Posterior multilevel vertebral osteotomy for correction of severe and rigid neuromuscular scoliosis: a preliminary study

Fifteen Years of Spinal Fusion Outcomes in Children With Cerebral Palsy: Are We Getting Better?

STUDY DESIGN

Retrospective multicenter study.

OBJECTIVE

We reviewed 15-year trends in operative factors, radiographic and quality of life outcomes, and complication rates in children with cerebral palsy (CP)-related scoliosis who underwent spinal fusion.

SUMMARY OF BACKGROUND DATA

Over the past two decades, significant efforts have been made to decrease complications and improve outcomes of this population.

MATERIALS AND METHODS

We retrospectively reviewed a multicenter registry of pediatric CP patients who underwent spinal fusion from 2008 to 2020. We evaluated baseline and operative, hospitalization, and complication data as well as radiographic and quality of life outcomes at a minimum 2-year follow-up.

RESULTS

Mean estimated blood loss and transfusion volume declined from 2.7±2.0 L in 2008 to 0.71±0.34 L in 2020 and 1.0±0.5 L in 2008 to 0.5±0.2 L in 2020, respectively, with a concomitant increase in antifibrinolytic use from 58% to 97% (all, P <0.01). Unit rod and pelvic fusion use declined from 33% in 2008 to 0% in 2020 and 96% in 2008 to 79% in 2020, respectively (both, P <0.05). Mean postoperative intubation time declined from 2.5±2.6 to 0.42±0.63 days ( P< 0.01). No changes were observed in preoperative and postoperative coronal angle and pelvic obliquity, operative time, frequency of anterior/anterior-posterior approach, and durations of hospital and intensive care unit stays. Improvements in the Caregiver Priorities and Child Health Index of Life with Disabilities postoperatively did not change significantly over the study period. Complication rates, including reoperation, superficial and deep surgical site infection, and gastrointestinal and medical complications remained stable over the study period.

CONCLUSIONS

Over the past 15 years of CP scoliosis surgery, surgical blood loss, transfusion volumes, duration of postoperative intubation, and pelvic fusion rates have decreased. However, the degree of radiographic correction, the rates of surgical and medical complications (including infection), and health-related quality of life measures have broadly remained constant.

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.

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.

Comparison of Overall Complication Rates in VCR-Based vs Non-VCR-Based Corrective Techniques in Severe Rigid Kyphoscoliosis Patients: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

Compilation of complication outcomes data from the surgical management of severe rigid kyphoscoliosis patients using VCR-based vs non-VCR-based corrective maneuvers is lacking. This meta-analysis aimed to compare complication outcomes between those classified osteotomy approaches.

METHODS

Thorough literature review and meta-analysis were conducted between January 2000 and September 2021. The selection criteria were studies: i) reporting major curve Cobb angle of ≥80° and flexibility of <25% or 30%; ii) comparing VCR or ≥ Type V Schwab osteotomy defined as VCR-based vs [non-VCR-based] techniques, (any osteotomy or technique other than VCR); iii) published in English with ≥10 patients; iv) reporting complication rates; and v) having minimum of 2-year follow-up. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Significance level was set at (P < .05).

RESULTS

Of the 174 patients included, 52.30% (n = 91) and 47.70% (n = 83) were VCR-based and non-VCR-based, respectively. The incidence of dural tears/nerve injuries/significant intraoperative-neuromonitoring changes was significantly higher; [OR = 6.78, CI= (1.75 to 26.17), I2 = 0%, (P = .006)] in the VCR-based group than the non-VCR-based group. The 'overall surgical and medical' complication rate was significantly higher in the VCR-based group, [OR = 1.94, CI= (1.02 to 3.67), I2 = 31%, (P = .04)].

CONCLUSION

Both VCR-based and non-VCR-based surgical techniques for management of severe rigid scoliosis and kyphoscoliosis patients pose comparable overall surgical complication rates, while a significantly higher perioperative neurological complication incidence was associated with VCR-based technique compared to the non-VCR-based techniques. The VCR-based technique was associated with 6.78 times higher incidence of neurological complications compared to non-VCR-based techniques.

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.

A 3D-printed Personalized, Combined, Modular Pedicle Subtraction Osteotomy Guide Plate System: An Experimental Study

STUDY DESIGN

Experimental study.

OBJECTIVES

The goal of this study was to develop a threedimensional (3D)-printed pedicle subtraction osteotomy (PSO) guide plate system. A 3D model and postoperative computed tomography (CT) data were used to evaluate the accuracy of osteotomy with this system.

SUMMARY OF BACKGROUND DATA

The key to the success of spinal orthopedic treatment is an effectively performed osteotomy. A 3D-printed osteotomy plate can be used for preoperative surgical planning. Due to the anatomical complexity of the spinal region, the clinical application of 3D-printed osteotomy plates remains challenging.

METHODS

The CT scans of 10 patients with thoracolumbar spinal deformities were obtained in the digital imaging and communication in medicine (DICOM) format. The diseased vertebrae and adjacent vertebrae were reconstructed and reduced by computer- aided design software, and an osteotomy plate was designed for the diseased vertebrae. The 3D-printed spinal model and osteotomy plate were used to simulate the operation for PSO. After the operation, the vertebral body treated by osteotomy underwent a CT scan, and the findings were compared with the preoperative design to evaluate the osteotomy accuracy.

RESULTS

The new 3D guide plate and spine model were used to successfully simulate 10 cases of PSO, and the comparison of the preoperative and postoperative states indicated that the osteotomy outcomes were excellent.

CONCLUSIONS

The new 3D-printed PSO guide plate system can be used for preoperative osteotomy planning and demonstrates good accuracy. The results can be used to develop 3D-printed plans for PSO in clinical practice.

Evaluation of parallel endplate osteotomy for severe rigid spinal deformities: a retrospective analysis of 36 cases with a minimum 2-year follow-up

Background

To report on the technique and results of parallel endplate osteotomy (PEO) for severe rigid spinal deformity.

Methods

We retrospectively reviewed the clinical data of 36 patients with severe rigid spinal deformities who underwent PEO between July 2016 and December 2018 and who were followed up for at least 24 months.

Results

Following PEO, the kyphosis and scoliosis correction rates reached 77.4 ± 14.0% and 72.2 ± 18.2%, respectively. The median intraoperative estimated blood loss was 1500 mL and the median operative time was 6.8 h. The SF-36 scores of physical function, role-physical, bodily pain, general health, vitality, social function, role-emotional and mental health changed from 62 ± 28, 51 ± 26, 49 ± 29, 35 ± 30, 53 ± 28, 45 ± 30, 32 ± 34 and 54 ± 18 at baseline to 81 ± 16, 66 ± 41, 72 ± 40, 64 ± 44, 75 ± 25, 71 ± 46, 66 ± 34 and 76 ± 28 at 12 months postoperatively, 82 ± 32, 67 ± 42, 81 ± 30, 71 ± 41, 80 ± 30, 74 ± 36, 68 ± 35 and 85 ± 33 at 18 months postoperatively, and 86 ± 21, 83 ± 33, 88 ± 26, 79 ± 39, 86 ± 36, 86 ± 48, 80 ± 47 and 91 ± 39 at 24 months postoperatively, respectively.

Conclusions

PEO is an effective technique for successful correction of spinal deformities. At the two-year follow-up visit, all patients achieved better clinical results based on the SF-36 scores.

In vivo deformation of the spine canal before and after surgical corrections of severe and rigid kyphoscoliosis

Background

Ponte osteotomy and posterior vertebral column resection (PVCR) are two popular surgical techniques in treatment of severe and rigid kyphoscoliosis. However, quantitative effects of the two surgeries on spinal cord deformation are unclear. This information is critical for improvement of the treatment methods that can maximally correct the spinal deformity and prevent neurological complications.

Methods

Ten patients with severe kyphoscoliosis were investigated. X-ray and CT images of full spine of all patients were acquired before and 6–24 months after surgical treatment using either Ponte osteotomy or PVCR. A 3D model of the spine was constructed for each patient using the CT images that included the spinal canal between T2 and L2 vertebrae. The spinal canal length (SCL) was determined at 5 locations on the cross section of the canal: anterior, posterior, left, right (concave or convex side) and centre positions. The perpendicular distances between the T2 and L2 vertebrae, COBB angles and patient reported outcome measures before and after operations were determined.

Results

For patients treated with Ponte osteotomy, the SCLs were elongated by 12.7 ± 9.5 mm (5.4 ± 3.9%) at the concave side and 3.2 ± 6.8 mm (1.3 ± 2.8%) at the convex side. The COBB angle was corrected by 55.8% and the T2-L2 distance was increased by 66.1 ± 12.0 mm (68.4 ± 15.9%). For patients treated using PVCR, the SCLs were shortened by −5.5 ± 5.3 mm (−2.3 ± 2.2%) at the concave side and −14.0 ± 6.6 mm (−5.2 ± 2.6%) at the convex side. The COBB angle was corrected by 60.0% and the T2-L2 distance was increased by 41.5 ± 12.4 mm (32.1 ± 23.0%). The patient reported outcome scores were improved using both surgeries (p < 0.05).

Conclusion

Ponte and PVCR surgeries caused significant changes of the SCL in scoliosis patients in different ways. The Ponte osteotomy mainly caused elongation of the SCL at concave side and the PVCR caused compression of the SCL at the convex side. Both surgeries partially improved the spinal deformity. The data provide insights for development of new surgical techniques that integrates the advantages of both Ponte and PVCR osteotomies to maximally correct the spine deformity and prevent neurological complications.

The translational potential of this article

The methodology and the data presented in this paper could be instrumental for development of computer assisted surgical techniques that can maximally correct the spinal deformity and minimize the effect on the spinal cord in scoliosis patients.

Technical aspects of surgical correction of spinal deformities in cerebral palsy

PURPOSE

Cerebral palsy (CP) is a disorder arising from a non-progressive lesion in the developing immature brain with an encephalopathy, that results in various levels of motor and sensory dysfunction. Motor disability of these children can be assessed by the Gross Motor Function Classification System in five levels, and depending on their motor functional capability, the most severely affected children fall into levels IV and V. Children in groups IV and V present a full spectrum of musculoskeletal deformities, among which, scoliosis is the most frequently found spinal deformity that most often requires surgical treatment. However, these are procedures that are usually technically demanding, requiring experienced surgical teams and a multidisciplinary approach.

METHODS

In order to overcome some of the technical pitfalls that may complicate these complex surgical procedures, the authors have gathered together different tips and tricks that may help surgeons performing surgical correction of spinal deformities in CP children.

CONCLUSION

Although for these children surgery is a major undertaking, with the multidisciplinary approach and advances of technology, anaesthesia and optimization of pre- and postoperative care, complications are manageable in most cases, improving not only the outcome of surgery but also the patient's quality of life and satisfaction of parents and caretakers.

Effect of Spinal Shortening for Protection of Spinal Cord Function in Canines with Spinal Cord Angulation

Background

Posterior vertebral column resection (PVCR) has been widely used as a treatment for severe spinal deformity. By using the canine model of vertebral column resection, this study explored the effect of spinal shortening on blood flow and function of the spinal cord during spinal cord angulation.

Material/Methods

The canine model of L1 vertebral column resection was constructed with the PVCR technique. The canines were divided into 5 groups according to the degree of shortening: the 0/4 group, the 1/4 group, the 2/4 group, the 3/4 group, and the control group. Spinal cord blood flow, neuroelectrophysiology, HE staining, nitric oxide, and endothelin-1 were measured during the procedure of vertebral column resection and spinal cord angulation.

Results

The results showed that, in the 1/4 group and the 2/4 group, the blood flow of the spinal cord decreased by 16.5% and 10.6%, respectively, with no obvious damage in the spinal cord; in the 0/4 group and the 3/4 group, the blood flow decreased by 23.5% and 23.1%, respectively, with significant damage in the spinal cord.

Conclusions

When the spinal cord is shortened by 1/4 to 2/4, the tolerance of the spinal cord can increase and spinal cord injury resulting from angulation can be avoided. However, when the shortening reaches 3/4, it is harmful to the spinal cord. Proper shortening of the spinal cord by 1/4 to 2/4 may increase the tolerance of the spinal cord to the damage caused by angulation during PVCR.

Skull-femoral traction after posterior release for correction of adult severe scoliosis: efficacy and complications

Background

It is a great challenge for spine surgeons to correct severe rigid scoliosis. We developed a three- staged correction (one stage posterior release and screw placement, two stage skull-femoral traction and three stage posterior instrumentation) for adult severe scoliosis. The objective of this study is to investigate safety and efficacy of a three- staged correction for adult severe scoliosis.

Methods

A retrospective review was performed for patients with severe scoliosis receiving three- staged correction (one stage posterior release and screw placement, two stage skull-femoral traction and three stage posterior instrumentation) from June 2001 to October 2014. The inclusion criteria were as follows: [1] age more than 18 years; [2] main curve larger than 90°; [3] a minimum 2-year follow-up. Patients were excluded if they had a history of surgery or anterior release or receiving three column osteotomies.

Results

A total of 63 patients were included (37 female and 26 male), with a mean age of 22.7 years (range: 18–30 years) and follow-up of 42.6 months (range: 24–108 months). The aetiology was congenital in 27 patients, neuromuscular in 18, idiopathic in 11, neurofibromatosis-1 in 4 and Marfan syndrome in 3. The mean traction weight was 28.4 kg (range: 18–32 kg), equal to 57.2% of patients’ body weight (range: 42.7–72.3%). The mean traction time was 22.7 days (range: 12–44 days). Postoperative correction rate was 55% (range: 38–78%) for scoliosis and 51% (range: 32–75%) for kyphosis. Contribution of traction to correction was 51% (range: 36–70%) for scoliosis and was 43% (range: 34–55%) for kyphosis.

Conclusions

Three- staged correction (one stage posterior release and screw placement, two stage skull-femoral traction and three stage posterior instrumentation) could effectively correct adult severe scoliosis. The incidence of complications of skull-femoral traction was not low, but transient and could be successfully managed.

Pedicle Subtraction Osteotomy Versus Multiple Posterior Column Osteotomies in Severe and Rigid Neuromuscular Scoliosis

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

The aim of this study is to compare the safety and efficacy of the apical pedicle subtraction osteotomy (PSO) technique with multiple posterior column osteotomies (PCOs) in nonambulatory patients with severe, rigid neuromuscular scoliosis.

SUMMARY OF BACKGROUND DATA

Neuromuscular scoliosis frequently causes intolerance to sitting due to pelvic obliquity, trunk decompensation, and associated back and rib impingement pain which diminish the patient's functional capacity. In the case of rigid curves, spinal osteotomy techniques are occasionally required for effective correction.

METHODS

We retrospectively reviewed our patients with severe and rigid neuromuscular scoliosis with associated pelvic obliquity who were treated with posterior instrumented fusion extending to pelvis with more than 1-year postoperative follow-up. We compared radiological and clinical results of PSO and multiple PCO techniques in severe rigid neuromuscular scoliosis with pelvic obliquity of more than 15° in traction radiograph under general anesthesia. Hospital records were also reviewed for operative time, intraoperative blood loss, amount of blood transfusion, duration of hospital stay, and complications.

RESULTS

There were 12 patients in the PSO group and 10 patients in the PCO group. There was no significant difference between groups in terms of major curve magnitude, sagittal parameters or pelvic obliquity. Although not statistically significant, PSO technique did trend toward better scoliosis correction (post-op Cobb angle 56.1° vs. 66.7° [P = 0.415]). PSO technique provided a significantly better correction in pelvic obliquity (59% vs. 84%) (P = 0.001). There was no significant difference in average intraoperative blood loss, transfusion, and operative times including anesthesia time, hospital stay, or complications.

CONCLUSION

PSO may be an option in correction of severe and rigid neuromuscular scoliosis. It provides better correction of pelvic obliquity without increasing operative time, need for transfusion, or duration of hospitalization as compared to multiple apical PCO technique. Traction radiograph under general anesthesia is a valuable tool in surgical decision making.

LEVEL OF EVIDENCE

4.

Comparison of anterior and posterior vertebral column resection versus anterior and posterior spinal fusion for severe and rigid scoliosis

BACKGROUND CONTEXT

Many different correction methods have been reported to treat severe and rigid scoliosis. In the past, anterior and posterior spinal fusion (APSF), which included an anterior release followed by posterior instrumented fusion, was widely applied. In recent years, anterior/posterior vertebral column resection (APVCR) is used to treat severe and rigid scoliosis.

PURPOSE

We aimed to compare the clinical results of APSF and APVCR for severe and rigid scoliosis.

STUDY DESIGN

This is a retrospective, one-center, institutional review board-approved study.

PATIENT SAMPLE

A total of 48 patients with severe and rigid scoliosis treated by APSF or APVCR were enrolled.

OUTCOME MEASURES

Comparisons between groups were made regarding the following variables: age at surgery, gender, etiology, flexibility of main curve, anterior release length, posterior fusion length, screw number, operation time, estimated blood loss, hospitalization time, follow-up duration, different radiological parameters, complication rate, and Scoliosis Research Society (SRS)-22 scores.

METHODS

According to the operating technique, 48 patients with severe and rigid scoliosis were divided into two groups. In the first group, 26 patients were treated by APSF. In the second group, 22 patients were treated by APVCR. All patients had a minimum 2-year follow-up. The radiographic parameters as well as anterior release length, posterior fusion length, screw number, operation time, estimated blood loss, hospitalization time, complication rate, and demographic data were analyzed.

RESULTS

There was no significant difference in age, gender, etiology, flexibility of main curve, anterior release length, posterior fusion length, screw number, and follow-up between the two groups. The APVCR group had longer operation and hospitalization time, and more blood loss. There was no significant difference in the preoperative main curve between the two groups, but the APVCR group had smaller main curve at postoperation and final follow-up, and higher correction rate at immediate postoperation and final follow-up. There was no significant difference in the preoperative, postoperative, and final follow-up thoracic kyphosis, and coronal and sagittal balance between the two groups. There was no significant difference in complication rate between the two groups. Analysis of the preoperative SRS-22 questionnaire revealed no difference between the two groups. At final follow-up, APSF and APVCR groups had similar scores in the function, pain, self-image, mental health, and satisfaction with the treatment domains.

CONCLUSIONS

Compared with APSF, treating severe and rigid scoliosis by APVCR means longer operation and hospitalization time, and more blood loss, but it allows better correction rate of main curve. Furthermore, SRS-22 questionnaire improvement scores were similar for both correction methods.

Expert consensus for PVCR in severe, rigid and angular spinal deformity treatment: The Kunming consensus

In the past decades, an increasing number of surgeons started using posterior vertebral column resection (PVCR) to treat severe, rigid and angular spinal deformities. Little high-level evidence is available to guide surgical treatment. The aims of our study were to identify important surgical strategies and key technical points of Chinese experts who have extensive experience in the management of severe, rigid and angular spinal deformities using PVCR, and to standardize and unify the current core concepts. Workgroups of consensus were formed by selecting nationwide representing experts and comprehensive consultations. Eight task forces for major issues were established, then retrieval of literature, collection of expert opinions and writing of review articles were carried out. A modified Delphi process was chosen in round-table forum with three face-to-face meetings. Consensus was reached with items graded more than seven points including: indications and contraindications of PVCR; review PVCR in the evolution of spinal osteotomies; The corrective mechanism and safety of spinal cord; monitoring and responses of spinal cord crisis; characteristics and therapeutic outcome of pulmonary function; management of bleeding during PVCR; relationship of pedicle screw insertion and spinal cord safety; and analysis of non-neurologic complications and prevention strategies. In conclusion, The essential properties regarding PVCR procedure are tightly linked with various factors such as medical and surgical indication, range and level of vertebral column resection, strategies of correction, corrective efficiency and control of neurological risk. PVCR is used mainly for severe, rigid spinal deformity that is not manageable by other osteotomy techniques.

Radiologic comparison of posterior release, internal distraction, final PSO and spinal fusion with one-stage posterior vertebral column resection for multi-level severe congenital scoliosis

Background

To compare radiologic results of posterior release, internal distraction, and final pedicle subtraction osteotomy (PSO) and spinal fusionwith one-stage posterior vertebral column resection (PVCR) in treating multi-level severe congenital scoliosis.

Methods

Forty-onesevere congenital scoliosis patients were used in the study. Group A comprised 24 patients who underwent one-stage PVCR. Group B comprised 17 patients who underwent posterior release with internal distraction, followed by final posterior fusion and instrumentation. The average preoperative main curve was 110.4° (95–130°) in group A and 109.4° (range 90°–126°) in group B. Postoperative follow-up time was ≥2 years (2.0–4.5 years) to analyze the radiographic and clinical outcomes.

Results

A comparison of posterior release, internal distraction, and final spinal fusion with PVCR showed no significant differences in postoperative main curve and compensatory caudal curve correction, coronal and sagittal imbalance. However, significant differences were found between the 2 groups in compensatory cranial curve correction.

Conclusions

Posterior release, internal distraction, and final spinal fusion produce better corrective results in compensatory cranial curve correction than PVCR in treating severe multi-level congenital scoliosis.

The management of scoliosis in children with cerebral palsy: a review

Children who suffer with cerebral palsy (CP) have a significant chance of developing scoliosis during their early years and adolescence. The behavior of this scoliosis is closely associated with the severity of the CP disability and unlike idiopathic scoliosis, it continues to progress beyond skeletal maturity. Conservative measures may slow the progression of the curve, however, surgery remains the only definitive management option. Advances in surgical technique over the last 50 years have provided methods to effectively treat the deformity while also reducing complication rates. The increased risk of surgical complications with these complex patients make decisions about treatment challenging, however with careful pre-operative optimization and post-operative care, surgery can offer a significant improvement in quality of life. This review discusses the development of scoliosis in CP patient, evaluates conservative and surgical treatment options and assesses post-operative outcome.

Duchenne muscular dystrophy: the management of scoliosis

This study summaries the current management of scoliosis in patients with Duchenne Muscular Dystrophy. A literature review of Medline was performed and the collected articles critically appraised. This literature is discussed to give an overview of the current management of scoliosis within Duchenne Muscular Dystrophy. Importantly, improvements in respiratory care, the use of steroids and improving surgical techniques have allowed patients to maintain quality of life and improved life expectancy in this patient group.

Long-term management of congenital lordoscoliosis of the thoracic spine

PURPOSE

The objective of this study is to report the progression of congenital hyperlordoscoliosis in a 2-year-old patient and the use of multiple surgical interventions in the treatment of hyperlordoscoliosis of the thoracic spine.

METHODS

A 2-year-old patient with thoracic hyperlordosis underwent observation for 1 year. To halt the progression of hyperlordosis, a posterior laminectomy was carried out to remove all the fused segments. Despite surgery, lordosis progressed via spontaneous autofusion with development of scoliosis with unilateral unsegmented bar. At the age of 9 years, the patient underwent posterior osteotomy at the fused segments, which was unsuccessful in the correction of hyperlordosis, but was successful in the correction of scoliosis. At the age of 12 years, the patient complained of mild breathing difficulties resulting from hyperlordosis of the thoracic spine, and underwent posterior multilevel vertebral osteotomy (PMVO) again to correct lordoscoliosis.

RESULTS

Follow-up in the 3 years after PMVO showed that correction of the deformity was well maintained, with a good clinical outcome and a well-balanced spine.

CONCLUSIONS

PMVO is a potential intervention to manage rigid and severe congenital lordoscoliosis of the thoracic spine.

Continuous distraction-induced delayed spinal cord injury on motor-evoked potentials and histological changes of spinal cord in a porcine model

STUDY DESIGN

Experimental study.

OBJECTIVES

This study evaluated distraction-induced delayed spinal cord injury in a porcine model.

SETTING

Department of Orthopedics, Korea University Guro Hospital, Seoul, Korea.

METHODS

Global osteotomy of three columns was performed on the thirteenth thoracic vertebrae with 13 pigs. The osteotomized vertebrae were distracted to 57-103% of segmental vertebral height (SVH) length, which was less than the distraction length that induces prompt SCI. The vertebral height was maintained until the loss of motor-evoked potential (MEP) signals with continuous distraction. The distraction distance and the time at which SCI occurred were measured, and distraction was then released to observe MEP recovery patterns.

RESULTS

We found delayed SCI in 8 of the 12 pigs, with a mean 20.9 mm (range 19-25 mm) and 10.7 min (range 8-12 min) of continuous spinal distraction, which was equivalent to 74.3% (68-84%) of SVH and 3.63% (3.42-4.31%) of thoracolumbar spinal length. A continuous 74.3% SVH distraction over an average of 10.7 min caused a delayed SCI, which was indicated by mild histologic changes in the spinal cord. Recovery patterns from SCI after distraction release were compatible with the degree of histological change; however, these patterns differed from the previously investigated prompt type of SCI.

CONCLUSION

Late onset injury due to continuous spinal distraction, which is comparable to iatrogenic SCI in spinal correction surgery, is important for understanding the impact of corrective surgery.

Comparison of pulmonary function and back muscle strength according to the degree of spinal curvature of healthy adults

[Purpose] Degree of curvature on the spine is known to affect respiratory function and back muscle activation. We compared pulmonary function and back muscle strength according to the degree of curvature of the spine of healthy adults. [Subjects and Methods] Twenty-three healthy volunteers were enrolled. They were divided into two groups according to the degree of curvature of the spine: the below 2° group, and the above 2° group. The degree of curvature was assessed using the Adams forward bending test and a scoliometer. A pulmonary function test (PFT) was conducted, and back muscle strength was measured. [Results] No significant differences in PFT were found between the below 2° group and the above 2° group, in terms of forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), ratio of forced expiratory volume in one second to forced vital capacity (FEV₁/FVC), or peak expiratory flow (PEF). However, back muscle strength in the below 2 group was significantly higher than that of the above 2 group. [Conclusion] Our findings indicate that the degree of curvature of the spine is associated with back muscle strength in subjects who have spinal curvature within the normal range. Therefore, evaluation and treatment of back muscle strength might be helpful for preventing the progress of curvature of the spine in adolescents with potential scoliosis.

The impact of posterior temporary internal distraction on stepwise corrective surgery for extremely severe and rigid scoliosis greater than 130°

AIM

To investigate the efficacy and safety of temporary internal distraction corrective surgery for extremely severe scoliosis.

METHODS

Eleven scoliosis patients (3 males and 8 females) with curves ≥130° (mean 148.8°; range 130°-157°) who underwent a two-stage surgery, including a posterior temporary internal distraction correction and definitive posterior spinal correction with posterior pedicle screw instrumentation from 2008 to 2011 were retrospectively reviewed. Minimum follow-up was 2-years (mean 41.8 months; range 27.0-63.0 months). The analysis focused on the impact of temporary internal distraction on curve correction, pulmonary function tests (PFTs), complications and surgical outcomes. Neurosurveillance of sensory (somatosensory-evoked potentials) and motor (motor-evoked potentials) potential was performed in all cases. Posterior instrumentation was used in all patients.

RESULTS

After the use of internal distraction, the preoperative major curve (mean 148.8°; range 130°-157°) was corrected to a mean of 79° (range 63°-87°), the T5-T12 kyphosis Cobb angle (mean 79°; range 30°-97°) was corrected to a mean of 59° (range 20°-75°), the coronal imbalance (mean 0.8 cm; range -3.6 to 2.8 cm) was improved to a mean of 0.6 cm (range -1.5 to 2.0 cm), the forced vital capacity percentage (FVC%) was improved from 59.3 ± 11.6 to 68.7 ± 13.7, and the forced expiratory volume in 1 s (FEV1%) was improved from 61.4 ± 13.6 to 71.3 ± 9.3. The average increase in body height was 6.7 cm, and the dorsum razor was corrected to 3-5 cm. During definitive surgery, the final major curves were corrected to a mean of 55° (range 32°-72°), the T5-T12 kyphosis Cobb was corrected to 35° (range 15°-68°), the coronal imbalance was improved to 0.5 cm (range -1.2 to 1.8 cm), the FVC% was improved to 71.2 ± 8.3, the FEV1% was improved to 76.3 ± 16.7, the increase in body height was 3.1 cm, and the dorsum razor was corrected to 1-3 cm. The mean interval time between the two surgeries was 3.5 months. None of the patients exhibited postoperative neurologic deficits or infections. No instrument complications were found during the final follow-up.

CONCLUSIONS

Temporary internal distraction in a two-stage corrective surgery provided patients who had extremely severe and rigid scoliosis, an effective and safe solution for scoliosis without significant complications.

Anterior release posterior internal distraction and subsequent posterior spinal fusion for the treatment of severe kyphoscoliosis

PURPOSE

To evaluate the outcome and complications of anterior release, posterior internal distraction and subsequent posterior spinal fusion for the treatment of severe kyphoscoliosis.

METHODS

The medical records and spinal imaging of 17 consecutive severe kyphoscoliosis patients who underwent anterior release, posterior internal distraction and subsequent posterior spinal fusion were reviewed.

RESULTS

Patients underwent spinal deformity correction at the mean age of 22.6 ± 8.4 years (range 15-44 years) with mean follow-up of 37.4 ± 12.0 months (range 24-60 months). The preoperative thoracic kyphosis of 83.5° ± 16.3° (range 60°-115°) was corrected to 37.5° ± 7.9° (range 20°-49°) at the final follow-up. The preoperative major curve of 110.1° ± 16.8° (range 92°-145°) was corrected to 33.5° ± 13.9° (range 12°-63°) at the final follow-up, with a scoliosis correction of 70.3 %. At the most recent follow-up, the correction rate of proximal thoracic curve and thoracolumbar or lumbar curve was 57.1 and 74.8 %, respectively. Transient dyspnoea occurred in one patient after the initial surgery and subsequently resolved. No ventilator support was needed. Three patients complained the pain of concave soft tissue after the first distraction. There were no neurological complications or any deep wound infections. No complication of instrumentation was found at final follow-up.

CONCLUSIONS

In the treatment of severe kyphoscoliosis, anterior release, posterior internal distraction and subsequent posterior spinal fusion, which obviates three-column osteotomy, is a good alternative correction method.

The feasibility and safety of using sublaminar polyester bands in hybrid spinal constructs in children and transitional adults for neuromuscular scoliosis

OBJECT

The authors have previously reported on their early experience with sublaminar polyester bands in spine surgery. In this paper, the authors describe the use of sublaminar polyester bands in long-segment posterior instrumented spinal fusions from the upper thoracic spine to the ilium in 21 children and transitional adults with progressive neuromuscular scoliosis. Transitional adults were patients older than 18 years of age with a spinal disorder of pediatric onset, such as spina bifida. This dedicated study represents the first reported use of polyester bands in spine surgery for neuromuscular scoliosis in this patient population in the US.

METHODS

The authors retrospectively reviewed the demographics and procedural data of patients who underwent posterior instrumented fusion using sublaminar polyester bands for neuromuscular scoliosis.

RESULTS

Twenty-one pediatric and adult transitional patients, ranging in age from 10 to 20 years (mean 14 years), underwent posterior instrumented fusion for progressive neuromuscular scoliosis. The average coronal Cobb angle measured 66° before surgery (range 37°-125°). Immediately after surgery, the mean coronal Cobb angle was 40° (range 13°-85°). At last follow-up, the average coronal Cobb angle was maintained at 42° (range 5°-112°). Regarding sagittal parameters, thoracic kyphosis was restored by 8%, and lumbar lordosis improved by 20% after surgery. Mean follow-up duration was 17 months (range 2-54 months). One patient with an aborted procedure due to loss of intraoperative evoked potentials was excluded from the analysis of radiographic outcomes. Mean surgical time was 7 hours 43 minutes (range 3 hours 59 minutes to 10 hours 23 minutes). All patients received either a 12- or 24-mg dose of recombinant human bone morphogenetic protein-2. Average estimated blood loss was 976 ml (range 300-2700 ml). Complications directly related to the use of sublaminar instrumentation included transient proprioceptive deficit (1 patient) and prolonged paraparesis (1 patient). Other complications noted in this series included disengagement of the rod from an iliac screw (1 patient), proximal junctional kyphosis (1 patient), noninfected wound drainage (2 patients), and perioperative death (1 patient). The lessons learned from these complications are discussed.

CONCLUSIONS

Pedicle screws, laminar/pedicle/transverse process hooks, and sublaminar metal wires have been incorporated into posterior spinal constructs and widely reported and used in the thoracic and lumbar spines and sacrum with varying success. This report demonstrates the satisfactory radiological outcomes of hybrid posterior spinal constructs in pediatric and adult neuromuscular scoliosis that include sublaminar polyester bands that promise the technical ease of passing sublaminar instrumentation with the immediate biomechanical rigidity of pedicle screws and hooks. However, the high neurological complication rate associated with this technique (2/21, or 10%) tempers the acceptable radiographic outcomes.

Posterior-only spinal release combined with derotation, translation, segmental correction, and an in situ rod-contouring technique for treatment of severe and rigid scoliosis

OBJECT

The object of this study was to review the effectiveness in treating severe and rigid scoliosis with posterioronly spinal release combined with derotation, translation, segmental correction, and an in situ rod-contouring technique.

METHODS

Twenty-eight patients with severe and rigid scoliosis (Cobb angle>70° and flexibility<30%) were retrospectively enrolled between June 2008 and June 2010. The average age of the patients was 17.1 years old (range 12-22 years old), 18 were female, and 10 were male. Etiological diagnoses were idiopathic in 24 patients, neuromuscular in 2 patients, and Marfan syndrome in 2 patients. All patients underwent posterior spinal release, derotation, translation, segmental correction, and an in situ rod-contouring technique. The scoliosis Cobb angle in the coronal plane, kyphosis Cobb angle, apex vertebral translation, and trunk shift were evaluated preoperatively and postoperatively.

RESULTS

The average operative time was 241.8±32.1 minutes and estimated blood loss was 780.5±132.6 ml. The average scoliosis Cobb angle in the coronal plane was corrected from 85.7° (range 77°-94°) preoperatively to 33.1° (range 21°-52°) postoperatively, with a correction ratio of 61.3%. The average kyphosis Cobb angle was 64.5° (range 59°-83°) preoperatively, which was decreased to 42.6° (range 34°-58°) postoperatively, with a correction ratio of 33.9%. After an average of 24 months of follow-up (range 13-30 months), no major complications were observed in these patients, except screw pullout of the upper thoracic vertebrae in 2 patients and screw penetration into the apical vertebrae in 1 patient.

CONCLUSIONS

Posterior spinal release combined with derotation, translation, segmental correction, and an in situ rod-contouring technique has proved to be a promising new technique for rigid scoliosis, significantly correcting the scoliosis and accompanied by fewer complications.

Effect of posterior multilevel vertebral osteotomies on coronal and sagittal balance in fused scoliosis deformity caused by previous surgery: preliminary results

STUDY DESIGN

Prospective case series study.

OBJECTIVE

To study the effect of posterior multilevel vertebral osteotomy (posterior crack osteotomy) on coronal and sagittal balance in patients with the fusion mass over the spine caused by previous surgery.

SUMMARY OF BACKGROUND DATA

Few studies have investigated revisional scoliosis surgery with the fusion mass using osteotomy.

METHODS

Among patients who had a history of prior surgery for scoliosis correction and posterior fusion, those showing progression of the curve postoperatively due to nonunion, implant failure, or adding-on phenomenon were enrolled. All patients were treated using posterior crack osteotomy. For clinical evaluation, the pre- and postoperative Gross Motor Function Classification System score for walking status and the Berg balanced scale were used. For radiological evaluation, pre- and postoperative Cobb angle, and coronal and sagittal balance factors were used.

RESULTS

Ten patients (5 males and 5 females) were enrolled. The preoperative diagnosis was neuromuscular scoliosis (3 cases), syndromic scoliosis (1 case), congenital scoliosis (5 cases), and neurofibromatosis (1 case). Osteotomies were performed at 3.3±1.3 levels on average. Pre- and postoperative Cobb angles were 70.8°±30.0° and 28.1°±20.0° (P=0.002 (0.97)), respectively. In pre- and postoperative evaluation of coronal balance, the coronal balance, clavicle angle, and T1-tilt angle were 36.8±27.1 mm and 10.4±8.5 mm, 6.7°±8.0° and 3.3°±1.5°, and 7.8°±19.0° and 4.7°±2.1°, respectively (P=0.002, 0.002, 0.002). In pre- and postoperative evaluation of sagittal balance, the spinal vertical axis, thoracic kyphosis, and lumbar alignments were 25.1±37.8 mm and 14.1±21.8 mm, 33.5°±51.1° and 29.7°±27.4°, and 45.7°±34.8° and 48.9°±23.1° (P=0.002, 0.169, 0.169). The walking and functional statuses did not change (P=0.317, 0.932). Although pulmonary and gastrointestinal complications were noted, the patients were discharged without complications.

CONCLUSION

Posterior crack osteotomy can be used effectively in revisional scoliosis surgery and the clinical and radiological results seem to be acceptable.

LEVEL OF EVIDENCE

4.

Anterior release internal distraction and posterior spinal fusion for severe and rigid scoliosis

STUDY DESIGN

Retrospective study.

OBJECTIVE

To report on the results of anterior release, posterior internal distraction (with or without further distraction), and subsequent posterior spinal fusion for severe and rigid scoliosis.

SUMMARY OF BACKGROUND DATA

For severe and rigid scoliosis, conventional procedures, such as posterior instrumentation combined with an anterior release, enable limited correction. Posterior vertebral column resection brings better correction but with a high rate of neurological complications or intraoperative neurological events.

METHODS

A total of 15 patients with severe and rigid scoliosis who underwent anterior release, posterior internal distraction (with or without further distraction), and subsequent posterior spinal fusion were retrospectively reviewed after a minimum follow-up of 2 years. The radiographical parameters were evaluated, and clinical records were reviewed.

RESULTS

The average number of anteriorly removed discs was 4.1. Average posterior fusion length comprised 14.3 vertebrae. Overall, internal distraction corrected the mean Cobb angle by 58.1% (from 105.1° to 44.2°) compared with the initial curve magnitude. The mean preoperative scoliosis of 105.1° was corrected to 27.5° (74.3% correction) at the most recent follow-up. The correction rate of the proximal thoracic and thoracolumbar or lumbar curves was 48.1% and 82.1%, respectively. The preoperative thoracic kyphosis of 62.3° was corrected to 33.8° at the most recent follow-up. The preoperative lumbar lordosis of -66.1° was corrected to -46.3° at the most recent follow-up. The mean preoperative coronal imbalance of 0.8 cm improved to 0.5 cm at the most recent follow-up, and sagittal imbalance of 0.3 cm improved to 0.2 cm. Transient dyspnea occurred in one patient after the initial surgery and subsequently resolved. Two patients complained of concave soft-tissue pain after the first distraction. There were no neurological complications.

CONCLUSION

Anterior release, posterior internal distraction, and subsequent posterior spinal fusion provide an effective alternative for severe and rigid scoliosis.

LEVEL OF EVIDENCE

4.

Anterior release generates more thoracic rotation than posterior osteotomy: a biomechanical study of human cadaver spines

STUDY DESIGN

Biomechanical testing of human cadaveric spines.

OBJECTIVE

To determine the effect of anterior and posterior anatomic structures on the rotational stability of the thoracic spine.

SUMMARY OF BACKGROUND DATA

Historically, large and/or stiff spinal deformities were treated with anterior release to facilitate correction. However, anterior release increases risks and requires a 2-part procedure. Recently, large or rigid deformities have been treated with a single posterior procedure using pedicle screws and spinal osteotomies. No study has yet evaluated the effect of anterior release or posterior osteotomy on thoracic spinal column rotation.

METHODS

Thoracolumbar spines were obtained from cadavers and segmented into upper, middle, and lower specimens. Specimens were cyclically loaded with a ±5 N·m moment in axial rotation for 10 cycles. Specimens were tested intact and then retested after sectioning or removal of each structure to simulate those removed during anterior release and posterior osteotomy. The total increases in axial rotation after posterior and anterior resections were calculated using a 3-dimensional motion capture camera system. For each ligament resection, the absolute and percent change in degrees of rotation was calculated from comparison with the intact specimen. The median data points were compared to account for outliers.

RESULTS

Resection of anterior structures was more efficacious than resection of posterior structures. An 8.8% to 71.9% increase in the amount of axial rotation was achieved by a posterior release, whereas resection of anterior structures led to a 141% to 288% increase in rotation. The differences between the anterior and posterior resections at all levels tested (T2-T3, T6-T7, and T10-T11) were significant (P < 0.05).

CONCLUSION

Anterior release generated significantly more thoracic rotation than posterior osteotomy in biomechanical testing of human cadaver spines.

LEVEL OF EVIDENCE

N/A.

Effects of vertebral column distraction on transcranial electrical stimulation-motor evoked potential and histology of the spinal cord in a porcine model

BACKGROUND

Spinal cord injury can occur following surgical procedures for correction of scoliosis and kyphosis, as these procedures produce lengthening of the vertebral column. The objective of this study was to cause spinal cord injury by vertebral column distraction and evaluate the histological changes in the spinal cord in relationship to the pattern of recovery from the spinal cord injury.

METHODS

Global osteotomy of all three spinal columns was performed on the ninth thoracic vertebra of sixteen pigs. The osteotomized vertebra was distracted until transcranial electrical stimulation-motor evoked potential (TES-MEP) signals disappeared or decreased by >80% compared with the baseline amplitude; this was defined as spinal cord injury. The distraction distance at which spinal cord injury occurred was measured, the distraction was released, and the TES-MEP recovery pattern was observed. A wake-up test was performed, two days of observations were made, and histological changes were evaluated in relationship to the recovery pattern.

RESULTS

Spinal cord injury developed at a distraction distance of 20.2 ± 4.7 mm, equivalent to 3.6% of the thoracolumbar spinal length, and the distraction distance was correlated with the thoracolumbar spinal length (r = 0.632, p = 0.009). No animals exhibited complete recovery according to TES-MEP testing, eleven exhibited incomplete recovery, and five exhibited no recovery. During the two days of observation, all eleven animals with incomplete recovery showed positive responses to sensory and motor tests, whereas none of the five animals with no recovery had positive responses. On histological evaluation, three animals that exhibited no recovery all showed complete severance of nerve fibers (axotomy), whereas six animals that exhibited incomplete recovery all showed partial white-matter injury.

CONCLUSIONS

Parallel distraction of approximately 3.6% of the thoracolumbar length after global osteotomy resulted in spinal cord injury and histological evidence of spinal cord damage. The pattern of recovery from the spinal cord injury after release of the distraction was consistent with the degree of axonal damage. Axotomy was observed in animals that exhibited no recovery on TES-MEP, and only hemorrhagic changes in the white matter were observed in animals that exhibited incomplete recovery.

Two-stage vertebral column resection for severe and rigid scoliosis in patients with low body weight

BACKGROUND CONTEXT

To date, there are no clinical series documenting the treatment of severe and rigid scoliosis in patients with low body weight. To optimize curve correction and minimize the risk of complications, we performed a two-stage vertebral column resection (VCR) with posterior pedicle screw instrumentation to treat patients with severe and rigid scoliosis and low body weight.

PURPOSE

The purposes of this study were to report the results of a two-staged VCR for patients with severe and rigid scoliosis and low body weight.

STUDY DESIGN

This was a prospective, longitudinal, and descriptive study with a minimum follow-up of 2 years.

PATIENT SAMPLE

Sixteen patients (nine women and seven men) with severe and rigid scoliosis and low body weight from the department of orthopedics, West China hospital, Sichuan University.

OUTCOME MEASURES

Clinical analysis included rib hump and lumbar hump. Radiographic analysis consisted of Cobb angle measurements of coronal curves, apical vertebral translation, coronal balance, sagittal balance, thoracic kyphosis, and lumbar lordosis. All measurements were taken before surgery, after surgery, and in the final follow-up period.

METHODS

For evaluation of surgical effectiveness, comparative analysis of rib hump, lumbar hump, Cobb angle of coronal curves, apical vertebral translation, coronal balance, sagittal balance, thoracic kyphosis, and lumbar lordosis before operation, after operation, and at the most recent follow-up was done.

RESULTS

The body weight of patients averaged 33.8 kg (range 27-40 kg). Mean operating time was 580.3 minutes, with a blood loss of 1,581.3 mL. The correction rates of rib hump and lumbar hump were 77% and 85%. Preoperative major curves ranged from 90° to 130° Cobb angle. Coronal plane correction of the major curve averaged 70.7%, with an average loss of correction of 1.8%. The apical vertebral translation of the major curve was corrected by 73.2%. The preoperative coronal imbalance of 0.6 cm (range 0-1.4 cm) was improved to 0.5 cm (range 0-1.4 cm) at the most recent follow-up. The preoperative sagittal imbalance of 0.9 cm (range -3.1 to 4.6 cm) was improved to 0.8 cm (range -1.0 to 3.0 cm) at the most recent follow-up. The preoperative thoracic kyphosis of 50.1° (range 6°-86°) was corrected to 28.9°±7.7° (range 18°-42°) at the most recent follow-up. The preoperative lumbar lordosis of -57.9° (range -85° to -32°) was corrected to -49.0° (range -62° to -40°) at the most recent follow-up. Complications were encountered in two patients. One patient required ventilator support for 12 hours after anterior surgery. Malposition of one pedicle screw was found in one patient. There were no neurologic complications or any deep wound infections. No complication of instrumentation was found at final follow-up.

CONCLUSIONS

The use of two-stage VCR for patients with severe and rigid scoliosis and low body weight can achieve a good correction of scoliosis without serious complications.

Intraoperative skull-femoral (skeletal) traction in surgical correction of severe scoliosis (>80°) in adult neglected scoliosis

STUDY DESIGN

Retrospective review.

OBJECTIVE

To evaluate the effectiveness, safety, and reliability of intraoperative skeletal traction in the surgical correction of severe adult neglected scoliosis.

SUMMARY OF BACKGROUND DATA

Literature shows that curves more than 80° that do not reduce to 50° to 55° on bending radiographs require an anterior release. A combined anterior and posterior approach is often used for treating severe rigid scoliosis. However, anterior approach has its own complications in the form of increased morbidity, increased blood loss, operative time, and pulmonary complications. Corrective surgery gets even more challenging if the patients are adults.

METHODS

Ten patients with severe scoliosis (>80°) and low flexibility index (<0.5) treated with intraoperative skeletal traction were part of this study. The patients were operated between April 2008 and May 2010. Eight patients with neglected adolescent idiopathic scoliosis and 2 with neuromuscular scoliosis were included. The mean age was 27.4 years (19-36). Corrective surgery and fusion was performed using intraoperative skeletal traction.

RESULTS

The Cobb angle improved from a mean of 89.35° preoperatively to 40.25° postoperatively giving a mean correction of 55.29%. Apical vertebral rotation (Nash and Moe) improved from a mean of grade 3(2-4) to a mean of grade 2(1-3). Apical vertebral translation improved from a mean of 2.19 cm preoperatively to 0.98 cm postoperatively (55.41% correction). There were no intraoperative adverse events or postoperative complications. All patients had good shoulder balance and were satisfied with the correction achieved.

CONCLUSION

Intraoperative skull-femoral traction can be a safe and effective method to assist correction of severe and rigid scoliosis. It facilitates surgical exposure and pedicle screw insertion. It obviates the need of an anterior release surgery and associated morbidity, thus reducing the hospital stay and costs. It provides a much simpler way to correct the sagittal and coronal imbalance, as well as the pelvic obliquity.

Neuromuscular scoliosis

Scoliosis is a common deformity in many types of neuromuscular disease. Severe spinal curvature can cause difficulty in sitting. Conservative and surgical treatment of neuromuscular scoliosis differs from idiopathic scoliosis, being more complex and with a higher complications rate. Non-surgical measures rarely fully control progressive scoliosis, but aim to prevent spinal deformities secondary to muscular hypotonia or contracture. Twenty-four hour bracing should be adjusted throughout growth, and may induce functional impairment and loss of independence. Corrective surgery requires multidisciplinary management and perioperative screening. Pelvic obliquity is commonly associated with neuromuscular scoliosis, making sitting difficult: correction needs to be considered during surgical planning. The goal of surgical correction is to obtain and maintain a well-balanced spine above a well-positioned pelvis. Preoperative multidisciplinary assessment enables potential problems of terrain to be anticipated. Respiratory function investigation will guide possible non-invasive perioperative ventilation. Nutritional and psychosocial assessment should also be incorporated in this preparation, as should overall postoperative care. Implementing this overall strategic planning can achieve a good surgical and functional result in the vast majority of cases.

Posterior vertebral column resection for correction of rigid spinal deformity curves greater than 100°

OBJECT

The surgical treatment of severe and rigid spinal deformities poses difficulties and dangers. In this article, the authors summarize their surgical techniques and evaluate patient outcomes after performing posterior vertebral column resection (PVCR) for the correction of spinal deformities with curves greater than 100°, and investigate the crucial points to ensure neurological safety during this challenging procedure.

METHODS

The authors retrospectively reviewed their experience with 28 patients with extremely severe (Cobb angles in the coronal or sagittal plane > 100°) and rigid thoracic or thoracolumbar spine deformities who underwent PVCR. The average patient age was 20.2 years and all patients underwent a minimum follow-up of 24 months (range 24-60 months). Patients were divided into groups according to their morphological classification as follows: kyphosis alone (Group A, 6 patients with a mean Cobb angle of 109.0° [range 105°-120°]); kyphoscoliosis with coronal plane curves notably greater than sagittal plane curves (Group B, 14 patients with mean scoliotic curves of 116.6° [range 102°-170°] and kyphotic curves of 77.7° [range 42°-160°]); and kyphoscoliosis with sagittal curves notably greater than coronal plane curves (Group C, 8 patients with a mean coronal curve of 85.4° [range 65°-110°] and a mean sagittal curve of 117.6° [range 102°-155°]).

RESULTS

A total of 36 vertebrae were removed in 28 patients who had a severe rigid spinal deformity, and the mean fusion extent was 13.3 vertebrae (range 7-17 vertebrae). The mean operating time was 620 minutes (range 320-920 minutes) with an average operative blood loss of 6,680 ml (range 3,000-24,000 ml). The overall final correction rate of scoliosis was 59.0%, and average postoperative kyphotic Cobb angles ranged from 30.4° to 95.9°. In Group A the mean preoperative sagittal angle of 109.0° was corrected to a mean postoperative angle of 32.0°. In the Group B kyphoscoliotic patients, the correction rate in the coronal plane was 58.6%; the Cobb angle in the sagittal plane was corrected from a mean of 77.7° preoperatively to 25.1° postoperatively; in Group C, the correction rate in the coronal plane was 58.5%, and the mean sagittal angle was reduced from a mean of 117.6° preoperatively to 39.0°. Of the 28 patients who underwent PVCR, 46 complications were observed in 18 patients intra- and postoperatively. There were 5 neurological complications including 1 case of late-onset paralysis and 4 cases of thoracic nerve root pain, all of which resolved during the early follow-up period. Nonneurological complications occurred more often in kyphoscoliotic patients (41 complications). The mean follow-up of all patients was 33.7 months (range 24-60 months).

CONCLUSIONS

Posterior vertebral column resection was effective in correcting severe rigid spinal deformity, although the procedure was technically demanding, exhaustingly lengthy, and was associated with a variety of complications. The PVCR technique created a space for spinal correction and spinal cord tension adjustment and the correction could be performed under direct inspection and by palpation of the tension in the spinal cord through the space. Therefore, in terms of the spinal cord, the deformity correction process involved in the PVCR procedure is relatively safe.

Spinal muscular atrophy: manifestations and management

Spinal muscular atrophy (SMA) is an autosomal recessive disorder caused by a homozygous deletion in the SMN1 gene and is manifested by loss of the anterior horn cells of the spinal cord. Classifications of the disorder are based on age of onset and the patient's level of function. Scoliosis and hip subluxation or dislocation are two musculoskeletal manifestations associated with SMA. Severity of scoliosis correlates with age at presentation. Bracing has been unsuccessful in halting curve progression and may interfere with respiratory effort. Early onset scoliosis associated with SMA has been successfully treated with growing rod constructs, and posterior spinal fusion can be used in older children. Hip subluxations and dislocations are best treated nonsurgically if the patient reports no pain because a high rate of recurrent dislocation has been reported with surgical intervention.

The impact of halo-gravity traction on curve rigidity and pulmonary function in the treatment of severe and rigid scoliosis and kyphoscoliosis: a clinical study and narrative review of the literature

INTRODUCTION

The treatment of rigid and severe scoliosis and kyphoscoliosis is a surgical challenge. Presurgical halo-gravity traction (HGT) achieves an increase in curve flexibility, a reduction in neurologic risks through gradual traction on a chronically tethered cord and an improvement in preoperative pulmonary function. However, little is known with respect to the ideal indications for HGT, its appropriate duration, or its efficacy in the treatment of rigid deformities.

MATERIALS AND METHODS

To investigate the use of HGT in severe deformities, we performed a retrospective review of 45 patients who had severe and rigid scoliosis or kyphoscoliosis. The analysis focused on the impact of HGT on curve flexibility, pulmonary function tests (PFTs), complications and surgical outcomes in a single spine centre.

RESULTS

PFTs were used to assess the predicted forced vital capacity (FVC%). The mean age of the sample was 24±14 years. 39 patients had rigid kyphoscoliosis, and 6 had scoliosis. The mean apical rotation was 3.6°±1.4°, according to the Nash and Moe grading system. The curve apices were mainly in the thoracic spine. HGT was used preoperatively in all the patients. The mean preoperative scoliosis was 106.1°±34.5°, and the mean kyphosis was 90.7°±29.7°. The instrumentation used included hybrids and pedicle screw-based constructs. In 18 patients (40%), a posterior concave thoracoplasty was performed. Preoperative PFT data were obtained for all the patients, and 24 patients had ≥3 assessments during the HGT. The difference between the first and the final PFTs during the HGT averaged 7.0±8.2% (p<.001). Concerning the evolution of pulmonary function, 30 patients had complete data sets, with the final PFT performed, on average, 24 months after the index surgery. The mean preoperative FVC% in these patients was 47.2±18%, and the FVC% at follow-up was 44.5±17% (a difference that did not reach statistical significance). The preoperative FVC% was highly predictive of the follow-up FVC% and the response during HGT. The mean flexibility of the scoliosis curve during HGT was only 14.8±11.4%, which was not significantly different from the flexibility measures achieved on bending radiographs or Cotrel traction radiographs. In rigid curves, the Cobb angle difference between the first and final radiographs during HGT was only 8°±9° for scoliosis and 7°±12° for kyphosis. Concerning surgical outcomes, 13 patients (28.9%) experienced minor and 15 (33.3%) experienced major complications. No permanent neurologic deficits or deaths occurred. Additional surgery was indicated in 12 patients (26.7%), including 7 rib-hump resections. At the final evaluation, 69% of the patients had improved coronal balance, and at a mean follow-up of 33±23.3 months, 39 patients (86.7%) were either satisfied or very satisfied with the overall outcome.

CONCLUSION

The improvement of pulmonary function and the restoration of sagittal and coronal balance are the main goals in the treatment of severe and rigid scoliosis and kyphoscoliosis. A review of the literature showed that HGT is a useful tool for selected patients. Preoperative HGT is indicated in severe curves with moderate to severe pulmonary compromise. HGT should not be expected to significantly improve severe curves without a prior anterior and/or posterior release. The data presented in this study can be used in future studies to compare the surgical and pulmonary outcomes of severe and rigid deformities.

Two-stage posterior-only procedures for correction of severe spinal deformities

PURPOSE

To review the outcomes of surgical treatment for severe spinal deformities via a two-stage posterior-only approach.

METHODS

A total of 18 patients with large and rigid spinal deformities were studied based on clinical and radiographic data. All of them received a two-stage posterior-only approach: first on the concave side by internal distraction of pedicle screws and rods through intramuscular tunnels, followed by respiratory function exercise and improving nutritional status during the intervening period, and finally by posterior additional correction, ultimate instrumentation and spinal fusion in the second operation.

RESULTS

The mean major coronal curve was corrected by 46% after the first operation and by 60.4% after the second operation. The mean thoracic kyphosis was corrected by 50.9% after the first operation and by 64.8% after the second operation. The loss of correction mean was 3.3° for the major coronal curve and 2.6° for the thoracic kyphosis at a mean of 31.5 months follow-up. The mean operation time for the first and second operation was 186.2 and 300.6 min, and the mean intraoperative blood loss was 211.1 and 1,597.2 mL, respectively. No severe complication was noticed in this series.

CONCLUSIONS

The two-stage posterior-only procedures permitting stepwise correction for the treatment of severe spinal deformities provide safe and satisfactory outcomes in this patient population.

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

STUDY DESIGN

Retrospective review of a multicenter database.

OBJECTIVE

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

SUMMARY OF BACKGROUND DATA

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

METHODS

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

RESULTS

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

CONCLUSION

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

Anterior and posterior vertebral column resection for severe and rigid idiopathic scoliosis

A total of 16 patients with severe and rigid idiopathic scoliosis treated by anterior and posterior vertebral column resection (APVCR) were retrospectively reviewed after a minimum follow-up of 2 years. The indication for APVCR was scoliosis more than 90° with flexibility less than 20%. The radiographic parameters were evaluated, and clinical records were reviewed. All patients underwent APVCR with posterior pedicle screw instrumentation in a two-stage surgery. The rib hump was reduced from 7.2 cm preoperatively to 1.8 cm at final follow-up (75% correction). Preoperative curves ranged from 93° to 110° Cobb angle. Coronal plane correction of the major curve averaged 67% with an average loss of correction of 1.4%. The apical vertebral translation of the major curve was corrected by 63.5%. The preoperative coronal imbalance of 0.9 cm (range 0-2.4) was improved to 0.8 cm (range 0.1-1.7) at the most recent follow-up. The preoperative sagittal imbalance of 1.0 cm (range -3.1 to 4.6) was improved to 0.9 cm (range -2.6 to 3.0) at the most recent follow-up. Complications were encountered in four patients. One patient required ventilator support for 12 h after anterior surgery. Malposition of one pedicle screw was found in one patient. Malposition of titanium mesh cage happened to two patients. There were no neurological complications, deep wound infections or pseudarthrosis. APVCR is an effective alternative for severe and rigid idiopathic scoliosis.

The effect of posterior spinal releases on axial correction torque: a cadaver study

PURPOSE

Posterior only approaches for spinal deformity are increasingly popular and posterior spinal release is utilized to gain flexibility for correctional maneuvers. Prior biomechanical data support the use of facetectomy and rib head resection for gaining flexibility in the sagittal and coronal planes but to date there has been no quantification of stiffness reduction provided by these techniques for axial correction through a pedicle screw construct. We sought to determine the contribution of posterior spinal releases (facetectomy, rib head resection) on axial plane stiffness.

METHODS

Four fresh-frozen human cadavers were instrumented with fixed angle pedicle screws in the thoracic spine. The torque needed to produce 25° axial deflections at individual spinal segments (levels T5-T11) was measured using a custom needle deflection torque device attached to commercially available vertebral rotating construct. After the intact specimen was tested, torque measurements were repeated following a full facetectomy and posterior rib head resection

RESULTS

Complete facetectomy resulted in an 18% decrease of torque needed to produce 25° of axial deformity compared to the intact specimen (P < 0.001). Rib resection added an additional 36% decrease in torque (P < 0.001).

CONCLUSIONS

Complete facetectomies (Ponte or Smith-Petersen osteotomies) decrease the force required to rotate spinal segments with respect to the axial plane by approximately one-fifth. Posterior rib head resection should be considered to further loosen the spine if additional axial correction is desired.

Changes in level of the conus after corrective surgery for scoliosis: MRI-based preliminary study in 31 patients

BACKGROUND

Detection of postoperative spinal cord level change can provide basic information about the spinal cord status, and electrophysiological studies regarding this point should be conducted in the future.

METHODS

To determine the changes in the spinal cord level postoperatively and the possible associated factors, we prospectively studied 31 patients with scoliosis. All the patients underwent correction and posterior fusion using pedicle screws and rods between January 2008 and March 2009. The pre- and postoperative conus medullaris levels were determined by matching the axial magnetic resonance image to the sagittal scout image. The patients were divided according to the change in the postoperative conus medullaris level. The change group was defined as the patients who showed a change of more than one divided section in the vertebral column postoperatively, and the parameters of the change and non-change groups were compared.

RESULTS

The mean pre- and postoperative Cobb's angle of the coronal curve was 76.80° ± 17.19° and 33.23° ± 14.39°, respectively. Eleven of 31 patients showed a lower conus medullaris level postoperatively. There were no differences in the pre- and postoperative magnitude of the coronal curve, lordosis and kyphosis between the groups. However, the postoperative degrees of correction of the coronal curve and lumbar lordosis were higher in the change group. There were also differences in the disease entities between the groups. A higher percentage of patients with Duchenne muscular dystrophy had a change in level compared to that of the patients with cerebral palsy (83.3% vs. 45.5%, respectively).

CONCLUSIONS

The conus medullaris level changed postoperatively in the patients with severe scoliosis. Overall, the postoperative degree of correction of the coronal curve was higher in the change group than that in the non-change group. The degrees of correction of the coronal curve and lumbar lordosis were related to the spinal cord level change after scoliosis correction.

A new pelvic rod system for the surgical correction and fixation of pelvic obliquity in pediatric neuromuscular scoliosis

PURPOSE

To describe surgical outcomes using the new device in pediatric neuromuscular scoliosis.

METHODS

All patients with neuromuscular disorders requiring surgery with pelvic fixation for the correction of scoliosis in the period 2002-2009 were operated by the new pelvic rod fixation device. Coronal and sagittal alignment before and after surgery until the latest follow-up were evaluated by standard X-rays. Intraoperative and postoperative complications were recorded.

RESULTS

All 18 study patients (mean age at surgery 15 years, range 10-27) achieved solid fusion at a mean follow-up of 41 months. The coronal Cobb angle improved from 82° ± 31° (range 36-168) to 33° ± 25° at the last follow-up (range 9-95 months) (P < 0.0001). Pelvic obliquity improved from 19° ± 6° (range 10-30) to 5° ± 5° (range 0-14) (P < 0.0001). Early complications included pneumonia, urinary tract infection, disseminated intravascular coagulation (DIC), and hypovolemic shock. Three patients required debriding and received prolonged antimicrobial therapy for deep wound infection (none required implant removal). At the latest follow-up, no patient complained of lumbar pain or worsening of ambulatory status or level of activity.

CONCLUSION

Surgery employing the new pelvic rod fixation device allowed solid fusion and fixation with significant correction of multiplanar deformity, but the complication rate was high.

Surgical management of spinal deformities in cerebral palsy. A review

Cerebral palsy (CP) spinal deformities encompass a spectrum of deformities that are often initially treated nonoperatively, only to result in progression of scoliotic curves and further morbidity. Various surgical interventions have been devised to address the progressive curvature of the spine. This endeavor cannot be taken lightly and at times can be encumbered by prior treatments such as the use of baclofen pumps or dorsal rhizotomies. Care of these patients requires a multidisciplinary approach and comprehensive preoperative and postoperative management, including nutritional status, orthopedic assessment of functional level with specific emphasis on the hips and pelvic obliquity, and wheelchair modifications. The surgical techniques in CP scoliosis have progressively evolved from the classic Luque-Galveston fixation methods, the use of unit rods, and lately the use of pedicle screws, to modern sacropelvic fixation. With the latter method, the spinal deformity in patients with CP can usually be almost completely corrected.

Management of spinal deformity in cerebral palsy

An understanding of the three-dimensional components of spinal deformity in children with cerebral palsy is necessary to recommend treatments that will positively affect these patients' quality of life. Management of these deformities can be challenging and orthopedic surgeons should be familiar with the different treatments available for this patient population. This article discusses the incidence, causes, natural history, and treatment of patients with scoliosis.

Accuracy of thoracic pedicle screw using ideal pedicle entry point in severe scoliosis

BACKGROUND

The ideal pedicle entry point for the thoracic spine is described as the base of the superior facet at the junction of the lateral and middle thirds of the pedicle. Investigators have reported its accuracy in curves less than 90 degrees .

QUESTIONS/PURPOSES

Our aim was to measure the accuracy of this entry point for pedicle screw insertion in severe and rigid scoliotic curves.

PATIENTS AND METHODS

We retrospectively measured the accuracy of thoracic pedicle screws in 26 patients with severe and rigid scoliosis (Cobb angle > or = 90 degrees ) inserted using the free-hand technique and the ideal pedicle entry point. Placements of thoracic pedicle screws were reviewed on postoperative CT scans, and the incidence and severity of penetration were determined. Screws penetrating medially up to 2 mm and laterally up to 4 mm were considered within the safe zone.

RESULTS

One hundred sixty-eight (34.8%) of 482 inserted screws breached pedicle walls; 64 (13.2%) and 104 (21.6%) screws breached pedicle walls medially and laterally, respectively. Four hundred thirty-seven screws were within the safe zone, representing an accuracy rate of 90.7%. The accuracy rates of inserted screws in upper, middle, and lower thoracic pedicles were 93.4%, 87.7%, and 92%, respectively.

CONCLUSIONS

Use of the ideal pedicle entry point is safe and accurate for thoracic pedicle screw placement in rigid curves of 90 degrees or greater.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.