Comparison of anterior and posterior double-rod instrumentation for thoracic idiopathic scoliosis: results of 141 patients

Delayed hemothorax after anterior vertebral body tethering in adolescent idiopathic scoliosis: a case report

PURPOSE

The aim of this case report is to report that delayed hemothorax is possible after anterior vertebral body tethering (aVBT) and to illustrate the course of treatment.

METHODS

We present a 15-year-old boy with adolescent idiopathic scoliosis who underwent an anterior thoracoscopic assisted vertebral body tethering who developed a massive right-sided hemothorax 12 days post-operatively. A chest tube was placed to drain the hemothorax and later required embolectomy with tissue plasminogen activator (TPA) to drain the retained hemothorax.

RESULTS

At 1 month follow up post discharge the patient was asymptomatic, and radiograph did not demonstrate evidence of residual hemothorax and scoliosis. We have followed this patient for 5 years postoperative and he continues to do well clinically and radiographically.

CONCLUSIONS

Pulmonary complications are a known drawback of anterior thoracoscopic spinal instrumentation. Delayed hemothorax is possible after aVBT. In the case of a retained hemothorax, chest tube treatment with TPA is a safe and effective method of embolectomy.

Return to Sport after Adolescent Idiopathic Scoliosis (AIS) Correction Surgery: A Retrospective Data Analysis

Sports are relevant to younger populations in society. Adolescent idiopathic scoliosis (AIS) patients who undergo surgical correction of the spine are often intensively involved in sports. For that, returning to the sport is often an important concern for the patients and their families. To the best of our knowledge, there is still a lack of scientific data indicating established recommendations about the time of returning to sport activities after surgical spinal correction. The aim of this study was to investigate (1) when AIS patients return to athletic activities after a posterior fusion, and (2) if they change their activities postoperatively. Furthermore, another question was (3) if the length of the performed posterior fusion or (4) fusion to the lower lumbar spine could have an influence on the rates or time of returning to sport activities postoperatively. Data collection was performed using questionnaires assessing patients' contentment and athletic activity. Athletic activities were categorized into three categories: (1) contact, (2) contact/non-contact and (3) non-contact sports. The intensity of exercised sports, the time of returning to the sport and changes in sport habits were documented. Radiographs were evaluated pre- and postoperatively to determine the Cobb angle and the length of the posterior fusion via the identification of the upper (UIV) and lower instrumented vertebra (LIV). Stratification analysis due to the fusion length was performed to answer a hypothetical question. This retrospective survery of 113 AIS patients treated with a posterior fusion revealed that, on average, returning to sport activities required 8 months of postoperative rest. The preoperative to postoperative rate of patients participating in sport activities increased from 88 (78%) to 94 (89%). Furthermore, postoperatively, a relevant shift of exercised activities from contact to non-contact sports was noted. Further subanalysis revealed that only 33 subjects were able to return to exactly the same athletic activities as before surgery (10 months postoperatively). The assessment of radiographs revealed that in this study group, the length of the performed posterior fusion and fusions to the lower lumbar spine had no influence on the time of return to athletic activities. The results of this study might shed some light on postoperative recommendations for sport activities after AIS treatment with a posterior fusion and may be beneficial for surgeons treating patients.

Effectiveness and safety of surgical interventions for treating adolescent idiopathic scoliosis: a Bayesian meta-analysis

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is the most common form of spinal deformity in children and adolescents which presents as complex three-dimensional (3D) deformity of the spine and rib cage. This study aimed to estimate the effectiveness and safety of surgical interventions for AIS using Bayesian meta-analysis.

METHODS

The PubMed, EMBASE, and Cochrane Controlled Register of Trials were searched through Oct 1, 2019, without language restrictions. Relevant studies evaluating combined effectiveness and safety of surgical interventions for AIS were included according to eligibility criteria. The primary outcome measures included pulmonary function (change of absolute forced vital capacity and forced expiratory volume in 1 second from pre-operation to post-operation) and incidence of complications. The secondary outcome measure was change of Cobb angle from pre-operation to post-operation. Data was pooled using a random effects model in pairwise meta-analysis. Bayesian meta-analysis combined direct and indirect evidence using a Bayesian framework.

RESULTS

Twenty-eight case-controlled studies with totally 1970 participants were included. This Bayesian meta-analysis combining direct and indirect evidences indicated that posterior fusion with instrumentation without thoracoplasty (PSF) had the highest probability to achieve better pulmonary function and lower complication rate; video assisted anterior fusion with instrumentation without thoracoplasty (VAT) had the highest probability to obtain better Cobb angle correction based on analysis of rank probability.

CONCLUSION

This Bayesian meta-analysis demonstrated that PSF had the highest probability to achieve better post-surgical pulmonary function and lower complication rate, which gives a practical recommendation of PSF as a primary surgical treatment for AIS. The results also support statistics that current surgeries adopted more PSF but less open anterior approach surgery and thoracoplasty. More research work is required to address the effectiveness and safety of VAT for treating AIS more convincingly.

Accurate prediction of spontaneous lumbar curve correction following posterior selective thoracic fusion in adolescent idiopathic scoliosis using logistic regression models and clinical rationale

INTRODUCTION

Accurate prediction of spontaneous lumbar curve correction (SLCC) after selective thoracic fusion (STF) remains difficult. This study sought to improve prediction accuracy of SLCC. The hypothesis was preoperative and intraoperative variables could predict SLCC < 20°.

METHODS

A multicenter observational prospective analysis was conducted to determine predictors of SLCC in AIS patients that had posterior STF. Curve types included major thoracic curves (Lenke 1, 3-4).The primary outcome variable was to establish prediction models, and a postoperative lumbar curve (LC) ≤ 20° was defined as the target variable. Multivariate logistic regression models were established to study the relationship between selected variables and a LC ≤ 20° versus a LC > 20° at ≥ 2-year follow-up. Single and dual thresholds models in perspective of clinical rationales were applied to find models with the highest positive/negative predictive values (PPV/NPV). The secondary outcome measure was SRS scores at ≥ 2-year follow-up.

RESULTS

410 patients were included. At ≥ 2-year follow-up 282 patients had LC ≤ 20°. These patients had better SRS-22 scores than those with LC > 20° (P = 0.02). The postoperative LC and LC ≤ 20° were predicted by preoperative LC and LC-bending Cobb angle (P < 0.01, r = 0.4-0.6). Logistic regression models could be established to identify patients at risk for failing the target LC ≤ 20°.For preoperative LC and LC-bending, the prediction model achieved a NPV/PPV of 80%/72%. If the postoperative main thoracic curve is combined with the preoperative LC and a gray area for difficult decisions was allowed, model accuracy could even be improved (NPV/PPV = 96%/81%).

CONCLUSION

An accurate prediction model for postoperative SLCC was established based on a large analysis of prospective STF cases. These models can support prediction and understanding of postoperative SLCC aiding in surgical decision making when contemplating a selective thoracic fusion. These slides can be retrieved under Electronic Supplementary Material.

Dual Sequential Short Anterior Correction in Double Major Adolescent Idiopathic Scoliosis

STUDY DESIGN

retrospective comparative study.

INTRODUCTION

The standard surgical technique for double major adolescent idiopathic scoliosis (AIS) has been the fusion of both thoracic and thoracolumbar/lumbar curves from the posterior approach. Although short anterior correction is established in AIS with single thoracic or thoracolumbar/lumbar curves, anterior correction in double major curves has not yet been described. The purpose of this study is to compare this novel technique with standard posterior pedicle screw instrumentation in double major AIS.

METHODS

19 consecutive patients with a double major AIS were treated surgically either with pedicle screw instrumentation and posterior fusion (n = 11) or dual anterior short instrumentation and fusion (n = 8) of both curves. The mean follow-up was 5.6 ± 3 years (2-10 years). Clinical and radiologic results, results of pulmonary function, and Scoliosis Research Society (SRS) questionnaire are analyzed and compared.

RESULTS

The length of fusion was 7.6 ± 0.7 vertebrae with the anterior technique and 12 ± 1 vertebrae with the posterior technique (p < .001). Cobb angle correction was 78% and 53% in thoracic curves, and 80% and 59% in lumbar curves with posterior and anterior technique respectively (p < .05). The preoperative pulmonary function remained unchanged to the last follow-up in both groups. The scores of SRS-24 questionnaire were similar preoperatively and at the last follow-up in both groups.

CONCLUSION

This novel technique of dual sequential short anterior correction is an alternative to the standard posterior long fusions in the double major AIS. A significantly less amount of mobile segments needs to be fused leaving the thoracolumbar junction mobile and saving at least one lumbar mobile segment distally.

LEVEL OF EVIDENCE

Level III.

Anterior release may not be necessary for idiopathic scoliosis with a large curve of more than 75° and a flexibility of less than 25

BACKGROUND CONTEXT

To improve correction and fusion rates, an anterior release is often needed for the treatment of idiopathic scoliosis with a curve of more than 75° before posterior correction, instrumentation, and fusion. However, there are disadvantages to anterior release, and we are concerned about whether it is necessary for anterior-posterior spinal fusion in these patients.

PURPOSE

The objective of this study was to compare the surgical results for idiopathic scoliosis with a curve of more than 75° and a flexibility of less than 25% between using posterior-only approach and combined anterior release followed by posterior correction with a hybrid construct (hooks and pedicle screws) and spinal fusion.

STUDY DESIGN/SETTING

This was a retrospective cohort study.

PATIENT SAMPLE

From 2000 to 2014, 388 consecutive patients with idiopathic scoliosis were treated surgically at our hospital. Of these patients, 53 whose primary curves were more than 75° with a flexibility of less than 25%, at an incidence of 13.6%, were included and divided into two groups. Thirty-one patients (mean age: 16.3 years old) who underwent anterior release followed by posterior correction, instrumentation, and fusion were included in the A+P group, and the remaining 22 patients (mean age: 17.3 years old) were designated as the P group for posterior procedure alone.

OUTCOME MEASURES

The clinical outcomes were analyzed in terms of correction and loss of correction and by the Scoliosis Patient Questionnaire: Version 30 functional questionnaire.

MATERIALS AND METHODS

In the A+P group, halo-femoral traction was applied for 1 week between the anterior release and the posterior procedure. Posterior instrumentation with a hybrid construct with hooks and pedicle screws was used for both groups. The radiological and functional outcomes were compared between the two groups.

RESULTS

The average preoperative Cobb angle was 85.3° for the A+P group, with an average 17.4% flexibility, and 80° for the P group, with 15.3% flexibility. The postoperative Cobb angle was 53.1° for the A+P group and 45.6° for the P group. The Cobb angle at the final follow-up for the A+P group was 55.2° and that for the P group was 48°. The average correction rates of the A+P and P groups were 37% and 43.4%, respectively. There were no statistically significant differences between the groups in gender, age, number of levels fused, and flexibility of coronal curve. With a minimum 2-year follow-up, similar results were found between these two groups in terms of correction rate, loss of correction, and functional outcome.

CONCLUSIONS

In this study, we found that a posterior-only approach with hybrid construct (hooks and pedicle screws) could provide a correction similar to that of an anterior-posterior approach. Also, the disadvantages of anterior release could be avoided by the posterior-only approach.

A Comparison of Patient-Reported Outcome Measures Following Different Treatment Approaches for Adolescents with Severe Idiopathic Scoliosis: A Systematic Review

Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine which is usually not symptomatic and which can progress during growth and cause a surface deformity. In adulthood, if the final spinal curvature surpasses a certain critical threshold, the risk of health problems and curve progression is increased. Although surgery is usually recommended for curvatures exceeding 40° to 50° to stop curvature progression, recent reviews have shed some light on the long-term complications of such surgery and to the lack of evidence for such complicated procedures within the scientific literature. Furthermore, a number of patients are very fearful of having surgery and refuse this option or live in countries where specialist scoliosis surgery is not available. Other patients may be unable to afford the cost of specialist scoliosis surgery. For these patients the only choice is an alternative non-surgical treatment option. To examine the impact of different management options in patients with severe AIS, with a focus on trunk balance, progression of scoliosis, cosmetic issues, quality of life, disability, psychological issues, back pain, and adverse effects, at both the short-term (a few months) and the long-term (over 20 years). We searched CENTRAL, MEDLINE, EMBASE, CINHAL and two other databases up to January 2016 with no language limitations. We also checked the reference lists of relevant articles and conducted an extensive hand search of the grey literature. We searched for randomised controlled trials as well as prospective and retrospective controlled trials comparing spinal fusion surgery with no treatment or conservative treatment in AIS patients with a Cobb angle greater than 40°. We did not identify any evidence of superiority of effectiveness of operative compared to nonoperative interventions for patients with severe AIS. Within the present literature there is no clear evidence to suggest that a specific type of treatment is superior to other types of treatment.

Hemoptysis Due to Anterior Scoliosis Implants: A Case Report

CASE

A twenty-five-year-old man presented with recurrent episodes of hemoptysis requiring hospitalization and interventional embolization. Instrumentation that had been implanted ten years previously for anterior spinal correction and fusion to treat adolescent idiopathic scoliosis adjoined the medial border of the right lung. The instrumentation eroded the lung during respiration, which prompted the formation of adhesions and fibrosis. Because of the risk of additional hemoptysis events, we performed revision thoracotomy, removal of the spinal instrumentation, and partial lobectomy.

CONCLUSION

This rare and serious complication underscores the importance of meticulous surgical technique to ensure proper implant placement and of vigilant monitoring for late iatrogenic injury.

Anterior or posterior surgery for right thoracic adolescent idiopathic scoliosis (AIS)? A prospective cohorts' comparison using radiologic and functional outcomes

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

Prospectively compare patient-reported as well as clinical and radiologic outcomes after anterior or posterior surgery for right thoracic adolescent idiopathic scoliosis (AIS) in a single center by the same surgeons.

SUMMARY OF BACKGROUND DATA

Anterior and posterior spinal instrumentation and arthrodesis are both well-established treatments of thoracic AIS. The majority of studies comparing the 2 approaches have focused on radiographic outcomes. There remains a paucity of prospectively gathered patient-reported outcomes comparing surgical approaches.

METHODS

Forty-two consecutive patients with right thoracic AIS were treated in a single center by one of 2 surgeons with either anterior (n=18) or posterior (n=24) approaches and followed up for over 2 years. Radiographic, clinical, and patient-reported outcomes of the Modified Scoliosis Research Society Outcome Instrument were gathered and analyzed by an independent surgeon.

RESULTS

Patients reported significant improvements in all areas of the Modified Scoliosis Research Society Outcome Instrument, especially pain and self-image domains. There were no significant differences in the degree of improvement in any domains between the groups. Posterior and anterior surgery corrected rib hump by 53% and 61%, respectively (P=0.4). The Main thoracic curve Cobb angle was corrected from 69 to 26 degrees (62%) by posterior surgery and 61 to 23 degrees (64%) by anterior surgery (P=0.6). Posterior surgery significantly reduced kyphosis and lumbosacral lordosis. Anterior surgery had no overall affect of sagittal alignment but seemed able to correct those hypokyphotic preoperatively. Complications differed and were largely approach-related--intrathoracic in anterior and wound-related in posterior surgery.

CONCLUSIONS

Patients with right thoracic AIS of differing curve types but otherwise similar preoperatively demonstrated that anterior and posterior surgery are largely equivalent. Patient-reported outcomes are improved similarly by either approach. Both offer excellent radiographic and trunk deformity correction. Differences in the effect of sagittal alignment, operative time, and complications should be considered when selecting approach.

Comparison of combined anterior-posterior approach versus posterior-only approach in treating adolescent idiopathic scoliosis: a meta-analysis

PURPOSE

Choosing a surgical approach to treat adolescent idiopathic scoliosis (AIS) is still controversial. To compare the effectiveness and safety of combined anterior-posterior approach to posterior-only approach, we conducted a meta-analysis.

METHODS

We searched electronic database for relevant studies that compared anterior-posterior approach with posterior approach in AIS. Then data extraction and quality assessment were conducted. We used RevMan 5.1 for data analysis. A random effects model was used for heterogeneous data, while a fixed effect model was used for homogeneous data.

RESULTS

A total of ten non-randomized controlled studies involving 872 patients were included. There was no significant difference in Cobb angle (95 % CI -0.33 to 4.91, P = 0.09) and percent-predicted FEV1 (95 % CI -6.79 to 4.54, P = 0.70) between the two groups. In subgroup analysis, the kyphosis angle correction was significantly higher than posterior group in severe subgroup (95 % CI 0.72-6.50, P = 0.01), while no significant difference was found in no-restriction subgroup (95 % CI -2.75 to 5.42, P = 0.52). Patients in posterior group obtained a better percent-predicted FVC than those in anterior-posterior group (95 % CI -13.18 to -4.74, P < 0.0001). Significant less complication rate (95 % CI 2.75-17.49, P < 0.0001), blood loss (95 % CI 363.28-658.91, P < 0.00001), operative time (95 % CI 2.65-3.45, P < 0.00001) and length of hospital stay (95 % CI 1.98-22.94, P = 0.02) were found in posterior group.

CONCLUSIONS

Posterior-only approach can achieve similar coronal plane correction and percent-predicted FEV1 compared to combined anterior-posterior approach. The posterior approach even does better in sagittal correction in severe AIS patients. Significantly less complication rate, blood loss, operative time, length of hospital stay and better percent-predicted FVC are also achieved by posterior-only approach. Posterior-only approach seems to be effective and safe in treating AIS for experienced surgeons.

Comparison of the Combined Anterior-Posterior Approach versus Posterior-Only Approach in Scoliosis Treatment

Study Design

This is descriptive analytical study.

Purpose

The present study aims at comparing treatment results found between the two groups comprising of patients who underwent posterior spinal fusion using thoracic pedicle screws and the ones who underwent combined anterior-posterior method, respectively.

Overview of Literature

There was controversy about surgical techniques including anterior, posterior, or a combined anterior-posterior approaches are applied to treat non-congenital scoliosis with surgical indications.

Methods

Medical records of 50 patients suffering from thoracic non-congenital scoliosis with curves exceeding 70° were reviewed. In this study, 25 patients who underwent posterior spinal fusion using thoracic pedicle screws were compared with 25 patients who underwent combined anterior-posterior method.

Results

Patients treated through posterior-only and combined approaches were respectively hospitalized for 11.84±5.18 and 26.5±5.2 days (p=0.001). There was a significant difference between these two groups considering intensive care unit admission duration (p=0.001), correction in sagittal view of X-ray (p=0.01), and number of days the patients underwent traction (0.001). Finally, coronal view was corrected without any significant difference (p=0.2).

Conclusions

According to our findings, it is hypothesized that posterior-only method is associated with some significant advantages and is an advisable method in patients with severe scoliosis over than 70°.

Anterior surgery for adolescent idiopathic scoliosis

Anterior open scoliosis surgery using the dual rod system is a safe and rather effective procedure for the correction of scoliosis (50-60 %). Thoracic hypokyphosis and rib hump correction with open anterior rather than posterior instrumentation appear to be the better approaches, although the latter is somewhat controversial with current posterior vertebral column derotation devices. In patients with Risser grade 0, hyperkyphosis and adding-on may occur with anterior thoracic spine instrumentation. Anterior thoracoscopic instrumentation provides a similar correction (65 %) with good cosmetic outcomes, but it is associated with a rather high risk of instrumentation (pull-out, pseudoarthrosis) and pulmonary complications. Approximately 80 % of patients with adolescent idiopathic scoliosis (AIS) curves of >70° have restrictive lung disease or smaller than normal lung volumes. AIS patients undergoing anterior thoracotomy or anteroposterior surgery will demonstrate a significant decrease in percentage of predicted lung volumes during follow-up. The thoracoabdominal approach and thoracoscopic approach without thoracoplasty do not produce similar changes in detrimental lung volume. In patients with severe AIS (>90°), posterior-only surgery with TPS provides similar radiographic correction of the deformity (44 %) with better pulmonary function outcomes than anteroposterior surgery. Vascular spinal cord malfunction after segmental vessel ligation during anterior scoliosis surgery has been reported. Based on the current literature, the main indication for open anterior scoliosis instrumentation is Lenke 5C thoracolumbar or lumbar AIS curve with anterior instrumentation typically between T11 and L3.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Level II.

Long-term retrospective of the Kaneda anterior scoliosis system in thoracic adolescent idiopathic scoliosis

BACKGROUND

Currently, the Kaneda anterior scoliosis system (KASS) is reported to be acceptable for the treatment of adolescent idiopathic scoliosis (AIS), particularly thoracolumbar and lumbar deformities. Its use in thoracic AIS is not as established.

METHODS

Retrospective analysis of long-term results in patients treated with the KASS for thoracic AIS to determine specific factors associated with success or failure. We analyzed 16 consecutive patients who met the following criteria: thoracic AIS, anterior spinal fusion and KASS, and ≥24 months of follow-up or progression to failure, defined as the need for revision surgery or progression of the main thoracic curve (MTC) ≥50 degrees. Comparison of the MTC on the preoperative, postoperative, and final follow-up was the major evaluation criteria. On the basis of data analysis, patients were divided for comparison into 2 study groups: nonfailure group (n=11) and failure group (n=5). Statistical analysis was performed using paired and independent t tests.

RESULTS

All curves were classified as Lenke 1 (n=14) and 2 (n=2). Mean age at surgery and levels fused were 14.6±2.7 years and 5±1 vertebrae, respectively. Mean follow-up was 4.2 years (range, 1.0 to 6.2 y). The failure group consisted of 5 patients that progressed to ≥50 degrees. In the nonfailure group, the mean MTC preoperative, postoperative, and at final follow-up were 52±8, 19±8, and 29±7 degrees, respectively. In the failure group, these measurements were 74±11, 35±8, and 56±12 degrees, respectively.

CONCLUSIONS

This retrospective, long-term follow-up study found more KASS failures in thoracic AIS than previously reported. Even in the nonfailure group, 5 of the 11 patients progressed 10 degrees or more. Our results indicate an increased incidence of KASS failure with preoperative MTC curve ≥70 degrees. We consider an MTC≥70 degrees a likely contraindication for KASS instrumentation for thoracic AIS. Four of the 5 failures were fused short of the end vertebrae either proximally, distally, or both. Although short apical fusions were popular during the time these cases were done, fusion to the end vertebrae is an important principle for anterior fusions. Reaching the upper end vertebrae may be more difficult in these larger curves. We also recommend continued follow-up past 2 years as progression can occur after this time.

LEVEL OF EVIDENCE

Retrospective comparative study, level III.

Pulmonary function after anterior double thoracotomy approach versus posterior surgery with costectomies in idiopathic thoracic scoliosis

INTRODUCTION

The surgical approach in the treatment of idiopathic thoracic scoliosis depends on the type of curve involved. In anterior correction, the rib hump is corrected by derotating the thoracic spine. In posterior scoliosis surgery, additional rib hump resection is sometimes necessary to achieve an optimal cosmetic result. The aim of this study was to compare pulmonary function in these two patient groups.

MATERIALS AND METHODS

Forty patients in the anterior group (A) were treated with standard double thoracotomy, with an anterior derotation spondylodesis and a primary stable dual-rod system. The posterior group (P) included 29 patients who were treated with a pedicle screw-based posterior instrumentation spondylodesis, with additional rib hump resection. Pulmonary function was evaluated preoperatively, on the 12th postoperative day, and at 3, 6, 12 and 24 months during the follow-up.

RESULTS

The patients' mean age was 15 years in group A and 19 in group P with a standard deviation 8.7 years and a significant difference. With regard to body height or weight there were no significant differences between the two groups. In group A, the deterioration in pulmonary function immediately after the operation (from [Formula: see text] 75.3 %/71.3 % preoperatively to 38.5 %/36.1 % postoperatively) was clearer than in group P ([Formula: see text] 71.6 %/65.7 % preoperatively to 47.7 %/48.4 % postoperatively). During a follow-up period of 3 months, the values improved in both groups in comparison with the values immediately after the operation. Up to the 2 year follow-up, pulmonary function in the posterior and anterior groups corresponded to the preoperative values, with no significant differences. There was a trend toward moderately increased values in the posterior group and moderately decreased values in the anterior group at the 2-year follow-up examination, in comparison with the preoperative baseline, but without a statistically significant difference. Two major complications occurred in the anterior group, with reintubation and several bronchoscopy examinations due to atelectasis.

CONCLUSION

The severe deterioration in group A is caused by the substantial trauma with double thoracotomy in contrast to rib hump resection. For patients with severe restrictive pulmonary distress, posterior instrumentation in combination with rib hump resection would be preferable to an anterior procedure involving double thoracotomy. Respiratory physiotherapy exercise should be administered in order to minimise postoperative pulmonary distress. In conclusion opening of the chest wall leads to deterioration of pulmonary function with improvement to the preoperative values after 6 months in the posterior and after 24 months in the anterior group.

Residual thoracic hypokyphosis after posterior spinal fusion and instrumentation in adolescent idiopathic scoliosis: risk factors and clinical ramifications

STUDY DESIGN

A retrospective review of clinical and radiographic data from a single-center, prospectively collected scoliosis database.

OBJECTIVE

To assess risk factors for persistent thoracic hypokyphosis after posterior spinal fusion and instrumentation (PSFI) for adolescent idiopathic scoliosis (AIS) and to compare clinical outcomes between patients with residual thoracic hypokyphosis and those with normal thoracic kyphosis after PSFI for AIS.

SUMMARY OF BACKGROUND DATA

AIS is characterized by thoracic hypokyphosis, which should be corrected at the time of surgical treatment. Risk factors for residual thoracic hypokyphosis and the clinical ramifications have not been studied.

METHODS

Radiographic and clinical assessments by using the Scoliosis Research Society-30 (SRS-30) and Spinal Appearance Questionnaire (SAQ) were done preoperatively and at 2 years. Patients were divided into 2 groups on the basis of a threshold of 20° of thoracic kyphosis measured between T5 and T12 at 2-year follow-up.

RESULTS

Risk factors for being hypokyphotic at 2 years were male sex (21.69% vs. 12.21%, P = 0.084), preoperative kyphosis (11.4° vs. 22.8°, P < 0.0001), and smaller preoperative main thoracic coronal curves (58.4° vs. 62.0°, P = 0.004). A total of 71.5% of patients instrumented with 6.35-mm rods had normal thoracic kyphosis at 2 years compared with 47.0% instrumented with 5.5-mm rods (P = 0.0043). All-pedicle screw constructs remained hypokyphotic compared with hook-based constructs (P = 0.035). Logistic regression analysis demonstrated 2 parameters associated with persistent thoracic hypokyphosis at 2 years: preoperative hypokyphosis and larger rod diameter. Both groups had similar clinical results on the SRS-30 at 2-year follow-up (P > 0.05). There was a small but statistically significant correlation between sagittal Cobb angle and clinical deformity at 2 years based on the sagittal components of the SAQ.

CONCLUSION

There are 2 risk factors that lead to thoracic hypokyphosis in AIS: preoperative hypokyphosis and use of a 5.5-mm-diameter rod. A larger-diameter rod should be considered when planning surgery for thoracic AIS, especially when there is preoperative hypokyphosis. Despite thoracic kyphosis measuring less than 20°, these patients did not have decreased clinical outcomes as measured by the SRS-30 or SAQ.

Fixation points within the main thoracic curve: does more instrumentation produce greater curve correction and improved results?

STUDY DESIGN

Prospective consecutive multicenter case series.

OBJECTIVE

To compare fixation type and amount to curve correction controlled for curve flexibility.

SUMMARY OF BACKGROUND DATA

The enhanced spinal purchase from segmental fixation should increase the force implants can exert without failure. This study evaluates whether this translates into correction beyond that expected from preoperative bending radiographs in thoracic curves where maximum correction was feasible (1A, 1B, and nonselective 1C fusions).

METHODS

One hundred seventy-one Lenke type 1 curves (118 1A, 36 1B, 23 1C) with 2-year follow-up were evaluated for the number and type of fixation points within the main curves compared to the correction obtained on preoperative bend films. SRS scores were compared to the amount of correction.

RESULTS

The number of fixation points both within the curve (P = 0.01) and for each vertebral body (P = 0.002) was larger for curves with greater correction compared to the bend films than those with less correction. Overall absolute correction was best for all screw and screw and wire constructs, followed by hook and screw, and least with hooks. However, compared to the bend films, these differences were not significant (P = 0.132). For all groups, the SRS scores significantly improved (P < 0.001), and was slightly more notable for the all screw constructs than other instrumentation patterns (P = 0.023). However, there were no significant difference in this improvement between those correcting more and those correcting less than the bend films (P = 0.578).

CONCLUSION

Absolute curve correction improved most with all pedicle screw and screw and wire constructs, but, when compared to bending films, the number of fixation points is more important than fixation type for curve correction. Although SRS scores improved the most in those with all screw constructs, the significance of this improvement is uncertain, and the SRS scores did not relate to whether curve correction was more or less than the bend films.

Use of the Universal Clamp in adolescent idiopathic scoliosis for deformity correction and as an adjunct to fusion: 2-year follow-up

PURPOSE

Among posterior surgical techniques for treating adolescent idiopathic scoliosis (AIS), hybrid constructs with pedicle-screw fixation in the lumbar spine and other anchors in the thoracic spine have been reported to provide to be of more physiological value in postoperative thoracic kyphosis than all-screw constructs. The Universial Clamp (UC) equipped with a soft sublaminar band is a relatively new thoracic anchor that can be used in hybrid constructs. A dedicated reduction tool that applies traction to the sublaminar band permits gentle translation of the thoracic curve to the precontoured fusion rods, which have been previously anchored distally by pedicle screws and proximally by hooks in a claw configuration. The aim of this study was to evaluate radiographic results of AIS treatment using UC hybrid constructs.

METHODS

This was a prospective case series in which 29 consecutive patients with Lenke type 1, 2 or 3 AIS operated on by two surgeons in two centers were followed for 24 months. Necessity for anterior release was an exclusion criterion.

RESULTS

A total of 5.4 ± 1.4 UCs were used per patient. The major thoracic curve was reduced from 55 ± 7° to 14 ± 6° at 1 month and 17 ± 6° at 24 months (correction 70%) without complications. In the patients who had less than 20° of T5-T12 kyphosis preoperatively, thoracic kyphosis improved from 14 ± 4° to 20 ± 3° at 3 months and 24 ± 9° at 24 months. In the other patients, preoperative thoracic kyphosis (27° ± 6°) was unchanged by the operation.

CONCLUSION

UC hybrid constructs appear to safely provide satisfying coronal correction while consistently improving thoracic kyphosis in patients who also have preoperative hypokyphosis. We hypothesize that diminution in thoracic kyphosis was consistently avoided due to the straightforward traction of the spine to the fusion rods into which the chosen kyphosis was contoured by the surgeon before applying the reduction tool to the sublaminar bands.

[Modified primary stable ventral derotation spondylodesis with Halm-Zielke instrumentation for the treatment of idiopathic scoliosis]

OBJECTIVE

Surgical technique with an anterior double-rod system for thoracic, thoracolumbar, or lumbar scoliosis. The aim of the system is to correct the coronal plane deformity and normalize the sagittal balance.

INDICATIONS

Scoliosis which should have a coronal Cobb measurement of at least 40 degrees and should usually not exceed 90 degrees in between T4 and L4. In the Lenke classification, the curve types 1 (main thoracic) and curve type 5 (thoracolumbar/lumbar) are amenable to anterior instrumentation and fusion.

CONTRAINDICATIONS

Osteoporosis. Infection. Allergic reaction to implants. Minor curves that do not correct to < 25 degrees on flexibility maneuvers. Structured kyphosis in the major curve. Severe sagittal plane malalignment with pathologic kyphosis cranial or caudal of the instrumented segments.

SURGICAL TECHNIQUE

The spine is exposed via an open thoracotomy or a thoracoabdominal approach. After completion of diskectomies at each level, the anterior double-rod system is fixed with two bicortical screws per vertebral body. The longitudinal components consist of a solid rod and a threaded rod. The rods are contoured to maintain normal sagittal and coronal contour. The proximal screws are engaged first and then a cantilever force is used to correct the deformity. Occasionally, a partial rod rotation maneuver or intersegmental compression is performed. Morselized autograft (typically rib) is placed in the disk spaces. Intraoperative radiographs are taken to evaluate the correction.

POSTOPERATIVE MANAGEMENT

Brace-free mobilization. Physiotherapy. Respiratory therapy.

RESULTS

Very high rate of successful spondylodesis. Excellent frontal correction of about 60-70%. Very good spontaneous correction of adjacent minor curves of around 40%. Restoration of a physiological profile. Correction angle and length of fusion comparable to modern transpedicular double-rod systems.

Preservation of thoracic kyphosis is critical to maintain lumbar lordosis in the surgical treatment of adolescent idiopathic scoliosis

STUDY DESIGN

Retrospective analysis of prospectively collected multicenter series.

OBJECTIVE

To evaluate the sagittal profile of surgically treated adolescent idiopathic scoliosis (AIS) patients.

SUMMARY OF BACKGROUND DATA

With the increasing popularity of segmental pedicle screw spinal instrumentation, thoracic kyphosis (TK) is often sacrificed to achieve coronal and axial plane correction.

METHODS

Radiographs of AIS patients with a Lenke type 1 deformity and minimum 2-year follow-up after selective thoracic fusion (lowest instrumented vertebra of T11, T12, or L1) were evaluated. Changes in TK were correlated with changes in lumbar lordosis (LL). Patients were divided according to approach (open/thoracoscopic anterior vs. posterior). Analysis of variance was used to compare pre and postoperative radiographic measures.

RESULTS

Two hundred fifty-one patients (age: 14 +/- 2 years) were included. Sixty seven percentages of the patients had anterior surgery (97 open anterior, 71 thoracoscopic) and 33% (83 patients) had posterior spinal fusion. A decrease in postoperative TK was significantly correlated (P < or = 0.001) with a decrease in LL at first erect (r = 0.3), 1 year (r = 0.4) and 2 years (r = 0.4), independent of surgical approach. LL decreased significantly at the first erect regardless of approach (P = 0.003); however, at 2-year postoperative TK and LL were significantly decreased after a posterior approach (P < or = 0.001) when compared with an anterior approach that added kyphosis. The decrease in LL (5.6 degrees +/- 9.7 degrees) was nearly twice the decrease in TK (2.8 degrees +/- 11.4 degrees) in the posterior group at 2-years.

CONCLUSION

Given that thoracic AIS is often associated with a preexisting reduction in TK, ideal surgical correction should address this deformity. Procedures which further reduce TK also reduce LL. It is unclear if the loss of LL from thoracic scoliosis correction will compound the loss of LL that occurs with age and lead to further decline in sagittal balance. With this concern, we recommend a posterior column lengthening and/or an anterior column shortening to achieve restoration of normal TK and maximal LL.

Approach-related lesions of the sympathetic chain in anterior correction and instrumentation of idiopathic scoliosis

During anterior scoliosis instrumentation with a dual-rod system, the vertebrae are dissected anterolaterally. After surgery, some patients report a change in temperature perception and perspiration in the lower extremities. Sympathetic lesions might be an explanation for this. The aim of this clinical study was to investigate sympathetic function after anterior scoliosis instrumentation. A total of 24 female patients with idiopathic scoliosis (mean age at follow-up, 23.8 years) who had undergone anterior instrumentation on average 6.6 years earlier were included. Due to the suspected relevance of the sympathetic L2 ganglion, two groups were created: a T12 group, in which instrumentation down to T12 was carried out (n = 12), and an L3 group, in which instrumentation down to L3 was done (n = 12). Sympathetic function was assessed by measuring skin temperature at the back of the foot, a plantar ninhydrin sweat test and sympathetic skin responses (SSRs) following electrical stimulation. The side on which the surgical approach was carried out was compared with the contralateral, control side. Health-related quality of life was investigated using the Scoliosis Research Society SRS-22 patient questionnaire. In the T12 group, mean temperatures of 29.6 degrees C on the side of the approach versus 29.5 degrees C on the control side were measured (P > 0.05); in the L3 group, the mean temperatures were 33.2 degrees C on the approach side versus 30.5 degrees C on the control side (P = 0.001). A significant difference between the T12 group and the L3 group (P < 0.001) was observed on the approach side, but not on the control side (P = 0.15). The ninhydrin sweat test showed reduced perspiration in 11 of 12 patients in the L3 group on the approach side in comparison with the control side (P = 0.002). In the T12 group, no significant differences were noted between the left and right feet. SSRs differed significantly between the two groups (P = 0.005). They were detected in all nine analyzable patients in the T12 group on both sides. In the L3 group, they were found on the approach side only in 4 of 11 analyzable patients versus 11 patients on the control side. The results of the SRS-22 questionnaire did not show any significant differences between the two groups. In conclusion, anterior scoliosis instrumentation with a dual-rod system including vertebrae down to L3 regularly leads to lesions in the sympathetic trunk. These are detectable with an increase in temperature, reduced perspiration and reduced SSRs. The caudal level of instrumentation (T12 vs. L3) has an impact on the extent of impairment, supporting the suspected importance of the L2 ganglion. The clinical outcome does not seem to be significantly limited by sympathetic trunk lesions.

Adolescent idiopathic scoliosis treated with open instrumented anterior spinal fusion: five-year follow-up

STUDY DESIGN

A multicenter prospective database was queried for patients who underwent open instrumented anterior spinal fusion (OASF) for treatment of primary thoracic (Lenke 1) adolescent idiopathic scoliosis (AIS).

OBJECTIVES

To present the intermediate radiographic and pulmonary function testing (PFT) data from patients who underwent OASF using modern, rigid instrumentation.

SUMMARY OF BACKGROUND DATA

Anterior spinal fusion is an excellent method to correct the 3-dimensional deformity produced by AIS. Modern instrumentation consisting of stronger metals, unthreaded rods, and dual rod systems should theoretically decrease the incidence of rod breakage, pseudarthrosis, and loss of correction seen in earlier OASF studies. The paucity of intermediate and long-term data prevents surgeons and patients from making an informed decision regarding the true incidence of these complications.

METHODS

Of 101 potential patients who underwent OASF with a minimum 5-year follow-up, 85 (85%) were studied. Standing radiographs were analyzed before surgery and at first standing erect, 2-year, and 5-year follow-up. PFT data were collected before surgery and at 5 years after surgery.

RESULTS

Complete 5-year follow-up was obtained in 85 patients. Five years after surgery, the mean coronal correction was 26 degrees (51%; P < 0.05) and the thoracolumbar/lumbar curve improved 16 degrees (51%). There was a 9-degree (P < 0.001) increase in kyphosis, and there were 9 patients (11%) in whom the C7 plumb line translated >2 cm. There was a 6.7% decrease in predicted FEV1 over the 5-year period, from 75.5% +/- 13% before surgery to 68.8% +/- 2% at 5-year follow-up (P = 0.007); however, there was no significant change in FVC. There were 3 significant adverse events: 1 implant breakage requiring reoperation and 2 cases of progression of the main thoracic curve requiring reoperation.

CONCLUSION

OASF is a reproducible and safe method to treat thoracic AIS. It provides good coronal and sagittal correction of the main thoracic and compensatory thoracolumbar/lumbar curves that is maintained with intermediate term follow-up. In skeletally immature children, this technique can cause an increase in kyphosis beyond normal values, and less correction of kyphosis should be considered during instrumentation. As with any procedure that employs a thoracotomy, pulmonary function is mildly decreased at final follow-up.

[Anterior scoliosis surgery. State of the art and a comparison with posterior techniques]

For more than 2 decades ventral derotation spondylodesis (Zielke VDS) as a major improvement over Dwyer instrumentation (DI) was the gold standard of instrumented curve correction and stabilization from the anterior approach. As the first available system it enables a true three-dimensional curve correction. A disadvantage is the low internal stabilization capability with a need for long-term external stabilization by means of cast and brace treatment postoperatively. Meanwhile with the development of modern single and dual solid rod systems these disadvantages can be avoided completely. Video-assisted (thoracoscopic) anterior scoliosis surgery accounts for less than 2% of anteriorly treated scoliosis cases, mainly due to a long operating time and significant learning curve.From the posterior approach the Cotrel-Dubousset instrumentation (CDI) as a polysegmentally attached posterior hook threaded dual rod system used to be state of the art for a long time, since it eliminated the disadvantages of Harrington instrumentation (HI) in terms of only one-dimensional correction and low stabilization capabilities. However even with CDI effective derotation was impossible. In posterior scoliosis surgery there is a strong trend away from hook systems towards transpedicular segmentally fixed dual rod systems not only in the lumbar spine but also in the thoracic area. Advantages of these newer techniques are shorter fusion, improved correction, and less loss of correction over time.Advantages of modern anterior instrumentation systems in comparison to posterior transpedicular instrumented dual rod systems are less blood loss, better derotation, slightly shorter fusion levels, and a better influence on sagittal plane control or improvement especially for hypokyphotic thoracic scoliosis cases. Our data also document a superior spontaneous correction of the lumbar curve after selective anterior instrumented correction (Lenke 1B+C), although other studies could not find significant differences. In our experience the neurological risk of anterior instrumented correction is also lower than that of posterior scoliosis surgery, although the morbidity and mortality data of the Scoliosis Research Society could not prove that anymore in recent years. A negative effect of anterior transthoracic scoliosis surgery in comparison to posterior surgery is a more negative effect on lung function, which improves slower after surgery and does not quite reach the levels of posterior surgery at follow-up. But new data on posterior segmental transpedicular correction and fusion also prove a lordosating effect with negative effect on lung function.

Axial plane lumbar responses after anterior selective thoracic fusion for main thoracic adolescent idiopathic scoliosis

Study Design

A retrospective radiographic study.

Purpose

To evaluate the axial plane lumbar responses after anterior selective thoracic fusion (STF) in patients with main thoracic adolescent idiopathic scoliosis (MT-AIS).

Overview of Literature

Anterior scoliosis surgery induces more MT derotation through disc preparation than posterior surgery.

Methods

Twenty-eight MT-AIS patients treated with STF were evaluated after a minimum follow-up (FU) of 2 years. The MT and lumbar coronal angles, as well as the MT and lumbar rotational angles at the most rotated vertebrae were measured.

Results

At the last FU, the MT coronal correction and derotation rates were 65% and 41%, respectively. The lumbar coronal correction rate was 61% but there was minimal lumbar derotation (2%). Nine cases were decompensated (coronal balance >10 mm). After surgery, the compensated and decompensated groups showed similar MT coronal and axial correction rates. During the FU, the MT and lumbar apecies rotated in the same direction (r=0.443). In addition, significant MT derotation occurred in the decompensated group with increasing lumbar rotational correction loss. At the last FU, while the MT coronal correction was similar between the two groups, there was more MT derotation in the decompensated group. Furthermore, the MT rotational change was strongly associated with the coronal C7 plumb line position (r=0.728).

Conclusions

After anterior STF in patients with MT-AIS, the final MT derotation is strongly associated with the coronal C7 plumb line position. During the FU, the excessive MT derotation in the decompensated group was attributed to excessive lumbar rotational correction loss.

Inpatient complications, mortality, and discharge disposition after surgical correction of idiopathic scoliosis: a national perspective

BACKGROUND CONTEXT

Information about complications and mortality after surgery for correction of idiopathic scoliosis has been largely derived from single-institution series. Regional or national studies have been lacking.

PURPOSE

To report inpatient mortality, complications, and discharge disposition after surgical correction of idiopathic scoliosis on a national level.

STUDY DESIGN

Retrospective cohort study using National Inpatient Sample (NIS) administrative data.

PATIENT SAMPLE

All patients in the NIS with the primary diagnosis of idiopathic scoliosis who underwent a spinal fusion between 1993 and 2002 were included.

OUTCOME MEASURES

Inpatient complication rate, mortality rate, and adverse outcome defined by death or discharge to institution other than home.

METHODS

Outcome measures were abstracted from the NIS. Univariate and multivariate analyses were performed to analyze the effects of patient and hospital characteristics on outcome measures.

RESULTS

The NIS was used to identify 51,911 patients who underwent spinal fusion for idiopathic scoliosis in the United States from 1993 to 2002. The total inhospital complication rate was 14.9% for pediatric patients and 25.1% for adult patients. The inhospital mortality rate was 0.17% and 0.40% for pediatric and adult patients, respectively. Adverse outcome was noted in 2.3% of pediatric patients and 20.4% of adult patients. Pulmonary and postoperative hemorrhages/hematomas were the most common complications reported. Multivariate analysis for complications showed that morbidity was significantly lower for pediatric patients (odds ratio [OR] = 0.80; confidence interval [CI] = 0.68-0.94) and female patients (OR = 0.77; CI = 0.68-0.88). Patients with a preoperative comorbidity were 1.53 (CI = 1.32-1.76) times more likely to develop a complication. A single postoperative complication increased the mean length of stay by more than 2 days and increased the mortality rate, adverse outcome, and hospital charges significantly.

CONCLUSIONS

We have provided a national perspective on inpatient complications, mortality, and discharge disposition after spinal fusion for idiopathic scoliosis in the United States. The significant negative effects of postoperative complications on mortality and resource utilization have been demonstrated. Furthermore, we have identified adult age, male gender, and preoperative comorbidity as important risk factors and defined their impact on patient outcomes.

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.

ROD DEROTATION TECHNIQUES FOR THORACOLUMBAR SPINAL DEFORMITY

OBJECTIVE

The operative correction of scoliosis requires multiple intraoperative techniques and tools to achieve an adequate result. Frequently, multiple methods are used to accomplish this, such as rod cantilever techniques, in situ bending, Smith-Petersen and pedicle subtraction osteotomies, closed reduction methods, and rod derotation techniques. Rod derotation techniques will be reviewed and discussed in this article.

METHODS

A review of the available literature on anterior and posterior rod derotation is performed with a case example of the authors' experience utilizing this technique.

RESULTS

Rod derotation is one technique that can transform a pathological scoliotic curve to normal physiological kyphosis or lordosis by simply rotating a rod intraoperatively.

CONCLUSION

In this article, the authors present rod derotation as a valuable technique in the surgical arsenal for the treatment of scoliosis, including a discussion of the technique and its limitations.

Adolescent idiopathic scoliosis (AIS) - an indication for surgery? A systematic review of the literature

PURPOSE

Historically, the treatment options for AIS, the most common form of scoliosis are: Exercises, in-patient rehabilitation, braces and surgery. While there is evidence in the form of prospective controlled studies that Scoliosis Intensive Rehabilitation (SIR) and braces can alter the natural history of the condition, there is no review on prospective controlled trials for surgical treatment. The aim of this review was to perform a systematic search of the Pub Med literature to reveal the evidence on scoliosis surgery.

METHODS

A systematic review has been performed using the Pub Med database. Literature has been searched for the outcome parameter; 'rate of progression' and only prospective controlled studies that have considered the treatment versus the natural history have been included.

RESULTS

No controlled study, not in the short, mid or long term, searched within the review, has been found to reveal evidence to support the hypothesis that the effects of surgery as a treatment option for AIS is superior to natural history.

CONCLUSIONS

No evidence has been found in terms of prospective controlled studies to support surgical intervention from the medical point of view. In the light of the unknown long-term effects of surgery and in concluding on the lack of evidence already found that surgery might change the signs and symptoms of scoliosis, a randomized controlled trial (RCT) is long overdue. Until such a time that such evidence exists, there can be no medical indication for surgery. The indications for surgery are limited for cosmetic reasons in severe cases and only if the patient and the family agree with this.

Rate of complications in scoliosis surgery - a systematic review of the Pub Med literature

Background

Spinal fusion surgery is currently recommended when curve magnitude exceeds 40–45 degrees. Early attempts at spinal fusion surgery which were aimed to leave the patients with a mild residual deformity, failed to meet such expectations. These aims have since been revised to the more modest goals of preventing progression, restoring 'acceptability' of the clinical deformity and reducing curvature.

In view of the fact that there is no evidence that health related signs and symptoms of scoliosis can be altered by spinal fusion in the long-term, a clear medical indication for this treatment cannot be derived. Knowledge concerning the rate of complications of scoliosis surgery may enable us to establish a cost/benefit relation of this intervention and to improve the standard of the information and advice given to patients. It is also hoped that this study will help to answer questions in relation to the limiting choice between the risks of surgery and the "wait and see – observation only until surgery might be recommended", strategy widely used. The purpose of this review is to present the actual data available on the rate of complications in scoliosis surgery.

Materials and methods

Search strategy for identification of studies; Pub Med and the SOSORT scoliosis library, limited to English language and bibliographies of all reviewed articles. The search strategy included the terms; 'scoliosis'; 'rate of complications'; 'spine surgery'; 'scoliosis surgery'; 'spondylodesis'; 'spinal instrumentation' and 'spine fusion'.

Results

The electronic search carried out on the 1^st February 2008 with the key words "scoliosis", "surgery", "complications" revealed 2590 titles, which not necessarily attributed to our quest for the term "rate of complications". 287 titles were found when the term "rate of complications" was used as a key word. Rates of complication varied between 0 and 89% depending on the aetiology of the entity investigated. Long-term rates of complications have not yet been reported upon.

Conclusion

Scoliosis surgery has a varying but high rate of complications. A medical indication for this treatment cannot be established in view of the lack of evidence. The rate of complications may even be higher than reported. Long-term risks of scoliosis surgery have not yet been reported upon in research. Mandatory reporting for all spinal implants in a standardized way using a spreadsheet list of all recognised complications to reveal a 2-year, 5-year, 10-year and 20-year rate of complications should be established. Trials with untreated control groups in the field of scoliosis raise ethical issues, as the control group could be exposed to the risks of undergoing such surgery.

The changes of relative position of the thoracic aorta after anterior or posterior instrumentation of type I Lenke curve in adolescent idiopathic thoracic scoliosis

The risk of impingement of the aorta associated with thoracic vertebral screw or pedicle screw instrumentation in the treatment of thoracic scoliosis has been an important concern. To understand this phenomenon more systematically, the relative position of the aorta with reference to the thoracic vertebrae in right thoracic adolescent idiopathic scoliosis (AIS) following anterior and posterior spinal instrumentation was analyzed in detail quantitatively; 34 patients underwent anterior (n = 14) or posterior (n = 20) spinal instrumentation were recruited in the present study. The relative position of the thoracic aorta, vertebral rotation, apical vertebral translation and thoracic kyphosis were measured from pre- and post-operative CT images from T5 to T12. The aorta was found to shift antero-medially in the anterior instrumentation group but not in the posterior spinal instrumentation group. It is likely that the disc removal, soft tissue release and spontaneous vertebral derotation of the scoliosis could account for the antero-medial shifting of the aorta. By the shifting, the space for contralateral screw penetration was reduced.

Adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) affects 1-3% of children in the at-risk population of those aged 10-16 years. The aetiopathogensis of this disorder remains unknown, with misinformation about its natural history. Non-surgical treatments are aimed to reduce the number of operations by preventing curve progression. Although bracing and physiotherapy are common treatments in much of the world, their effectiveness has never been rigorously assessed. Technological advances have much improved the ability of surgeons to safely correct the deformity while maintaining sagittal and coronal balance. However, we do not have long-term results of these changing surgical treatments. Much has yet to be learned about the general health, quality of life, and self-image of both treated and untreated patients with AIS.

Perioperative outcomes and complications related to teaching residents and fellows in scoliosis surgery

STUDY DESIGN

Single-surgeon retrospective case series of 303 consecutive operative patients with idiopathic scoliosis (IS).

OBJECTIVE

The purpose of this study is to evaluate the perioperative outcomes in patients undergoing surgery for IS as a function of the experience level of the surgical assistant.

SUMMARY OF BACKGROUND DATA

The experience level of the surgical assistant, who is often a resident or fellow, has never before been evaluated as an independent factor in predicting perioperative outcomes and morbidity in scoliosis surgery. We hypothesize that there is no difference in perioperative outcomes with varying experience level of the surgical assistant.

METHODS

We evaluated the clinical, radiographic, and operative records from 303 consecutive operative patients from consecutive patients with IS. Group I was comprised of residents or spine fellows as assistants (teaching service, n = 175), and Group II consisted of junior or senior attendings as assistants (private practice service, n = 128). Multivariable linear regression was used to evaluate the relationship between experience level of the assistant and curve correction, operative time, estimated blood loss (EBL), complications, transfusions, and length of stay.

RESULTS

In the posterior spinal fusion group (PSF, n = 164), there were no statistically significant differences in operative times between Groups I and II. Group I operative time was significantly increased, however, in patients undergoing anterior spinal surgery (ASF, P = 0.01), video-assisted thoracoscopic surgery (P = 0.0004), and combined anterior/posterior surgeries (ASF/PSF, P = 0.0063). There were no differences in EBL in ASF, video-assisted thoracoscopic surgery, or PSF surgeries, however, Group I had significantly higher EBL in the ASF/PSF group (P = 0.0016). No group differences were detected with respect to curve correction, transfusion rates, length of stay, or early complication rates.

CONCLUSION

The experience level of surgical assistant had little bearing on perioperative morbidity or radiographic outcomes in scoliosis surgery. Marginally increased operative times and EBL, without an increase in transfusions or complications, is an acceptably safe tradeoff for educating orthopedic residents and fellows.

Sagittal plane lumbar responses after anterior selective thoracic fusion for main thoracic adolescent idiopathic scoliosis

Study Design

A retrospective radiographic study.

Purpose

To verify the correlation of sagittal and coronal plane changes after selective thoracic fusion in main thoracic (MT) adolescent idiopathic scoliosis (AIS).

Overview of Literature

Sagittal plane deformity is known to be essential in the evolution of scoliosis.

Methods

Twenty-eight MT AIS patients treated by anterior selective thoracic fusion were evaluated after minimal follow-up of two years. The unfused lumbar area was divided into proximal and distal parts by the lumbar apex in the coronal plane, and into proximal and distal lumbar lordosis by L2 in the sagittal plane. Surgical motion (the difference between preoperative and postoperative values) and follow-up motion (the difference between postoperative and the last follow-up values) were compared.

Results

Immediately after surgery, as thoracic kyphosis increased, lumbar lordosis decreased (r=0.734); proximal lumbar lordosis increased, and distal lumbar lordosis decreased. The proximal lumbar area was mobilized in the sagittal plane, and was straightened in the coronal plane. However, the distal lumbar area was stabilized in the sagittal plane, and showed resistant motion against MT translation in the coronal plane. The surgical motion was correlated to the follow-up motion, i. e., was regulated during follow-up, and the regulatory motion was more precise in the distal than proximal lumbar area in both sagittal and coronal planes.

Conclusions

Sagittal and coronal motions were co-related; optimal sagittal motions were necessary for optimal coronal motions after anterior selective thoracic fusion for MT AIS. Proximal and distal lumbar motions were different for different roles; the proximal lumbar area played a role as a bumper to absorb the MT translatory force, and the distal lumbar area played a role of resistance against MT translation.