Defining the pediatric spinal thoracoscopy learning curve: sixty-five consecutive cases

Video-Assisted Thoracoscopic Lateral Interbody Fusion for Symptomatic Pseudarthrosis in Neurofibromatosis 1-Associated Spinal Deformity

BACKGROUND

The treatment of symptomatic pseudarthrosis via posterior-only approaches in the setting of neurofibromatosis 1 (NF1) is challenging due to dural ectasias, resulting in erosion of the posterior elements. The purpose of this report is to illustrate a minimally invasive method for performing anterior thoracic fusion for pseudarthrosis in a patient with NF1-associated scoliosis and dysplastic posterior elements. To the best of our knowledge, this is the first documented case of using video-assisted thoracoscopic lateral interbody fusion to treat pseudarthrosis for NF1-associated spinal deformity.

CASE DESCRIPTION

The patient underwent video-assisted thoracoscopic anterior spinal fusion via a direct lateral interbody approach with interbody cage placement at T10-T11 and T11-T12, followed by revision of his posterior spinal fusion and instrumentation. The patient had an uneventful postoperative course. At 6 months of follow-up, the patient had complete resolution of his preoperative symptoms and had returned to full-time work with no complaints. At 3 years postoperatively, the patient reported being satisfied with the operation and had continued to work full-time without restrictions.

CONCLUSIONS

To the best of our knowledge, this is the first report of pseudarthrosis in the setting of NF1-associated scoliosis treated via minimally invasive anterior thoracic fusion facilitated by video-assisted thoracoscopic surgery. This is a powerful technique that allows for safe access for anterior thoracic fusion in the setting of dysplastic posterior anatomy and poor posterior bone stock.

The Thoracoscopic Approach in Spinal Cord Disease

Video-assisted thoracic surgery (VATS) has been growing in popularity over the past 2 decades as an alternative to open thoracotomy for the treatment of several spinal conditions, and in the field of minimally invasive surgery, it now acts as a keyhole to the thoracic spine.

MATERIALS AND METHODS

Most VATS approaches are from the right side for pathologies involving the middle and upper thoracic spine because there is a greater working spinal surface area lateral to the azygos vein than that lateral to the aorta. Below T-9, a left-sided approach is made possible because the aorta moves away from the left posterolateral aspect of the spine to an anterior position as it passes through the diaphragm.

RESULTS

VATS has been used extensively in spinal deformities such as scoliosis. The use of VATS in spine surgery includes the treatment of thoracic prolapsed disk diseases, vertebral osteomyelitis, fracture management, vertebral interbody fusion, tissue biopsy, anterior spinal release, and fusion without or with instrumentation (VAT-I) for spinal deformity correction. As the knowledge and the comfort of using such techniques have expanded, the indications have extended to corpectomy for tumor resections.

DISCUSSION AND CONCLUSIONS

In the field of minimally invasive surgery, VATS now acts as a keyhole to the thoracic spine and an alternative to open thoracotomy for the treatment of several spinal conditions.Although VATS can be performed in such spine conditions, it is most beneficial in the treatment of scoliotic deformity, which requires taking a multilevel approach, from the upper to the lower thoracic spine.

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.

Early operative morbidity in 184 cases of anterior vertebral body tethering

Fusion is the current standard of care for AIS. Anterior vertebral body tethering (AVBT) is a motion-sparing alternative gaining interest. As a novel procedure, there is a paucity of literature on safety. Here, we report 90-day complication rates in 184 patients who underwent AVBT by a single surgeon. Patients were retrospectively reviewed. Approaches included 71 thoracic, 45 thoracolumbar, 68 double. Major complications were those requiring readmittance or reoperation, prolonged use of invasive materials such as chest tubes, or resulted in spinal cord or nerve root injury. Minor complications resolved without invasive intervention. Mean operative time and blood loss were 186.5 ± 60.3 min and 167.2 ± 105.0 ml, respectively. No patient required allogenic blood transfusion. 6 patients experienced major (3.3%), and 6 had minor complications (3.3%). Major complications included 3 chylothoracies, 2 hemothoracies, and 1 lumbar radiculopathy secondary to screw placement requiring re-operation. Minor complications included 1 patient with respiratory distress requiring supplementary oxygen, 1 superficial wound infection, 2 cases of prolonged nausea, and 1 Raynaud phenomenon. In 184 patients who underwent AVBT for AIS, major and minor complication rates were both 3.3%.

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.

Is Anterior Release Obsolete or Does It Play a Role in Contemporary Adolescent Idiopathic Scoliosis Surgery? A Matched Pair Analysis

STUDY DESIGN

A retrospective analysis of a prospectively collected database was performed.

OBJECTIVE

The purpose of this study is to compare 3-dimensional correction associated with the anterior release (AR) and contemporary posterior instrumentation versus posterior-only surgery.

SUMMARY OF BACKGROUND DATA

The role of AR as a tool in the treatment of adolescent idiopathic scoliosis (AIS) has seen a decline with the popularization of thoracic pedicle screw instrumentation.

METHODS

Five surgeons were queried for all surgical thoracic AIS cases from 2003 to 2010 treated with thoracoscopic AR/fusion and contemporary posterior instrumentation and fusion and thoracic pedicle screw instrumentation (>80% screws) with 2-year follow-up. These cases were then matched with posterior spinal fusion only cases from a multicenter prospective database. The 2 groups were matched on the basis of major curve magnitude within 5 degrees, T5-T12 kyphosis within 9 degrees, and angle of trunk rotation within 9 degrees. Radiographic and clinical parameters were compared for the 2 groups. Continuous variables were analyzed with analysis of variance and categorical dependent variables with the χ test.

RESULTS

A total of 47 cases of AR were matched to 47 (1:1 match) posterior spinal fusion cases. Preoperative parameters were similar between groups (P>0.05). Postoperatively, AR cases had a lower major curve (20 vs. 25 degrees, P=0.034; 72% vs. 66% correction, P=0.037). T5-T12 kyphosis was greater in the AR cases (26 vs. 20 degrees; P=0.005). The angle of trunk rotation was similar for the groups. Anchor density was lower in the AR group (1.6 vs. 1.9; P<0.0001). There were 3 complications associated with the AR: 1 pneumothorax and 2 conversions to minithoracotomies for failure to maintain single lung ventilation.

CONCLUSIONS

AR improves coronal and sagittal plane correction in contemporary AIS surgery with a satisfactory complication profile with less pedicle screw density required for clinically similar corrections. A further prospective study on the benefits of AR may help define specific indications.

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.

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.

Evolution of Surgery for Adolescent Idiopathic Scoliosis Over 20 Years: Have Outcomes Improved?

STUDY DESIGN

Retrospective review of a prospective adolescent idiopathic scoliosis (AIS) registry.

OBJECTIVE

To study the evolution of the operative approach, outcomes, and complication rates in AIS surgery over the past 20 years.

SUMMARY OF BACKGROUND DATA

Surgical techniques in AIS surgery have evolved considerably over the past 20 years. We study the trends in the operative management of AIS over this period and their impact on perioperative outcomes.

METHODS

A total of 1819 AIS patients (1995-2013) with 2-year F/U were studied. Operative approach, perioperative parameters, major complication rates, and SRS outcomes were assessed. Linear regression was used to assess the trend of changes over 5-year quartiles.

RESULTS

Mean age at surgery was 14.6 ± 2.1 years, 80.2% were females, and this remained consistent throughout. Operative time, EBL/level, and LOS decreased over the 20 years (P < 0.0001). The use of antifibrinolytic (AF) increased from 6.7% to 68.8% in the past 10 years (P < 0.0001). Number of levels fused increased and LIV was more distal (in relation to stable vertebrae) over time in Lenke 1 and 2 curves (levels fused 7.97-9.94, P < 0.0001 and 9.8-11.0, P=0.0134, respectively). Anterior spinal fusion (ASF) in Lenke 1 curves decreased from 81% in the first quartile to 0% in the last (P = 0.0429). ASF for Lenke 5 curves evolved from 78% in the second quartile to 0 in the last. Thoracoplasty performance decreased from 76% to 20.3% (P = 0.1632). All screw constructs in PSF cases increased from 0% to 98.4% (P = 0.0095). Two-year major complication rates decreased over time (18.7%-5.1%; P = 0.0173). Increased improvement in SRS scores were observed in pain, image, function, and total domains.

CONCLUSION

Evolution of surgical technique in AIS over the past 20 years has resulted in a cessation of anterior only surgery, increasing use of all screw constructs, less blood loss, greater use of AF, shorter operative times and LOS, lower major complications rates, and greater improvements in SRS scores.

LEVEL OF EVIDENCE

2.

Learning curve of radiology residents during training in fluoroscopy-guided facet joint injections

OBJECTIVE

To develop a simulator for training in fluoroscopy-guided facet joint injections and to evaluate the learning curve for this procedure among radiology residents.

MATERIALS AND METHODS

Using a human lumbar spine as a model, we manufactured five lumbar vertebrae made of methacrylate and plaster. These vertebrae were assembled in order to create an anatomical model of the lumbar spine. We used a silicon casing to simulate the paravertebral muscles. The model was placed into the trunk of a plastic mannequin. From a group of radiology residents, we recruited 12 volunteers. During simulation-based training sessions, each student carried out 16 lumbar facet injections. We used three parameters to assess the learning curves: procedure time; fluoroscopy time; and quality of the procedure, as defined by the positioning of the needle.

RESULTS

During the training, the learning curves of all the students showed improvement in terms of the procedure and fluoroscopy times. The quality of the procedure parameter also showed improvement, as evidenced by a decrease in the number of inappropriate injections.

CONCLUSION

We present a simple, inexpensive simulation model for training in facet joint injections. The learning curves of our trainees using the simulator showed improvement in all of the parameters assessed.

Thoracoscopic Vertebrectomy for Thoracolumbar Junction Fractures and Tumors: Surgical Technique and Evaluation of the Learning Curve

STUDY DESIGN

Retrospective study.

OBJECTIVE

The authors evaluated the surgical technique and learning curve for video-assisted thoracoscopic surgery (VATS) for treating thoracolumbar junction burst fractures and bony tumors by examining surgical data and outcome for the first 30 VATS procedures performed by a single surgeon at a training institution.

SUMMARY OF BACKGROUND DATA

VATS is commonly used in the treatment of early-stage lung cancer. Widespread use of this technique among neurosurgeons is limited by the lack of cases and the steep learning curve.

METHODS

This study was a retrospective case series of the first 30 T12 and L1 thoracoscopic vertebrectomies from 2003 to 2008. The sample was limited to 1 surgeon and 1 region of the spine to minimize the potential variation so that a learning curve could be assessed. Surgical data and outcomes were analyzed. Estimated blood loss and operation time were analyzed using a linear generalized estimating equation model with a first-order autoregression correlation structure.

RESULTS

The average operative time for thoracoscopic corpectomy was 270±65 minutes (range, 160-416 min). Operating room time decreased significantly after the first 3 operations. The authors observed a stable linear decrease in operating time over the course of the study. The average blood loss during the thoracoscopic procedure was 433±330 mL (range, 100-1500 mL) and did not change as the series progressed. Complications and conversions to open procedures occurred in 2 patients and were evenly distributed throughout the series.

CONCLUSIONS

Thoracoscopic vertebrectomy at the thoracolumbar junction has a relatively long learning curve. In this series, operating room time improved dramatically after the first 3 cases but continued to improve subsequently. The learning curve can be accomplished without an increase in blood loss, complications, rate of conversion to open procedures, or frequency of misplaced instrumentation.

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.

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.

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.

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.

Quantitative evaluation of an automatic segmentation method for 3D reconstruction of intervertebral scoliotic disks from MR images

Background

For some scoliotic patients the spinal instrumentation is inevitable. Among these patients, those with stiff curvature will need thoracoscopic disk resection. The removal of the intervertebral disk with only thoracoscopic images is a tedious and challenging task for the surgeon. With computer aided surgery and 3D visualisation of the interverterbral disk during surgery, surgeons will have access to additional information such as the remaining disk tissue or the distance of surgical tools from critical anatomical structures like the aorta or spinal canal. We hypothesized that automatically extracting 3D information of the intervertebral disk from MR images would aid the surgeons to evaluate the remaining disk and would add a security factor to the patient during thoracoscopic disk resection.

Methods

This paper presents a quantitative evaluation of an automatic segmentation method for 3D reconstruction of intervertebral scoliotic disks from MR images. The automatic segmentation method is based on the watershed technique and morphological operators. The 3D Dice Similarity Coefficient (DSC) is the main statistical metric used to validate the automatically detected preoperative disk volumes. The automatic detections of intervertebral disks of real clinical MR images are compared to manual segmentation done by clinicians.

Results

Results show that depending on the type of MR acquisition sequence, the 3D DSC can be as high as 0.79 (±0.04). These 3D results are also supported by a 2D quantitative evaluation as well as by robustness and variability evaluations. The mean discrepancy (in 2D) between the manual and automatic segmentations for regions around the spinal canal is of 1.8 (±0.8) mm. The robustness study shows that among the five factors evaluated, only the type of MRI acquisition sequence can affect the segmentation results. Finally, the variability of the automatic segmentation method is lower than the variability associated with manual segmentation performed by different physicians.

Conclusions

This comprehensive evaluation of the automatic segmentation and 3D reconstruction of intervertebral disks shows that the proposed technique used with specific MRI acquisition protocol can detect intervertebral disk of scoliotic patient. The newly developed technique is promising for clinical context and can eventually help surgeons during thoracoscopic intervertebral disk resection.

Posterior extrapleural intervertebral space release combined with wedge osteotomy for the treatment of severe rigid scoliosis

STUDY DESIGN

Retrospective clinical case series.

OBJECTIVE

To report the technique and results of posterior extrapleural intervertebral space release (PEISR) combined with wedge osteotomy (WO) for the treatment of severe rigid scoliosis.

SUMMARY OF BACKGROUND DATA

Conventional surgical correction techniques for severe rigid scoliosis include anterior release combined with posterior instrumentation and fusion and vertebral column resection.

METHODS

Between 2004 and 2009, 18 patients underwent PEISR and WO at a single institution. The indications were scoliosis with coronal Cobb's angle greater than 90° and curve flexibility less than 25%. The median age at surgery was 18.1 years (range, 13-26 yr). Nine patients had a preoperative forced vital capacity that was less than 40% of predicted. All patients had a minimum 2-year radiographical and clinical follow-up (range, 2.0-5.7 yr).

RESULTS

A mean of 4.2 discs were excised per patient (range, 2-6 discs) along with a mean of 1.2 vertebrae removed in the osteotomy. Mean number of vertebrae fused was 13.8 (range, 10-16 vertebrae). Mean operating time was 8.8 hours (range, 6.2-12.6 hr), with a mean blood loss of 3990 mL (range, 2600-6100 mL). The mean preoperative Cobb angle of 108.5° (range, 92°-136°) was corrected to 30° at the most recent follow-up (72.4% correction rate). Preoperative thoracic kyphosis of 52° (range, 5°-115°) was corrected to 26° (range, 17°-52°). The mean preoperative coronal imbalance of 3.5 cm was corrected to 0.6 cm (83.8% correction) and the sagittal imbalance of 2.8 cm was corrected to 0.3 cm (90.3% correction). There were no neurological complications. There were no instances of infection or muscle necrosis. Hemopneumothorax occurred in 2 patients.

CONCLUSION

PEISR, combined with WO, through a single posterior approach is a technically challenging but safe and effective procedure for severe rigid scoliosis. This posterior-only approach allows for dramatic radiographical correction that surpasses that reported for posterior VCR.

Surgical treatment of severe congenital scoliosis with unilateral unsegmented bar by concave costovertebral joint release and both-ends wedge osteotomy via posterior approach

INTRODUCTION

Congenital scoliosis with unilateral unsegmented bar has remained a surgical challenge. If it is treated with a traditional release of the convex side and an apical wedge osteotomy, there is a risk of bony bridge fracture on the concave side and spine translation during correction maneuvers, which may then result in spinal cord injuries. The authors developed a technique that consists of a concave-side costovertebral joint release followed by both-ends wedge osteotomy via a posterior-only approach. In this article, we describe the technique in detail, and present the results of ten patients treated with this technique.

METHODS

A total of ten patients with congenital scoliosis with unilateral unsegmented bar, who had undergone a concave-side costovertebral joint release followed by both-end wedge osteotomy via a posterior-only approach were followed up for a mean of 34 months (range 26-48 months). The radiographic parameters and clinical records were all reviewed and analyzed.

RESULTS

Body height increased by a mean of 7.3 cm (range 6.0-9.0 cm). The preoperative coronal Cobb angle was 102° (range 83°-139°) with a mean flexibility of 14%. At the most recent follow-up visit, the mean Cobb angle was 35° (range 12°-53°) and the mean correction rate was 66%. The coronal imbalance improved from 3.4 cm (range 0.8-6.3 cm) preoperatively to 1.1 cm (range 0.6-1.8 cm) postoperatively, a 67% correction. There were no definite pseudarthroses, no implant failure, and no obvious loss of correction in the follow-up period. Complications included one patient with hemopneumothorax and another patient with incomplete paralysis of the left lower extremity caused by a pedicle screw violating the spinal canal at the T5 level. The screw was removed 4 h after the initial operation, and the patient fully recovered after 3 months.

CONCLUSION

We have had good results with our technique of concave-side costovertebral joint release and both-end wedge osteotomy. It has the advantage of remnant anulus fibrosus, the ligamentum flavum, and the facet joints on the concave side serving both as a hinge and to minimize translation of the spine ends. It can provide excellent three-dimensional curve correction for patients with severe rigid congenital scoliosis with unilateral unsegmented bar.

Complications in the surgical treatment of 19,360 cases of pediatric scoliosis: a review of the Scoliosis Research Society Morbidity and Mortality database

STUDY DESIGN

Retrospective review of a multicenter database.

OBJECTIVE

To determine the complication rates associated with surgical treatment of pediatric scoliosis and to assess variables associated with increased complication rates.

SUMMARY OF BACKGROUND DATA

Wide variability is reported for complications associated with the operative treatment of pediatric scoliosis. Limited number of patients, surgeons, and diagnoses occur in most reports. The Scoliosis Research Society Morbidity and Mortality (M&M) database aggregates deidentified data, permitting determination of complication rates from large numbers of patients and surgeons.

METHODS

Cases of pediatric scoliosis (age ≤18 years), entered into the Scoliosis Research Society M&M database between 2004 and 2007, were analyzed. Age, scoliosis type, type of instrumentation used, and complications were assessed.

RESULTS

A total of 19,360 cases fulfilled inclusion criteria. Of these, complications occurred in 1971 (10.2%) cases. Overall complication rates differed significantly among idiopathic, congenital, and neuromuscular cases (P < 0.001). Neuromuscular scoliosis had the highest rate of complications (17.9%), followed by congenital scoliosis (10.6%) and idiopathic scoliosis (6.3%). Rates of neurologic deficit also differed significantly based on the etiology of scoliosis (P < 0.001), with the highest rate among congenital cases (2.0%), followed by neuromuscular types (1.1%) and idiopathic scoliosis (0.8%). Neur-omuscular scoliosis and congenital scoliosis had the highest rates of mortality (0.3% each), followed by idiopathic scoliosis (0.02%). Higher rates of new neurologic deficits were associated with revision procedures (P < 0.001) and with the use of corrective osteotomies (P < 0.001). The rates of new neurologic deficit were significantly higher for procedures using anterior screw-only constructs (2.0%) or wire-only constructs (1.7%), compared with pedicle screw-only constructs (0.7%) (P < 0.001).

CONCLUSION

In this review of a large multicenter database of surgically treated pediatric scoliosis, neuromuscular scoliosis had the highest morbidity, but relatively high complication rates occurred in all groups. These data may be useful for preoperative counseling and surgical decision-making in the treatment of pediatric scoliosis.

Endoscopic minimally invasive neurosurgery: emerging techniques and expanding role through an extensive review of the literature and our own experience - part II: extraendoscopic neurosurgery

BACKGROUND/AIMS

The field of minimally invasive neurosurgery has grown dramatically especially in the last decades. This has been possible, in the most part, due to the advancements in technology especially in tools such as the endoscope. The contemporary classification scheme for endoscopic procedures needs to advance as well.

METHODS

The present classification scheme for neuroendoscopic procedures has become confusing because it mainly describes the use of the endoscope as an assisting device to the microscope. The authors propose an update to the current classification that reflects the independence of the endoscope as a tool in minimally invasive neurosurgery.

RESULTS

The proposed classification groups the procedures as 'intraendoscopic' neurosurgery or 'extraendoscopic' neurosurgery (XEN) in relation to the 'axis' of the endoscope. A review of the literature for the XEN group together with exemplary cases is presented.

CONCLUSION

We presented our proposed classification for the endoscope-only surgical procedures. The XEN group is expanded in this article.

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.

Thoracolumbar spinal deformity: Part II. Developments from 1990 to today: historical vignette

In the first part of this 2-part historical review, the authors outlined the early diagnostic and therapeutic strategies used in the management of spinal deformity. In this second part, they expand upon those early innovations and further detail the advances from 1990 to the modern era.

Thoracoscopy for minimally invasive thoracic spine surgery

Thoracoscopy has been used worldwide for many years by thoracic surgeons. Despite a long learning curve and technical demands of the procedure, thoracoscopy has several advantages, including better cosmesis, adequate exposure to all levels of the thoracic spine from T2 to L 1, better illumination and magnification at the site of surgery, less damage to the tissue adjacent to the surgical field, less morbidity when compared with standard thoracotomy in terms of respiratory problems, pain, blood loss, muscle and chest wall damages, consequent shorter recovery time, less postoperative pulmonary function impairment, and shorter hospitalization. Good results at short- and medium-term follow-up need to be confirmed at long-term follow-up.

The learning curve of pedicle screw placement: how many screws are enough?

STUDY DESIGN

A retrospective study.

OBJECTIVE

Assess the learning curve of pedicle screw (PS) placement of a Spinal Surgery Fellow (SSF) with no previous experience with the technique.

SUMMARY OF BACKGROUND DATA

Recent studies have attempted to identify the learning curve for different surgical procedures to define training requirements. Several authors have described a learning curve for PS placement. However, no one has defined the number of PS necessary to be competent in this skill.

METHODS

All patients who had PS inserted by the SSF under the supervision of an Attending Spinal Consultant (ASC) and had adequate postoperative radiographs and computed tomography scans available, were included in this study. PS position was assessed by 2 blinded independent observers using a grading scale. PS placement by the SSF was evaluated by examining the assessed position in chronological groups of 40 screws. RESULTS.: Ninety-four patients underwent internal fixation of the spine with 582 PS. Eight cases (40 screws) were excluded because of lack of imaging studies. Of the 542 screws under evaluation, 320 (59%) were performed by the SSF, 187 (34.5%) by the ASC, and 35 (6.5%) by advanced orthopedic or neurosurgical trainees.The rate of misplaced PS performed by the SSF for the first 80 PS was 12.5% and dropped to 3.4% for the remaining 240 screws, which is a statistically significant difference (P < 0.01). Evaluation of computed tomography of vertebrae with PS placed by the SSF on one side and by the ASC on the other showed that the ASC achieved better placement during the first 80 PS (P < 0.01). However, this difference disappeared in the last 240 (P = 1.00).

CONCLUSION

The findings demonstrate a learning curve for PS placement. In this series, the asymptote for this technique for an inexperienced SSF, started after about 80 screws (approximately 25 cases).

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).

Radiographic outcomes over time after endoscopic anterior scoliosis correction: a prospective series of 106 patients

STUDY DESIGN

A prospective, consecutive series of 106 patients receiving endoscopic anterior scoliosis correction.

OBJECTIVE

To analyze changes in radiographic parameters and rib hump in the 2 years after surgery.

SUMMARY OF BACKGROUND DATA

Endoscopic anterior scoliosis correction is a level sparing approach and therefore, it is important to assess the amount of decompensation which occurs after surgery.

METHODS

All patients received a single anterior rod and vertebral body screws using a standard compression technique. Cleared disc spaces were packed with either mulched femoral head allograft or rib head/iliac crest autograft. Radiographic parameters (major, instrumented, minor Cobb, T5-T12 kyphosis) and rib hump were measured at 2, 6, 12, and 24 months after surgery. Paired t tests and Wilcoxon signed ranks tests were used to assess the statistical significant of changes between adjacent time intervals.

RESULTS

Mean loss of major curve correction from 2 to 24 months after surgery was 4 degrees. Mean loss of rib hump correction was 1.4 degrees. Mean sagittal kyphosis increased from 27 degrees at 2 months to 30.6 degrees at 24 months. Rod fractures and screw-related complications resulted in several degrees less correction than patients without complications, but overall there was no clinically significant decompensation after complications.

CONCLUSION

There are small changes in deformity measures after endoscopic anterior scoliosis surgery, which are statistically significant but not clinically significant.

Novel dual-rod screw for thoracoscopic anterior instrumentation: biomechanical evaluation compared with single-rod and double-screw/double-rod anterior constructs

STUDY DESIGN

A novel dual-rod screw was designed to provide a second-rod augmentation at the critical apical/middle segments of the single-rod thoracoscopic anterior construct. Biomechanical testing was performed on pig thoracic spines instrumented with 7-segment anterior scoliosis constructs.

OBJECTIVES

To analyze the biomechanical performance of the new implant, and compare it to a single-rod and double-rod anterior constructs.

SUMMARY OF BACKGROUND DATA

Using single-rod thoracoscopic anterior instrumentation for thoracic scoliosis, the complications of rod breakage at apex, high rate of nonunion, and resultant loss of coronal and sagittal correction has been reported. Inadequate construct stiffness because of a smaller diameter single rod has been implicated as the cause of these complications.

METHODS

Twelve pig thoracic spines were instrumented over 7 segments with: (1) single-rod construct, (2) short second-rod augmentation at the apex of the single-rod construct, (3) long second-rod augmentation at middle segments of the single-rod construct, and (4) double-screw/double-rod anterior construct. The spines were tested in flexion-extension, left-right lateral bending, and torsion, using pure bending moments. Strain gauges attached to the primary single rod at the cephalad, middle, and caudal portions were used and the maximum tensile stress was recorded.

RESULTS

In the single-rod construct, the middle portion stress was 39% to 51% greater than the stress in the cephalad and caudal portions in flexion-extension (P < 0.05), and the cephalad portion stress was 39% to 65% greater than the stress in the middle and caudal portions in right lateral bending and torsion (P < 0.05). When a second rod was added at the apical/middle portion, the middle portion stress decreased from 50% to 72% in flexion-extension and right lateral bending (P < 0.05). In addition, the second rod decreased the primary single-rod stress at the cephalad portion by 48% (left torsion) and the caudal portion by 50% (flexion). Double-screw/double-rod construct significantly increases the construct stiffness in comparison with the single-rod construct. However, it did not add any construct stiffness at the critical apical segments when compared to the constructs in which the second rod augmented the single-rod constructs.

CONCLUSION

A novel dual-rod screw was designed to combine the standard single-rod construct with the addition of a second rod at the critical apical/middle segments and increase construct stiffness and stability. This implant may therefore prevent pseudarthrosis and rod breakage by enhancing construct stiffness.

Accuracy of thoracic vertebral screw insertion in adolescent idiopathic scoliosis: a comparison between thoracoscopic and mini-open thoracotomy approaches

STUDY DESIGN

A cross-sectional study with axial computed tomography (CT) to compare the accuracy of vertebral screw insertion in the thoracic spine for adolescent idiopathic scoliosis (AIS) between the thoracoscopic and the mini-open thoracotomy approach.

OBJECTIVE

To evaluate the safety of vertebral screw placement in anterior instrumentation for thoracic AIS.

SUMMARY OF BACKGROUND DATA

Thoracoscopic anterior instrumentation has been used with good results for AIS. It is technically demanding especially for the insertion of vertebral screws. The important issue of whether the screws inserted thoracoscopically is as accurate and safe as those inserted through thoracotomy approach has not been well studied.

METHODS

Thirty-one patients with thoracic AIS receiving thoracoscopic or mini-open thoracotomy anterior instrumentation were included in this study. They were divided into Group A and B, respectively. Postoperative sequential CT scanning on the thoracic vertebral screws was carried out. The relative position between screws and the spinal canal, the aorta, and the bicortical purchase were analyzed with CT images. The percentage of screws in good position was defined and further analyzed.

RESULTS

Seventy-three and 162 thoracic vertebral screws were inserted in 10 patients in Group A and 21 patients in Group B, respectively. Eighty-nine percent of screw tips in Group A and 80.2% in Group B were distant from the aorta, 89.0% and 87.0% of screws achieved bicortical purchase in Group A and B, respectively. No significant difference was found in all thoracic levels including the upper thoracic, periapical, or lower thoracic vertebrae. Seventy-four percent and 66.7% of screws were in good positions in Group A and B, respectively and there was no statistically significant difference between the 2 groups.

CONCLUSION

The vertebral screws inserted through thoracoscopic approach were as accurate as those inserted through a mini-open thoracotomy approach. The accuracy could be enhanced by using screws with smaller increments, with special attention to the possible migration of aorta with anterior spinal instrumentation.

Surgical treatment of main thoracic scoliosis with thoracoscopic anterior instrumentation. a five-year follow-up study

BACKGROUND

The surgical outcomes in patients with scoliosis at two years following anterior thoracoscopic spinal instrumentation and fusion have been reported. The purpose of this study was to evaluate the results at five years.

METHODS

A consecutive series of forty-one patients with major thoracic scoliosis treated with anterior thoracoscopic spinal instrumentation was evaluated at regular intervals. Prospectively collected data included patient demographics, radiographic measurements, clinical deformity measures, pulmonary function, an assessment of intervertebral fusion, and the scores on the Scoliosis Research Society (SRS-24) outcomes instrument. Perioperative and postoperative complications were recorded. Patient data for the preoperative, two-year, and five-year postoperative time points were compared. In addition, a univariate analysis compared selected two-year radiographic, pulmonary function, and SRS-24 data of the study cohort and those of the patients lost to follow-up.

RESULTS

Twenty-five (61%) of the original forty-one patients had five-year follow-up data and were included in the analysis. Between the two-year and five-year follow-up visits, no significant changes were observed with regard to the average percent correction of the major Cobb angle (56% +/- 11% and 52% +/- 14%, respectively), average total lung capacity as a percent of the predicted value (95% +/- 14% and 91% +/- 10%), and the average total SRS-24 score (4.2 +/- 0.4 and 4.1 +/- 0.7). Radiographic evaluation of intervertebral fusion at five years revealed convincing evidence of a fusion with remodeling and trabeculae present at 151 (97%) of the 155 instrumented motion segments. No postoperative infections or clinically relevant neurovascular complications were observed. Rod failure occurred in three patients, and three patients required a surgical revision with posterior spinal instrumentation and fusion.

CONCLUSIONS

Thoracoscopic anterior instrumentation for main thoracic idiopathic scoliosis results in five-year outcomes comparable with those reported previously for open anterior and posterior techniques. The radiographic findings, pulmonary function, and clinical measures remain stable between the two and five-year follow-up time points. Thoracoscopic instrumentation provides a viable alternative to treat spinal deformity; however, the risks of pseudarthrosis, hardware failure, and surgical revision should be considered along with the advantages of limited muscular dissection and improved scar appearance.

LEVEL OF EVIDENCE

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

Comparison between 4.0-mm stainless steel and 4.75-mm titanium alloy single-rod spinal instrumentation for anterior thoracoscopic scoliosis surgery

STUDY DESIGN

Retrospective review of a consecutive, single surgeon case series.

OBJECTIVE

To compare minimum 2-year postoperative outcomes between 4.0-mm stainless steel and 4.75-mm titanium alloy single-rod anterior thoracoscopic instrumentation for the treatment of thoracic idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Advances in anterior thoracoscopic spinal instrumentation for scoliosis have attempted to mitigate the postoperative complications of rod failure, pseudarthrosis, and deformity progression. Biomechanical data suggest that the 4.75-mm titanium construct has a lower risk of fatigue failure compared to the 4.0-mm stainless steel construct.

METHODS

Sixty-four consecutive anterior thoracoscopic spinal instrumentation cases in patients with thoracic scoliosis performed by a single surgeon and with minimum 2-year follow-up were retrospectively reviewed. The first 34 cases used a 4.0-mm stainless steel (SS) construct, whereas the subsequent 30 cases used a 4.75-mm titanium (Ti) alloy instrumentation system. The first 10 SS cases and the first 5 Ti cases were excluded from the statistical comparison to account for a potential learning curve effect. A multivariate analysis of variance (P < 0.05) was used to compare radiographic, perioperative, and postoperative complication data between patients surgically treated with the 2 different instrumentation systems.

RESULTS

Patients in the SS group (n = 24) underwent surgery from 2000 to 2001, whereas patients in the Ti group (n = 25) underwent surgery from 2002 to 2004. The mean age at surgery, gender ratio, length of hospitalization, estimated blood loss, and operative time were not statistically different between the 2 patient groups (P > 0.13). The average follow-up in the SS group was, however, significantly longer than in the Ti group (4.0 +/- 1.4 years vs. 2.3 +/- 1.0 years; P = 0.001). Preop main thoracic Cobb angles were similar between the 2 groups (P = 0.62); however, the 2-year main thoracic Cobb was significantly smaller (P = 0.03) and the 2-year percent correction was significantly greater in the Ti group (P = 0.03). Five patients (21%) in the SS group had a pseudarthrosis, 3 (13%) experienced rod failure, and 2 (8%) required a revision posterior spinal fusion. In the Ti group, 2 patients (8%) had a pseudarthrosis, and no patient experienced rod failure or required a revision procedure.

CONCLUSION

Although the average follow-up in the Ti group was significantly shorter than in the SS group, the 4.75-mm titanium alloy construct resulted in improved maintenance of deformity correction at 2-years postop and a lower incidence of instrumentation-related complications (pseudarthrosis, rod breakage, and surgical revisions) compared to the 4.0-mm stainless steel construct. Improved outcomes with the titanium alloy construct are likely because of the mechanical properties of the implant, refined patient selection criteria, and greater surgical experience gained with time.

DECISION MAKING IN PEDIATRIC SPINAL DEFORMITY

OBJECTIVE

To review the concepts involved in the decision-making process for management of pediatric patients with spinal deformity.

METHODS

The literature was reviewed in reference to pediatric deformity evaluation and management.

RESULTS

Pediatric spinal deformity includes a broad range of disorders with differing causes, natural histories, and treatments. Appropriate categorization of pediatric deformities is an important first step in the clinical decision-making process. An understanding of both nonoperative and operative treatment modalities and their indications is requisite to providing treatment for pediatric patients with spinal deformity. The primary nonoperative treatment modalities include bracing and casting, and the primary operative treatments include nonfusion instrumentation and fusion with or without instrumentation. In this article, we provide a review of pediatric spinal deformity classification and an overview of general treatment principles.

CONCLUSION

The decision-making process in pediatric deformity begins with appropriate diagnosis and classification of the deformity. Treatment decisions, both nonoperative and operative, are often predicated on the basis of the age of the patient and the natural history of the disorder.

Anterior thoracoscopic instrumentation in adolescent idiopathic scoliosis: a systematic review

STUDY DESIGN

A Systematic Review of published series of patients with adolescent idiopathic scoliosis treated with anterior thoracoscopic instrumentation.

OBJECTIVE

To conduct a systematic review of the results of thoracoscopic surgery and to compare them with those of open anterior and posterior spine instrumentation to enable surgeons judge the applicability of the method.

SUMMARY OF BACKGROUND DATA

Instrumentation through video-assisted thoracoscopic surgery is an attractive alternative for the treatment of thoracic adolescent idiopathic scoliosis. The advantages claimed by its proponent over conventional instrumentations are better cosmesis and reduced morbidity due its minimal invasive nature. However, superiority of thoracoscopic instrumentation over conventional methods has not been proven so far.

METHODS

Via Medline, Pubmed, and other literature searches, 8 articles met the inclusion criteria for our systematic review. The evaluations were made according to the parameters employed for evaluating spinal deformities. Instrumentation through video-assisted thoracoscopic surgery results were compared to those of open anterior or posterior surgeries.

RESULTS

Mean number of instrumented levels was 7. The extent of disc excision was not indicated in any of the studies. The mean operative time was found to be approximately 5.2 hours. Average blood loss was 391.7 mL (100-1300 mL). The average Cobb curve correction was 64.6%. The mean preoperative kyphosis angle was 21.3 degrees ; the postoperative kyphosis angle was 25.2 degrees . These angular corrections were found to be comparable to posterior procedures using hooks, but less than with pedicle screws. Two studies reported on patient satisfaction favoring thoracoscopic instrumentation. Instrumentation-related complications were the most predominant.

CONCLUSION

Anterior thoracoscopic instrumentation is comparable in terms of curve correction to anterior or posterior procedures. Theoretical advantages of better cosmesis and less aggressiveness seem to be offset by the increased operative and intensive care unit time, and complication rate. More prospective studies need to be conducted to determine the benefit and general applicability of this procedure.

Minimally invasive posterior thoracic fusion

Thoracic spine fusion may be indicated in the surgical treatment of a wide range of pathologies, including trauma, deformity, tumor, and infection. Conventional open procedures for surgical treatment of thoracic spine disease can be associated with significant approach-related morbidity, which has motivated the development of minimally invasive approaches. Thoracoscopy and, later, video-assisted thoracoscopic surgery were developed to address diseases of the thoracic cavity and subsequently adapted for thoracic spine surgery. Although video-assisted thoracoscopic surgery has been used to treat a variety of thoracic spine diseases, its relatively steep learning curve and high rate of pulmonary complications have limited its widespread use. These limitations have motivated the development of minimally invasive posterior approaches to address thoracic spine pathology without the added risk of morbidity involved in surgically entering the chest. Many of these advances are ongoing and represent the forefront of minimally invasive spine surgery. As these techniques are developed and applied, it will be important to assess their equivalence or superiority in comparison with standard open techniques using prospective trials. In this paper the authors focus on minimally invasive posterior thoracic procedures that include fusion, and provide a review of the current literature, a discussion of future pathways for development, and case examples. The topic is divided by pathology into sections including trauma, deformity, spinal column tumors, and osteomyelitis.

Financial analysis of circumferential fusion versus posterior-only with thoracic pedicle screw constructs for main thoracic idiopathic curves between 70 degrees and 100 degrees

PURPOSE

Reports on thoracic pedicle screw (TPS) constructs have demonstrated their safety and efficacy; however, concerns exist regarding their increased cost. This is a review of adolescents with main thoracic scoliosis surgically treated with anterior release and posterior fusion or posterior fusion only. The objectives were to compare the radiographic outcomes and financial data of two surgical treatments: anterior/posterior spinal fusion (APSF) versus posterior spinal fusion (PSF-TPS) alone with TPSs, in patients with large 70-100 degrees main thoracic adolescent idiopathic scoliosis (AIS) curves.

METHODS

We identified 43 patients with main thoracic Lenke type 1-4 AIS curves between 70 and 100 degrees who had been treated with either APSF or PSF-TPS.

RESULTS

Both groups had equivalent radiographic corrections postoperatively. The PSF-TPS group patients had higher implant charges, but the APSF group had higher surgeon procedural charges, operating room charges, anesthesia charges, and inpatient room charges. Total charges were $75,295 for the APSF group and $71,236 for the PSF-TPS group (P > 0.05). Analyses of two subgroups of the APSF group, anterior release via thoracotomy versus VATS and same-day versus staged surgeries, failed to change any of the above findings.

CONCLUSION

Based on this financial analysis, there was no statistically significant differences between the APSF and PSF-TPS groups, with equivalent radiographic corrections.

Training and evaluating spinal surgeons: the development of novel performance measures

STUDY DESIGN

Cohort study.

OBJECTIVE

The purpose of this study was to develop and validate a series of novel assessment measures for use during a lumbar pedicle cannulation task.

SUMMARY OF BACKGROUND DATA

There is increasing pressure being placed on the surgical community to develop appropriate assessment measures of technical skills as an indicator of surgical competence. To date, little research has been performed in this area in spinal surgery.

METHODS

Twelve novice and 7 expert spine surgeons cannulated a complete set of lumbar pedicles on a synthetic model. Electromagnetic markers were traced to record their dominant hand and arm movements while the forces applied to the model were measured using a small force plate. The amount of wrist motion, mean forces, peak forces, and task time were evaluated. Following task completion, angles of pedicle cannulation and the number and location of all breaches in the models were recorded.

RESULTS

Novice surgeons used less mean force (91 N vs. 115 N, P = 0.001) but required more time to perform each cannulation task (12.4 seconds vs. 8.2 seconds, P < 0.001). Cannulation by novices demonstrated a greater mean number of frank (far lateral) pedicle breaches (1.5 vs. 0 per individual, P = 0.002), but no differences in the angles of cannulation were seen (P = 0.988).

CONCLUSION

Four variables, 3 involving process measures and 1 an outcome measure, can be used to distinguish between novice and expert spine surgeons using a simple lumbar spine pedicle cannulation task, providing evidence of their construct validity. Knowledge of these differences may be useful in objective evaluation of surgical competence and providing precise feedback during the training of this skill, thereby enhancing learning.

Comparison of effectiveness of Halo-femoral traction after anterior spinal release in severe idiopathic and congenital scoliosis: a retrospective study

Background

Halo-femoral traction could gradually improve the coronal and sagittal deformity and restore the trunk balance through the elongation of the spine. The purpose of this retrospective study was to assess the effectiveness of Halo-femoral traction after anterior spinal release in the management of severe idiopathic and congenital scoliosis.

Methods

Sixty patients with severe and rigid curve treated with anterior spinal release, Halo-femoral traction, and second stage posterior spinal fusion were recruited for this retrospective study. Idiopathic Scoliosis (IS) group was 30 patients (23 females and 7 males) with mean age of 15.5 years. The average coronal Cobb angle was 91.6° and the mean global thoracic kyphosis was 50.6°. The curve type of these patients were 2 with Lenke 1AN, 4 with Lenke 1A+, 1 with Lenke 1BN, 10 with Lenke 1CN, 3 with Lenke 1C+, 3 with Lenke 3CN, 3 with Lenke 3C+, and 4 with Lenke 5C+. Congenital Scoliosis (CS) group included 30 patients (20 females and 10 males) with average age of 15.2 years. The average coronal Cobb angle of the main curve before operation was 95.7° and the average thoracic kyphosis was 70.2°. All patients had a minimum 12-month follow-up radiograph (range 12–72 months, mean 38 months).

Results

The average traction time was 23 days and the average traction weight was 16 kg. Four patients experienced brachial plexus palsy and complete nerve functional restoration was achieved at two months follow-up. For the IS group, the post-operative mean Cobb angle of major curve averaged 40.1° with correction rate of 57.5%. For the CS group, the post-operative mean Cobb angle was 56.5° with average correction rate of 45.2%. The difference in curve magnitude between the IS and CS patients after posterior correction was statistically significant (t = 4.15, p < 0.001). The correction rate of kyphosis between IS and CS patients was also statistically significant (t = -2.59, p < 0.016).

Conclusion

Halo-femoral traction was a safe, well-tolerated and effective method for the treatment of severe and rigid scoliosis patients. The posterior correction rate obtained after anterior release and traction was significant superior than that recorded from side bending film in current study.

Anterior and thoracoscopic scoliosis surgery for idiopathic scoliosis

Surgical management of idiopathic scoliosis is based on the natural history of this spinal disorder and on the likelihood of developing a worsening deformity. Anterior surgical treatments continue to evolve and provide advantages over posterior procedures in specific instances. Open and thoracoscopic anterior approaches allow direct access to the anterior stabilizing structures of the spine, enable mobilization of a rigid deformity, and provide a large surface area for arthrodesis. Thoracoscopic procedures provide a more cosmetically appealing alternative to a large midline posterior or anterolateral thoracotomy scar. Although the indications and contraindications for anterior versus posterior surgical intervention (for thoracic and thoracolumbar curve patterns) have been defined to some degree, there remains appropriate flexibility in the decision-making process, allowing the surgeon to make an optimal recommendation for each patient based on surgeon experience and patient needs.

Emerging minimally invasive technologies for the management of scoliosis

Surgery for scoliosis has evolved dramatically over the past century -- from posterior surgery and casting that resulted in poor deformity correction and high pseudarthrosis rates and that required prolonged bed rest to anterior thoracoscopic and miniopen approaches that result in reproducible curve correction ranging from 55% to 70% with high fusion rates. The future of scoliosis surgery lies in the application of growth-modulation approaches by way of minimally invasive techniques, which will result in curve correction while maintaining spinal motion and disc and motion segment integrity. The optimal approach will use genetic testing to predict curve progression, thereby providing the clinical data required for determining the appropriate candidate for the use of this strategy.

Video-assisted thoracoscopic surgery compared with thoracotomy: early and late follow-up of radiographical and functional outcome

BACKGROUND CONTEXT

Video-assisted thoracoscopic surgery (VATS) is a new technique that allows for access to anterior spinal pathology using a minimally invasive approach. Proponents of this procedure argue that anterior thoracic spine surgery can be performed with the same accuracy and completeness as is possible by the conventional open approach but through much smaller skin and muscle incisions. Advantages of VATS include decreased blood loss, shorter hospital stay, and improved cosmesis.

PURPOSE

To detect if VATS is equally as effective as open thoracotomy, both combined with instrumented posterior spinal fusion, with respect to fusion rate, percent curve correction, and functional outcome.

STUDY DESIGN

Retrospective case control.

PATIENT SAMPLE

Seventeen patients underwent VATS/instrumented posterior spinal fusion for thoracic curvatures exceeding 50 degrees . A control cohort of patients that were age matched, sex matched, and curve magnitude matched underwent open thoracotomy/instrumented posterior spinal fusion.

OUTCOME MEASURES

Percentage of curve correction, fusion rate, intraoperative and postoperative clinical parameters, and functional outcome scores.

METHODS

Preoperative and postoperative radiographs were analyzed to calculate the percentage of major curve correction in the coronal and sagittal planes as well as the rate of fusion. In addition, operative reports and medical records were analyzed for the following outcomes: estimated operative blood loss, length of surgery, chest tube output, length of hospitalization, and complications. Average follow-up time was 26 months in the VATS group and 27 months in the thoracotomy group. Finally, functional outcome was assessed using the Scoliosis Research Society (SRS-22) and Oswestry Disability Index (ODI) scoring system.

RESULTS

The VATS group (mean age, 30) averaged 5.4 anterior levels and 11 posterior levels fused. The thoracotomy group (mean age, 32) averaged 5.8 anterior levels and 12 posterior levels fused. Estimated blood loss was nearly identical for the posterior procedures in both groups, whereas the anterior blood loss was significantly higher in the thoracotomy group as compared with the VATS group (541 cc vs. 288 cc). Operative time did not differ significantly between the two cohorts. Percent curve correction immediately postoperative (52% correction VATS; 51% correction thoracotomy) as well as at the 2-year follow-up (50% VATS and 54% thoracotomy) was nearly identical. There was no difference in postoperative ODI (p=.6) or SRS scores (p=.5) between groups. Complications were frequent but not significantly different between the two groups (p=.3).

CONCLUSION

VATS is equally effective as thoracotomy with respect to fusion rate, major curve correction, and functional outcome scores. Although a decrease in operative blood loss was seen in the VATS patients, this was not clinically significant.

Perioperative Aspects of Endoscopic Anterior Scoliosis Surgery: The Learning Curve for a Consecutive Series of 100 Patients

The reported benefits of endoscopic versus open scoliosis surgery include improved visualization, a muscle sparing approach, reduced pulmonary morbidity, reduced pain, and improved cosmesis. Some aspects of the surgical learning curve for this technically demanding method have been previously reported; however, improvements in other factors with increasing experience have not been quantified. This paper presents a series of 100 consecutive endoscopic anterior scoliosis corrections performed between April 2000 and February 2006. We report changes in the following perioperative factors with increasing experience; operative set-up time, operative time, x-ray irradiation time, number of instrumented levels, blood loss, intercostal catheter drainage, chest drain removal time, days in intensive care, days to mobilize, days in hospital, and early complications. Statistical comparisons were made between the first 20 (1 to 20), middle 20 (41 to 60), and last 20 (81 to 100) cases. Results showed statistically significant improvements and increased consistency in operative time, operative set-up time, x-ray irradiation time, blood loss, hospital stay, and mobilization time with experience. The complication rate was comparable to other recently published endoscopic studies. In the last 20 cases of the series, operative times had reduced to 35 minutes per level, x-ray irradiation times to 15 seconds per level, and blood loss to 38 mL per level. Most perioperative surgical factors therefore improve significantly with increasing experience in endoscopic anterior scoliosis correction.

The anatomical relationship between the aorta and the thoracic vertebral bodies and its importance in the placement of the screw in thoracoscopic correction of scoliosis

Thoracoscopically-assisted anterior spinal instrumentation is being used widely to treat adolescent idiopathic scoliosis (AIS). Recent studies have showed that screws placed thoracoscopically could counter the aorta or entrance into the spinal canal. There are a few studies defining the anatomic landmarks to identify the relationship between the aorta and the thoracic vertebral body using quantitative measurement for the sake of safe placement of thoracoscopic vertebral screw in anterior correction for AIS. The CT scanning from T4 to T12 in 64 control subjects and 30 AIS patients from mainland China were analyzed manually. Parameters to be measured included the angle for safety screw placement (alpha), the angle of the aorta relative to the vertebral body (beta), the distance from the line between the left and the right rib heads to the anterior wall of the vertebral canal (a), the distance from the left rib head to posterior wall of the aorta (b), the vertebral body transverse diameter (c) and vertebral rotation (gamma). No significant differences were found between the groups with respect to age or sex. Compared with the control group, alpha angle from T7 to T10, beta angle from T5 to T10 and b value at T9, T10 were significantly lower in the scoliotic group. The a value was significantly lower in the scoliotic group. The c value showed no significant difference between the two groups. In conclusion, to place the thoracoscopic vertebral screw safely, at the cephalad thoracic spine (T4-T6), the maximum ventral excursion angle should decrease gradually from 20 degrees to 5 degrees , the entry-point of the screw should be close to the rib head. For apical vertebrae (T7-T9), the maximum ventral excursion angle increased gradually from 5 degrees to 12 degrees. At the caudal thoracic spine (T10-T12), the maximum ventral excursion angle increased, the entry-point should shift 3 approximately 5 mm ventrally.

[Video-assisted thoracic surgery to treat spinal deformities: climbing the learning curve]

OBJECTIVE

The aim of this study was to analyze the impact of the learning curve on the preliminary results of video-assisted thoracic surgery for spinal deformities in a general hospital setting.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of 15 patients who underwent video-assisted thoracic surgery performed by a multidisciplinary team comprising orthopedic and thoracic surgeons. Endoscopic anterior release and fusion were followed by posterior instrumentation in a single procedure. Demographic, orthopedic, morbidity, and mortality statistics were compiled for the 15 patients and compared to results reported for similar series.

RESULTS

Endoscopic surgery was indicated for 15 patients: 11 women (73.3%) and 4 men (26.7%). The median age was 15 years (interquartile range [IQR], 14-19 years). Three patients (20%) required conversion to thoracotomy. There were 2 serious (13.3%) and 3 minor complications (20%). They all resolved satisfactorily and there was no perioperative mortality. The median Cobb angle was 71 degrees (IQR, 63.75 degrees -75.25 degrees ) before surgery and 41 degrees (IQR, 30 degrees -50 degrees ) after surgery. Median duration of surgery was 360 minutes (IQR, 300-360 minutes), duration of postoperative recovery unit stay was 1.5 days (IQR, 1-2.75 days), and total hospital stay was 11.5 days (IQR, 8.25-14 days).

CONCLUSIONS

Despite the complexity of video-assisted thoracic surgical procedures, we believe they will become the standard approach to treating spinal deformities in the near future. By working together in general hospital settings, orthopedic and thoracic surgeons can help to overcome the steep yet manageable learning curve.

Video-assisted thoracoscopic surgery in idiopathic scoliosis: evaluation of the learning curve

STUDY DESIGN

Retrospective review of patients with idiopathic scoliosis who underwent same-day or staged anterior and posterior spinal fusion and segmental spinal instrumentation.

OBJECTIVE

Evaluation of our learning curve with video-assisted thoracoscopic surgery (VATS) with respect to operative time, blood loss, and complications in patients with idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

VATS is a minimally invasive alternative to thoracotomy in the management of idiopathic scoliosis. An increased or steep learning curve has been described in the initial application of this technique.

METHODS

We began performing VATS in 1998. We compared our first 25 consecutive VATS patients (Group 2) and subsequent 28 consecutive VATS patients (Group 3) to our previous 16 consecutive patients (Group 1) with a thoracotomy (1991-1998) for idiopathic scoliosis. Training at a sponsored regional course was obtained before performing our first VATS procedure.

RESULTS

VATS allowed more disc to be excised in Group 2 (4.5 +/- 1, 5.7 +/- 1, and 4.4 +/- 1 discs in Group 1, Group 2, and Group 3, respectively) and significantly decreased the anterior operative time (215 +/- 33, 260 +/- 56, and 177 +/- 47 minutes) and time per individual disc excision (50 +/- 13, 47 +/- 12, and 41 +/- 12 minutes), while providing comparable correction of the thoracic deformity (67% +/- 12%, 66% +/- 10%, and 70% +/- 13% correction). There was no increase in estimated intraoperative anterior blood loss (228 +/- 213, 183 +/- 136, and 211 +/- 158 mL), estimated blood loss per disc excised (51 +/- 42, 34 +/- 29 and 48 +/- 37 mL), or complications in the VATS groups. Complications were primarily pulmonary and resolved with medical therapy. Postoperative chest tube drainage (855 +/- 397, 462 +/- 249, and 561 +/- 261 mL) and total perioperative anterior blood loss (1083 +/- 507, 647 +/- 309, and 773 +/- 308 mL) were significantly decreased in the VATS groups, but this was attributed to the use of Amicar.

CONCLUSIONS

VATS is an effective procedure for anterior spinal fusion in idiopathic scoliosis. The learning curve is short, provided appropriate training is obtained.

Sagittal plane analysis of adolescent idiopathic scoliosis after VATS (video-assisted thoracoscopic surgery) anterior instrumentations

Radiographic sagittal plane analysis of VATS (video-assisted thoracoscopic surgery) anterior instrumentation for adolescent idiopathic scoliosis. This is retrospective study. To report, in details about effects of VATS anterior instrumentation on the sagittal plane. Evaluations of the surgical outcome of scoliosis have primarily studied in coronal plane correction, functional, and cosmetic aspects. Sagittal balance, as well as coronal balance, is important in functional spine. Recently, scoliosis surgery applying VATS has been increasingly performed. Its outcome has been reported several times; however, according to our search of the literature, the only one study partially mentioned. The study population was a total of 42 cases of idiopathic scoliosis patients (8 male, 34 female). Their mean age was 15.6 years (13 to 18 years). The 18 cases were Lenke IA type, 16 cases were Lenke IB type, and 8 cases were Lenke IC type. The preoperative Cobb's angle was 54.5 +/- 13.9 degrees. All patients were followed up for a minimum of 2 years and implanted, on average, at the 5.9 level (5 to 8 levels). The most proximal implant was the 4th thoracic spine, and the most distal implant was the 1st lumbar spine. Whole spine standing PA and lateral radiographs were taken before surgery, 2 months after surgery, and at the last follow up (range 24-48 months, mean 35 months). The C7 plumbline proximal junctional measurement (PJM), distal junctional measurement (DJM), thoracic kyphosis, and lumbar lordosis angles were measured and compared. In all cases, follow-ups were possible and survived till the last follow up. The Cobb's angle in coronal plane at the last follow up was 19.7 +/- 9.3 degrees and was corrected to 63.8% on average. The preoperative C7 sagittal plumbline before surgery was -13.9 +/- 29.1 mm, the final follow up was -9.9 +/- 23.8 mm, and the average positive displacement was 4 mm. Thoracic kyphosis was increased from preoperative 18.2 +/- 7.7 degrees to 22.4 +/- 7.2 degrees on average at the last follow up, and the increase was, on average, 4.2 degrees. The PJM angel was increased from 6.2+/- 4.3 degrees preoperative to 8.8 +/- 3.7 degrees at the last follow up, and the increment was, on the average, 2.6 degrees. The DJM angle before surgery was 6.8 +/- 5.1 degrees and 6.7 +/- 4 degrees at the last follow up, and did not change noticeably. Preoperative lumbar lordosis was 42 +/- 10.7 degrees and 43.5 +/- 11.1 degrees after surgery. Similarly, it did not change greatly. The scoliosis surgery applying VATS displaced the C7 sagittal plumb line by 4 mm to the anteriorly, increased thoracic kyphosis by 4.2 degrees, and increased PJM by 2.6 degrees. DJM and lumbar lordosis, before and after operation, were not significantly different. Although the surgical technique of VATS thoracic instrumentation is difficult to make the normal thoracic kyphosis, an acceptable sagittal balance can be obtained in Lenke type I adolescent idiopathic scoliosis using VATS.