surgical details and postoperative thoracic complications were recorded.

Results

Forty-two patients were administered thoracic tether, whereas five and nine patients were administered thoracolumbar tether and both approaches concomitantly, respectively. Two patients developed ipsilateral total atelectasis, one patient contralateral lobar atelectasis, one patient chylothorax, one patient pleural effusion, and one patient pneumothorax after chest drain removal. Overall thoracic complication rate was 9.2% and 30-day readmission rate was 1.8%. All patients achieved their rehabilitation goals.

Conclusion

Videothoracoscopy-assisted anterior vertebral body tethering is a safe and efficient technique that yields low complication rates. Early postoperative functional results are promising with high patient satisfaction. Pre- and postoperative respiratory rehabilitation may decrease thoracic complication rates.

Mixed Reality-Based Preoperative Planning for Training of Percutaneous Transforaminal Endoscopic Discectomy: A Feasibility Study

OBJECTIVE

To explore the effect of preoperative planning using mixed reality (MR) on training of percutaneous transforaminal endoscopic discectomy (PTED).

METHODS

Before the training, we invited an experienced chief physician to plan the puncture path of PTED on the X-ray films of the lumbar spine model and the 3D Slicer platform, respectively, and used this as the standard to guide trainees. In the aggregate, 60 young residents were randomly divided into Group A (N = 30) and Group B (N = 30). Group A learned the 2-dimensional standard planning route, whereas Group B learned the standard route planning based on MR through the 3D Slicer platform. Then, trainees were asked to conduct PTED puncture on a lumbar spine model. Questionnaires were distributed to trainees before and after the training. During the training, puncture times, operating time (minutes), and fluoroscopy times were recorded.

RESULTS

After the training, it was obvious that more trainees showed their recognition of MR, believing that MR could help preoperative planning and training of PTED. Their high satisfaction with the training indicated the success of our training. Moreover, puncture times, operating time (minutes), and fluoroscopy times of Group B were significantly lower than those of Group A.

CONCLUSIONS

MR technology contributes to preoperative planning of PTED and is beneficial in the training of PTED. It significantly reduces puncture times and fluoroscopy times, providing a standardized method for the training of PTED.

The Effect of the Level of Training of the First Assistant on the Outcomes of Adolescent Idiopathic Scoliosis Surgery

BACKGROUND

At academic medical centers, residents and fellows play an integral role as surgical first assistants in spinal deformity surgery. However, limited data exist on whether the experience level of the surgical assistant affects outcomes.

METHODS

We conducted a multicenter, multisurgeon study comparing perioperative and postoperative outcomes after adolescent idiopathic scoliosis (AIS) surgery for the same 11 surgeons who performed cases that were assisted by residents compared with cases that were assisted by fellows. Blood loss, operative time, duration of hospitalization, complication rates, Scoliosis Research Society (SRS)-22 questionnaire scores, and radiographic outcomes were compared between the 2 groups.

RESULTS

We evaluated outcomes for 347 surgical procedures; 118 cases were assisted by residents and 229 were assisted by fellows. Preoperative radiographic and demographic parameters were not different between the groups. The resident group had significantly more estimated blood loss than the fellow group (939 compared with 762 mL, p = 0.02). Otherwise, the perioperative characteristics were similar between the groups, including the volume of the autologous blood recovery system product that was transfused, the operative time, and the occurrence of intraoperative neuromonitoring changes. Postoperatively, the percentage correction of the Cobb angle, the number of levels that had been fused, the number of days until the discharge criteria had been met, and the rate of major complications were similar between the groups. At the 2-year follow-up, the overall and subdomain SRS-22 questionnaire scores were not different between the groups, except that patients in the resident-assisted group had slightly worse pain scores than those in the fellow-assisted group (4.3 compared with 4.5, p = 0.01).

CONCLUSIONS

The first assistant's level of training did not affect clinical or radiographic outcomes following AIS surgery.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Surgeon Experience Does Not Change Rate of Perioperative Surgical Complication in Rib-Based Distraction Surgery for Early-Onset Scoliosis

OBJECTIVE

To report on the surgical learning curve in treating early-onset scoliosis with rib-based distraction.

SUMMARY OF BACKGROUND DATA

The idea of a surgical learning curve proposes improved outcomes with experience. Early-onset scoliosis (EOS) is a challenging condition to treat and complication rates are high.

METHODS

All patients from a single experienced spine surgeon's practice who had undergone placement of rib-based distraction constructs between 2002 and 2013 were identified. A retrospective chart review was performed to determine patient characteristics at implantation and follow-up surgeries and complications. The primary outcome was complication rate per surgical encounter. Experience was analyzed both by number of surgical procedures and year in study period.

RESULTS

The surgeon began using rib-based distraction in 2002, and between 2002 and 2013, a total of 101 patients underwent 1,009 implantation or expansion surgeries involving rib-based distraction at a median age of 6 years at implantation (10 months-9.4 years). The median preoperative Cobb angle was 67° (8°-125°; IQR: 57°-76°) and follow-up was a median of 4.4 years (IQR 3.7-5.6 years). Overall, 65.3% of patients experienced complications, including 40 Grade I, 20 Grade II, 126 Grade IIA, and 3 Grade III. Univariate analysis identified a trend toward cumulative number of surgeries relating to a decreased complication rate, with every 50 surgeries decreasing the complication rate by 3% (p = .071). However, multivariate analysis found cumulative number of surgeries and complication rate to not be significantly related (p = .12). Surgeon experience as measured by study time (as both a continuous and categorical predictor) did not achieve statistical significance in either the univariate or multivariate models.

CONCLUSION

This is the largest single-surgeon series of EOS patients treated with rib-based distraction. Surgeon experience defined either as number of procedures or years of experience within the study period did not impact the rate of complications.

Thoracoscopic Anterior Instrumentation and Fusion as a Treatment for Adolescent Idiopathic Scoliosis: A Systematic Review of the Literature

STUDY DESIGN

A systematic review and meta-analysis on thoracoscopic anterior instrumentation and fusion as a treatment for adolescent idiopathic scoliosis (AIS).

OBJECTIVE

The goal of this study is to determine the current status of thoracoscopic instrumentation and fusion as a treatment for AIS.

SUMMARY OF BACKGROUND DATA

Traditional surgical techniques for AIS have been open anterior thoracotomy with instrumentation and posterior spinal fusion and instrumentation. With the growing clinical interest in growth modulation surgeries, such as vertebral body tethering, there is a resurgence of interest in a thoracoscopic technique.

METHODS

The most commonly used medical databases (PubMed, Medline, EMBASE, CINAHL, and the Cochrane library) were searched up to November 2016 using the search terms VATS, thoracoscopic scoliosis, and thoracoscopic scoliosis instrumentation.

RESULTS

Thirteen studies met the strict inclusion criteria. Five hundred thirty patients were reported: 81.7% females, with the majority diagnosed as AIS. The mean operative time was 371.5 minutes, mean blood loss of 502.85 mL, and mean hospital stay of 5.9 days. Mean preoperative curve magnitude was 52.9°; postoperative curve magnitude was 17.9°, with a correction of 62.7%. Number of levels instrumented was 6.3, pulmonary function tests returned to preoperative values by 2 years postoperation, and the complication rate was 21.3%. Compared to thoracotomy, VATS had similar complication rates, blood loss, operation theater time, curve correction, and number of fused levels. Compared to posterior fusion, VATS has higher complication rates and operation theater time. Blood loss and percentage correction were similar. VATS had a smaller number of fused segments.

CONCLUSIONS

Advantages include less invasive, excellent curve correction, few levels fused, good satisfaction, and no long-term effect on pulmonary function. Drawbacks are increased operative time and incidence of pulmonary complications. With appropriate surgeon training and careful patient selection, this technique offers an acceptable alternative to the more traditional procedures.

LEVEL OF EVIDENCE

Level II.

Perioperative Safety: Keeping Our Children Safe in the Operating Room

The entire operating room team is responsible for the safety of children in the operating room. As a leader in the operating room, the surgeon is impactful in ensuring that all team members are committed to providing this safe environment. This is achieved by the use of perioperative huddles or briefings, the use of appropriate surgical checklists, operating room standardization, surgeons proficient in the care they provide, and team members that embrace Just Culture.

Isocentric Navigation for the Training of Percutaneous Endoscopic Transforaminal Discectomy: A Feasibility Study

Background

Percutaneous endoscopic transforaminal discectomy (PETD) is usually chosen for lumbar disc herniation due to its obvious advantages such as small incision and absence of nerve or muscular traction. However, learning PETD is a great challenge for inexperienced surgeons.

Objective

The study aimed to investigate whether isocentric navigation would be beneficial in PETD training.

Methods

A total of 117 inexperienced surgeons were trained with PETD at L2/3, L3/4, L4/5, and L5/S1 on the cadavers without (Group A n=58) or with (Group B n=59) isocentric navigation. Puncture times, fluoroscopy times, exposure time, and radiation dose were recorded and analyzed. Questionnaires were conducted before and after the training program.

Result

Isocentric navigation could improve young surgeons' satisfaction with the training program and decrease the puncture times, fluoroscopy times, exposure time, and radiation dose significantly (P<0.001).

Conclusion

Isocentric navigation contributes to the training of PETD and may improve its standardization, homogenization, and generalization.

Comparison of Complications and Surgical Outcomes of Adolescent Idiopathic Scoliosis Between Junior Attending Surgeons and Senior Attending Surgeons

BACKGROUND

To our knowledge, few studies have compared complications and surgical outcomes of adolescent idiopathic scoliosis (AIS) between junior attending surgeons and senior attending surgeons.

OBJECTIVES

To compare surgical strategies, complications, and outcomes of posterior corrective surgery for AIS between junior attending surgeons and senior attending surgeons.

METHODS

According to experience level of operation surgeons, the patients were assigned to 2 groups. Group A was the "junior surgeon" group. Group B was the "senior surgeon" group. The following parameters were compared between the 2 groups: age, sex, diagnosis, hospital of record, surgeon experience level, type of instrumentation, type of screws, estimated blood loss, duration of surgery, length of fusion, correction techniques, main curve correction, and thoracic kyphosis correction.

RESULTS

A total of 132 patients with AIS were included in group A, whereas 207 were in group B. The translational technique was used more often in group A (P < 0.05). whereas the derotation technique was used more often in group B (P < 0.05). Senior surgeons used more monoaxial screws than junior surgeons (P < 0.05). The junior group had significantly greater estimated blood loss than the senior group (P < 0.05). The senior group had significant better correction rates of severe main curve (>70°) and thoracic kyphosis than the junior group (P < 0.05).

CONCLUSIONS

Senior attending surgeons outperformed junior surgeons in blood loss control, thoracic kyphosis correction, and correction of severe curves.

Youth and Experience: The Effect of Surgeon Experience on Outcomes in Cerebral Palsy Scoliosis Surgery

BACKGROUND

Series on the learning curve in spinal deformity surgery have been published, but none has addressed neuromuscular spinal deformity, comprised of arguably the most complex cases. We present the first multi-center analysis of the impact of surgeon experience on neuromuscular spinal deformity surgery.

METHODS

A multi-center prospective study of spinal deformity surgery for cerebral palsy (CP) with at least 2 years of follow-up provided the dataset for assessment. Surgeons were categorized into one of two groups based on their self-reported first year of practice: an experienced surgeons (ES) group included those with at least 10 years of experience at the time of surgery and a young surgeons (YS) group included those with fewer than 10 years of experience at time of surgery. Groups were compared in multiple pre-operative, operative, and post-operative outcomes.

RESULTS

The YS group had 8 surgeons who performed 59 surgeries; the ES group had 13 surgeons who performed 103 cases, with one surgeon's cases distributed in both groups. The YS group had a greater proportion of patients with severe mental retardation (89.7% vs. 68.6%, p = .01). Duration of surgery was greater in the YS group (456 vs. 344 minutes, p < .001). The mean number of levels fused was greater in the ES group (15.9 vs. 15.6, p = .024), caused by increased variation in the upper level of fusion among the ES group. No significant differences were found between groups for estimated blood loss, length of hospitalization, or in percentage of Cobb correction. Years of experience of the operating surgeon was inversely correlated with duration of surgery (rho = -0.476, p < .001).

CONCLUSIONS

In performing scoliosis surgery on CP patients, surgeons with fewer than ten years of practice experience demonstrate significantly greater average operative time and decreased mean number of levels fused, yet produce similar clinical outcomes to more experienced surgeons.

LEVEL OF EVIDENCE

Level III, therapeutic.

Surgical and Radiographic Outcomes After Pedicle Subtraction Osteotomy According to Surgeon's Experience

STUDY DESIGN

Retrospective case series.

OBJECTIVE

The aim of this study was to evaluate and compare the surgical, radiographic, and clinical outcomes of pedicle subtraction osteotomy (PSO) according to surgeon's experience.

SUMMARY OF BACKGROUND DATA

Although PSO has been widely used to correct spinal deformities, it still remains technically demanding procedure with high complications.

METHODS

Comparative analysis of 40 consecutive patients treated with lumbar PSOs was performed. According to time period, the former and latter 20 patients were divided into group 1 and group 2, respectively. Patients' demographic data, operative, radiographic/clinical outcomes, and complications were compared between the groups.

RESULTS

Baseline characteristics and preoperative radiographic parameters were not different between the groups. Significant reductions of operative time (569.6 vs. 392.0 minutes, P = 0.000), surgical bleeding (1777.5 vs. 949.5 mL, P = 0.002), and transfused volume of red blood cell (1232.6 vs. 864.1 mL, P = 0.041) in group 2 were observed. Postoperative sagittal vertical axis was significantly different between the groups (40.1 and -3.6 mm, groups 1 and 2, respectively, P = 0.008), and the difference was sustained to the ultimate follow-up (59.4 vs. 13.2 mm, P = 0.003). There was a difference regarding the amount of curve correction by PSO, which was significantly greater in group 2 (25.7° vs. 35.8°, P = 0.023). Intraoperative complications (7 vs. 1, P = 0.019) were significantly lower in group 2. Total complications (20 vs. 10, P = 0.070), postoperative transient neurologic deficit (2 vs. 1), and revision surgery (4 vs. 3) were also lower in group 2, without statistical significance. The amount of the improvement of SRS-22 score was not different between the groups (P = 0.395).

CONCLUSION

PSO may be performed in patients with fixed sagittal imbalance with an acceptable rate of complications after about 20 cases. With acquisition of surgical experiences, surgeons could perform PSO more effectively and safely.

Development of Consensus-Based Best Practice Guidelines for Postoperative Care Following Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis

STUDY DESIGN

Delphi process with multiple iterative rounds using a nominal group technique.

OBJECTIVE

The aim of this study was to use expert opinion to achieve consensus on various aspects of postoperative care following posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Significant variability exists in postoperative care following PSF for AIS, despite a relatively healthy patient population and continuously improving operative techniques. Current practice appears based either on lesser quality studies or the perpetuation of long-standing protocols.

METHODS

An expert panel composed of 26 pediatric spine surgeons was selected. Using the Delphi process and iterative rounds using a nominal group technique, participants in this panel were presented with a detailed literature review and asked to voice opinion collectively during three rounds of voting (one electronic and two face-to-face). Agreement >80% was considered consensus. Interventions without consensus were discussed and revised, if feasible.

RESULTS

Consensus was reached to support 19 best practice guideline (BPG) measures for postoperative care addressing non-ICU admission, perioperative pain control, dietary management, physical therapy, postoperative radiographs, surgical bandage management, and indications for discharge.

CONCLUSION

We present a consensus-based BPG consisting of 19 recommendations for the postoperative management of patients following PSF for AIS. This can serve to reduce variability in practice in this area, help develop hospital specific protocols, and guide future research.

LEVEL OF EVIDENCE

5.

Invasiveness Reduction of Recent Total En Bloc Spondylectomy: Assessment of the Learning Curve

STUDY DESIGN

Case-control study.

PURPOSE

To evaluate the surgical magnitude and learning curve of "second-generation" total en bloc spondylectomy (TES).

OVERVIEW OF LITERATURE

In June 2010, we developed second-generation TES combined with tumor-induced cryoimmunology, which does not require autograft harvesting.

METHODS

TES was performed in 63 patients between June 2010 and September 2013. Three groups of patients were evaluated: 20 undergoing surgery in the first year of development of second-generation TES (group I), 20 in the second year (group II), and 23 in the third year (group III). Patient backgrounds showed no remarkable differences. Operating time, intraoperative blood loss, blood transfusion, and postoperative C-reactive protein and creatine phosphokinase were compared among the groups.

RESULTS

Mean±standard deviation operating time was 486±130 minutes in group I, 441±85 minutes in group II, and 396±75 minutes in group III. The time was significantly shorter in group III than in group I (p<0.05). Intraoperative blood loss was 901±646 mL in group I, 433±177 mL in group II, and 411±167 mL in group III. Blood loss was significantly lower in groups II and III than in group I (p<0.01). Transfusion was not required in 20 of 23 patients in group III, and mean C-reactive protein levels on postoperative day 3 were significantly lower in this group than in group I (6.12 mg/L vs. 10.07 mg/L; p<0.05). Postoperative creatine phosphokinase levels did not differ among the groups.

CONCLUSIONS

TES is associated with a significant learning curve. Thus, second-generation TES can no longer be considered highly invasive.

Quantitative analysis of a spinal surgeon’s learning curve for scoliosis surgery

Aims

The aim of this study was a quantitative analysis of a surgeon’s learning curve for scoliosis surgery and the relationship between the surgeon’s experience and post-operative outcomes, which has not been previously well described.

Patients and Methods

We have investigated the operating time as a function of the number of patients to determine a specific pattern; we analysed factors affecting the operating time and compared intra- and post-operative outcomes. We analysed 47 consecutive patients undergoing scoliosis surgery performed by a single, non-trained scoliosis surgeon. Operating time was recorded for each of the four parts of the procedures: dissection, placement of pedicle screws, reduction of the deformity and wound closure.

Results

The median operating time was 310 minutes (interquartile range 277.5 to 432.5). The pattern showed a continuous decreasing trend in operating time until the patient number reached 23 to 25, after which it stabilised with fewer patient-dependent changes. The operating time was more affected by the patient number (r =- 0.75) than the number of levels fused (r = 0.59). Blood loss (p = 0.016) and length of stay in hospital (p = 0.012) were significantly less after the operating time stabilised. Post-operative functional outcome scores and the rate of complications showed no significant differences. Take home message: We describe a detailed learning curve for scoliosis surgery based on a single surgeon’s practise, providing useful information for novice scoliosis surgeons and for those responsible for training in spinal surgery. Cite this article: Bone Joint J 2016;98-B:679–85.

Partial Intervertebral Fusion Secures Successful Outcomes After Thoracoscopic Anterior Scoliosis Correction: A Low-Dose Computed Tomography Study

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVES

To analyze intervertebral (IV) fusion after thoracoscopic anterior spinal fusion (TASF) and explore the relationship between fusion scores and key clinical variables.

SUMMARY OF BACKGROUND INFORMATION

TASF provides comparable correction with some advantages over posterior approaches but reported mechanical complications, and their relationship to non-union and graft material is unclear. Similarly, the optimal combination of graft type and implant stiffness for effecting successful radiologic union remains undetermined.

METHODS

A subset of patients from a large single-center series who had TASF for progressive scoliosis underwent low-dose computed tomographic scans 2 years after surgery. The IV fusion mass in the disc space was assessed using the 4-point Sucato scale, where 1 indicates <50% and 4 indicates 100% bony fusion of the disc space. The effects of rod diameter, rod material, graft type, fusion level, and mechanical complications on fusion scores were assessed.

RESULTS

Forty-three patients with right thoracic major curves (mean age 14.9 years) participated in the study. Mean fusion scores for patient subgroups ranged from 1.0 (IV levels with rod fractures) to 2.2 (4.5-mm rod with allograft), with scores tending to decrease with increasing rod size and stiffness. Graft type (autograft vs. allograft) did not affect fusion scores. Fusion scores were highest in the middle levels of the rod construct (mean 2.52), dropping off by 20% to 30% toward the upper and lower extremities of the rod. IV levels where a rod fractured had lower overall mean fusion scores compared to levels without a fracture. Mean total Scoliosis Research Society (SRS) questionnaire scores were 98.9 from a possible total of 120, indicating a good level of patient satisfaction.

CONCLUSIONS

Results suggest that 100% radiologic fusion of the entire disc space is not necessary for successful clinical outcomes following thoracoscopic anterior selective thoracic fusion.

Association Between Surgeon Experience and Complication Rates in Adult Scoliosis Surgery: A Review of 5117 Cases From the Scoliosis Research Society Database 2004-2007

STUDY DESIGN

Retrospective review of a multicenter database.

OBJECTIVE

To evaluate whether surgeon experience is associated with complication rates in adult spinal deformity (ASD) surgery.

SUMMARY OF BACKGROUND DATA

Multiple patient- and surgery-related factors have been shown to increase the risk of complications in ASD. No study exists evaluating surgeon experience as an associated factor with complications in ASD.

METHODS

The Scoliosis Research Society Morbidity and Mortality database was queried for patients older than 18 years who underwent ASD from 2004 to 2007. Patient demographics, surgical characteristics, complications, and surgeon membership status were analyzed. Two-tailed t test and χ tests were performed, with P value of less than 0.05 considered significant.

RESULTS

A total of 5117 patients underwent ASD surgery. The average patient age was 51.8 years. Patients operated by candidate members were older than those operated by active members (53.1 vs. 51.4, P = 0.003). Active members performed 3836 (75%) cases whereas candidate members performed 1281 cases. There were 1110 (21.7%) revisions. A total of 681 (13.3%) complications were recorded, 498 (13.0%) for active and 183 (14.3%) for candidate members, respectively (P = 0.24). Mortality rate was 0.29%. Spinal cord complications accounted for 0.68% of all cases. Active members had 21 (0.55%) spinal cord complications, whereas candidates had 14 (1.1%) (P = 0.049). There were a total of 174 (3.4%) surgical site infections (SSI). Active members had 82 (2.1%) deep SSI, whereas candidate members had 36 (2.8%) deep SSI (P = 0.164). Active members had 33 (0.9%) superficial SSI whereas candidate members had 23 (1.8%) superficial SSI (P = 0.008).

CONCLUSION

There was a statistically significant, 2-fold increase in the rate of spinal cord complications and superficial SSI among candidate compared with active members. Overall complication rates were similar between candidate and active members.

LEVEL OF EVIDENCE

4.

Postoperative infection in spine surgery: does the month matter?

OBJECT

The relationship between time of year and surgical site infection (SSI) following neurosurgical procedures is poorly understood. Authors of previous reports have demonstrated that rates of SSI following neurosurgical procedures performed during the summer months were higher compared with rates during other seasons. It is unclear, however, if this difference was related to climatological changes or inexperienced medical trainees (the July effect). The aim of this study was to evaluate for seasonal variation of SSI following spine surgery in a network of nonteaching community hospitals.

METHODS

The authors analyzed 6 years of prospectively collected surveillance data (January 1, 2007, to December 31, 2012) from all laminectomies and spinal fusions from 20 hospitals in the Duke Infection Control Outreach Network of community hospitals. Surgical site infections were defined using National Healthcare Safety Network criteria and identified using standardized methods across study hospitals. Regression models were then constructed using Poisson distribution to evaluate for seasonal trends by month. Each analysis was first performed for all SSIs and then for SSIs caused by specific organisms or classes of organisms. Categorical analysis was performed using two separate definitions of summer: June through September (definition 1), and July through September (definition 2). The prevalence rate of SSIs during the summer was compared with the prevalence rate during the remainder of the year by calculating prevalence rate ratios and 95% confidence intervals.

RESULTS

The authors identified 642 SSIs following 57,559 neurosurgical procedures (overall prevalence rate = 1.11/100 procedures); 215 occurred following 24,466 laminectomies (prevalence rate = 0.88/100 procedures), and 427 following 33,093 spinal fusions (prevalence rate = 1.29/100 procedures). Common causes of SSI were Staphylococcus aureus (n = 380; 59%), coagulase-negative staphylococci (n = 90; 14%), and Escherichia coli (n = 41; 6.4%). Poisson regression models demonstrated increases in the rates of SSI during each of the summer months for all SSIs and SSIs due to gram-positive cocci, S. aureus, and methicillin-sensitive S. aureus. Categorical analysis confirmed that the rate of SSI during the 4-month summer period was higher than the rate during the remainder of the year, regardless of which definition for summer was used (definition 1, p = 0.008; definition 2, p = 0.003). Similarly, the rates of SSI due to grampositive cocci and S. aureus were higher during the summer months than the remainder of the year regardless of which definition of summer was used. However, the rate of SSI due to gram-negative bacilli was not.

CONCLUSIONS

The rate of SSI following fusion or spinal laminectomy/laminoplasty was higher during the summer in this network of community hospitals. The increase appears to be related to increases in SSIs caused by gram-positive cocci and, more specifically, S. aureus. Given the nonteaching nature of these hospitals, the findings demonstrate that increases in the rate of SSI during the summer are more likely related to ecological and/or environmental factors than the July effect.

Greater operative volume is associated with lower complication rates in adolescent spinal deformity surgery

STUDY DESIGN

Retrospective analysis of prospectively collected data from the 2001 to 2010 Nationwide Inpatient Sample database.

OBJECTIVE

To assess complication rates in adolescent spinal deformity by surgeon operative volume for procedures with a range of complexity.

SUMMARY OF BACKGROUND DATA

Surgeons performing higher volumes of lumbar spinal fusion have been associated with improved surgical outcomes, according to studies using the Nationwide Inpatient Sample. This relationship has not been shown in adolescent spinal deformity surgery.

METHODS

The Nationwide Inpatient Sample was queried for patients aged 10 to 18 years with in-hospital stays including spinal arthrodesis for scoliosis (adolescent idiopathic, neuromuscular, and congenital scoliosis). The primary end point was hospital stay morbidity: database-defined surgical, mechanical, major medical, and neurological complications. Length of stay and hospital charges were also analyzed. Annual surgeon volumes were stratified into quartiles based on number of cases (Q1: 1, Q2: 2-7, Q3: 8-19, and Q4: 20-97). To account for variation in surgical invasiveness, an operative complexity index was used. One-way analysis of variance was used to assess differences between quartiles for continuous measures and χ for categorical measures.

RESULTS

A total of 6100 spine fusion cases met inclusion criteria for adolescent scoliosis. All complications categories were less frequent for higher volume surgeons after a primary fusion for all diagnoses. This pattern held for increasing surgical invasiveness, such as fusing 9 or more levels and became more distinct for neurological complications when comparing surgeons performing combined anterior-posterior procedures. Including all adolescent scoliosis fusions, higher surgical volume was associated with decreased length of stay and hospital charges.

CONCLUSION

Perioperative complications after adolescent scoliosis fusion surgery are more frequent in lower volume settings. This may reflect a learning curve required for more complex cases as the trends are magnified in neuromuscular/congenital scoliosis cases or simply that higher volume surgeons are more adept at these fusions. The impact of volume on reduced length of stay and hospital charges has implications for future health care economics measures.

LEVEL OF EVIDENCE

2.

The effect of surgeon experience on outcomes of surgery for adolescent idiopathic scoliosis

BACKGROUND

Single-surgeon series investigating the learning curve involved in surgery for spinal deformity may be confounded by changes in technology and techniques. Our objective with this multicenter, prospective study was to present a cross-sectional analysis of the impact of surgeon experience on surgery for adolescent idiopathic scoliosis.

METHODS

All posterior-only surgical procedures for adolescent idiopathic scoliosis performed in the 2007 to 2008 academic year, with a minimum of two years of patient follow-up, were included. Two groups were created on the basis of surgeon experience: a young surgeons' group, which included patients of surgeons with less than five years of experience, and an experienced surgeons' group, which included patients of surgeons with five or more years of experience.

RESULTS

Nine surgeons (four young and five experienced) operated on a total of one hundred and sixty-five patients with adolescent idiopathic scoliosis. The surgeons' experience ranged from less than one year to thirty-six years in practice. The two groups had similar preoperative curve-magnitude measurements, SRS-22 (Scoliosis Research Society-22) scores, and distribution by Lenke curve type. There were significant operative and postoperative differences. The young surgeons fused an average of 1.2 levels more than the experienced surgeons (p = 0.045). The mean intraoperative estimated blood loss (EBL) of the young surgeons' group was more than twice that of the experienced surgeons' group (2042 mL compared with 1013 mL; p < 0.001). The duration of surgery was 458 minutes for the young surgeons compared with 265 minutes for the experienced surgeons (p < 0.001). The overall SRS-22 scores were significantly worse in the young surgeons' group (a mean of 4.1 compared with 4.5; p = 0.001). The difference between groups was also significant for the domains of pain (p = 0.016), self-image (p = 0.008), and function (p < 0.001). Complication rates did not differ significantly between the groups.

CONCLUSIONS

Operative results and health-related quality of life following surgery for adolescent idiopathic scoliosis were significantly and positively correlated with surgeon experience.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

An institutional six-year trend analysis of the neurological outcome after lateral lumbar interbody fusion: a 6-year trend analysis of a single institution

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To evaluate the proportional trend over time of neurological deficits after lateral lumbar interbody fusion (LLIF) at a single institution.

SUMMARY OF BACKGROUND DATA

Because lumbar nerve roots converge to run as the lumbar plexus within or less frequently underneath the posterior part of the psoas muscle, they are prone to iatrogenic damage during the transpsoas approach in LLIF, and adverse postoperative neurological sequelae remain a major concern.

METHODS

The electronic medical records and office notes of 451 patients who had consecutively undergone LLIF between March 2006 and April 2012 at a single institution were retrospectively reviewed for reports on postoperative neurological deficits.

RESULTS

A total of 293 patients (173 females and 120 males) met the study inclusion criteria and were followed postoperatively for a mean period of 15.4 ± 9.2 months (range: 6-53 mo). The number of included patients who underwent LLIF at our institution was 47 in the years 2006 to 2008 (group A), 155 in 2009 to 2010 (group B), and 91 in 2011 to 2012 (group C). Our data indicate a decreasing proportional trend during the past 6 years for postoperative sensory deficits (SDs), motor deficits (MDs), and anterior thigh pain (TP). The decreasing trends were statistically significant for the proportion of SDs in the immediate postoperative setting (P = 0.018) and close to statistically significant for SDs at last follow-up (P = 0.126), TP immediately after surgery (P = 0.098), and TP at last follow-up (P = 0.136).

CONCLUSION

To the authors' best knowledge, this study constitutes the largest series of this sort to date, with regard to both sample size and study period. The present data indicate a decreasing proportional trend over time for SDs, MDs, and anterior TP, which can be considered a representation of an institutional learning curve during a 6-year time period of performing LLIF.

Effect of spine fellow training on operative outcomes, affirming graduated responsibility

STUDY DESIGN

Retrospective review of prospectively collected surgical data.

OBJECTIVE

This study sought to determine the effect of fellow education during the course of the academic year (August-July) on surgical outcomes in adolescent idiopathic scoliosis. One surgeon and one type of surgery were chosen to minimize confounding factors.

SUMMARY OF BACKGROUND DATA

Educating and training the next generation of physicians and surgeons is necessary for the survival and continuation of medical care. There has been recent momentum to document scientifically that medical education is safe. Spine surgery is complex and demanding, with a steep learning curve, making it an ideal model to detect any potential negative impact of medical education.

SUBJECTS

adolescent patients undergoing posterior spinal surgery, between August 2007 and July 2010, by a single senior surgeon at one institution with a fellow as the only surgical assistant. Demographic and perioperative data were collected and then segmented by surgical date into quarters according to the rotations of the academic year. One fellow was included in each quarter during the 4 years, resulting in 16 fellows across the 4 quarters. An analysis of variance model was used to assess differences in operative time, blood loss, length of stay, and complications between the quarters of the year.

RESULTS

There were no significant differences between the groups regarding age, sex, or Lenke curve type. No statistically significant differences were found between the 4 quarters of the fellowship year for estimated blood loss, use of cell saver, length of stay, operative time, and complication rate.

CONCLUSION

This study is the first to show that fellow education during the course of the academic year did not impact the patient outcomes studied. It is clear that while there is significant academic benefit for the fellows as they complete their spine fellowship, there is no negative impact for patients.

LEVEL OF EVIDENCE

4.

Surgical treatment of Lenke 1 main thoracic idiopathic scoliosis: results of a prospective, multicenter study

STUDY DESIGN

Prospective, consecutive, nonrandomized, multicenter study.

OBJECTIVE

The purpose of this study was to compare the outcomes of idiopathic scoliosis treatment for Lenke 1 curves with 3 treatment approaches.

SUMMARY OF BACKGROUND DATA

Surgical treatment options for Lenke 1 or primary main thoracic curve pattern in adolescent idiopathic scoliosis include thoracoscopic anterior spinal fusion, open anterior spinal fusion, and posterior spinal fusion (PSF) and instrumentation procedures.

METHODS

This was a prospective, consecutive, nonrandomized, multicenter study of surgical correction in adolescent idiopathic scoliosis. Patients with Lenke type 1 curve patterns from 7 sites were enrolled in this minimum 2-year follow-up study. Changes in pre- to postoperative radiographs, pulmonary function tests, Scoliosis Research Society questionnaire scores, and trunk rotation measures were compared.

RESULTS

A total of 149 patients (age: 14.5 ± 2 yr) were included (91% follow-up at 2 yr). The 3 groups were similar preoperatively in thoracic and lumbar curve size. There were 55 patients with thoracoscopic anterior spinal fusion, 17 patients with open anterior spinal fusion, and 64 patients with PSF. The fusion included on average 3 to 4 more levels in PSF than the 2 anterior approaches (P ≤ 0.001). Surgical time tended to be greater in the anterior groups by approximately 2 to 3 hours; however, blood loss was greatest with PSF. At 2 years, all 3 approaches showed similar improvements in the thoracic Cobb angle, coronal balance, the lumbar Cobb angle, Scoliosis Research Society questionnaire scores, and trunk rotation measures. The PSF approach resulted in overall reduction in kyphosis compared with the anterior approaches. Postoperative hyperkyphosis was an issue only in the 2 anterior groups. Major complication rates were similar.

CONCLUSION

All 3 approaches resulted in similarly satisfactory outcomes for the majority of patients with specific advantages to each technique. The patients with PSF had more levels fused, yet with the shortest operative time. The thoracoscopic anterior spinal fusion group had the smallest incisions and the lowest requirement for transfusion. The open anterior spinal fusion group had a modest loss of pulmonary function without any clear advantages compared with the other 2 groups.

LEVEL OF EVIDENCE

2.

ProDisc-L learning curve: 24-Month clinical and radiographic outcomes in 44 consecutive cases

Background

Total disc replacement (TDR) promises preservation of spine biomechanics in the treatment of degenerative disc disease but requires more careful device placement than tradition fusion and potentially has a more challenging learning curve.

Methods

A cohort of 44 consecutive patients had 1-level lumbar disc replacement surgery at a single institution by a single surgeon. Patients were followed up clinically and radiographically for 24 months. Patients were divided into 2 groups of 22 sequential cases each. Clinically, preoperative and postoperative Oswestry Disability Index, visual analog scale, Short Form 12 (SF-12) Mental and Physical Components, and postoperative satisfaction were measured. Radiographically, preoperative and postoperative range of motion (ROM) dimensions, prosthesis deviation from the midline, and disc height were measured. TDR-related complications were noted. Logarithmic curve–fit regression analysis was used to assess the learning curve.

Results

Operative time decreased as cases progressed, with an asymptote after 22 cases. The operative time for the later group was significantly lower (P < .0005), but hospital stay was significantly longer (P = .03). There was no significant difference in amount of blood loss (P = .10) or prosthesis midline deviation (P = .86). Clinically, there was no significant difference in postoperative scores between groups in Oswestry Disability Index (P = .63), visual analog scale (P = .45), SF-12 Mental Component (P = .66), SF-12 Physical Component (P = .75), or postoperative satisfaction (P = .92) at 24 months. Radiographically, there was no significant difference in improvement between groups in ROM (P = .67) or disc height (P = .87 for anterior and P = .13 for posterior) at 24 months. For both groups, there was significant improvement for all clinical outcomes and disc height over preoperative values. One patient in the later group had device failure with subluxation of the polyethylene, which required revision.

Conclusions/level of evidence

Early experience can quickly reduce operative time but does not affect clinical outcomes or ROM significantly (level IV case series).

Clinical relevance

Lumbar TDR is a rapidly learnable technique in treatment of degenerative disc disease.

Anterior versus posterior approach in 3D correction of adolescent idiopathic thoracic scoliosis: a meta-analysis

PURPOSE

Systematic review was conducted to compare effectiveness and safety of anterior and posterior surgical approach in 3D correction of adolescent idiopathic thoracic scoliosis.

METHODS

Data sources were MEDLINE and SCOPUS databases. We included studies on the use of either anterior or posterior instrumentation, or their combination, in surgical correction of adolescent idiopathic thoracic scoliosis, with at least 10 enrolled patients, aged less than 20 years at the time of surgery, and a follow-up of at least 24 months. A study was eligible if it reported the number of patients, mean estimate and dispersion of three key outcome measures (frontal and sagittal Cobb angle, apical vertebra rotation according to Perdriolle) at three measurement points (preoperatively, postoperatively, at follow-up). The quality of studies was assessed using the scale by Pilkington.

RESULTS

Although 24 articles met the inclusion criteria, no randomized controlled trials (RCT) was identified. None of the articles was of high quality. Both instrumentations provided a similar degree of reduction of frontal Cobb angle. Long-term effects of surgical correction on the sagittal Cobb angle seemed to be more stable in patients treated by posterior approach, while the anterior approach was more effective in the reduction of apical vertebral rotation. The surgery parameters were more favorable for anterior approach, particularly for the number of fused vertebrae.

CONCLUSIONS

Although the available evidence favors neither of the two approaches, our study revealed several important issues: the reports are heterogeneous and provide incomplete relevant information. High quality studies, particularly RCT, are called for.

LEVEL OF EVIDENCE

Level II.

Learning curve and clinical outcomes of minimally invasive transforaminal lumbar interbody fusion: our experience in 86 consecutive cases

STUDY DESIGN

Consecutive case series with prospective data collection.

OBJECTIVE

To define and analyze the learning curve for minimally invasive transforaminal lumbar interbody fusion (TLIF).

SUMMARY OF BACKGROUND DATA

Minimally invasive TLIF using a unilateral approach has recently been gaining popularity because of its potential for minimizing soft-tissue damage and reducing recovery time. However, a steep learning curve has been described for surgeons first performing this technique.

METHODS

Eighty-six consecutive patients with degenerative lumbar diseases who were treated by TLIF were included in the study. Surgeries were performed using a tubular retractor, and a cage was inserted using a unilateral transforaminal approach by a single surgeon. The corresponding segments were fixed with percutaneous pedicle screws. Eighty-three patients were followed up for more than 1 year, and the average follow-up period was 25 months. Single-level TLIF was performed in 60 cases, single-level TLIF plus adjacent-level decompression was performed in 13 cases, and double-level TLIF was performed in 13 cases. Corrected operative time per level, operative blood loss, postoperative blood drainage, total blood loss, and ambulation recovery time were measured. Transfusion rates and complication incidence were also identified. Clinical results were assessed using the Oswestry Disability Index (ODI) and a visual analogue scale (VAS). The learning curve was assessed using a logarithmic curve-fit regression analysis. In the single-level TLIF group (n = 60), 22 patients were defined as the "early" group (among the first 30 cases of the series), and the subsequent 38 cases were defined as the "late" group for comparison.

RESULTS

Corrected operative time gradually decreased as the series progressed, and an asymptote was reached after about 30 cases. ODI significantly decreased from an average of 24 at the preoperative stage to 10 at the final follow-up. Average VAS scores for lower back pain and radiating pain also significantly decreased from an average of 5.2 to 1.9 and 6.8 to 0.9, respectively. In the single-level TLIF series, operative time was significantly shorter in the late group (183 ± 23 min) than the early group (254 ± 44 min), and blood loss during the operation was significantly reduced in the late group (292 ± 280 mL) compared with the early group (508 ± 278 mL). Ambulation recovery time significantly decreased from 2.4 ± 0.6 days in the early group to 2.0 ± 0.5 in the late group. ODI and VAS scores for lower back pain and radiating pain did not differ between the 2 groups.

CONCLUSION

Although it is not easy to master the minimally invasive TLIF technique, the surgeon's experience with this operation correlated with reduced operation time and blood loss during surgery. After the initial learning curve, this technique could be an effective and reliable option for the surgical treatment of lumbar degenerative disease.

Is there a learning curve in foot and ankle surgery?

BACKGROUND

Previous studies of orthopaedic learning curves have largely described the introduction of new techniques to experienced consultants. End points have usually involved technical considerations. A paucity of evidence surrounds foot and ankle surgery. This study investigates the learning curve during a foot and ankle surgeon's first year, defined by functional outcome.

METHODS

150 patients underwent elective foot or ankle surgery during the whole period. Preoperative and 6 month postoperative functional scores were compared between the first and second 6 month groups.

RESULTS

Functional improvement was greater, approaching significance, in the second group (p=0.0605). There was no difference for forefoot cases (p=0.345). Functional improvement was significantly greater in the second group with forefoot cases removed (p=0.0333).

CONCLUSIONS

A learning curve exists in the first year of practice of foot and ankle surgery, demonstrated by functional outcome. This is confined to ankle, hindfoot and midfoot, but not forefoot surgery.

The relationship between deformity correction and clinical outcomes after thoracoscopic scoliosis surgery: a prospective series of one hundred patients

STUDY DESIGN

Prospective clinical case series of 100 patients receiving thoracoscopic anterior scoliosis correction.

OBJECTIVE

To evaluate the relationship between clinical outcomes of thoracoscopic anterior scoliosis surgery and deformity correction, using the Scoliosis Research Society (SRS) outcomes instrument.

SUMMARY OF BACKGROUND DATA

Surgical treatment of scoliosis is quantitatively assessed in the clinic, using radiographic measures of deformity correction and the rib hump, but it is important to understand the extent to which these quantitative measures correlate with self-reported improvements in patients' quality of life after surgery.

METHODS

A series of 100 consecutive adolescent idiopathic scoliosis patients received a single anterior rod via a thoracoscopic approach at the Mater Children's Hospital, Brisbane, Australia. Patients completed SRS outcomes questionnaires before surgery and at 24 months after surgery. Multiple regression and t tests were used to investigate the relationship between SRS scores and deformity correction achieved (radiographic measurements and rib hump) after surgery.

RESULTS

There were 94 females and 6 males with a mean age of 16.1 years. The mean Cobb angle improved from 52° before surgery to 25° after surgery (52%) and the mean rib hump improved from 16° to 8° (51%). The mean total SRS score for the cohort was 99.4/120. None of the deformity-related parameters in the multiple-regression were significant. However, patients with the lowest postoperative major Cobb angles reported significantly higher SRS scores than those with the highest postoperative Cobb angles, but there was no difference on the basis of rib hump correction. There were no significant differences between patients with either rod fractures or screw-related complications compared to those without complications.

CONCLUSION

Patients undergoing thoracoscopic anterior scoliosis correction reported good SRS scores which are comparable with those in previous studies. Postoperative major Cobb angle is a significant predictor of patient satisfaction when comparing subgroups of patients with the highest and lowest postoperative Cobb angles.

Pulmonary function changes after various anterior approaches in the treatment of adolescent idiopathic scoliosis

STUDY DESIGN

Prospective radiographic and chart review of pulmonary function in patients who underwent 3 different anterior spinal surgery approaches for adolescent idiopathic scoliosis (AIS).

OBJECTIVE

To assess the impact on pulmonary function in patients with AIS after anterior surgical approaches, including open thoracotomy, thoracoscopic with and without thoracoplasty, and thoracoabdominal 2 years after surgery.

SUMMARY OF BACKGROUND DATA

Potential advantages of anterior surgery in the treatment of AIS include saving of distal motion segments and improving kyphosis restoration in the thoracic spine, possibly at the cost of pulmonary function impairment. Although thoracoscopic spinal instrumentation and fusion has recently been shown to induce less pulmonary impairment compared with open thoracotomy, no study has evaluated the effect of thoracoplasty as an adjunct to thoracoscopic surgery, nor the effects of the thoracoabdominal approach for thoracolumbar curvature.

METHODS

A multicenter spinal deformity database was queried for patients who underwent an anterior approach for either Lenke I or Lenke V idiopathic scoliosis. There were 68 patients in the thoracotomy group, 44 in the thoracoscopic group, and 19 in the thoracoabdominal group. Absolute and percent-predicted values of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and total lung capacity (TLC) were evaluated preoperatively and at 2-year follow-up, and comparisons were made within and between each group.

RESULTS

Comparing between groups at 2 years postoperatively, the thoracotomy group demonstrated significantly greater decreases (-10.97% and -12.97%) in both percent-predicted FEV1 and FVC, respectively, when compared with the thoracoscopic group (-4.40% and -4.73%), respectively. Percent-predicted TLC in the thoracoscopic group increased (3.19%), but decreased in the thoracotomy group (-8.00%). Subanalysis of the thoracoscopic group at 2 years revealed that the addition of a thoracoplasty (3 to 5 ribs) significantly reduced percent-predicted FEV1 (-11.6%, P = 0.0013) and percent-predicted FVC (-16.0%, P = 0.017) from baseline. Patients who underwent thoracoscopy alone without a thoracoplasty experienced no significant detrimental changes in these parameters at 2 years, and instead experienced significant increases in absolute TLC (P < 0.001) and percent-predicted TLC (P = 0.035). There were no significant changes demonstrated in the thoracoabdominal group for all 3 parameters.

CONCLUSIONS

Slight declines in pulmonary function at 2-year follow-up were noted in both the thoracotomy and thoracoscopic groups, but to a significantly greater extent in those with an open thoracotomy. Significantly greater impairment in pulmonary function was seen in thoracoscopic patients who underwent thoracoplasty, whereas those without thoracoplasty either had no significant declines at 2 years or experienced slight but significant improvement. No significant diminishment was noted for the thoracoabdominal approach, despite disruption of the diaphragm.

Thoracic pedicle screw instrumentation: the learning curve and evolution in technique in the treatment of adolescent idiopathic scoliosis

STUDY DESIGN

Retrospective review.

OBJECTIVE

The purpose of this study is to evaluate the learning curve and associated evolution in surgical technique with thoracic pedicle screw instrumentation in adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Common treatment for AIS now includes posterior spinal fusion, using thoracic pedicle screws (TPS). It is critical to assess the efficacy, safety profile, and learning curve associated with this technique as its use becomes more widespread among inexperienced surgeons.

METHODS

Retrospective review of the senior author's first 96 TPS cases for Lenke Type I AIS curves. Multiple regression techniques were used to discern whether increasing case number (CN) was associated with improved perioperative and 2-year minimum radiographic and clinical outcomes. The 96 cases were divided into 4 equal quartiles of 24 cases/group (i.e., Q1-Q4) and compared using analysis of variance measures.

RESULTS

A total of 1169 thoracic pedicle screws were placed in 96 patients. We found a significant correlation between CN and major curve correction at 2 years (P < 0.0001), inverse correlation between CN and length of stay (P = 0.02), and estimated blood loss (P = 0.03), but no differences in cell saver or complications. Univariate analysis revealed significant inverse correlations between increasing CN and transfusion rate (P = 0.02) and operative times (P = 0.0001). Total number of screws placed (Q1:9.4 vs. Q4:16.2, P < 0.0001) and number of screws/level (Q1:0.98 vs. Q4:1.64, P < 0.0001) increased linearly with increasing CN, whereas the average time for screw placement (Q1:24.2 vs. Q4:11.4 minutes, P < 0.0001) and ability to maintain T2-T12 kyphosis decreased (Q1:0.21 vs. Q4:-5.5 P = 0.02) with increasing CN.

CONCLUSION

There is a significant learning curve associated with thoracic pedicle screw placement in AIS. We describe several technical steps that can be taken to increase the safety of screw placement at the beginning of the learning curve. Inexperienced surgeons should expect a gradual improvement over time in radiographic and clinical outcomes.

Thoracoscopic anterior instrumented fusion for adolescent idiopathic scoliosis with emphasis on the sagittal plane

BACKGROUND CONTEXT

Anterior fusion through an open thoracotomy restores kyphosis more reliably than posterior techniques in patients with thoracic adolescent idiopathic scoliosis (AIS). Video-assisted thoracoscopic spinal fusion and instrumentation (VATS) minimizes the morbidity, from soft tissue and muscle dissection that accompanies traditional open thoracotomy. To our knowledge, there has not been a comprehensive analysis of VATS with respect to radiographic and clinical outcomes in the sagittal plane.

PURPOSE

To measure the radiographic and clinical outcomes after VATS with emphasis on the sagittal plane.

STUDY DESIGN/SETTING

A retrospective, radiographic review of 26 consecutive patients with Lenke type-I AIS who underwent VATS.

METHODS

Radiographs of 26 consecutive patients with Lenke type-I AIS curves operated by a single surgeon were retrospectively reviewed after VATS. Sagittal and coronal parameters were compared with reported data for open anterior and posterior procedures.

RESULTS

There was an increase in kyphosis from baseline to final follow-up by 6.6 degrees (25%) from T2 to T12 (p<.0001), 8.7 degrees (50%) from T5 to T12 (p<.0001), and 8 degrees (54%) in the instrumented segment (p<.0001). Junctional kyphosis did not occur. No differences were detected in sagittal measurements between the first postoperative erect and the final radiographs. Patients experienced significant improvements from baseline to 2 years in Scoliosis Research Society-22 Health-Related Quality-of-Life Outcome Questionnaire scores (p<.0001).

CONCLUSIONS

Video-assisted thoracoscopic spinal fusion and instrumentation, in agreement with results reported for open anterior instrumentation, reliably restores or increases thoracic kyphosis while preserving junctional alignment in thoracic AIS.

Thoracoscopic anterior instrumentation for idiopathic scoliosis

Lonner BS, Auerbach JD, Levin R, et al. Thoracoscopic anterior instrumented fusion for adolescent idiopathic scoliosis with emphasis on the sagittal plane. Spine J 2009;9:523-9 (this issue).