Effect of anterior mobilization and shortening in the correction of rigid idiopathic thoracic scoliosis

Anterior instrumented fusion for adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity of the spine consisting of a lateral curvature, apical vertebral rotation, and an impairment of the sagittal profile. Surgical options include anterior and posterior approaches. Anterior instrumented fusion is suitable in Lenke type 1 and 5 curves. It supplies excellent results in coronal plane correction and is superior in the restoration of the sagittal profile and apical derotation. Fusion is shorter compared to posterior correction, and the complication rate is low. Pulmonary function is impaired postoperatively but recovers within a few years.

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.

Preoperative Sagittal Spinal Profile of Adolescent Idiopathic Scoliosis Lenke Types and Non-Scoliotic Adolescents: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

This study aims to determine the differences in sagittal spinopelvic parameters between adolescent idiopathic scoliosis (AIS) Lenke types and non-scoliotic controls through a systematic review and meta-analysis of the available literature.

SUMMARY OF BACKGROUND DATA

AIS classification mainly focuses on frontal curve differences; however, the variations in the sagittal spinopelvic alignment in the current classification system is not fully established.

METHODS

Following preferred reporting items for systematic reviews and meta-analyses guidelines, searches were performed for sagittal spinal and pelvic parameters of Lenke types and non-scoliotic controls in PubMed, Scopus, EMBASE, and Cochrane databases. Selection criteria were: (1) age range 10 to 21 years; (2) Lenke types 1-6 (for AIS group) or non-scoliotic adolescents (for the control group); (3) preoperative data for T5-T12 thoracic kyphosis (TK), L1-S1 lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and sagittal vertical axis (SVA). (4) Written in English language. PI-LL mismatch was calculated from the weighted average of PI and LL. Publication bias between studies and within studies quality were assessed. A meta-regression compared each measured variable between groups. Thoracic (Lenke1 and 2) and thoracolumbar/lumbar (Lenke 5 and 6) scoliosis were combined and statistically compared with the control group.

RESULTS

Meta-analysis, including 81 AIS and 18 control studies, showed no significant differences in sagittal parameters between Lenke types and controls for LL, PI, PI-LL mismatch, SS, and SVA (P > 0.05). Publication bias was significant in Lenke 1 TK, Control LL, and Lenke 1, and 5 SVA. Stratification based on deformity region (thoracic vs. thoracolumbar/lumbar) showed no significant differences in sagittal spinopelvic parameters (P > 0.05).

CONCLUSION

No definitive difference was found between non-scoliotic adolescents and Lenke types in sagittal spinal and pelvic parameters. Future studies on developing a sagittal classification specific to AIS patients with a goal to improve surgical planning and outcome prediction are highly encouraged.

LEVEL OF EVIDENCE

4.

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.

Incidence of Pleural Fluid and Its Associated Risk Factors After Posterior Spinal Fusion in Patients With Adolescent Idiopathic Scoliosis

STUDY DESIGN

Retrospective review of prospectively-collected data.

OBJECTIVE

To determine the incidence pleural fluid (PF) and its associated risk factors after posterior corrective spinal fusion (PCSF) in patients with adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Subclinical PF is often observed after PCSF in AIS patients. However, a few reports have been published regarding the incidence, characteristics, and associated risk factors.

METHODS

A total of 76 AIS patients who underwent PCSF and followed up for a minimum of 1 year were enrolled in this study. The volume of PF in each thorax was detected with thoracolumbar CT images taken preoperatively, at 1 week and 3 months follow up. Patient demographics, comorbidities, operation factors, serum albumin levels, scoliotic parameters, occurrence of malposition of pedicle screw insertion, and complications were collected and analyzed with univariate and multivariate analyses.

RESULTS

There were 71 female and five male patients (mean age, 16.2 yrs). All cases had a right convex curve in thoracic spine. Other causes of PF were not observed. PF was detected in 54 cases (71%) at 1 week postsurgery. It accumulated bilaterally in 36 cases, only in the right thorax in 13 cases, and only in the left thorax in five cases. There was significant difference between the depth of PF in the right and left sides (P < 0.001). The independent risk factor for PF was increased number of fused levels (OR: 3.88, 95% CI: 1.31-11.47). The mean coronal curve correction rate and other scoliotic factors were not significantly correlated.

CONCLUSION

PF was observed in 71% of the patients who underwent PCSF for AIS. The right thorax was more commonly involved than the left. A higher number of fused levels (11 or more) was an independent risk factor of PF.

LEVEL OF EVIDENCE

3.

Posterior-only surgery with preoperative skeletal traction for management of severe scoliosis

PURPOSE

The surgical treatment of severe adolescent spinal deformities is challenging and carries substantial risks of mortality and morbidity. To mitigate this risk, surgeons have employed various methods as this study designed to evaluate the safety and effectiveness of preoperative halo-femoral or halo gravity traction (HGT) followed by posterior-only surgery in the management of severe scoliosis.

METHOD

A total number of 23 patients with severe scoliosis treated by preoperative skeletal traction (halo gravity or halo femoral) followed by posterior fusion and instrumentation in one stage. All patients were followed for a minimum of 2 years after surgery.

RESULTS

The average age of the patients was 12.7 years at the time of surgery. Mean of the Cobb angle improved from 99.9° ± 8.2° preoperatively to 75.3° ± 8° post-traction and 49.5° ± 7.7° postoperatively. Kyphosis angle corrected from 56.4° ± 9.5° to 38.6° ± 5.8°. The preop-FVC% was 41 ± 6.1% and after 1 year follow-up FVC% was 45.7 ± 7.7%. No patients required an anterior release due to amount of their deformity.

DISCUSSION

Despite the benefits of modern instrumentation procedures, the treatment of severe scoliosis can be very competing. We think that by applying preoperative halo femoral traction and halo-gravity traction, managing severe scoliosis will be in safe and easy manner and can lead to better deformity correction and less neurological complications and facilitate to avoid anterior operation for severe scoliosis and its related complications.

Preoperative halo-gravity traction for severe spinal deformities at an SRS-GOP site in West Africa: protocols, complications, and results

STUDY DESIGN

Retrospective analysis of a prospectively collected single-center database.

OBJECTIVE

We describe a modified halo-gravity traction (HGT) protocol for patients with severe spinal deformities in West Africa, and assess the clinical and radiographic outcomes.

SUMMARY OF BACKGROUND DATA

Three-column osteotomies are frequently used in the correction of severe spinal deformities; however, these can be associated with high complication rates and significant risk for neurological injury. Preoperative traction is one modality used to obtain a partial correction prior to definitive fusion. Low numbers and variability of traction protocols, however, have limited previous reports of sustained HGT.

METHODS

All patients who underwent HGT in Ghana from April 2012 to August 2013 were reviewed. HGT was started at 20% body weight and increased by 10% per week until 50% body weight was reached by 4 weeks or thereafter as tolerated. Demographic variables, operative data, radiographic parameters, and health-related quality of life scores were collected. A deformity reduction index was calculated at each time point by summing the scoliosis and abnormal kyphosis for each patient and reported as a percentage of the preoperative deformity.

RESULTS

Twenty-nine patients underwent HGT for an average 107 days prior to definitive posterior spinal fusion (24 patients) or placement of growing rods (5 patients). The major curve improved from an average 131° to 90° (31%) after HGT, and to an average 57° (56%) postoperatively. Pure kyphotic curves were rigid (flexibility 22% after traction), with a correction index of 3.88, which is similar to historical controls. Deformity correction with HGT plateaued at 63 days. Overall Scoliosis Research Society-22 questionnaire scores improved significantly pretraction versus postoperatively, but there was no change after traction versus before traction. There were 11 pin tract infections, with no neurological complications.

CONCLUSION

HGT is a safe method to partially correct severe spinal deformities prior to a definitive procedure, and may reduce the need for higher risk 3-column osteotomies. Importantly, kyphosis secondary to infection with spontaneous apical ankylosis is relatively resistant to HGT.

LEVEL OF EVIDENCE

4.