Convex instrumented hemiepiphysiodesis with concave distraction: a preliminary report

Optimal timing of starting growing rod treatment for early-onset scoliosis

BACKGROUND CONTEXT

Growing rod (GR) systems require periodical surgical intervention and may cause associated complications, as well as worsened sagittal plane deformity. Generally, the risk of complications decreases with an increment in age at the time of the index surgery with GR construct placement. However, the optimal timing to begin GR treatment has not reached a consensus yet.

PURPOSE

This study was performed to investigate the effect of age at the index GR surgery on the complication rates and formulate clinical guidelines for the optimal timing to begin GR treatment for EOS patients.

STUDY DESIGN

Kaplan-Meier analysis was used to determine complication occurrence as a function of the age at the index surgery and to determine the survival rates for the procedures. The receiver operator characteristic (ROC) curve was used to determine optimal cut-off values for the optimal timing of index surgery based on whether complications occurred or not.

PATIENT SAMPLE

54 patients who met the criteria were enrolled in this study.

OUTCOME MEASURES

The following spinal parameters were measured: major coronal Cobb angle, global kyphosis (GK), and coronal balance (CB). CB was defined as the horizontal distance from the C7 plumb line to the center sacral vertical line.

METHODS

All patients had completed GR treatment and had a minimum 1-year follow-up duration after the final surgical intervention. Patient data were collected as follows: age at the index surgery, gender, diagnosis, type of GR construct, and the number of lengthening procedures. The standing full-spine radiographs were obtained before and after the index surgery, before and after each lengthening procedure, before and after the final surgical intervention, and at the latest follow-up. Complications were categorized as implant, alignment, and general.

RESULTS

Kaplan-Meier analysis of complications demonstrated a declining trend in complication rates with increasing age at the index surgery. The absence of perioperative complications was targeted, we constructed the ROC curve and the cut-off value was 71.0 months. Age at the index surgery was therefore categorized into two groups: younger-age group (≤ 71.0 months) and advanced-age group (> 71.0 months). There was a higher complication rate for the younger-age group than versus the advanced-age group (61.5% vs 22.0%, p=.011). PJK as a major alignment-related complication, was more frequent in the younger-age group than in the advanced-age group (30.8% vs 4.9%, p=.025). But the advanced-age group exhibited significantly more severe deformities before GR surgery compared to the younger-age group.

CONCLUSIONS

This study shows that the elevated risk of complications observed in the younger-age group, which can be attributed to the younger age at the index surgery and the increased number of lengthening procedures during treatment. We suggest deferring the initiation of GR treatment until after the age of six years for EOS patients. We hope it will serve as a basis for GR technique in the treatment of EOS, with the ultimate goal of enhancing treatment outcomes for this challenging disorder.

Dual Growing Rods and the Apical Control Technique for Treating Congenital Early-Onset Scoliosis: Lessons Learned

BACKGROUND

Congenital early-onset scoliosis (CEOS) is characterized by a spectrum of vertebral anomalies, including formation failures and segmentation failures at the apex segment, which makes CEOS different from other etiologies of early-onset scoliosis. To date, studies on patients who have graduated from CEOS treatment using traditional dual growing rods (TDGR) have been scarce, and the preliminary results of TDGR with or without the apical control technique (ACT) have varied. We therefore compared the final outcomes of patients with CEOS who graduated from TDGR with or without the ACT.

METHODS

A retrospective study of patients with CEOS who had graduated from TDGR treatment performed from 2007 to 2020 was conducted. Graduation included final fusion or observation after reaching skeletal maturity. Patients were divided into the ACT-TDGR group (apical vertebrectomy and/or hemivertebrectomy with short fusion and TDGR) and the TDGR-only group. Demographic characteristics, radiographic data, patient-reported clinical outcomes, pulmonary function, and complications were analyzed.

RESULTS

A total of 41 patients with CEOS were enrolled: 13 in the ACT-TDGR group and 28 in the TDGR-only group. The lengthening intervals were longer in the ACT-TDGR group (mean [and standard deviation], 1.26 ± 0.66 years) than in the TDGR-only group (0.80 ± 0.27 years). The preoperative main curve was larger in the ACT-TDGR group (80.53° ± 19.50°) than in the TDGR-only group (64.11° ± 17.50°). The residual curve was comparable between groups (26.31° ± 12.82° in the ACT-TDGR group compared with 27.76° ± 15.0° in the TDGR group) at the latest follow-up. The changes in apical vertebral rotation and thoracic rotation were significantly larger in the ACT-TDGR group. Patients had comparable T1-12 and T1-S1 heights, pulmonary function, and 22-item Scoliosis Research Society (SRS-22) scores at the latest follow-up. The mean number of mechanical-related complications per patient was lower in the ACT-TDGR group (0.77 ± 0.73) than in the TDGR-only group (1.54 ± 1.43). Seventeen patients underwent final fusion.

CONCLUSIONS

In this small-scale study, we observed that both ACT-TDGR and TDGR-only could correct the deformity while allowing for spinal growth in patients with CEOS. ACT-TDGR yielded better correction in severe cases and did not have a deleterious effect on spinal height. A large number of cases will be needed to validate the clinical value of the ACT.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Traditional Dual Growing Rods With 2 Different Apical Control Techniques in the Treatment of Early-Onset Scoliosis

OBJECTIVE

Based on traditional dual growing rods (TDGR), apical control techniques (ACTs) were introduced as adjuvant procedures to improve deformity correction at the apex segment in the treatment of early-onset scoliosis (EOS). We aimed to explore whether TDGR+ ACTs have different indications, attain more deformity correction, have negative effects on spinal growth, and have different complications.

METHODS

Between 2004 and 2019, a retrospective study of EOS patients treated with TDGR with or without ACTs was conducted and divided into 3 groups: TDGR group; hybrid technique (HT) group: Vertebrectomy/hemivertebrectomy with short fusion and TDGR; ACPS group: apical convex control pedicle screws (ACPS) and TDGR. Demographic, radiographic parameters, clinical outcomes, complications, and revisions were analyzed and compared.

RESULTS

Seventy-eight EOS patients were enrolled. The preoperative main curve was the largest in the HT group. ACPS group had the smallest residual curve (19° ± 8.9°) and apical vertebral translation (12.0 ± 9.0 mm) at the latest follow-up, followed by the HT group (30° ± 17.4°, 22.1 ± 13.4 mm) and TDGR group (30° ± 13.2°, 32.8 ± 17.1 mm). ACPS group had the largest T1-12 height and T1-S1 height after index surgery. Complications and revisions in the ACTs groups was lower than the TDGR group. Scoliosis Research Society-22 self-image questionnaire was superior in the ACPS group.

CONCLUSION

According to our intermediate results, TDGR+ACTs could improve correction ability of apex deformity. ACTs had little deleterious effects on spinal height during the lengthening procedures, with a lower complication rate than TDGR. TDGR+ACTs might be a supplemental option for suitable EOS patients.

Early-onset scoliosis: a narrative review

Early-onset scoliosis (EOS) is defined as any spinal deformity that is present before 10 years old, regardless of etiology.

Deformity must be evaluated based on the intercorrelation between the lungs, spine, and thorax.

Curvatures of early-onset have increased risk of progression, cardiorespiratory problems, and increased morbidity and mortality.

Progression of the deformity may produce thoracic insufficiency syndrome, where a distorted thorax is unable to support normal respiratory function or lung growth.

Management and treatment of EOS should pursue a holistic approach in which the psychological impact and quality of life of the patient are also taken into consideration.

Growth-friendly surgical techniques have not met the initial expectations of correcting scoliotic deformity, promoting thoracic growth, and improving pulmonary function.

Failure of Posterior Lower Lumbar/Lumbosacral Hemi-Vertebra Resection: An Analysis of Reasons and Revision Strategies

OBJECTIVE

To investigate the causes of failed primary surgery and the revision strategies for congenital scoliosis (CS) patients with lower lumbar/lumbosacral (LL/LS) hemi-vertebra (HV).

METHODS

Fifteen CS patients with LL/LS HV (seven females and eight males) with a mean age of 20.4 ± 10.4 years undergoing revision surgery in our center were retrospectively reviewed. The radiographic parameters including Cobb angle, distance between C₇ plumb line and center sacral vertical line (C₇ PL-CSVL), thoracic kyphosis (TK), lumbar lordosis (LL) and sagittal vertical axis (SVA) were assessed at pre-revision, post-revision and the last follow-up. The causes of failure in primary operation, and radiographic and clinical outcomes of revision procedures were analyzed.

RESULTS

The revision rate of patients undergoing LL/LS HV resection and correction surgery was 11.4%. The average time interval between primary surgery and revision surgery was 18.2 ± 10.6 months. The operation duration and estimated blood loss of revision surgery were 194 ± 56 min and 326 ± 74 ml, respectively. Reasons for failed primary operations were as follows: internal fixation fracture in 10 cases, curve progression in two cases, implant loose in two cases and post-operative coronal imbalance in one case. The post-revision Cobb angle was significantly improved from 29.9° ± 8.3° to 18.7° ± 6.7° (P < 0.001) with a correction rate of 37.5% ± 12.6%. At the final follow-up, the average Cobb angle was 18.9° ± 6.2° and the correction was well maintained (P = 0.788). The C₇ PL-CSVL at pre-revision, post-revision and at last follow-up were 23.2 ± 9.3 mm, 14.8 ± 4.8 mm and 14.9 ± 5.4 mm, respectively. Significant improvements (P = 0.004) were observed after revision surgery and there was no evident loss of correction (P = 0.703). There was no significant difference in TK, LL and SVA before and after revision surgery (all P > 0.05). At the last follow-up, no significant correction loss of above coronal and sagittal parameters were observed (all P > 0.05). The revision methods were individualized according to the primary surgical procedures and the reasons for revision. The recommended revision strategies include incision of pseudarthrosis with sufficient bone graft, fixation of satellite rods, thorough residual HV excision, prolonged fusion to S₂ and transforaminal lumbar interbody fusion at lumbosacral region. Solid bony fusion and no implant-related complication were detected during the follow-up.

CONCLUSIONS

The causes of revision surgery for patients with congenital scoliosis (CS) due to lumbosacral HV were verified and implant failure with pseudarthrosis was the main reason for failed primary operation.

Comparison of the Effects of Magnetically Controlled Growing Rod and Tradiotinal Growing Rod Techniques on the Sagittal Plane in the Treatment of Early-Onset Scoliosis

Objective

Comparing the effects of magnetically controlled growing rod (MCGR) and traditional growing rod (TGR) techniques on the sagittal plane in the treatment of early-onset scoliosis (EOS).

Methods

Twelve patients were operated using dual MCGR technique in one center, while 15 patients were operated using dual TGR technique for EOS in another center. Patients’ demographic characteristics, complications and radiological measurements such as cobb angle, thoracic kyphosis, lumbar lordosis, T1–S1 range (mm), proximal junctional angle, distal junctional angle, sagittal balance, coronal balance, pelvic incidence, sacral slope and pelvic tilt were assessed and compared in preoperative, postoperative and last follow-up period.

Results

Age and sex distributions were similar in both groups. The mean number of lengthening in the MCGR group was 12 (8–15) and 4.8 (3–7) in the TGR group. Two techniques were shown to be effective in controlling the curvature and in the increase of T1–S1 distance. In TGR group, four patients had rod fractures, six patients had screw pull-out and four patients had an infection, whereas three patients had screw pull-out and one patient had infection complications in the MCGR group.

Conclusion

There was no significant difference between the two groups in terms of cobb angle, coronal and sagittal balance and sagittal pelvic parameters. MCGR can cause hypokyphosis and proximal junctional kyphosis in a minimum 2-year follow-up period. The implant-related complications were less in the MCGR group. However, larger case groups and longer follow-up periods are required for the better understanding of the superiority of one method on other in terms of complications.

Is Magnetically Controlled Growing Rod the Game Changer in Early-onset Scoliosis? A Preliminary Report

BACKGROUND

Magnetically controlled growing rod (MCGR) concept was introduced with the premise of minimizing the repetitive lengthening surgeries, which is default in traditional growing rod (TGR) treatment for early-onset scoliosis (EOS). Despite good radiographic outcomes, previous studies did not compare identical patient groups in terms of etiology and deformity characteristics; therefore, a true comparison of the MCGR and TGR is essential. This study was designed to compare 2 techniques in terms of clinical, radiologic, and health-related quality of life (HRQoL) outcomes.

METHODS

Patients with long sweeping congenital curves who underwent convex growth arrest and concave distraction (with TGR or MCGR) were retrospectively reviewed. Instrumented all-posterior convex growth arrest and concave distraction with growing rod technique were performed. Demographic parameters, follow-up time, number of lengthening procedures, radiographic parameters, number of unplanned surgeries, and complications were recorded. The Early-Onset Scoliosis Questionnaire (EOSQ-24) was used to evaluate HRQoL outcomes.

RESULTS

A total of 20 patients were included (10 MCGR, 10 TGR). No significant differences were found with regard to average age, follow-up time, radiographic parameters, or complications. Overall surgery per patient including index surgery, and planned and unplanned procedures were significantly lower in the MCGR group (8.8 vs. 1.3) (P=0.01). No patient in either group had graduated from growing rod treatment. HRQoL analysis revealed no significant difference between the 2 groups in any specific domain or in the overall score of the EOSQ-24.

CONCLUSIONS

Although equally effective in controlling the deformity and superior in reducing the number of surgeries with comparable complication rates, MCGR does not offer any significant improvement in HRQoL outcomes or the overall complication rate. Despite the obvious advantages, according to this preliminary report, the current technology and technique of MCGR may not be sufficient to be the long-awaited "game changer" in the treatment of EOS.

The Results of Hemivertebra Resection by the Posterior Approach in Children with a Mean Follow-Up of Five Years

AIM

To evaluate the radiologic and clinical results of patients who underwent deformity correction and stabilization for congenital spinal deformities using pedicle screws after hemivertebra resection.

MATERIAL AND METHOD

Nine patients, mean age 9.2, who underwent posterior hemivertebrectomy and transpedicular fixation for congenital spinal deformity and had longer than five years of follow-up were evaluated retrospectively. The hemivertebrae were located in the thoracic region in 4 patients and thoracolumbar transition region in 5 patients. The patients were evaluated radiologically and clinically in the postoperative period.

RESULTS

Mean length of follow-up was 64.2 months. The mean operating time was 292 minutes. The mean blood loss was 236 mL. The average hospitalization time was 7 days. The amount of correction on the coronal planes was measured as 31%. The mean segmental kyphosis angle was 45.7 degrees preoperatively and it was measured 2.7 degrees in the follow-up period. There were no statistically significant differences between the early postoperative period and final follow-up X-rays with respect to coronal and sagittal plane deformities.

CONCLUSION

The ability to obtain a sufficient and balanced correction in the cases accompanied by long compensator curvatures that have a structural character in hemivertebra may require longer fusion levels.

One-stage posterior excision of lumbosacral hemivertebrae: Retrospective study of case series and literature review

Lumbosacral hemivertebrae causes unique problems as early trunk decompensation and long compensatory curve above. There are only a few reports on it. This case series is a fair supplement in the literatures.To evaluate the clinical and radiological outcomes of lumbosacral hemivertebrae resection through 1-stage posterior approach.Between 2005 and 2014, a consecutive series of congenital scoliosis due to lumbosacral hemivertebrae underwent hemivertebrae excision through 1-stage posterior only approach. Demographic, operative, radiological, and quality of life data were reviewed.The mean lumbosacral curve was 29 ± 7° preoperatively, 10 ± 3° postoperatively, and 13 ± 5° at the final follow up. The final correction rate was 55 ± 9%. The gravity trunk shift was 11 ± 3 mm preoperatively, 37 ± 12 mm (range, 6-49 mm) postoperatively, 14 ± 9 mm at final follow up. The rib cage shift was 36 ± 12 mm preoperatively, 19 ± 5 mm postoperatively, and 15 ± 4 mm at the final follow up. The mean blood loss was 527 ± 125 mL and the mean surgery time was 336 ± 98 minutes. The mean follow up period was 41 ± 6 months. Two patients underwent transient neurological complications, 2 had wound bad healing, and 1 got wound infection. No pseudoarthrosis and instrumentation failure was observed.One-stage posterior hemivertebrae excision could gain reasonable outcome. It is crucial to completely resect the hemivertebrae and the Y-shaped disc. Bending the rod to appropriate lordosis is helpful to close the convex side. Early surgical intervene is a preferred choice to restore the trunk balance and avoid extensive fusion. The neurological complication rate is high. Convex radiculopathy is often caused by retraction, it could recover at follow up.

Current Concepts - Congenital Scoliosis

Background:

Congenital scoliosis is one of the ‘difficult to treat’ scenarios which a spine surgeon has to face. Multiple factors including the age of child at presentation, no definite pattern of deformity and associated anomalies hinder the execution of the ideal treatment plan. All patients of congenital scoliosis need to be investigated in detail. X rays and MRI of spine is usually ordered first. Screening investigations to rule out VACTERL (Visceral, Anorectal, Cardiac, Tracheo-esophageal fistula, Renal and Lung) abnormalities are required. They are cardiac echocardiography and ultrasonography of abdomen and pelvis. CT scan is required to understand the complex deformity and is helpful in surgical planning.

Methods:

A comprehensive medical literature review was done to understand the current surgical and non surgical treatment options available. An attempt was made to specifically study limitations and advantages of each procedure.

Results:

The treatment of congenital scoliosis differs with respect to the age of presentation. In adults with curves more than 50 degrees or spinal imbalance the preferred treatment is osteotomy and correction. In children the goals are different and treatment strategy has to be varied according to the age of patient. A single or two level hemivertebra can easily be treated with hemivertebra excision and short segment fusion. However, more than 3 levels or multiple fused ribs and chest wall abnormalities require a guided growth procedure to prevent thoracic insufficiency syndrome. The goal of management in childhood is to allow guided spine growth till the child reaches 10 - 12 years of age, when a definitive fusion can be done. The current research needs to be directed more at the prevention and understanding the etiology of the disease. Till that time, diagnosing the disease early and treating it before the sequels set in, is of paramount importance.

Conclusion:

The primary aim of treatment of congenital scoliosis is to allow the expansion of chest and abdominal cavity, while keeping the deformity under control. Various methods can be categorized into definitive (hemivertebrectomy) or preventive (guided growth). Casting, Growth rods, Convex Epiphysiodesis are all guided growth measures. The guided growth procedure either ‘corrects the deformity’ or will have to be converted to a final fusion surgery once the child completes the spinal growth which is preferably done around 10 - 12 years of age. Future directions should aim at genetic counselling and early detection.

Convex Instrumented Hemiepiphysiodesis With Concave Distraction: A Treatment Option for Long Sweeping Congenital Curves

BACKGROUND

Convex hemiepiphysiodesis has been reported to have mixed results in the treatment of congenital spine deformities. Multiple modifications of the original technique were suggested to improve the results. The purpose of this study is to report the results and complications of an instrumented convex growth arrest procedure modified with concave distraction.

METHODS

The records of 11 patients with long sweeping congenital curves (involving multiple anomalous vertebrae) who underwent convex instrumented hemiepiphysiodesis with concave distraction were evaluated. Mean age at index operation was 58 months (range, 29 to 101 mo). Lengthening of the concave distraction rod was done every 6 months. The magnitude of coronal/sagittal deformity and T1-T12 height were measured on the preoperative, postoperative, and latest follow-up radiographs. Average follow-up was 44.9 months (range, 24 to 89 mo).

RESULTS

In the coronal plane, the convex hemiepiphysiodesis segment was corrected from an average of 60.5 to 40.4 degrees postoperatively and further improved to 35.5 degrees at the latest follow-up. The distracted segment was corrected from 33.4 to 15.2 degrees postoperatively and to 12.7 degrees at the latest follow-up. Sagittal plane alignment was minimally affected. The average T1-T12 height was 157.1 mm in the early postoperative period and 181.1 mm at last follow-up. During follow-up, we identified partial pull-out of screws on the distraction side in 5 of the 11 patients and rod breakages in 3 patients. These were revised during planned lengthenings. There were no unplanned surgeries, deep wound infections, nor neurological complications.

CONCLUSIONS

Convex instrumented hemiepiphysiodesis with concave distraction resulted in good curve correction while maintaining the growth of thorax. The correction of the anomalous segment improved over time, proving the effectiveness of the hemiepiphysiodesis. Addition of a concave distraction construct appears to enhance spinal growth, thereby augmenting the hemiepiphysiodesis effect.

The effect of serial growing rod lengthening on the sagittal profile and pelvic parameters in early-onset scoliosis

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To report the effect of repeated growing rod (GR) lengthenings on the sagittal and pelvic profile in patients with early-onset scoliosis.

SUMMARY OF BACKGROUND DATA

Posterior distraction-based GRs have gained popularity as a technique for the surgical management of early-onset scoliosis. However, there are no published studies on the effect of serial GR lengthenings on sagittal balance, thoracic kyphosis (TK), lumbar lordosis (LL), and pelvic parameters.

METHODS

We retrospectively reviewed data from a multicenter early-onset scoliosis database. Forty-three patients who were able to walk with minimum 2-year follow-up who underwent single- or dual-GR surgery were included for review. Mean number of lengthenings was 6.4 (range, 3-16). Mean preoperative age was 5.6 years (standard deviation, 2.4 yr), and mean follow-up was 3.5 years. Maximum TK, LL, and sagittal balance were assessed preoperatively, after index surgery, and at the latest follow-up.

RESULTS

There was a significant decrease both in TK and LL after index surgery, which then increased during the lengthening period. There was a significant increase in both proximal junctional kyphosis and distal junctional angle. Pelvic parameters (pelvic tilt, pelvic incidence, sacral slope) were unchanged during the treatment period. Significant improvement was observed in sagittal balance. There was a correlation between the change in TK and change in LL.

CONCLUSION

TK decreased after index surgery and increased between the index surgery and the latest follow-up, which was accompanied by an increase in LL. All-screw proximal constructs had mean 9° more proximal junctional kyphosis than all-hook proximal constructs. An increase in proximal junctional kyphosis and distal junctional angle was found during the treatment period. Although there was an independent effect of number of lengthenings on TK, there was no significant detrimental effect on other sagittal spinopelvic parameters. GRs had a positive effect on sagittal vertical axis, which returned patients to a more neutral alignment through the course of treatment.

LEVEL OF EVIDENCE

4.