Evaluation of a combined approach to the correction of congenital cervical or cervicothoracic scoliosis

Posterior-only approach cervical hemivertebrectomy and short fusion with pedicle screws in young children with cervical scoliosis: case report and technical note

PURPOSE

Cervical hemivertebrae (C3-6) causing significant osseous torticollis, head tilt and facial asymmetry are rare and complicated. Cervical hemivertebrectomy (CHVE) by a posterior-only approach was never reported because it is highly risky and its efficacy remains controversial. This study is to evaluate the feasibility and preliminary clinical outcomes of posterior-only approach for CHVE and torticollis correction in young children.

METHODS

Four young children aged 5-9 years old with significant torticollis caused by cervical hemivertebrae underwent deformity correction consisting of cervical pedicle screw (CPS) placement with O-arm-based intraoperative navigation, CHVE using ultrasonic bone scalpel and short-segmental posterior instrumentation and fusion. Details of this novel technique were presented. The preliminary short-term clinical and radiographic outcomes were assessed.

RESULTS

On average, the operative time was 312.5 ± 49.9 min, and the surgical blood loss was 375.0 ± 150.0 ml. The structural cervical scoliosis was corrected from 31.5 ± 7.3° to 11.0 ± 4.1°, and the average correction rate was 64.9%. Head tilt was favorably corrected from 11.0 ± 4.2° to 3.5 ± 2.6°. The shoulder balance improved from 6.3 ± 1.3° to 1.5 ± 1.9°. One case with C6 CHVE had convex side radiating nerve root pain but no sign of muscle power weakness. Full recovery was achieved one month after surgery. No other complication occurred.

CONCLUSIONS

CHVE by a posterior-only approach was a feasible alternative option for the treatment of congenital cervical scoliosis. It could resect the CHV effectively and achieve satisfactory torticollis correction without additional anterior access surgery. Successful CPS placement in this child population was essentially important to enable reliable osteotomy closure and firm posterior instrumentation.

Risk Factors for Progression of Cervical Congenital Scoliosis and Associated Compensatory Curve Behavior

Background: This study investigated risk factors for progression of deformity in pediatric congenital cervical scoliosis (CCS) and evaluated the correlation between congenital cervical curves and compensatory thoracic and lumbar curves. Methods: Medical records were retrospectively reviewed for 38 pediatric patients with CCS with a minimum 2-year follow-up. Curve progression was defined as >10° increase in cervical coronal curve angle between presentation and last follow-up. Results: A total of 38 patients (16 girls, 22 boys) with a mean age at presentation of 5.6 ± 4.1 years met the inclusion criteria. Sixteen patients (42%) had curve progression with a mean follow-up of 3.1 ± 3.0 years. At presentation, T1 slope was significantly larger among children with progressive deformities (p = 0.041). A total of 18 of the 38 patients with strictly cervical spine deformity were then selected for subanalysis to evaluate the progression of compensatory curves. Cervical major coronal curves were found to significantly correlate with lumbar major coronal curves (r = 0.409), C2 central sacral vertical line (CSVL) (r = 0.407), and C7-CSVL (r = 0.403) (p < 0.05). Thoracic major coronal curves did not significantly correlate with cervical major coronal curves (r = 0.218) (p > 0.05). Conclusion: In conclusion, 42% of osseous CCS curves progressed over time in the overall cohort, and high initial T1 slope was found to be most highly correlated with progression of cervical deformity. Cervical major coronal curves significantly correlated with lumbar curve magnitude but not with thoracic curve size in isolated CCS, possibly due to the increased flexibility of the lumbar spine which may allow greater compensatory balance and thus have a greater correlation with cervical curve magnitude and possibly progression.

Progressive coronal caudal curve after corrective osteotomies for congenital cervicothoracic scoliosis: incidence and predictors

OBJECTIVE

Postoperative progressive coronal caudal curve (PCC) was characterized by a postoperative de novo caudal S-curve ≥ 20° following congenital cervicothoracic scoliosis (CTS) corrective osteotomies, and at least 20° greater than the preoperative measurement, while the incidence was uncertain and the pathogenesis was equivocal. The objective of this study was to investigate the morbidity and potential factors contributing to PCC following CTS surgery.

METHODS

This study reviewed 72 CTS patients between 2005 and 2021. Patients were categorized into two groups according to the absence or presence of PCC at last follow-up, namely the nonprogressive curve group (NPC-group) and the progressive curve group (PC-group). Demographics, radiographic data and the Scoliosis Research Society-22 (SRS-22) questionnaire results were reviewed. Multivariate linear regression analyses were utilized to determine possible predictors for PCC.

RESULTS

PCC was observed in 11 (15%) of the total 72 patients. Compared with the NPC-group, the PC-group exhibited greater postoperative residual local curve (24.0 ± 9.7° vs. 9.1 ± 4.4°, P < 0.001), upper instrumented vertebra (UIV) tilt (16.9 ± 7.4° vs. 6.2 ± 3.7°, P < 0.001), T1 tilt (14.3 ± 9.4° vs. 6.6 ± 3.9°, P = 0.022) and neck tilt (10.1 ± 6.7° vs. 3.7 ± 2.5, P = 0.009). The multivariable linear regression demonstrated that the larger postoperative UIV tilt, residual local curve and neck tilt were associated with PCC. In addition, patients with PCC showed lower SRS-22 scores in terms of pain, mental health, self-image and satisfaction (P < 0.05).

CONCLUSIONS

The morbidity of PCC was 15% in CTS patients who underwent corrective osteotomies. Greater residual local curve, postoperative UIV tilt and neck tilt were identified as predictors for PCC.

Congenital Cervical Scoliosis Treated with Concave Side Distraction with Three-Dimensional Printed Titanium Cage

STUDY DESIGN

Single-center, retrospective study.

OBJECTIVE

Hemivertebra resection is the only treatment option for congenital cervical scoliosis (CCS). However, this procedure is complex and technically demanding. It often requires a considerably long operation, and there is substantial intraoperative bleeding. Therefore, we have attempted to treat CCS with a concave side distraction comprising a three-dimensional (3D) printed titanium cage. The purpose of this study is to evaluate the safety and efficacy of this technique for the treatment of patients with CCS.

METHODS

A series of 22 patients with CCS who underwent a concave side distraction technique between 2019 and 2021 were retrospectively reviewed and analyzed. Radiological measurements included the Cobb angle of the distraction segments, the kyphosis angle, the range of movement, and the distraction correction angle. Student's t-test and Spearman correlation analysis were used for statistical analysis. p < 0.05 was considered statistically significant.

RESULTS

The study included 12 males and 10 females whose ages ranged from 6 to 14 years old (9.8 ± 2.1 years old). Follow-up times ranged from 15 to 30 months (25.8 ± 3.6 months). Among 22 patients, two patients developed a postoperative C5 nerve root palsy and recovered after being treated with conservative treatment for 6 months. The duration of surgery ranged from 229 to 756 min (389 ± 112 min), and the estimated volume of blood loss ranged from 100 to 600mL (235 ± 121 mL). The coronal Cobb angle (p < 0.001), kyphosis angle (p < 0.05), and range of movement (p < 0.001) between the last follow-up and preoperative period were significantly different. A total of 28 segments were distracted, and the Cobb angle of the distraction segment ranged from 2.4 to 14.1° (8.5 ± 3.0°). There were six upper cervical spines (8.9 ± 1.9°) and 22 lower cervical spines (8.4 ± 3.2°) with no significant difference between them (p = 0.130). In addition, there was no correlation between the angle of the concave side distraction and patients' age (r = 0.018, p = 0.315). The fusion was solid between the bone and the customized 3D-printed pore metal cage at the final follow-up.

CONCLUSION

The concave side distraction comprising a customized 3D-printed titanium cage implantation can provide satisfactory correction results and is a safe and reliable procedure for treating CCS.

How does congenital cervicothoracic scoliosis bring about early trunk tilt and coronal imbalance during curve progression: a radiographic analysis to dissect the mechanism of proximal takeoff phenomenon

PURPOSE

To dissect the mechanism of how congenital cervicothoracic scoliosis (CTS) drive the occurrence of early trunk tilt, namely proximal takeoff phenomenon (PTO) during curve progression.

METHODS

CTS patients were stratified into case and control groups according to the presence of PTO. The radiographic deformity parameters of head-neck-shoulder complex were measured and compared between the two groups. The main risk factors for PTO were identified through multiple linear regression analysis.

RESULTS

16 CTS patients with PTO were recruited, and the non-PTO group consisted of 19 CTS patients without PTO. The average Cobb angle was 64.9 ± 19.8° in PTO group and 57.7 ± 21.9° in control group (p > 0.05). Significant difference could be observed for head shift, neck tilt, trunk inclination, apex-C7 deformity angular ratio (DAR), apex translation ratio, C6 tilt, clavicle angle (CA), radiographic shoulder height (RSH), head-neck translation and coronal balance distance (CBD) (All p < 0.05) but not head tilt (p > 0.05). Multiple linear regression analysis revealed that head shift, but not neck tilt correlated significantly with the severity of trunk inclination (β = 0.106, p = 0.003), while apex-C7 DAR and apex translation ratio were the two factors contributing significantly to the severity of head shift (β = 0.620, p = 0.020; β = - 0.371, p = 0.004).

CONCLUSIONS

Development and progression of head shift rather than neck tilt is a significant causative factor initiating the occurrence of trunk tilt and proximal takeoff in CTS. A higher apex-C7 DAR representing a short angular upper hemi curve and a lower apex translation ratio representing poor proximal coronal compensation are key risk factors predisposing to head shift.

A novel classification of subaxial cervical hemivertebrae and associated surgical management

Objective

To propose and validate a new classification of surgical methods for patients with subaxial cervical hemivertebrae.

Method

This article reviewed cases diagnosed with subaxial cervical hemivertebrae in our hospital from January 2008 to December 2019. The results of preoperative (initial visit), postoperative and/or final follow-up were assessed using the Japanese Orthopaedic Association (JOA) score, Neck Disability Index (NDI) score, spinal balance parameters, and Scoliosis Research Society-22 Questionnaire (SRS-22). We also performed a reliability study to assess this classification.

Result

The classification includes three types. Each type can be divided into two subtypes, and a preliminary algorithm is proposed. Type I: There is an obvious appearance deformity in the neck, there are hemivertebrae in the cervical spine, and only a single hemivertebra of the subaxial cervical hemivertebra needs to be resected. Type II: There is an obvious appearance deformity in the neck, there are hemivertebrae in the cervical spine, and multiple subaxial cervical hemivertebrae need to be removed. Type III: No apparent deformity in the neck, at least one subaxial cervical hemivertebra existed or Klipper-Feil syndrome. Each type is divided into two subtypes, A and B, according to whether the upper and lower adjacent vertebral bodies of the rescected hemivertebra(e) are fused. We propose corresponding treatment methods for different types. We included a total of 121 patients and reviewed the prognosis for each type of patient. All patients achieved satisfactory results. The reliability study showed that the mean interobserver agreement was 91.8% (89.3%–93.4%), and the κ value was 0.845 (0.800–0.875). The intraobserver agreement ranged from 93.4% to 97.5%, with a mean κ value of 0.929 (0.881 to 0.954).

Conclusion

In our study, we proposed and validated a new classification of subaxial cervical hemivertebrae and proposed corresponding treatment plans for different classifications.

Evaluation and Comparation of a Novel Surgical Technique and Hemivertebra Resection to the Correction of Congenital Cervical Scoliosis in Lower Cervical and Cervicothoracic Spine

OBJECTIVE

To report concave-side distraction technique to treat congenital cervical scoliosis in lower cervical and cervicothoracic spine. To evaluate and compare clinical and radiographic results of this procedure with classic hemivertebra resection procedure.

METHODS

This study reviewed 29 patients in last 13 years. These patients were divided into convex-side resection group (group R) and concave-side distraction group (group D). Radiographic assessment was based on parameter changes preoperatively, postoperatively and at last follow-up. Demographic data, surgical data and complications were also evaluated and compared between the 2 groups.

RESULTS

In group R, mean age was 8.9 ± 3.3 years and follow-up was 46 ± 18 months. Operation time and blood loss averaged 500 ± 100 minutes, 703 ± 367 mL. In group D, mean age was 9.9 ± 2.8 years and follow-up was 34 ± 14 months. Operation time and blood loss averaged 501 ± 112 minutes, 374 ± 181 mL. Structural Cobb angle was corrected from 29.4° ± 12.5° to 5.3° (2.1°-18.1°) (p = 0.001) and 33.7° ± 14.1° to 12.8° ± 11.4° (p < 0.001) in groups R and D. Compensatory Cobb angle had a spontaneous correction rate of 59.6% (40.0%-80.8%) and 59.7% ± 23.0% in groups R and D. Mandibular incline, clavicle angle and spine coronal balance were significantly improved at last follow-up in both groups. All correction rates were not statistically different between groups. However, group D had significant less blood loss (p < 0.001) and operation time (p = 0.004) per vertebra than group R. Seven patients developed C5 nerve root palsy and recovered by 6 months of follow-up.

CONCLUSION

Both surgical procedures are safe and effective in correcting congenital cervical scoliosis. But concave-side distraction technique has less blood loss and time-consuming during surgery, which provides a better option for the treatment of congenital cervical scoliosis.

Strategy and Efficacy of Surgery for Congenital Cervicothoracic Scoliosis with or without Hemivertebra Osteotomy

OBJECTIVE

Cervicothoracic scoliosis will cause severe deformities in the early stage, and its structure is complex and the surgical methods are varied. The purpose of this research is to explore the indication and analyze the corrective effect of the two different posterior approach surgical strategies, including correction with fusion and hemivertebra osteotomy, for congenital cervicothoracic scoliosis deformities in children and adolescents.

METHODS

This was a retrospective study of 21 patients with cervicothoracic scoliosis who received surgical treatment from January 2010 to June 2020, including nine cases of posterior hemivertebra osteotomy and fusion surgery and 12 cases of posterior correction and fusion alone. The Cobb angle, T1 tilt angle, clavicular angle, neck tilt angle, radiographic shoulder height, sagittal vertical axis, coronal balance distance, and local kyphosis angle were measured preoperatively, postoperatively, and at the last follow-up. Posterior approach hemivertebra resection or correction with fusion surgery was adopted based on the different individual characteristics of deformity such as main curve Cobb angle, growth potential, and flexibility. Patients were divided into two groups (osteotomy group and nonosteotomy group) according to whether a hemivertebra osteotomy was performed, and the corrective results in the two groups were compared. Paired-sample t tests or independent-sample t tests were used.

RESULTS

The median follow-up after surgery of the 21 patients was 36 months (range, 18-72 months). The Cobb angle was corrected from 45.81° ± 14.23° preoperatively to 10.48° ± 5.56° postoperatively (correction rate, 77.78% ± 8.93%). The T1 tilt angle decreased from 15.26° ± 7.08° preoperatively to 3.33° ± 2.14° postoperatively (correction rate,73.42% ± 21.86%). The radiographic shoulder height was corrected from 1.13 ± 0.74 cm preoperatively to 0.52 ± 0.42 cm postoperatively (correction rate, 39.51% ± 35.65%). The clavicular angle improved from 2.52° ± 1.55° preoperatively to 1.16° ± 0.96° postoperatively (correction rate, 47.18% ± 35.84%). No significant differences were found at the last follow-up (p > 0.05). The Cobb angle of the main curve, T1 tilt angle, clavicular angle, cervical tilt angle, and shoulder height difference were similar in the two groups (p > 0.05).

CONCLUSIONS

Posterior approach hemivertebra resection or correction with fusion surgery can be used in the treatment of congenital cervicothoracic scoliosis with satisfactory results, and the surgeon can make an individualized surgical plan according to individual characteristics of deformity.

Surgical outcomes following hemivertebrectomy in congenital scoliosis: a systematic review and observational meta-analysis

BACKGROUND

Hemivertebrectomy is widely used definitive correction surgery in congenital scoliosis due to hemivertebrae. It may be done either as combined anterior and posterior approach or a single-stage posterior approach only. The purpose of this meta-analysis was to compare two techniques with regards to blood loss, operative time, deformity correction and complications.

METHODS

The systematic review and meta-analysis were conducted according to PRISMA guidelines among peer-reviewed journals published in English between June 2000 and June 2020. Quality appraisal of all selected articles was done and data extracted.

RESULTS

After thorough literature search and excluding, 37 studies were included for review. The commonest location of the hemivertebrae was thoracolumbar spine (51.3%), thoracic (26.2%), lumbar/lumbosacral (21.6%) followed by cervical (0.7%). Pooled data showed a significant difference (p < 0.05) in mean operative time with posterior only approach (227 min, 95% CI 205-250) as compared to Combined Anterior Posterior Approach (CAPA) (316 min 95% CI 291-341). Significant difference (p < 0.05) in mean blood loss was observed in posterior only approach (522 ml, 95% CI 434-611) as compared to CAPA (888 ml, 95% CI 663-1113). No significant difference was noted in mean correction in either of the approaches and overall pooled mean correction rate was 66%, 95% CI 61-72.

CONCLUSION

This review and meta-analysis of two surgical techniques of hemivertebrectomy, shows that operative time and blood loss is significantly lower in posterior only approach with no difference in correction rate as compared to CAPA. There was significant correlation between age at surgery and need for revision surgeries.

LEVEL OF EVIDENCE

IV.

Congenital Scoliosis of the Pediatric Cervical Spine: Characterization of a 17-Patient Operative Cohort

BACKGROUND

Congenital cervical scoliosis is rare, and there is a paucity of literature describing surgical outcomes. We report surgical outcomes in a 17-patient cohort with surgical correction for congenital cervical scoliosis and identify risk factors associated with complications.

METHODS

Data were retrospectively collected from a single-center cohort of 17 consecutive patients (9 boys, 8 girls) receiving surgical deformity correction for congenital cervical scoliosis. The mean age at surgery was 7.1±3.4 years with an average follow-up of 3.6±1.1 years.

RESULTS

There were 24 operations performed on 17 patients, and 4 complications (17%) were reported in the series, including one each of pressure ulcer, asystole, vertebral artery injury, and pseudarthrosis. The mean preoperative major curve angle was 36±20 degrees, which improved to 24±14 degrees (P=0.02). The mean operative time was 8±2 hours with a mean estimated blood loss of 298±690 mL. Halo-gravity traction was used in 5 patients and 6 cases were staged with anterior/posterior procedures.

CONCLUSIONS

Congenital scoliosis of the cervical spine is a complex process. The spinal deformity of this nature can be managed successfully with carefully planned and executed surgical correction.

LEVEL OF EVIDENCE

Level IV-retrospective review.

Vertebral Artery Variation in Patients With Congenital Cervical Scoliosis: An Anatomical Study Based on Radiological Findings

STUDY DESIGN

Observational, anatomical, radiological study.

OBJECTIVE

The aim of this study was to explore the incidence and type of vertebral artery (VA) variation in patients with congenital cervical scoliosis and approach their clinical importance during surgery.

SUMMARY OF BACKGROUND DATA

Congenital scoliosis of the cervical spine is usually sporadic and caused by a variety of bone structural anomalies. Most of the cases remain asymptomatic. Surgical intervention is the main management for patients with neurological compromise or with cosmetic demands. The operation involved more screw insertion and osteotomy than the regular degenerative cases. The incidence and pattern of VA variants in these patients have not been reported.

METHODS

Patients with congenital cervical scoliosis treated in our department were reviewed. We measured Cobb angle of cervical spine. We observed bilateral VAs and recorded variants. We measured their diameter in each segment through CT angiography. The bilateral diameter in each patient was then compared respectively.

RESULT

There is a total of 44 patients enrolled. The incidence of VA variation was 41% (18/44). Fifty percent (22/44) of patients had the dominant VA with no difference between concave side and convex side. Patients with a dominant VA had a larger Cobb angle than those who had not (30.25° vs. 23.24°, P < 0.05). The courses of VA were abnormal in 18 patients. Two patients had unilateral variant in V1 segment. Twelve patients had variants in V2 segment. Eight patients had variants in V3 segment. Three patients had VA variants in multiple sites.

CONCLUSION

In patients with congenital cervical scoliosis, the dominance of VA is not related to the convex side or concave side, but patients with a dominance of VA have a larger Cobb angle. The incidence of variant in V2 and V3 segment is higher. A thorough evaluation of bilateral VAs is required before surgery. Extra cautions must be taken during surgery.Level of Evidence: 5.

Severe persistent coronal imbalance following instrumented posterior spinal fusion for adolescent idiopathic scoliosis

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

The aim of this study was to identify the risk factors and health-related quality of life (HRQoL) impact of severe (> 4 cm) post-operative coronal imbalance at 2 years following posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). Coronal imbalance is an unfavorable outcome following PSF for AIS, though the degree of imbalance in such patients is typically mild. We hypothesize that a small number of patients become and remain severely imbalanced post-operatively, though this phenomenon has not been well studied.

METHODS

Prospectively collected data from a large multicenter registry were reviewed. Patients with severe coronal imbalance (SCIB; > 4 cm) 2 years after PSF were included. Matched controls without SCIB at 2 years were included at a 3:1 ratio. Comparisons were made between demographics, pre-operative radiographic measures, surgical factors, residual post-operative radiographic measures, and 2-year SRS-22 scores.

RESULTS

Nine of 954 (0.9%) patients (88.9% females; mean age 14.8 ± 2.3 years) were found to be severely imbalanced at 2 years. These patients had significantly greater pre-operative bending thoracic curve magnitude (45° vs. 33°; p = 0.013), curve flexibility (22.9% vs. 63.3%; p = 0.004), and kyphosis (41° vs. 26.5°; p = 0.034) compared to matched controls. Pre-operative curve flexibility of < 20% was associated with a 23.8 times greater odds of SCIB (95% CI 2.1-250; p = 0.008). With respect to HRQoL, median SRS-22 pain (4.1 vs. 4.8; p = 0.041), self-image (3.9 vs. 4.6; p = 0.013), general function (4.5 vs. 5; p = 0.022), and total (4.1 vs. 4.7; p = 0.012) scores at 2 years were significantly lower in cases compared to controls.

CONCLUSIONS

In the present study, thoracic curve stiffness was a strong risk factor for severe post-operative coronal imbalance, which was associated with poor HRQoL measures. Increased pre-operative thoracic curve stiffness (< 20% flexibility) should raise surgeon awareness for altering surgical approach to minimize the risk of severe post-operative coronal imbalance.

LEVEL OF EVIDENCE

Level III.

Anterior Reconstruction Techniques for Cervical Spine Deformity

Cervical spine deformity is an uncommon yet severely debilitating condition marked by its heterogeneity. Anterior reconstruction techniques represent a familiar approach with a range of invasiveness and correction potential-including global or focal realignment in the sagittal and coronal planes. Meticulous preoperative planning is required to improve or prevent neurologic deterioration and obtain satisfactory global spinal harmony. The ability to perform anterior only reconstruction requires mobility of the opposite column to achieve correction, unless a combined approach is planned. Anterior cervical discectomy and fusion has limited focal correction, but when applied over multiple levels there is a cumulative effect with a correction of approximately 6° per level. Partial or complete corpectomy has the ability to correct sagittal deformity as well as decompress the spinal canal when there is anterior compression behind the vertebral body. If pathoanatomy permits, a hybrid discectomy-corpectomy construct is favored over multilevel corpectomies. The anterior cervical osteotomy with bilateral complete uncinectomy may be necessary for angular correction of fixed cervical kyphosis, and is particularly useful in the midcervical spine. A detailed understanding of the patient's local anatomy, careful attention to positioning, and avoiding long periods of retraction time will help prevent complications and iatrogenic injury.