Management of severe spinal deformity: scoliosis and kyphosis

Preoperative Echocardiogram Does Not Contribute to Surgical Risk Assessment in Patients With Large Curve Scoliosis and No Cardiac Risk Factors

OBJECTIVE

Severe scoliosis can affect thoracic organs, potentially leading to cardiovascular abnormalities. Thus, echocardiograms have been suggested for use in preoperative screening in patients with significant scoliosis. However, the utility of preoperative heart screenings in patients without known or suspected heart problems is not well understood. This study aims to find the incidence of cardiac findings in patients with severe scoliosis ≥90° without cardiac history.

METHODS

A single-institution retrospective chart review was performed. Inclusion criteria were scoliosis patients with curves ≥90 degrees and a screening echocardiogram performed within 6 months of spine surgery. Patients with a previous cardiac history, diagnosis associated with cardiac comorbidities (eg, connective tissue disease), or major coronal curves <90 degrees were excluded. Echocardiogram reports and perioperative clinical notes from involved services (including orthopaedics, cardiology, and anesthesia) were reviewed. Any postoperative use of vasopressors and reasons for their use were recorded.

RESULTS

Overall, 50 patients met the inclusion criteria. The mean age at surgery was 14.0 ± 4.9 years old (range: 2 to 33). The mean major curve was 108 ± 19 degrees (range: 90 to 160 degrees). A normal echocardiogram was seen in 38 (76%), whereas 6 patients (12%) had mild dilation of the aortic sinus or root, 4 (8%) had mild valvular regurgitation, 1 patient had a small atrial septal defect, and 1 had a trace pericardial effusion. No patient had any changes made to their perioperative plan and one patient was advised to see a cardiologist postoperatively. Postoperatively, 8 patients (16%) received vasopressors to raise blood pressure to meet preset goal MAP, but only one of these 8 had a positive echocardiogram (mild valvular insufficiency), which was not seen as a contributing factor to the use of pressors.

CONCLUSIONS

This study suggests that screening echocardiograms for patients without a cardiac history or related symptoms does not contribute to the evaluation of perioperative risk or anesthetic management. Creating clear, evidence-based guidelines for the utilization of perioperative testing, like echocardiograms, can reduce the social, time, and financial burdens on families. Such guidelines are vital for appropriate risk assessment and proper utilization of health care resources.

LEVEL OF EVIDENCE

Level III.

Efficacy and safety of halo-gravity traction in the treatment of spinal deformities: A systematic review of the literature

OBJECTIVE

To determine, through a systematic review, the effects of halo gravity traction in spinal deformity.

METHODS

Prospective studies or case series of patients with scoliosis or kyphosis treated with cranial halo gravity traction (HGT) were included. Radiological outcomes were measured in the sagittal and/or coronal planes. Pulmonary function was also assessed. Perioperative complications were also collected.

RESULTS

Thirteen studies were included. Congenital etiology was the most frequent etiology observed. Most studies provided clinically relevant curve correction values in the sagittal and coronal planes. Pulmonary values improved significantly after the use of HGT. Finally, there were a pool of 83 complications in 356 patients (23.3%). The most frequent complications were screw infection (38 cases).

CONCLUSIONS

Preoperative HGT appears to be a safe and effective intervention for deformity that allows correction prior to surgery. However, there is a lack of homogeneity in the published studies.

Efficacy and safety of halo-gravity traction in the treatment of spinal deformities: A systematic review of the literature

OBJECTIVE

To determine, through a systematic review, the effects of halo-gravity traction (HGT) in spinal deformity.

METHODS

Prospective studies or case series of patients with scoliosis or kyphosis treated with cranial HGT were included. Radiological outcomes were measured in the sagittal and/or coronal planes. Pulmonary function was also assessed. Perioperative complications were also collected.

RESULTS

Thirteen studies were included. Congenital etiology was the most frequent etiology observed. Most studies provided clinically relevant curve correction values in the sagittal and coronal planes. Pulmonary values improved significantly after the use of HGT. Finally, there were a pool of 83 complications in 356 patients (23.3%). The most frequent complications were screw infection (38 cases).

CONCLUSIONS

Preoperative HGT appears to be a safe and effective intervention for deformity that allows correction prior to surgery. However, there is a lack of homogeneity in the published studies.

A novel uniplanar clamp-hinge correction system for vertebral column resection of severe angular kyphosis: an experimental study using a sawbone model

PURPOSE

To introduce a novel uniplanar clamp-hinge (Uni-CH) correction system designed for vertebral column resection (VCR) of severe angular kyphosis and test its efficacy using a sawbone simulating model.

METHODS

The Uni-CH was introduced and its functionality was demonstrated on a sawbone model simulating severe angular kyphosis. An 83° thoracolumbar angular kyphosis with the apex at T11 was simulated in the sawbone spine model. The deformity was then corrected using the Uni-CH to identify the optimal hinge position for VCR reduction of severe angular kyphosis.

RESULTS

The thoracolumbar angular kyphosis, initially measuring a mean of 82.7 ± 0.5°, was corrected to 0°, achieving a 100% correction rate. The optimal hinge position was identified to be at the level of the posterior vertebral body wall (PVBW), which allowed for the maintenance of the spinal cord with a slight shortening of 3%. In contrast, hinge positions located more posteriorly to the PVBW resulted in a greater 42% lengthening of the spinal cord, while positions located more anteriorly led to a greater 27% shortening of the spinal cord.

CONCLUSIONS

The Uni-CH proves its efficacy in providing consistent stability to the spinal segments and acts as an adjustable and controllable hinge for VCR correction of severe angular kyphosis in the sawbone model. Placing the hinge pivot at the level of the PVBW preserves the spinal cord, preventing excessive shortening or lengthening during VCR reduction of severe angular kyphosis.

Effectiveness of Halo-Pelvic Traction and Thoracoplasty for Pulmonary Artery Pressure and Cardiopulmonary Function in Patients With Severe Spinal Deformity

STUDY DESIGN

Retrospective review.

OBJECTIVE

To evaluate the effectiveness of halo-pelvic traction and thoracoplasty for pulmonary artery pressure (PAP) and cardiopulmonary function in patients with severe spinal deformity.

SUMMARY OF BACKGROUND DATA

The effect of severe spinal deformity on pulmonary arterial hypertension, cardiac structure, and function has received little attention before.

PATIENTS AND METHODS

A total of 21 patients with severe spinal deformity were included in our study; all patients were examined by echocardiography and pulmonary function test before and after treatment. The correlations between PAP and pulmonary function were examined using Pearson correlation analysis.

RESULTS

The PAP decreased from 58.67 ± 20.24 to 39.00 ± 12.51 mm Hg, and the PAP of 42.86% of the patients returned to normal after treatment. Right cardiac enlargement, left ventricular diastolic function, and pulmonary function were improved at the same time. The ratio of left ventricular to right ventricular diameter returned to normal. Moderate correlations (correlation coefficient: -0.513 to -0.559) between PAP and forced vital capacity and forced expiratory volume in the first second were identified.

CONCLUSIONS

Pulmonary arterial hypertension, ventricular diastolic function, and pulmonary function were improved after halo-pelvic traction and thoracoplasty. A moderate negative correlation was identified between PAP and pulmonary function: the more pulmonary function improved, the more PAP decreased.

Sequential Correction versus Conventional Correction for Severe and Rigid Kyphoscoliosis: A Retrospective Case Control Study

OBJECTIVE

Conventional correction techniques were challenging and of high risk of neurological complications for the correction of severe and rigid kyphoscoliosis. A new technical note we developed and named as sequential correction, was used to treat severe and rigid kyphoscoliosis. The present study was to compare the clinical outcomes of sequential correction versus conventional correction for the treatment of severe and rigid kyphoscoliosis.

METHODS

This is a respectively case-control study. Between January 2014 and December 2019, 36 adults underwent the surgical correction of severe and rigid kyphoscoliosis and were included in the present study. Among them, 20 adults underwent conventional correction, 16 adults underwent sequential correction. Major curve Cobb angle, kyphotic angle, coronal imbalance, and sagittal vertical axis were compared between two groups. The patient-reported health-related quality of life outcomes, including the Oswestry disability index score, and SRS-22 questionnaire, were recorded. Independent samples t-test, Mann-Whitney U test, and Wilcoxon signed-rank test, were used to compare the differences between two groups according to the results of normal distribution test.

RESULTS

In conventional correction group, the mean major curve Cobb angle was 122.50° preoperatively, 40.35° immediately after surgery, and 43.95° at final follow-up postoperatively; the mean kyphotic angle was 97.45° preoperatively, 34.45° immediately after surgery, and 38.30° at final follow-up postoperatively. In the sequential correction group, the mean major angle was 134.44° preoperatively, 44.56° immediately after surgery, and 46.25° at final follow-up postoperatively; the mean kyphotic angle was 112.31° preoperatively, 39.00° immediately after surgery, and 40.38° at final follow-up postoperatively. The mean major curve Cobb angle and kyphotic angle of both groups were improved significantly, while there were no significant differences between two groups (p > 0.001). Improved self-reported quality of life scores were achieved postoperatively and at final follow-up postoperatively, and there were no significant differences between the two groups. The total complication rate of the patients underwent conventional correction was 55%, and the total complication rate of the patients underwent sequential correction was 43.75%. The complication rate of the two groups showed no significant difference.

CONCLUSIONS

Sequential correction is an excellent and safe treatment for severe and rigid kyphoscoliosis in adults, with similar clinical outcomes with conventional correction. The total complication rate of the patients who underwent sequential correction was slightly lower than conventional correction.

Biomechanical analysis of rod contouring in posterior spinal instrumentation and fusion for 3D correction of adolescent idiopathic scoliosis

PURPOSE

To biomechanically evaluate 3D corrective forces and deformity correction attributable to key parameters of rod contouring in posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS).

METHODS

Computerised patient-specific biomechanical models of six AIS cases were used to simulate PSF and evaluate the effects of 5.5-mm cobalt-chrome rod contouring angle (concave-convex angles: 30°-15°, 45°-15° and 60°-15°), length (spanning 4 and 7 vertebrae), and apex location (T7, T9). 3D correction and bone-implant forces were computed and analysed.

RESULTS

By increasing the concave rod contour from 30° to 60°, thoracic kyphosis (TK) increased from 18° ± 2° (15°-19°) to 24° ± 2° (22°-26°), apical vertebra rotation (AVR) correction increased from 41% (SD8%) to 66% (SD18%) whilst the main thoracic curve (MT) correction decreased from 68% (SD6%) to 56% (SD8%). With a contouring length of 4 vs. 7 vertebrae, the resulting TK, AVR and MT corrections were 22° ± 1° (19°-26°) vs. 19° ± 10° (15°-22°), 57% (SD18%) vs. 50% (SD26%) and 59% (SD1%) vs. 69% (SD35%), respectively. With the rod contouring apex at T7 (vs. T9), AVR corrections were 69% (SD19%) vs. 44% (SD9%), with no significant difference in TK and MT corrections, and with comparatively 67% of screw pull-out forces. Corrective forces were more evenly shared with fixation on 7 vs. 4 vertebrae.

CONCLUSION

Rod contouring of a greater angulation, over a shorter portion of the rod, and more centred at the apex of the main thoracic curve apex improved AVR correction and allowed greater restoration of TK, but resulted in significantly higher screw pull-out forces and came at the expense of less coronal plane correction.

Concave rod first vs. convex rod first in AIS instrumentation with differential rod contouring: computer modeling and simulations based on ten AIS surgical cases

PURPOSE

To assess biomechanical differences between AIS instrumentations using concave vs. convex rod first.

METHODS

Instrumentations of ten AIS patients were simulated first with major correction maneuvers using the concave rod then with convex rod. Correction maneuvers were concave/convex rod translation, followed by apical vertebral derotation and then convex/concave rod translation. The concave/convex rods were 5.5/5.5 and 6.0/5.5 mm diameter Co-Cr and contoured to 35°/15°, 55°/15°, 75°/15° and 85°/15°, respectively.

RESULTS

Differences in simulated thoracic Cobb angle (MT), thoracic kyphosis (TK) and apical vertebral rotation (AVR) were less than 5° between the two techniques; mean bone-screw force difference was less then 15N (p > 0.1). Increasing differential contouring angle from 35°/15° to 85°/15°, the MT changed from 14 ± 7° to 15 ± 8°, AVR from 12 ± 4° to 6 ± 5°, TK from 23 ± 4° to 42 ± 4°, and bone-screw forces from 159 ± 88N to 329 ± 170N (P < 0.05). Increasing the concave rod diameter from 5.5 to 6 mm, the mean MT correction improvement for both techniques was less than 2°, the AVR correction was improved by 2°, the TK increased by 4° and bone-screw force increased by about 25N (p < 0.05).

CONCLUSION

There was no significant difference in deformity corrections and bone-screw forces between the two techniques. Increasing differential contouring angle and rod diameter improved AVR and TK corrections with no significant effect on the MT Cobb angle. Although this study simplified the complexity of a generic surgical technique, the main effects of a limited number of identical steps were replicated for each case in a systematic manner to analyze the main first-order effects.

Perioperative Complications and Health-related Quality of Life Outcomes in Severe Pediatric Spinal Deformity

STUDY DESIGN

Prospective multicenter cohort study.

OBJECTIVE

To evaluate perioperative complications and mid-term outcomes for severe pediatric spinal deformity.

SUMMARY OF BACKGROUND DATA

Few studies have evaluated the impact of complications on health-related quality of life (HRQoL) outcomes in severe pediatric spinal deformity.

METHODS

Patients from a prospective, multicenter database with severe pediatric spinal deformity (minimum of 100 degree curve in any plane or planned vertebral column resection (VCR)) with a minimum of 2-years follow-up were evaluated (n=231). SRS-22r scores were collected preoperatively and at 2-years postoperatively. Complications were categorized as intraoperative, early postoperative (within 90-days of surgery), major, or minor. Perioperative complication rate was evaluated between patients with and without VCR. Additionally, SRS-22r scores were compared between patients with and without complications.

RESULTS

Perioperative complications occurred in 135 (58%) patients, and major complications occurred in 53 (23%) patients. Patients that underwent VCR had a higher incidence of early postoperative complications than patients without VCR (28.9% vs. 16.2%, P =0.02). Complications resolved in 126/135 (93.3%) patients with a mean time to resolution of 91.63 days. Unresolved major complications included motor deficit (n=4), spinal cord deficit (n=1), nerve root deficit (n=1), compartment syndrome (n=1), and motor weakness due to recurrent intradural tumor (n=1). Patients with complications, major complications, or multiple complications had equivalent postoperative SRS-22r scores. Patients with motor deficits had lower postoperative satisfaction subscore (4.32 vs. 4.51, P =0.03), but patients with resolved motor deficits had equivalent postoperative scores in all domains. Patients with unresolved complications had lower postoperative satisfaction subscore (3.94 vs. 4.47, P =0.03) and less postoperative improvement in self-image subscore (0.64 vs. 1.42, P =0.03) as compared to patients with resolved complications.

CONCLUSION

Most perioperative complications for severe pediatric spinal deformity resolve within 2-years postoperatively and do not result in adverse HRQoL outcomes. However, patients with unresolved complications have decreased HRQoL outcomes.

Pulmonary and clinical outcomes of patients with severe rigid scoliosis and type I respiratory failure treated with halo-pelvic distraction

BACKGROUND

The severe rigid scoliosis patients with type I respiratory failure could not tolerate complicated corrective surgery. Preoperative halo-pelvic distraction (HPD) is used to reduce the curve magnitude and improve the pulmonary function before surgery. The present study aimed to retrospectively analyze the pulmonary and clinical outcomes of preoperative HPD in severe rigid spinal deformity with type I respiratory failure.

METHODS

Eighteen cases of severe rigid scoliosis and type I respiratory failure treated with preoperative HPD and corrective surgery for spinal deformity between 2016 and 2018 were retrospectively reviewed. Patient demographics, major coronal curve and kyphosis, correction rates, heights, pulmonary function, distraction time, and postoperative neurological complications were recorded for all cases.

RESULTS

The averaged duration of distraction was 9.1 ± 2.3 months. The coronal curve was corrected from 168° ± 14° to 58° ± 11° at the end of HPD. The kyphosis curve reduced from 151° ± 29° to 65° ± 10°. Meanwhile, the mean stand body height increased by 23.9 ± 5.3 cm. Significantly increased mean FVC (1.52 ± 0.43 L vs. 0.95 ± 0.44 L) and improved percent-predicted values for FVC (37 ± 10% vs. 23 ± 9%) were observed after HPD. The pressure of oxygen (PaO2) increased from 54.5 ± 2.0 to 84.8 ± 4.7 mmHg. Scoliosis and kyphosis curve, respectively, averaged 48 ± 8°and 30 ± 14° after final fusion and instrumentation, with a mean correction of 71% and 80%, respectively. No severe complication occurred during the distraction.

CONCLUSIONS

HPD may be useful for severe rigid scoliosis patients with type I respiratory failure. Pulmonary functions in patients with severe rigid scoliosis can be significantly improved by HPD. They are then better able to tolerate complicated corrective surgery.

Sequential correction of severe and rigid kyphoscoliosis: a new technical note and preliminary results

OBJECTIVE

The present study is to evaluate the clinical outcomes of the sequential correction of severe and rigid kyphoscoliosis.

METHODS

Between January 2014 and December 2020, 27 adults with severe and rigid kyphoscoliosis underwent sequential correction combined with posterior grade 4 or grade 5 spinal osteotomy. Radiological parameters, including the major curve Cobb angle, kyphotic angle, coronal imbalance, and sagittal vertical axis (SVA), were compared. Patient self-reported health-related quality of life (HRQOL) scores were used to evaluate clinical outcomes.

RESULTS

The mean major curve Cobb angle improved from 134.30 ± 13.24° to 44.48 ± 9.34° immediately after surgery and to 46.11 ± 8.94° at the final follow-up. The mean kyphotic angle improved from 112.15 ± 20.28° to 38.63 ± 15.00° immediately after surgery and to 39.85 ± 14.92° at the final follow-up. The mean preoperative major curve Cobb angle of grade 5 spinal osteotomy group was higher than that of grade 4 spinal osteotomy group. Coronal imbalance and SVA slightly improved. The patient self-reported HRQOL scores improved postoperatively and at the final follow-up. Activity, appearance and total scores of the SRS-22 of the grade 5 spinal osteotomy group at the final follow-up were significantly better than those of the grade 4 spinal osteotomy group.

CONCLUSIONS

Sequential correction combined with posterior grade 4 or grade 5 spinal osteotomies is an excellent and safe treatment for severe and rigid kyphoscoliosis in adults. Sequential correction combined with posterior grade 5 spinal osteotomies can be used to correct severe and rigid kyphoscoliosis with higher major curve Cobb angle.

Temporary Flexible Rods for Correction of Severe Pediatric Spinal Deformity

Surgical correction of large, rigid scoliotic and kyphotic curves carries an increased risk of perioperative complications, such as neurological injury and excessive blood loss, compared with correction of less severe curves. Titanium temporary flexible rods (TFRs), designed for pediatric long bone fracture fixation, may be helpful as adjuncts to achieve gradual, stepwise intraoperative correction of severe pediatric spinal deformities. A retrospective review was conducted of spinal fusion cases for pediatric scoliosis or kyphosis at our institution that used TFRs as a correction technique from 2007 to 2019. Patients underwent posterior spinal fusion with predominantly pedicle screw instrumentation. Intraoperatively, a non-contoured titanium elastic nail was temporarily positioned in the screws unilaterally to achieve partial correction while the contralateral side was instrumented. Then, the TFR was removed and replaced with a permanent rod. Thirty-four patients with severe spinal deformities underwent posterior spinal fusion. Seventeen had scoliosis (mean major Cobb angle, 89.3°) and 17 had kyphosis (mean T5-T12 kyphosis, 73.8°). Idiopathic deformity was the most common etiology; neuromuscular, syndromic, and postsurgical causes contributed to the remainder of cases. All patients had Ponte osteotomies. Four patients (11.8%) had neuromonitoring alerts, 1 of which was related to insertion of the TFR; all were reversible. For patients with scoliosis, the mean postoperative Cobb angle measured 40.2° (53.6% correction). For patients with kyphosis, the mean postoperative T5-T12 angle measured 43.3° (30.4° of correction). TFRs appear to be helpful adjuncts for correction of severe pediatric spinal deformities, facilitating gradual intraoperative correction in a single-stage operation. Neuromonitoring alerts are common but reversible. [Orthopedics. 2023;46(4):234-241.].

Halo-pelvic traction in the treatment of severe scoliosis: a meta-analysis

PURPOSE

To provide better evidence of the efficacy and safety of preoperative halo-pelvic traction on the improvements of deformity and pulmonary functions in patients with severe scoliosis.

METHODS

Electronic database searches were conducted including the Cochrane Library, PubMed, Web of Science and Embase. All studies of halo-pelvic traction for the management of severe spinal deformity were included. We referred to a list of four criteria developed by the Agency for Healthcare Research and Quality (AHRQ) to assess the quality of included studies. The meta-analysis was performed using RevMan 5.4 software.

RESULTS

Based on the study selection criteria, a total of eight articles consisting of a total of 210 patients were included. Statistically significant differences were found in coronal Cobb angle (P < 0.001), sagittal Cobb angle (P < 0.001) and height (P < 0.001) between pre- and post-traction. Sensitivity analysis was conducted, and there were substantial changes in heterogeneity with preoperative thoracoplasty subgroup in coronal Cobb angle (P < 0.001). Three trials including 74 subjects reported FVC and FEV1 predicted value between pre- and post-traction. There were statistically significant differences in FVC, FVC%, FEV1 and FEV1% (P < 0.001). The complication rate was 6.6-26.7%, and symptoms disappeared after reasonable traction strategy and intensive care.

CONCLUSIONS

Preoperative halo-pelvic traction achieved significant improvements in spinal deformity and pulmonary functions, with minor and curable complications. Thus, it is an effective and safe solution before surgery and may be the optimal choice for severe scoliosis. In light of the heterogeneity and limitations, future researches are needed to better determine the long-term efficacy on comprehensive assessment and to explore the appropriate traction system.

A novel Hinge-Link correction system for vertebral column resection: a pilot study in a porcine model

PURPOSE

To introduce a novel Hinge-Link (HL) correction system for vertebral column resection (VCR) in the most severe scoliosis and surgically assess the device in a porcine scoliosis model.

METHODS

The HL was introduced and described how it works on a reproduced three-dimensional spine model of severe scoliosis. A right thoracic scoliosis was surgically created in five 4-month-old pigs. Two weeks later, the VCR was performed to correct the deformity using the HL to test its feasibility and neurological safety in the pig scoliosis model.

RESULTS

The surgically created right thoracic scoliosis averaged 32° ± 9.3 prior to the VCR. All animals tolerated the VCR procedure awakening neurologically intact and ambulated for 24 h. The HL takes advantage of the ability to provide three-dimensional correction of the deformity and excellent control of the spine segments to prevent damage to the spinal cord in the VCR procedure. The mean correction of the scoliosis was 94% correcting to 1.8° ± 0.8. At sacrifice, the pathological anatomy of the neural axis demonstrated no vertebral subluxation and no dural impingement in any animal.

CONCLUSION

The HL was feasible and neurologically safe for the VCR procedure in the pig scoliosis model. It can provide significant correction of the spinal deformity with appropriate mild shortening at the resected levels and overall lengthening without neurologic deficits. The rigid control of the spine segments provided by this device should allow for improved correction with decreased neurologic deficits and potentially shorter surgical time.

The impacts of waiting for surgical correction of Adolescent Idiopathic Scoliosis and its repercussions for publicly funded health systems: systematic review

PURPOSE

To investigate, through a systematic review, the impact of the waiting time for Adolescent Idiopathic Scoliosis (AIS) surgical correction from the point of view of deformity evolution, treatment cost, and quality of life.

METHODS

PubMed, Embase, LILACS, SciELO, Scopus, Web of Science, LIVIVO, and Cochrane Library databases were searched by two researchers to select the articles. The eligibility criteria were: Patients diagnosed with AIS with indication for surgical correction and submitted to waiting lists until treatment. The risks of bias were evaluated using the Risk Of Bias In Non-randomized Studies-Interventions (ROBINS-I) tool, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used to classify the level of the evidence for each outcome. The summary of the available evidence is presented in a narrative synthesis.

RESULTS

Six observational studies were included. In a Canadian study, the primary outcome was the need for additional spine surgery in patients who had to wait more than three months due to spine deformity progression. American researchers presented a sample of premenarcheal and skeletally immature patients with AIS showing increased Cobb angle and attributed this to a six-month waiting for the surgical treatment. Another study included 177 patients with AIS with a mean waiting time of 225.7 days. There was a worsening average of 7.7° ± 8.6° in Cobb angle, and there was a change in surgical plan in 28 patients, which increased surgical time. Studies that evaluated the treatment cost showed significantly higher mean costs in those who waited longer than six months. Regarding the quality of life, while waiting for surgery, a retrospective study found that patients who underwent surgery earlier showed better results in a questionnaire that assessed their quality of life compared to those who were still waiting.

CONCLUSION

Observational studies show that, in individuals who are on waiting lists for AIS surgery, there is a worsening of the spinal deformity (substantial evidence), an increasing cost of treatment (moderate evidence) and it may negatively impact patients' quality of life (insufficient evidence). Performing better methodological quality studies to investigate these outcomes can violate good research practices since randomized clinical trials on this subject have ethical limitations to be carried out.

TRIAL REGISTRATION

The authors declare that the systematic review protocol was registered at the international prospective register of systematic reviews (PROSPERO), CRD42020212134, and it was accepted for publication.

Nomogram for predicting the distal adding-on phenomenon in severe and rigid scoliosis

Background

The distal adding-on phenomenon has attracted extensive discussion in the field of spine surgery due to the continual occurrence after scoliosis correction. Previous work has mainly focused on adolescent idiopathic scoliosis (AIS), and a relatively high number of theories for the mechanism of the distal adding-on phenomenon has been proposed for these kinds of patients. Severe and rigid scoliosis, as a special disease form, has a unique etiology, clinical manifestations and internal mechanisms distinct from those of AIS. Given the uniqueness of this disease, the mechanism and causes of the distal adding-on phenomenon have been infrequently studied in depth.

Objective

To define clinical and radiological factors associated with distal adding-on in patients with severe and rigid scoliosis.

Methods

Radiographic parameters and demographic data of patients with severe and rigid scoliosis were evaluated preoperatively, after posterior instrumentation and fusion surgery, and at the final follow-up via radiographs. According to the appearance of distal adding-on at the final follow-up, the patients were grouped into the Adding-on and the Non-adding-on groups. Various radiological parameters were analyzed in stepwise multivariate logistic regression to identify the variables associated with distal adding-on, which were then incorporated into a nomogram. The predictive performance and calibration of the nomograms for distal adding-on were assessed using C statistics and calibration plots.

Results

93 patients (21 in the Adding-on and 72 in the Non-adding-on group) were included. The incidence of distal adding-on was 22.6%. The variables associated with distal adding-on were the anterior release, posterior internal distraction, and later posterior spinal fusion (IP) procedure, the posterior vertebral column resection and posterior spinal fusion (PVCR) procedure, postoperative apical vertebral translation (Post-AVT) and preoperative slope of the line linking the pedicles on the concave side of the upper- and lower-end vertebrae (Tan α). Combining these factors, the nomogram achieved a concordance index of 0.92 in predicting distal adding-on and had well-fitted calibration curves.

Conclusions

For patient with a negative Tanα in severe and rigid scoliosis, the risk of distal adding-on tended to increase, and it is recommended to give priority to IP or PVCR. In the final correction, a smaller Post-AVT should not be pursued excessively.

Paediatric Spinal Deformity Surgery: Complications and Their Management

Surgical correction of paediatric spinal deformity is associated with risks, adverse events, and complications that must be preoperatively discussed with patients and their families to inform treatment decisions, expectations, and long-term outcomes. The incidence of complications varies in relation to the underlying aetiology of spinal deformity and surgical procedure. Intraoperative complications include bleeding, neurological injury, and those related to positioning. Postoperative complications include persistent pain, surgical site infection, venous thromboembolism, pulmonary complications, superior mesenteric artery syndrome, and also pseudarthrosis and implant failure, proximal junctional kyphosis, crankshaft phenomenon, and adding-on deformity, which may necessitate revision surgery. Interventions included in enhanced recovery after surgery protocols may reduce the incidence of complications. Complications must be diagnosed, investigated and managed expeditiously to prevent further deterioration and to ensure optimal outcomes. This review summarises the complications associated with paediatric spinal deformity surgery and their management.

Efficacy of Halo-Gravity Traction in the Perioperative Treatment of Severe Scoliosis and Kyphosis: A Comparison of Adolescent and Adult Patients

OBJECTIVE

The objective of the study was to compare the efficacy of halo-gravity traction (HGT) with subsequent surgical treatment in adolescent and adult patients with severe scoliosis by evaluating the radiographic outcomes and clinical complications.

METHODS

We performed a retrospective analysis of 51 patients with severe scoliosis who underwent a posterior spinal instrumented fusion with HGT during the perioperative period between March 2010 and June 2017. The patients were divided into 2 groups: adults (age >18 years) and adolescents (age 10-18 years). All patients were followed with full posteroanterior and lateral spine radiographs, bending films, neurological complications, and lung function tests for a minimum of 2 years. Deformity correction, pulmonary function testing, and clinical complications were compared between the 2 groups.

RESULTS

We identified 29 adults (8 males and 21 females, mean age = 23.7 ± 8.7 years) and 22 adolescents (10 males and 12 females, mean age = 13.0 ± 4.5 years). In the adult group, the mean Cobb angle of the main curve before HGT was 141.7 ± 18.2°, which improved to 126.4 ± 8.6° and 67.5 ± 10.2° after traction and operation, respectively. The kyphotic angle was corrected from 137.1 ± 15.6° before traction to 122.5 ± 11.3° after traction to 67.6 ± 13.8° after operation. The mean functional vital capacity% and forced expiratory volume in one second% were 43.1% and 37.5%, which improved to 46.7% and 41.7% after traction, respectively. In the adolescent group, the mean correction of the main curve improved from 139.3 ± 12.6° before traction to 112.1 ± 8.3° after traction to 59 ± 13.1° after surgical intervention. The kyphotic angle was corrected from 130.7 ± 9.4° before traction to 101.5 ± 12.2° after traction and then to 48.2 ± 10.1° after surgical intervention. Overall, patients in both groups showed significant improvement in their main scoliosis and kyphosis (P < 0.05), while the correction rate of the main curve and kyphosis was significantly higher in the adolescent group than that in the adult group (P < 0.05). The functional vital capacity% increased from 44.8% to 55.0% and the forced expiratory volume in one second% increased from 44.0% to 51.0% after using HGT. In terms of surgical outcomes, the incidence of postoperative neurological complications was 27.6% and 18.2% in the 2 groups, respectively.

CONCLUSIONS

HGT is an effective and safe method to correct spinal deformities and improve lung function, especially in adolescent patients with severe scoliosis. In addition, it can potentially reduce the risk of neurological complications and the level of osteotomy in posterior spinal instrumented fusion surgery.

Posterior Vertebral Column Resection for Severe Spinal Deformity Correction: Comparison of Pediatric, Adolescent, and Adult Groups

We compared the pre-, intra-, and postoperative characteristics among three groups of patients who underwent posterior vertebral column resection (PVCR) to clarify age-related characteristics and to guide patient management, surgical planning, and complication avoiding. We compared and analyzed the etiology, surgical events, outcomes, and complications among pediatric, adolescent, and adult patients who underwent PVCR in a single-center database retrospectively. Patients were categorized into pediatric (0–12 yr), adolescent (13–19 yr), and adult (>20 yr) cohorts. Demographics, surgical events, clinical and radiographic results, and major complications were compared between groups. A total of 87 patients with a mean follow-up 42 (24–96) months were identified. Pediatric group (14) had a high frequency of congenital vertebral and cardiac abnormal, adolescents (47) presented more intracanal malformations, and idiopathic was common in the adult group (26). Although pediatric patients had shorter fusion levels than adolescent and adult, their mean resected vertebrae (1.91), percentage of blood loss (estimated blood loss per total blood volume) (201.9%), and operative time were much higher. The coronal/sagittal correction rate was significantly higher in the pediatric group (73.6%/72.3%). Overall, surgical complications were more frequent in adults, particularly neuromonitoring alert and implant failure. However, more severe complications were noted in younger patients. For pediatric patients with PVCR, poor physiological conditions and frequent comorbidities indicated cautious patient selection and sufficient preoperative preparation. The higher correction rate may be due to the excellent compliance of the spinal cord. For adult patients, preoperative traction and adjusting the tension of the spinal cord during surgery could contribute to neurological safety.

Comparison of operative implications between adolescent and young adult idiopathic scoliosis patients from scoliosis research society mortality and morbidity database

PURPOSE

To compare the operative implications between adolescent idiopathic scoliosis patients (10-18 years) and young adult idiopathic scoliosis (YAdIS) patients (19-30 years).

METHODS

This was a retrospective study querying the SRS M&M database for AIS (10-18 years) and YAdIS (19-30 years) cases enrolled between 2009 and 2015. Demographic and surgical parameters (Lenke curve classification, preoperative curve magnitude, approach type, osteotomy type, estimated blood volume (EBV), levels of fusion and ASA scores) were evaluated and compared between groups.

RESULTS

N = 690: AIS (n = 607) and YAdIS (n = 83). Lenke curve classification distributions in AIS and YAdIS cases were: main thoracic, 293 vs. 34; double thoracic, 42 vs. 5; double major, 159 vs. 15; triple major, 15 vs. 5; thoracolumbar, 85 vs. 17; and lumbar, 5 vs. 6, respectively. Patients with a coronal curve > 90° were significantly greater in YAdIS vs. AIS patients, p = 0.008. Anterior and combined surgery rates were significantly higher in YAdIS, p = 0.028. Two-staged surgeries were significantly higher for YAdIS cohort, p = 0.01. Osteotomy rate was similar between groups, p = 0.42, but proportion of 3-column osteotomies was significantly higher for YAdIS, p < 0.001. ASA (severe systemic disease and some functional limitation) score 3 patients' rate was higher in YAdIS cohort, p = 0.01. EBV was significantly higher in YAdIS, p = 0.01. Average number of levels of fusions between cohorts was not significant, p = 0.87.

CONCLUSIONS

The operative implications observed with young adult idiopathic scoliosis patients may potentially result in more complex surgical procedures and operative-associated complications than their adolescent counterparts. Further studies are required and should include a larger number of cases, be prospective in nature and verifiable data.

LEVEL OF EVIDENCE

II.

Impactos da espera para correção cirúrgica da escoliose idiopática do adolescente e suas repercussões para o Sistema Único de Saúde: Protocolo de revisão sistemática

A correção cirúrgica é uma opção efetiva de tratamento para casos de Escoliose Idiopática do Adolescente (EIA) com curvas acima de 45°. No âmbito do Sistema Único de Saúde (SUS), os pacientes avaliados nos centros de referência e com indicação cirúrgica são cadastrados em fila de espera até que o tratamento definitivo possa ser realizado. Um período de espera extenso pode ser prejudicial, do ponto de vista de piora dos sintomas e de aumento do custo de tratamento, além de gerar efeitos negativos na saúde mental e na qualidade de vida do paciente. O presente artigo trata-se do protocolo de uma revisão sistemática que buscará responder o questionamento: “Qual o impacto do tempo de espera para correção cirúrgica da EIA do ponto de vista de custo e qualidade de vida?.” O aperfeiçoamento das ações de saúde pública, na esfera da alta complexidade, inicia-se com o levantamento de informações sobre a situação de saúde de determinada condição. Diante disso, as futuras publicações provenientes deste protocolo poderão servir como subsídio para apontar possíveis critérios de prioridade, com o intuito de promover melhoria tanto no âmbito da saúde global de portadores de EIA, quanto na gestão financeira da saúde pública brasileira.

Is There a Correlation Between Cobb Angle and Pulmonary Function Tests at 2-year Follow-up in Patients With Severe Spinal Deformity Treated by Posterior Vertebral Column Resection?

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim was to evaluate the relationships of Cobb angle and pulmonary function tests (PFTs) changes in severe spinal deformity and underwent posterior vertebral column resection (PVCR).

SUMMARY OF BACKGROUND DATA

No previous study focused on the correlation of deformity correction and PFTs changes in patients with cobb angle >90 degrees.

METHODS

PFTs values [forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and percent-predicted values FVC%, FEV1%] were evaluated preoperative and at 2 years after PVCR. FVC% <80% were defined as restrictive ventilation dysfunction (RVD), the severity of RVD were divided into mild (FEV1% ≥70%), moderate (70% > FEV1% ≥50%) and severe (FEV1% <50%). The relationships among PFTs values improvements and all possible impact factors (mainly correction cobb angle) collected in this study were analyzed. PFTs data were compared among the 3 RVD subgroups (mild vs. moderate vs. severe) and between residual >30 versus <30 degrees.

RESULTS

A total of 53 cases (28 male/25 female, mean ages 18.9 Y) underwent PVCR in one center from 2004 to 2016 were enrolled cobb angle. When 2 years after PVCR, average PFTs values showed significant improvements. PFTs values changes showed no correlation with correction rate and correction angle. The only significant impact factor in this study for FVC, FVC%, FEV1 improvements was preoperative FVC% and the only impact factor for FEV1% improvement was preoperative FEV1%, the relationships were negative. In accordance with the regression analysis, PFTs values improvements among the 3 RVD subgroups from high to low was severe>moderate>mild. However, patients with residual cobb angle <30 degrees had less PFTs values improvements than patients with residual cobb angle >30 degrees.

CONCLUSIONS

Two years after PVCR, PFTs values were significantly improved. There is no linear correlation between cobb angle change and PFTs values improvements. Lower preoperative FVC% and FEV1% indicate more PFTs values improvements at 2 years post-PVCR.

LEVEL OF EVIDENCE

Level III.

Scheuermann Kyphosis Patients Have a Similar Revision and Infection Rate to Adolescent Idiopathic Scoliosis Patients

STUDY DESIGN

Multicenter retrospective review.

OBJECTIVE

This study aims to address major postoperative complications associated with Scheuermann kyphosis (SK) when compared with adolescent idiopathic scoliosis (AIS) in a large population matched by demographic characteristics, levels fused and operative technique.

SUMMARY OF BACKGROUND DATA

Prior studies have found that SK patients are 3.86 times more likely to experience major postoperative complications than in AIS. Historically, however, these studies have often had populations that were significantly different between the two groups in terms of disease severity, demographics, and small sample sizes.

METHODS

AIS patients were compared to SK patients between 2006 and 2018 contemporaneously. All surgeries were conducted by six surgeons among two institutions. Complications and revisions were calculated. A sub-analysis comparing SK and AIS patients by age, sex, and levels-fused in one-to-one matched pairs was performed as well as a sub-analysis matched by levels fused only in one-to-one matched pairs.

RESULTS

One thousand three hundred twenty two patients were reviewed (1222 AIS; 100 SK). There were 52 (4.3%) complications in the AIS group compared with 20 (20%) complications in the SK group (P < 0.001), with infections and revisions consisting of the majority of complication rates in both cohorts.When matched by age, sex, and levels fused, there were eight complications in the AIS group and 11 in the SK group (P = 0.63), with infection and revision rates being similar, (P = 0.29) and (P = 0.26) respectively.When matched by levels fused only, EBL, operative time and complication rates remained similar (P > 0.05).

CONCLUSION

Contrary to previously published literature, our analyses indicate that in a matched population, postoperative complication rates (i.e., infection and revision rates) are not significantly different between SK and AIS patients.Level of Evidence: 4.

Development and initial validation of classification for severe spinal deformity based on X-ray features

PURPOSE

To develop a clinically feasible classification for severe spinal deformity based on X-ray features.

METHODS

A total of 223 consecutive severe spinal deformity cases who underwent corrective operation were enrolled from 2004 to 2015 retrospectively. Based on X-ray features, a novel classification was developed containing three components: curve types, curve angle and apex location. There were five curve types as follows: single scoliosis (SS), kyphoscoliosis (KS), angular deformity (AD), long curve (LC), and double curves (DC). Curve angle subsection on coronal and sagittal planes including A:90-109, B:110-129, C:130-149, D: > 150. Apex location means the exact level of apex located. Reliability of the classification was tested.

RESULTS

The kappa values for inter-observer and intra-observer reliability of the curve types, curve angle, and apex level were larger than 0.80. X-ray classification for overall patients with severe spinal deformity showed that there were 101 SS cases, 47 KS, 46 AD, 19 LC and 10 DC. For the curve angle, there were grade A 123 cases, B 43, C 18, D 15 on coronal plane and grade A 38, B 17, C 16, and D 19 on sagittal plane. Apex location showed there were 27 patients at T7 or upper levels, 31 on T8, 58 on T9, 45 on T10, 18 on T11, and 44 at T12 or lower levels.

CONCLUSION

A novel classification for severe spinal deformity was described based on X-ray morphology. A high value for inter-observer and intra-observer reliability was shown. Each subgroup has its particular influence on decision-making and prognostic prediction.

Does Navigation Make Spinal Fusion for Adolescent Idiopathic Scoliosis Safer? Insights From a National Database

STUDY DESIGN

Retrospective Cohort.

OBJECTIVE

To evaluate the effect of computer-assisted navigation (NAV) on rates of complications and reoperations after spinal fusion (SF) for adolescent idiopathic scoliosis (AIS) using a nationally representative claims database.

SUMMARY OF BACKGROUND DATA

Significant controversy surrounds the reported benefits of NAV in SF for AIS. Previous studies have demonstrated decreased rates of pedicle screw breaches with NAV compared to free-hand methods but no impact on complication rates. Thus, the clinical utility of NAV remains uncertain.

METHODS

Analyses were performed using the IBM MarketScan databases. Patients aged 10 to 18 undergoing SF for AIS were grouped by use of NAV. Patients with nonidiopathic scoliosis were excluded. Univariate and risk-adjusted multivariate analyses were performed. Primary outcomes were neurological complications, any medical complications, and reoperations. Secondary outcomes included adjusted total reimbursements and length of stay.

RESULTS

A total of 12,046 patients undergoing SF for AIS were identified, and 8640 had 90-day follow-up. NAV was used in 467 patients (5.4%), increasing from 2007 to 2015. After risk adjustment, the odds for any complication within 90 days were lower with NAV (OR = 0.61, P = 0.025), but neurological complications were unrelated to NAV (P = 0.742). NAV was not associated with reoperation within 90 days (P = 0.757) or 2 years (P = 0.095). We observed a $25,038 increase in adjusted total reimbursements (P < 0.001) and a 0.32-day decrease in length of stay (P = 0.022) with use of NAV.

CONCLUSION

In this national sample, NAV was associated with a lower rate of total complications but no change in rates of neurological complications or reoperations. In addition, NAV was associated with a large increase in total payments, despite a modest decrease in hospital stay. Considering the increasing popularity of NAV, this study provides important context regarding the utility of NAV for AIS.Level of Evidence: 3.

How helpful is the halo-gravity traction in severe spinal deformity patients?: A systematic review and meta-analysis

PURPOSE

This study sought to evaluate the complications and clinic outcome in radiographic parameters, pulmonary function, and nutritional status of halo-gravity traction (HGT) in treating severe spinal deformity.

METHODS

Embase, PubMed, Cochrane, Web of Science databases were searched comprehensively for relevant studies from inception to February 2021, by using combined text and MeSH terms and English language restriction was used. The data, including radiographic parameters, pulmonary function (FVC %), and nutritional status (BMI) was extracted from included studies. All meta-analyses were conducted using random or fixed-effects models according the between-study heterogeneity, estimated with I².

RESULTS

Four hundred and forty-six studies were identified and twelve studies with a total of 372 patients were included in this review. Compared with pre-traction values, there were reduction in cobb angle of 28.12° [95% CI (22.18, 34.18)], decrease in thoracic kyphosis of 26.76°[95% CI (20.73, 32.78)], improvements in spine height[SMD = -0.89, 95% CI (- 1.56, - 0.21)] and in coronal balance[WMD = - 0.03, 95% CI (- 1.56, - 0.21), P = 0.84] with preoperative halo-gravity traction for severe spinal deformity patients. Besides, our pooled analysis showed the improvement in pulmonary function (FVC %) [WMD = - 9.56, 95% CI (- 1.56, - 0.21)] and increase in nutritional status (BMI) [WMD = - 0.50, 95% CI (- 1.56, - 0.21)].

CONCLUSION

Partial correction can be achieved by preoperative HGT, thereby reducing the difficulty of the operation and the risk of neurologic injury caused by excessive correction. Moreover, preoperative HGT can improve pulmonary function and nutritional status and, thus, increase patients' tolerance to surgery.

Low-Dose MDCT of Patients With Spinal Instrumentation Using Sparse Sampling: Impact on Metal Artifacts

OBJECTIVE. The purpose of our study was to evaluate simulated sparse-sampled MDCT combined with statistical iterative reconstruction (SIR) for low-dose imaging of patients with spinal instrumentation. MATERIALS AND METHODS. Thirty-eight patients with implanted hardware after spinal instrumentation (24 patients with short- or long-term instrumentation-related complications [i.e., adjacent segment disease, screw loosening or implant failure, or postoperative hematoma or seroma] and 14 control subjects with no complications) underwent MDCT. Scans were simulated as if they were performed with 50% (P50), 25% (P25), 10% (P10), and 5% (P5) of the projections of the original acquisition using an in-house-developed SIR algorithm for advanced image reconstructions. Two readers performed qualitative image evaluations of overall image quality and artifacts, image contrast, inspection of the spinal canal, and diagnostic confidence (1 = high, 2 = medium, and 3 = low confidence). RESULTS. Although overall image quality decreased and artifacts increased with reductions in the number of projections, all complications were detected by both readers when 100% of the projections of the original acquisition (P100), P50, and P25 imaging data were used. For P25 data, diagnostic confidence was still high (mean score ± SD: reader 1, 1.2 ± 0.4; reader 2, 1.3 ± 0.5), and interreader agreement was substantial to almost perfect (weighted Cohen κ = 0.787-0.855). The mean volumetric CT dose index was 3.2 mGy for P25 data in comparison with 12.6 mGy for the original acquisition (P100 data). CONCLUSION. The use of sparse sampling and SIR for low-dose MDCT in patients with spinal instrumentation facilitated considerable reductions in radiation exposure. The use of P25 data with SIR resulted in no missed complications related to spinal instrumentation and allowed high diagnostic confidence, so using only 25% of the projections is probably enough for accurate and confident diagnostic detection of major instrumentation-related complications.

Clinical efficacy of short-term pre-operative halo-pelvic traction in the treatment of severe spinal deformities complicated with respiratory dysfunction

Background

Halo traction has been used as an adjunctive method in the treatment of severe spinal deformities. But there are few reports on the clinical efficacy of halo-pelvic traction (HPT) in the treatment of severe spinal deformities complicated with respiratory dysfunction. This study was to evaluate the clinical efficacy and complications associated with pre-operative HPT in the treatment of severe spinal deformities with respiratory dysfunction.

Methods

Thirty patients with severe spinal deformities complicated with respiratory dysfunction treated with short-term pre-operative HPT were retrospectively reviewed. Inclusion criteria were: (1) patients with severe kyphoscoliosis (coronal Cobb angle or kyphosis angle ≥100°) and respiratory failure, (2) patients undergoing HPT until posterior fusion surgery. All patients underwent general anesthesia for HPT application, which the pelvic ring used in this study was a half-ring, and the rods were all placed on the anterolateral side of the truck.

Results

The major coronal curve scoliosis averaged 116.00 ± 16.70° and was reduced to 63.23 ± 14.00° after HPT, 46.33 ± 10.70° after surgery. The major kyphosis was 102.40 ± 27.67° and was reduced to 52.23 ± 14.16° after HPT, 42.0 ± 11.92° after surgery. A significantly increased FVC was observed after HPT (p < 0.001), with a significantly improved FVC% (p < 0.001). Similarly, a significantly increased FEV1 was also observed (p < 0.001), with a significantly improved FEV1% (p < 0.001).

Conclusion

This study indicated that the modified HPT could be used to help patients with severe spinal deformities complicated with respiratory dysfunction achieve significant correction in both the coronal and sagittal deformities during the pre-operative treatment period along with improved respiratory function and in the absence of severe complications.

Effectiveness and safety of a modified (rib ends fixed under transverse process) thoracoplasty for rib hump deformity in adults with severe thoracic scoliosis: A retrospective study

Razor back deformity is one of the most noticeable problems of severe scoliosis. Thoracoplasty has been reported to be a useful approach to correct the rib hump deformity. However, the outcomes of thoracoplasty in patients with severe, rigid, thoracic scoliosis have not yet been evaluated.To evaluate the effectiveness and safety of a modified technique of thoracoplasty (rib ends fixed under transverse process) for rib hump deformity in adults with severe thoracic scoliosis and severe pulmonary dysfunction.Patients with severe thoracic scoliosis and severe pulmonary dysfunction who underwent staged surgical strategy including halo-pelvic traction, spinal osteotomy combined with the modified thoracoplasty were included. To avoid paradoxical breathing result from multiple rib resections and enlarge the capacity of thoracis, the ends after rib resection were fixed under transverse process compared with conventional thoracoplasty. Patients were excluded on the basis of pulmonary diseases and inadequate follow-up. Data on deformity correction and pulmonary complications were reviewed. A t test was performed on the pre- and postoperative data of pulmonary function, height of the rib hump deformity, and total lung area.Eighteen patients (5 men and 13 women) with a major thoracic curve of >130° were included. The mean age of patients was 25.3 ± 3.6 years (range, 19-32 years), with an average length of follow-up of 30.2 months. After application of halo-pelvic traction, the mean major thoracic curve decreased from 168.2° ± 14.28° to 97.3° ± 10.75° and the thoracic kyphosis decreased from 159.4° ± 20.60° to 94.8° ± 9.58°. On average, 6.3 (range, 4-8) ribs were resected. The height of the rib hump decreased from 84.6 ± 13.3 to 15.3 ± 3.4 mm. The average predicted forced vital capacity (FVC%) before surgery was 37.2 ± 13.30%, indicative of severe pulmonary impairment, with a small but non-significant improvement in the FVC% at the final follow-up. The mean total lung area increased from 2583.2 ± 501.36 to 2890.1 ± 537.30 mL at the last follow-up. No severe pulmonary complications occurred.Our modified approach to thoracoplasty procedure is effective and safe in correcting a razor back deformity in patients with severe, rigid, scoliosis, and severe pulmonary dysfunction, without causing any significant change in long-term pulmonary function.

Multidisciplinary approaches to complication reduction in complex spine surgery: a systematic review

BACKGROUND CONTEXT

Complex spine surgery carries a high complication rate that can produce suboptimal outcomes for patients undergoing these extensive operations. However, multidisciplinary pathways introduced at multiple institutions have demonstrated a promising potential toward reducing the burden of complications in patients being treated for spinal deformities. To date, there has been no effort to systematically collate the multidisciplinary approaches in use at various institutions.

PURPOSE

The present study aims to determine effective multidisciplinary strategies for reducing the complication rate in complex spine surgery by analyzing existing institutional multidisciplinary approaches and delineating common themes across multiple practice settings.

STUDY DESIGN

Systematic review.

METHODS

We followed guidelines established under the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The studies reported on data from PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science and Cochrane. We included articles that described either approaches to, or results from, the implementation of multidisciplinary paradigms during the preoperative, perioperative, and postoperative phases of care for patients undergoing complex spine surgery. We excluded studies that only targeted one complication unless such an approach was in coordination with more extensive multidisciplinary planning at the same institution.

RESULTS

A total of 406 unique articles were identified. Following an initial determination based on title and abstract, 22 articles met criteria for full-text review, and 10 met the inclusion criteria to be included in the review. Key aspects of multidisciplinary approaches to complex spine surgery included extensive preoperative workup and interdisciplinary conferencing, intraoperative communication and monitoring, and postoperative floor management and discharge planning. These strategies produced decreases in surgical duration and complication rates.

CONCLUSIONS

This study represents the first to systematically analyze multidisciplinary approaches to reduce complications in complex spine surgery. This review provides a roadmap toward reducing the elevated complication rate for patients undergoing complex spine surgery.

Severe adolescent idiopathic scoliosis: posterior staged correction using a temporary magnetically-controlled growing rod

PURPOSE

A two-staged posterior correction, using a temporary magnetically controlled growing rod (MCGR), was employed to gradually and safely correct severe adolescent idiopathic scoliosis (AIS). The aim of the study is illustrating the results of this procedure.

METHODS

A retrospective review of a consecutive series of 17 severe AIS. The first surgery was a posterior release (multiple Ponte osteotomies) with implant of pedicle screws and MCGR on the concave side of the curve. In post-operative days, a distraction was applied with MCGR, which allowed to obtain a total mean lengthening of 2 cm in about 2 weeks, with no complications arising. In the second posterior surgery, MCGR was removed and the definitive rods were applied for final fusion. The mean pedicle screws density was 93.3% (85-100). The extension of the final posterior fusion-instrumentation was of 13.8 levels (12-15).

RESULTS

At an average follow-up (FU) of 2.9 years, the main scoliosis curves from average pre-operative Cobb angle of 98.2° (91°-138°) bent down to 38.3° (35°-76°) after definitive fusion (p < 0.05); at last FU, the overall correction was 58.7% (50.4-71.2), with an average correction loss of 2.1° (1.5°-3.1°). At last FU, no complications were reported.

CONCLUSIONS

Gradual traction with MCGR in severe AIS proved to be a safe method to achieve progressive curve correction before posterior final fusion, with no neurologic complications associated to more aggressive one-stage surgeries. In a staged approach, MCGR appears as an alternative to halo traction, avoiding frequent traction-related complications.

Cervical Abnormalities in Severe Spinal Deformity: A 10-year MRI Review

Objective

To investigate the incidence of cervical anomalies (CA), including cervical intraspinal neural axis abnormalities (CIINAA) and/or cervical osseous abnormalities (COA), and the clinical relevance in severe spinal deformities (SSD) at a single center.

Methods

A retrospective study of SSD admitted for spinal surgery from January 2003 to January 2015 was conducted at a single center. Inclusion criteria: patients who present with coronal Cobb over 90° (and/or sagittal cobb ≥90°); and patients with complete imaging and clinical data preoperatively. Exclusion criteria: ankylosing spondylitis, adult onset scoliosis, scoliosis secondary to bone destruction. There were 108 SSD patients who fulfilled the criteria in this research (41 males and 67 females). The mean age of the patients was 18.1 ± 2.7 years (range, 10–45 years). The clinical and radiological data of these patients were reviewed to identify CA and to analyze the relationship between clinical and radiographic characteristics in the population of SSD.

Results

The major curves of scoliosis and segmental kyphosis were 109.1° ± 24.7° and 91.2° ± 29.1°. Cervical abnormalities were detected in 56 patients (51.85%) with 9 different CA, including 28 patients (25.9%) with 6 different COA, 21 patients (19.4%) with 3 different CIINAA, and 7 patients (6.5%) with a combination of COA and cervical intraspinal neural axis abnormalities (CINAA). Basilar invagination and Klippel–Feil syndrome were the most frequent COA. Syringomyelia was the most frequent CINAA. SSD with COA in upper vertebral levels (UVL) had a higher incidence of CINAA than those in subaxial vertebral levels (SVL) (P = 0.024) and SSD with multiple COA (mCOA) in UVL had a higher incidence of CINAA than those with single COA (sCOA) (P = 0.029). In the present study, 83.9% of the SSD with CA were asymptomatic.

Conclusion

The incidence of CA in SSD was 51.85%, with most presenting with intact neurologic status. As the diversity of COA increased, we found a higher incidence of CINAA, especially in UVL.

Halo-gravity traction for the treatment of pediatric cervical spine disorders

OBJECTIVE

Halo-gravity traction (HGT) is an effective and safe method for gradual correction of severe cervical deformities in adults. However, the literature is limited on the use of HGT for cervical spine deformities that develop in children. The objective of the present study was to evaluate the safety and efficacy of HGT for pediatric cervical spine deformities.

METHODS

Twenty-eight patients (18 females) whose mean age was 11.3 ± 5.58 years (range 2-24.9 years) underwent HGT. Common indications included kyphosis (n = 12), rotatory subluxation (n = 7), and basilar invagination (n = 6). Three children (11%) received traction to treat severe occipitocervical instability. For these 3 patients, traction combined with a halo vest, with bars attached rigidly to the vest, but with the ability to slide through the connections to the halo crown, was used to guide the corrective forces and moments in a specific and controlled manner. Patients ambulated with a wheelchair or halo walker under constant traction. Imaging was done before and during traction to evaluate traction efficacy. The modified Clavien-Dindo-Sink classification was used to categorize complications.

RESULTS

The mean duration of HGT was 25 days (IQR 13-29 days), and the mean traction was 29% ± 13.0% of body weight (IQR 19%-40% of body weight). The mean kyphosis improved from 91° ± 20.7° (range 64°-122°) to 56° ± 17.6° (range 32°-96°) during traction and corresponded to a mean percentage kyphosis correction of 38% ± 13.8% (range 21%-57%). Twenty-five patients (89%) underwent surgical stabilization, and 3 patients (11%) had rotatory subluxation that was adequately reduced by traction and were treated with a halo vest as their definitive treatment. The mean hospital stay was 35 days (IQR 17-43 days).Nine complications (32%) occurred: 8 grade I complications (28%), including 4 cases of superficial pin-site infection (14%) and 4 cases of transient paresthesia (14%). One grade II complication (4%) was seen in a child with Down syndrome and a preexisting neurological deficit; this patient developed flaccid paralysis that rapidly resolved with weight removal. Six cases (21%) of temporary neck discomfort occurred as a sequela of a preexisting condition and resolved without treatment within 24-48 hours.

CONCLUSIONS

HGT in children is safe and effective for the gradual correction of cervical kyphosis, atlantoaxial subluxation, basilar invagination, and os odontoideum. Cervical traction is an additional tool for the pediatric spine surgeon if uncertainties exist that the spinal alignment required for internal fixation and deformity correction can be safely achieved surgically. Common complications included grade I complications such as superficial pin-site infections and transient paresthesias. Halo vest gravity traction may be warranted in patients with baseline neurological deficits and severe occipitocervical instability to reduce the chance of catastrophic movement.

Anterior and Posterior Fusion for Large, Rigid Idiopathic Scoliosis: Does Implant Density Matter?

BACKGROUND

Despite advancements in surgical techniques, controversy remains regarding the optimal implant density for the correction of idiopathic scoliosis. Recent evidence has suggested that equivalent radiographic and clinical outcomes can be achieved with lower implant densities for those with moderate curves and good flexibility. Among the experts, the consensus has continued that higher implant densities should be used for larger, stiffer curves. The purpose of the present study was to compare the radiographic results between high-implant density (HID) and low-implant density (LID) constructs in patients with large (>65°), rigid (<50% flexibility) curves who had undergone anterior release and posterior spinal fusion.

METHODS

We reviewed the idiopathic scoliosis cases performed at a single institution from 2006 to 2014. Only those meeting the inclusion criteria were selected. The patients were divided into HID and LID groups. The postoperative radiographs were compared for coronal correction, thoracic kyphosis, pelvic tilt, lumbar lordosis, and sagittal vertical axis.

RESULTS

A statistically significant improvement in coronal correction was detected in the HID group at all follow-up points (final follow-up: HID, 81.1% vs. LID, 70.4%; P = 0.01). When preoperative thoracic kyphosis was considered, no differences were found between the 2 groups. No differences were found in the other sagittal parameters.

CONCLUSION

In patients with large, rigid idiopathic scoliosis undergoing anterior release and posterior spinal fusion, a small, but statistically, significant improvement in the coronal Cobb angle was seen. It remains to be determined whether this small difference in radiographic correction will have any influence on the clinical outcome.

Neurologic Deficit During Halo-Gravity Traction in the Treatment of Severe Thoracic Kyphoscoliotic Spinal Deformity

Correction of severe spinal deformity is a significant challenge for spinal surgeons. Although halo-gravity traction (HGT) has been shown to be well-tolerated and safe, we report here a case of neurologic decline during treatment. A 24-year-old male presents with severe thoracic kyphoscoliosis with > 180° of 3-dimensional deformity. Magnetic resonance imaging showed his thoracic spinal cord draped across his T7-9 apex. His neurologic exam showed lower extremity myelopathy. During week 7 at a goal traction weight of 18.1 kg, his distal lower extremity exam declined from 4+/5 to 2/5. His traction weight was lowered to 11.3 kg. He subsequently sustained a ground-level fall and became paraparetic with a motor exam of 1-2/5. He subsequently underwent a T1-L4 posterior spinal instrumentation and fusion with a T7-9 vertebral column resection. Postoperatively, he was noted to have a complete return to his baseline neurologic exam. At his 4-month postoperative visit, he was now full strength in his lower extremities with complete resolution of his myelopathy. We present here a case of neurologic decline in a patient with severe kyphoscoliosis who underwent HGT and discuss the management decisions associated with this challenging scenario.

An Overview of the Current State of Pediatric Scoliosis Management

Historically pediatric scoliosis represents a condition deeply rooted within the origins of orthopedic surgery. Today only a few subspecialized surgeons treat pediatric scoliosis patients. In severe cases surgery can hold progression of and correct pathologic spinal curvature. The goal of this article is to provide an overview of the current state of pediatric scoliosis management. It aims to increase the attention of general physicians and orthopedic surgeons to a niched but rather frequently encountered pediatric pathology to facilitate early recognition and diagnosis. A thorough research of literature was conducted to summarize the different scoliosis types, their etiology and presentation. Classification, normal human growth phases and curve progression risk have been further elaborated. Finally, current treatment options with their benefits, shortcomings and complications were laid out and discussed. Among the etiological groups a focus was put on idiopathic scoliosis, in particular adolescent idiopathic scoliosis as the most frequently encountered subtype.

A Novel Posterior Rod-Link-Reducer System Provides Safer, Easier, and Better Correction of Severe Scoliosis

STUDY DESIGN

Retrospective review.

OBJECTIVES

To compare the Cobb >75° scoliosis correction obtained using a novel Rod-Link-Reducer (RLR) system versus traditional corrective techniques (TCT) in patients with severe adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Current implant strategies provide for good correction, especially for moderate curves; however, severe scoliosis continues to be challenging to obtain correction in a safe and effective manner.

METHODS

A novel correction device was developed so that two provisional rods are placed on the convex side of the scoliosis proximally and distally, which are then linked to an external reduction device termed the RLR. A retrospective analysis was performed to compare the RLR versus the TCT in patients with curve >75° with the diagnosis of AIS with respect to the radiographic outcomes, operative time, intraoperative blood loss, complications, and SRS-30 scores of a minimum 2-year follow-up.

RESULTS

A total of 36 patients were evaluated (RLR-18, TCT-18). The data sets were similar for age, gender, coronal Cobb, curve flexibility, and follow-up period. The mean preoperative Cobb for the RLR group was 91.7° (76°-113°) and 91.8° (78°-108°) for the TCT group. The mean coronal Cobb correction rate was significantly greater for the RLR group (73.1% vs. 56.6%, p < .0001). The mean operative time was 74.8 minutes shorter in the RLR group (316.6 minutes vs. 391.4 minutes, p = .03). There were 2 late-developing infections and 3 intraoperative neuro-monitoring changes during the correction maneuvers in the TCT group compared with none in the RLR group (p = .02).

CONCLUSION

In a matched cohort, the use of the RLR exhibited greater coronal Cobb correction, shorter operative time, and was less likely to have critical neuro-monitoring changes compared with the TCT group. The RLR provides safer and improved correction for severe curves without adding surgical risk.

LEVEL OF EVIDENCE

Level III.

Surgical growth guidance with non-fused anchoring segments in early-onset scoliosis

PURPOSE

Surgical treatment of early-onset scoliosis (EOS) requires a balance between maintained curve correction and the capacity for spinal and thoracic growth. Spinal fusion creates irreversible conditions that prevent the implementation of further treatment methods. Our hypothesis was that non-fused anchors in growth guidance show a comparable outcome as the technique described in the literature, which involves spondylodesis of the anchoring segments.

METHODS

This retrospective study analysed 148 surgeries in 22 EOS patients (11 female, 11 male) over a 15-year period. Patients underwent surgery with non-fused anchors and growth guidance techniques. Scoliosis, kyphosis, growth and anchoring segments were measured. For the latter, a new measuring technique was developed. Complications were recorded and classified.

RESULTS

The mean Cobb angle reduced from 73.5 ± 24.4° to 28.4 ± 16.2° (60.2 ± 22.9%, p < 0.001) at the last follow-up. Spinal growth T1-S1 and T1-T12 were 41.1 ± 23.3 mm and 24.9 ± 16.6 mm (p < 0.001), respectively. Growth at the cranial and caudal anchoring segment was 1.5 mm/segment/year and 1.9 mm/segment/year, respectively. A total of 63 complications were documented in 20 patients, with 40 requiring unplanned revision surgery. Definitive spondylodesis was performed in three patients.

CONCLUSION

Patients demonstrated a significant spinal growth including the anchoring segments. A comparable correction in Cobb angle and the type of complications was noted, although the rate of device-related complications was higher. No permanent impairment was reported. The rate of device-related complications is acceptable and outweighed by the significant degree of growth preservation and more flexible and individualised treatment strategy for patients with EOS. These slides can be retrieved under Electronic Supplementary Material.

2016 SOSORT guidelines: orthopaedic and rehabilitation treatment of idiopathic scoliosis during growth

BACKGROUND

The International Scientific Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT) produced its first guidelines in 2005 and renewed them in 2011. Recently published high-quality clinical trials on the effect of conservative treatment approaches (braces and exercises) for idiopathic scoliosis prompted us to update the last guidelines' version. The objective was to align the guidelines with the new scientific evidence to assure faster knowledge transfer into clinical practice of conservative treatment for idiopathic scoliosis (CTIS).

METHODS

Physicians, researchers and allied health practitioners working in the area of CTIS were involved in the development of the 2016 guidelines. Multiple literature reviews reviewing the evidence on CTIS (assessment, bracing, physiotherapy, physiotherapeutic scoliosis-specific exercises (PSSE) and other CTIS) were conducted. Documents, recommendations and practical approach flow charts were developed using a Delphi procedure. The process was completed with the Consensus Session held during the first combined SOSORT/IRSSD Meeting held in Banff, Canada, in May 2016.

RESULTS

The contents of the new 2016 guidelines include the following: background on idiopathic scoliosis, description of CTIS approaches for various populations with flow-charts for clinical practice, as well as literature reviews and recommendations on assessment, bracing, PSSE and other CTIS. The present guidelines include a total of 68 recommendations divided into following topics: bracing (n = 25), PSSE to prevent scoliosis progression during growth (n = 12), PSSE during brace treatment and surgical therapy (n = 6), other conservative treatments (n = 2), respiratory function and exercises (n = 3), general sport activities (n = 6); and assessment (n = 14). According to the agreed strength and level of evidence rating scale, there were 2 recommendations on bracing and 1 recommendation on PSSE that reached level of recommendation "I" and level of evidence "II". Three recommendations reached strength of recommendation A based on the level of evidence I (2 for bracing and one for assessment); 39 recommendations reached strength of recommendation B (20 for bracing, 13 for PSSE, and 6 for assessment).The number of paper for each level of evidence for each treatment is shown in Table 8.

CONCLUSION

The 2016 SOSORT guidelines were developed based on the current evidence on CTIS. Over the last 5 years, high-quality evidence has started to emerge, particularly in the areas of efficacy of bracing (one large multicentre trial) and PSSE (three single-centre randomized controlled trials). Several grade A recommendations were presented. Despite the growing high-quality evidence, the heterogeneity of the study protocols limits generalizability of the recommendations. There is a need for standardization of research methods of conservative treatment effectiveness, as recognized by SOSORT and the Scoliosis Research Society (SRS) non-operative management Committee.

Surgical correction of severe spinal deformities using a staged protocol of external and internal techniques

INTRODUCTION

There is high risk of neurologic complications in one-stage management of severe rigid spinal deformities in adolescents. Therefore, gradual spine stretching variants are applied. One of them is the use of external transpedicular fixation.

PURPOSE

Our aim was to retrospectively study the outcomes of gradual correction with an apparatus for external transpedicular fixation followed by internal fixation used for high-grade kyphoscoliosis in adolescents.

METHODS

Twenty five patients were reviewed (mean age, 15.1 ± 0.4 years). Correction was performed in two stages: 1) gradual controlled correction with the apparatus for external transpedicular fixation; and 2) internal posterior transpedicular fixation. Rigid deformities in eight patients required discapophysectomy. Clinical and radiographic study of the outcomes was conducted immediately after treatment and at a mean long-term period of 3.8 ± 0.4 years. Pain was evaluated using the visual analogue scale (VAS, 10 points). The Oswestry questionnaire (ODI scale) was used for functional assessment.

RESULTS

Deformity correction with the external apparatus was 64.2 ± 4.6% in the main curve and 60.7 ± 3.7% in the compensatory one. It was 72.8 ± 4.1% and 66.2 ± 5.3% immediately after treatment and 70.8 ± 4.6% and 64.3 ± 4.2% at long term, respectively. Pain relieved by 33.2 ± 4.2% (p < 0.05) immediately after treatment and by 55.6 ± 2.8% (p < 0.05) at long term. ODI reduced by 30.2 ± 1.7% (p < 0.05) immediately after treatment and by 37.2 ± 1.6% (p < 0.05) at long term.

CONCLUSION

The apparatus for external transpedicular fixation provides gradual controlled correction for high-grade kyphoscoliosis in adolescents. Transition to internal fixation preserves the correction achieved, and correction is maintained at long term.

Proper Responding Strategies to Neuromonitoring Alerts During Correction Step in Posterior Vertebral Column Resection Patients With Severe Rigid Deformities Can Reduce Postoperative Neurologic Deficits

MINI: The neurological risks in posterior vertebral column resection can be resulted from spinal cord tension changes following correction maneuvers being performed. On the basis of intraoperative neuromonitoring alerts, to timely identify them as well to act prompt surgical interventions can decrease the risks.

STUDY DESIGN

Retrospective study.

OBJECTIVE

To analyze the intraoperative neuromonitoring (IOM) changes in posterior vertebral column resection (PVCR) for severe rigid deformity patients, and describe our stepwise responding strategies.

SUMMARY OF BACKGROUND DATA

Obvious neurological deficit risk accompanied with PVCR correction has been emphasized repeatedly.

METHODS

The records of 46 patients who underwent PVCR achieved IOM were reviewed. IOM alerts triggered responding protocols: (1) exchange the convex corrective rod to concave stabilizing rod, (2) appropriate compression for spinal shortening, (3) reversed in situ rod bending, (4) translation technique and unisegmental derotation, (5) adjacent segmental resection.

RESULTS

The overall scoliotic correction rate was 65.4% (from 112 ± 28.6 to 39 ± 13.4) and segmental kyphotic correction rate was 64.2% (from 101 ± 37.3 to 36 ± 19.2). During correction step, somatosensory-evoked potential warning (3) and somatosensory-evoked potential/transcranial motor-evoked potential warning (8) were detected in 11 patients (23.9%). Probable cause identification including rule out IOM technical factors, residual impingement, and if there was unstable spinal column (1), spinal cord excessive tension on concave side (3), and the excessive opposite spinal displacement between two aspects of resected area (7). After rod change (1), compression (2), bending (3), derotation (3), and adjacent resection (2), all IOM changes went to under warning criteria. All 11 patients revealed neurologically intact postoperatively. There was no difference of correction rate between IOMs alert or not. However, adult, extremely severe or sharp angular curves tend to be more common in IOM alert patients.

CONCLUSION

As three-dimensional spinal column divided and relinked in PVCR, and the correction maneuvers were restricted on single dimension, inevitably resulted in spinal cord tension changes and spinal column opposite displacement. To timely identify them, prompt interventions should be performed, and even enlarge the resected area to reduce the abrupt turning tendency of the spinal cord.

LEVEL OF EVIDENCE

5.

Effect on Chest Deformation of Simultaneous Correction of Pectus Excavatum with Scoliosis

Objective

This paper is to understand the effect of simultaneous correction of pectus excavatum with scoliosis and to provide some useful information for clinical orthopedic surgery design.

Methods

The method of a three-dimensional reconstruction has been used to the reconstruction of the chest model of pectus excavatum with scoliosis, and the numerical stimulation has been conducted to the process of minimally invasive correction. Three kinds of correction methods have been considered in the numerical simulation, stretch spine, stretch spine and minimally invasive correction at the same time, and release stretch spine after stretch spine and minimally invasive correction of pectus excavatum at the same time.

Results

It is found that stretch spine may help to correction of scoliosis but aggravate the sternum collapse, and release stretch spine after stretch spine and minimally invasive correction at the same time could not only be good at scoliosis but also improve the collapse of the sternum, which could help to improve the heartbeat and breath of the patients.

Conclusion

Among the three kinds of correction methods, release stretch spine after stretch spine and minimally invasive correction at the same time could help to improve both the scoliosis and the collapse of the sternum.

Three-dimensional Cross-Platform Planning for Complex Spinal Procedures: A New Method Adaptive to Different Navigation Systems

STUDY DESIGN

A feasibility study.

OBJECTIVE

To develop a method based on the DICOM standard which transfers complex 3-dimensional (3D) trajectories and objects from external planning software to any navigation system for planning and intraoperative guidance of complex spinal procedures.

SUMMARY OF BACKGROUND DATA

There have been many reports about navigation systems with embedded planning solutions but only few on how to transfer planning data generated in external software.

MATERIALS AND METHODS

Patients computerized tomography and/or magnetic resonance volume data sets of the affected spinal segments were imported to Amira software, reconstructed to 3D images and fused with magnetic resonance data for soft-tissue visualization, resulting in a virtual patient model. Objects needed for surgical plans or surgical procedures such as trajectories, implants or surgical instruments were either digitally constructed or computerized tomography scanned and virtually positioned within the 3D model as required. As crucial step of this method these objects were fused with the patient's original diagnostic image data, resulting in a single DICOM sequence, containing all preplanned information necessary for the operation. By this step it was possible to import complex surgical plans into any navigation system.

RESULTS

We applied this method not only to intraoperatively adjustable implants and objects under experimental settings, but also planned and successfully performed surgical procedures, such as the percutaneous lateral approach to the lumbar spine following preplanned trajectories and a thoracic tumor resection including intervertebral body replacement using an optical navigation system. To demonstrate the versatility and compatibility of the method with an entirely different navigation system, virtually preplanned lumbar transpedicular screw placement was performed with a robotic guidance system.

CONCLUSIONS

The presented method not only allows virtual planning of complex surgical procedures, but to export objects and surgical plans to any navigation or guidance system able to read DICOM data sets, expanding the possibilities of embedded planning software.

Severe Rigid Scoliosis: Review of Management Strategies and Role of Spinal Osteotomies

Severe rigid curves pose a considerable challenge to the treating spine surgeon. In our practice, approximately 30%–40% of patients with scoliosis present late with severe rigid scoliosis (>90° and <30% correction on bending films). Controversy still exists with regard to the ideal surgical strategy for correcting these rigid curves. Rigid scoliosis often presents in the form of either sharp angular or rounded deformities. Rounded deformities can be effectively managed with an anterior release to loosen the apex and posterior instrumentation (with osteotomies, if required). In contrast, severe rigid scoliosis, which is a sharp angular deformity, is not very amenable to anterior release and is best managed by posterior-only vertebral column resection and posterior instrumentation.