A brief history and review of modern casting techniques in early onset scoliosis

Institutional Variability in Anesthesia Time for Mehta Casting in Early-Onset Scoliosis (EOS)

PURPOSE

Mehta casting is a potentially curative intervention for early-onset scoliosis (EOS) that typically requires multiple anesthetics. The Food and Drug Administration (FDA) reported that >3 hours of anesthesia under the age of 3 years old may alter brain development; however, no standard exists for the duration of anesthesia during casting. The purpose of this study is to quantify the variability in anesthesia during Mehta casting. We hypothesize that significant institutional variability exists and may be attributed to modifiable factors.

METHODS

An EOS registry was used to identify patients who underwent at least one Mehta casting procedure. Anesthesia exposure was quantified, and site variability was assessed by patient characteristics, cast placement, procedure type, and equipment used.

RESULTS

Our cohort consisted of 208 patients from 5 institutions (age 2.6±1.4 y). There were 1097 Mehta casting procedures, with 5.4±3.6 castings per patient. Of these patients, 106 (51%) were female, with an average age of 2.11±1.29 years old at the time casting was initiated. Patient etiologies included 154 idiopathic (74.0%), 22 syndromic (10.6%), 18 congenital (8.7%), 11 neuromuscular (5.3%), and 3 unknown (1.4%). Anesthesia time was 69±31 minutes and varied significantly between sites (59±14 to 117±46 min; P <0.001). Cumulative anesthesia time for patients under 3 years was 320±197 minutes with 120/161 (74.5%) patients exceeding 3 hours. Anesthesia time was lower after the FDA warning in 2016 compared with pre-2016 (71±30 vs. 66±32, P =0.008).

CONCLUSIONS

Patients undergoing Mehta casting are at significant risk of exceeding 3 hours of anesthesia, which the FDA has stated may be harmful for children <3 years. Significant site variability indicates that standardization protocols should be developed to encourage best practices and minimize anesthetic times.

LEVEL OF EVIDENCE

Prognostic Level II.

The role and mechanism of inflammatory response to growing rod implantation in early onset scoliosis

Growing rod implantation, a surgery treatment for EOS (early onset scoliosis), may cause a kind of chronic inflammation called metalosis and all other implant-related complications because of the metal debris released by the implants as a result of fraction and corrosion. There is no complete explanation of immunologic mechanisms of metalosis up to now. This review demonstrates the researches on metalosis from the clinical issues down to basic immunologic mechanisms. Adverse reactions of metal implants are mainly the formation of NLRP3 (nod-like receptor protein 3) inflammasome, primed by TLR4 (toll-like receptor protein 4), activated by phagocytosis and often accompanied by type Ⅳ hypersensitive reaction. Recent studies found that TNF-α (tumor necrosis factor α) also participates in priming, and activation of inflammasome requires disturbance of lysosome and release of cathepsin B. Ca-074Me and MCC950 are therapeutic interventions worth exploring in aseptic loosening of orthopedic implants.

Minimum 5-Year Results of Elongation Derotation Flexion Casting for Early Onset Scoliosis: The Story Is Not Over Until Skeletal Maturity

BACKGROUND

Early conservative treatment for patients with idiopathic infantile scoliosis (IIS) with elongation derotation flexion (EDF) casting and subsequent serial bracing has become widely utilized. However, the long-term outcomes of patients treated with EDF casting are limited.

METHODS

We performed a retrospective chart review of all patients who had undergone serial elongation derotation flexion casting and subsequent bracing for scoliosis presenting at a single large tertiary center. All patients were followed for a minimum of 5 years or until surgical intervention.

RESULTS

Our study included 21 patients diagnosed with IIS and treated with EDF casting. At a mean 7-year follow-up, 13 of the 21 patients were considered successfully treated with a mean final major coronal curvature of 9 degrees compared to a pretreatment coronal curve of 36 degrees. These patients, on average, began casting at 1.3 years old and spent 1 year in a cast. Patients that did not have substantial improvement began casting at mean 4 years old and remained in a cast for 0.8 years. Three patients initially had substantial improvement with the correction to <20 degrees at a mean age of 7; however, their curves worsened in adolescence with poor brace compliance. All 3 patients will require surgical intervention. Of the patients not successfully treated with casting, 7 required surgery at a mean 8.2 years of age, 4.3 years after initiation of casting. A significant predictor of treatment failure was older age of cast initiation (P<0.001).

CONCLUSIONS

EDF casting can be an effective cure for IIS patients if initiated at a young age with 15 of 21 patients successfully treated (76%). However, 3 patients had a recurrence in adolescence resulting in an overall success rate of only 62%. Casting should be initiated early to maximize the likelihood of treatment success and periodic monitoring should be continued through skeletal maturity as recurrence during adolescence can occur.

Does Transitioning to a Brace Improve HRQoL After Casting for Early Onset Scoliosis?

BACKGROUND

Serial casting is favored for the initial treatment of early onset scoliosis (EOS), but there is concern about significant morbidity and caregiver burden. Studies have examined the utility of bracing as an alternative to casting, but little is known about differences in health-related quality of life (HRQoL) between treatments. We hypothesized that patients with a diagnosis of idiopathic EOS experience an improvement in HRQoL when transitioning from serial casting to bracing as measured by the 24-Item Early Onset Scoliosis Questionnaire (EOSQ).

METHODS

Subjects with idiopathic EOS were retrospectively identified from a multicenter database. EOSQ scores were compared before treatment, after index casting, after transition out of cast to brace, and at the most recent follow-up. Available major curve magnitudes were also compared during these time points. Data were compared using repeated-measures ANOVA with post hoc Bonferroni correction.

RESULTS

Sixty-six subjects met the inclusion criteria. Thirty-seven (56%) subjects were male and the average age at the time of index treatment was 1.9 (0.37-6.4) years. The average follow-up was 3.2 (0.90-6.8) years. In 57 subjects, the major curve magnitude improved from a mean of 33 (CI 28-37) degrees before treatment initiation to 27 (CI 23-30) degrees after casting and to 24 (CI 20-29) degrees at the most recent follow-up. The HRQoL subdomain showed a significant decrease in HRQoL during casting treatment 75.7 (CI 72.9-78.5) from pre-index treatment 84.9 (CI 81.4-88.5), during brace treatment 84.8 (CI 81.8-88.0) and at most recent follow-up 87.0 (CI 83.6-90.3) ( P <0.001). The parental impact subdomain improved from the beginning to the end of treatment (77.7 to 87.7, P =0.001) (n=64). Satisfaction improved from casting to bracing (73.4 to 86.7, P <0.001) (n=63) and to the most recent follow-up (73.4 to 87.9, P <0.001).

CONCLUSION

Patients treated with casting for EOS experience reversible declines in HRQoL. After patients transition from casting to bracing, EOSQ scores recover to pretreatment baseline levels and are maintained at follow-up. This information must be balanced with the effectiveness of treatment for EOS with either method and customized for each patient.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Innovative technique for early-onset scoliosis casting using Jackson table

PURPOSE

Early-onset scoliosis (EOS) can have harmful effects on pulmonary function. Serial elongation, derotation, and flexion (EDF) casting can cure EOS or delay surgical intervention. Most described casting techniques call for specialized tables, which are not available at many institutions. We describe an innovative technique for EDF casting utilizing a modified Jackson table (MJ) and compare results to a Risser frame (RF).

METHODS

All patients who underwent EDF casting at our institution between January 2015 and January 2019 were identified and retrospectively reviewed. Patients were stratified by type of table used and clinical and radiographic outcomes were compared. Standard descriptive statistics were calculated.

RESULTS

We identified 25 patients who underwent 77 casting events, 11 on an MJ table and 14 on a RF. Mean follow-up was 32 months (range 11-61 months). 28% of patients had idiopathic scoliosis. There was no significant difference in age at initiation of casting (P = 0.3), initial Cobb angle (equivalence, P = 0.009), or rate of idiopathic scoliosis between the MJ and RF groups. There was no significant difference in initial coronal Cobb angle percent correction (equivalence, P = 0.045) or percent correction at 1-year follow-up (equivalence, P = 0.010) between the two groups. There was no difference in cast related complications. There was a significant difference in surgical time, with the MJ group 11 min shorter than the RF (P = 0.005).

CONCLUSION

The MJ table is a safe and effective alternative for applying EDF casts under traction without the need for a specialized table.

LEVEL OF EVIDENCE

III.

Outcomes for patients with infantile idiopathic scoliosis by casting table type

PURPOSE

Serial casting is an effective treatment for infantile idiopathic scoliosis. The most common casting table types are Mehta, Risser, and spica tables. We compared major curve correction between patients with infantile idiopathic scoliosis treated using pediatric hip spica tables versus Risser or Mehta tables.

METHODS

In this multicenter retrospective study, we included 52 children younger than 3 years (mean ± standard deviation age, 1.6 ± 0.68 years) treated with ≥2 consecutive casts for infantile idiopathic scoliosis between September 2011 and July 2018. We compared major curve angle (measured using the Cobb method) before and after treatment and improvement in curve angle between the spica tables group (n = 12) and the Risser or Mehta tables group (n = 40). The primary outcome was the difference in percentage correction of the major curve according to radiographs taken after first casting and at final follow-up.

RESULTS

The mean major curve was 47° ± 18° before casting. A median of six casts (range: 2-14) were applied. Mean follow-up after treatment initiation was 22 months (range: 7-86 months). At baseline, the major curve was significantly larger in the spica tables group (58°) than in the Risser or Mehta tables group (43°) (p = 0.01). We found no differences in the percentage curve correction in the spica tables group versus Risser or Mehta tables group after first casting or at final follow-up.

CONCLUSION

Serial casting was associated with substantial major curve correction in patients with infantile idiopathic scoliosis. Curve correction did not differ between patients treated with a spica table versus a Risser or Mehta table.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Elongation-Derotation-Flexion Casting Treatment of Early-Onset Progressive Scoliosis in Skeletal Dysplasia

BACKGROUND

Early-onset scoliosis in children with skeletal dysplasia is progressive, contributing to cardiopulmonary restrictive disease. Serial elongation-derotation-flexion (EDF) casting, used in other etiologies of scoliosis to delay curve progression, may be beneficial in maximizing spine growth. Our hypothesis is serial EDF casting can be safely used as a temporary alternative to surgery, delaying progression and preserving growth, to treat scoliosis in skeletal dysplasia.

METHODS

All patients with skeletal dysplasia treated at a single institution with serial EDF casting for scoliosis were reviewed retrospectively. Radiographic parameters: Cobb angle of major and minor curves, curve location, thoracic height, thoracolumbar height, space available for lung, and rib vertebra angle difference were measured before casting (C1), in first casting (C2), in last casting (C3), and out of last casting (C4). Peak inspiratory pressure (PIP) values were monitored and recorded during the casting application.

RESULTS

Eleven patients met the inclusion criteria (mean 9.7 castings). The mean duration of EDF serial casting was 35 months. The mean major Cobb angles were 54 degrees° (C1), 30 degrees (C2), 37 degrees (C3), and 49 degrees (C4) with no statistically significant differences. The mean minor Cobb angles were 35 degrees (C1), 25 degrees (C2), 33 degrees (C3), and 51 degrees (C4) with no statistically significant differences. The mean thoracic heights were 130 mm (C1), 155 mm (C2), 173 mm (C3), and 160 mm (C4). The 19-mm mean difference between C2 and C3 represents spinal growth. The PIP-1, PIP-2, and PIP-3 mean values were 15, 27, and 18 cmH2O, respectively. Changes in PIP-1 and PIP-2 and PIP-2 and PIP-3 were statistically significant.

CONCLUSION

Serial EDF casting can delay surgical scoliosis correction in children younger than 7 years with a diagnosis of skeletal dysplasia. Our study showed that serial casting controls progression of the major curve and allows longitudinal growth of the spine with possible expansion of lung volume for nearly 3 years. During cast application, PIP increased with molding and traction, and improved until windowing and trimming of the cast.

LEVEL OF EVIDENCE

Level IV-retrospective study.

Clinical Results of Corrective Cast and Brace Treatment for Early-onset Scoliosis: The Effectiveness of Long-term Cast Treatment That Extends into Children's Schooldays

BACKGROUND

Cast and brace treatment is a conservative treatment for early-onset scoliosis (EOS). We analyzed the clinical results of this treatment when extended into patients' schooldays.

METHODS

Twenty-two children with EOS underwent alternatively repetitive cast and brace treatment (ARCBT). Cast was applied under general anesthesia and remained for some weeks, and the brace was continuously worn, which was repeatedly applied when scoliosis progressed. The change in the major curve angle, requirement for surgical intervention, and complications of ARCBT were analyzed.

RESULTS

Six patients had idiopathic scoliosis (IS), 9 had syndromic scoliosis (SS), and 7 had neuromuscular scoliosis. Cast treatment started at 4.9±2.1 years of age, and the patients were followed up for 8.3 years. The average total number of cast applications was 5.5 per patient. The mean major scoliosis angle was 45.4±12.5 degrees at the first visit; this was corrected to 26.5±8.7 degrees at the first cast application and progressed to 75.4±22.1 degrees at the final visit. Nine patients whose scoliosis progressed finally underwent surgery. The mean age at surgery was 11.0 years (range, 8.8 to 13.1 y), and the mean period from first cast application to surgery was 6.1 years (range, 5.0 to 8.9 y). Four patients' IS rapidly progressed after 9 years of age, and all of them underwent final fusion surgery with a correction rate of 56.9%. Among patients with SS, 1 final fusion, and 2 growth-friendly surgeries were performed at a mean age of 9.2 years; the correction rate was 21.5%. Among patients with neuromuscular scoliosis, 2 final fusion surgeries were performed at a mean age of 11.3 years; the correction rate was 30.7%. The cast-related complication rate was 5.0%, and most complications were skin problems.

CONCLUSIONS

Long-term ARCBT extended into schooldays might be effective for IS. This should be considered as a time-saving treatment option for EOS.

LEVEL OF EVIDENCE

Level IV-case series.

EDF Casting for Early Onset Scoliosis: What We Learned From 175 Castings

STUDY DESIGN

IRB approved prospective case series.

OBJECTIVES

This study attempts to determine the effects of elongation, derotation, and flexion (EDF) casting on pulmonary function. We also attempted to define prognostic factors and determine the ideal amount of traction for casting in patients with early onset scoliosis (EOS).

SUMMARY OF BACKGROUND DATA

No literature on effects of serial casting on pulmonary parameters in EOS, or on the ideal amount of traction to be used for EOS Casting.

METHODS

Fifty consecutive children with EOS treated by the senior author using EDF casting were studied prospectively. Traction and lung function parameters (compliance, tidal volume, peak inspiratory pressure, and resistance) were measured at different periods during cast application. Etiology, age, weight, Cobb angles, and RVAD were monitored.

RESULTS

All lung function parameters decline during cast application but rise to near baseline levels at the time of next cast application. Near full curve correction was achieved in every patient with (A) idiopathic scoliosis who (B) presented prior to 20 months of age with (C) a moderate main curve at presentation (<45°) and in those (D) without a phase II rib-vertebral relationship at presentation. The best response to casting was seen with 1 pound traction per pound body weight during application.

CONCLUSION

EDF casting can delay progression or improve curves in patients with larger curves, nonidiopathic scoliosis, and older patients. Idiopathic patients, moderate curve sizes, and younger patients had a better response to casting. Even though lung function declines during cast application, it returns to near baseline levels at the time of the next cast application, suggesting that EDF casting may not have any long-term effects on lung function, and also may protect pulmonary function in EOS from its natural history of progressive deterioration.Level of Evidence: 4.

Diverse approaches to scoliosis in young children

Management of scoliosis in young children needs a comprehensive approach because of its complexity. There are many debatable points; however, only serial casting, growing rods (including traditional and magnetically controlled) and anterior vertebral body tethering will be discussed in this article.Serial casting is a time-gaining method for postponing surgical interventions in early onset scoliosis, despite the fact that it has some adverse effects which should be considered and discussed with the family beforehand.Use of growing rods is a growth-friendly surgical technique for the treatment of early onset spine deformity which allows chest growth and lung development. Magnetically controlled growing rods are effective in selected cases although they sometimes have a high number of unplanned revisions.Anterior vertebral body tethering seems to be a promising novel technique for the treatment of idiopathic scoliosis in immature cases. It provides substantial correction and continuous curve control while maintaining mobility between spinal segments. However, long-term results, adverse effects and their prevention should be clarified by future studies. Cite this article: EFORT Open Rev 2020;5:753-762. DOI: 10.1302/2058-5241.5.190087.

Evolution of casting techniques in early-onset and congenital scoliosis

Casting is being utilized as a therapeutic strategy in some mild to moderate cases obviating surgical intervention for management of early-onset scoliosis (EOS). Bracing, another conservative modality, applies comparable correcting forces on chest wall and axial skeleton. But cast application carries additional advantage of sustained restorative force which bypasses issue of compliance seen with brace wear. There is no specific blanket treatment, conservative or surgical, for the early-onset spinal deformities. Serial cast application provides near total correction of less severe curves (less than 500 to 600) if treatment is initiated before age of 2 yrs. In this review article, we will assess the evolution of plaster cast application in management of EOS and also describe technique of EDF (Elongation- Derotation- Flexion) casting.

Early onset scoliosis and current treatment methods

OBJECTIVE

Provide an update of the management options for early onset scoliosis patients, including general assessment, conservative and surgical options.

METHODS

We included the updated information about the assessment and management options of Early Onset Scoliosis, taking into consideration the non-fusion methods, including the burden on the patient and their family.

RESULTS

With the heterogeneity of this population, it is difficult to get a consensus about a unified protocol for management. Accordingly, the surgeon dealing with these cases needs to be aware of the broad range of surgical and non-surgical methods when treating these patients.

CONCLUSION

The main aim of early onset scoliosis treatment is to gain a flexible spine associated with normal lung development and thoracic growth. Management needs to be individualized between the surgeon and patient in relation to the etiology and patient conditions.

Serial casting in early onset scoliosis: syndromic scoliosis is no contraindication

BACKGROUND

Serial casting is a treatment for early onset scoliosis (EOS) in young children to achieve curve correction before bracing or to postpone initial surgical treatment until the patient is older. Good results have been reported for patients with idiopathic early onset scoliosis (IS). However, there are few reports of results in non-idiopathic cases, and the benefits of non-surgical methods in the syndromic-associated early onset scoliosis subgroup are unknown.

METHODS

Retrospective single-institution study of patient charts and X-rays of all cases of sustained serial casting for EOS. Staged correction was obtained by applying three consecutive casts under general anaesthesia. These were changed every 4 weeks, followed by the implementation of a custom-made full-time Chêneau brace. Correction was measured by Cobb angle (CA) and rib-vertebra angle difference (RVAD) on whole spine anterior-posterior radiographs. Statistical analysis was performed via ANOVA.

RESULTS

The study group consisted of 6 patiens with IS and 10 with non-idiopathic scoliosis (NIS) - exclusively syndromic-associated. The mean age at onset of treatment was 35 months (±15). The mean follow up was 21 months (±15). In IS patients average CA/RVAD before treatment was 46°(±8)/20°(±12). In NIS patients average CA/RVAD before treatment was 55°(±15)/24°(±14). After application of the third cast, the CA/RVAD was reduced to 20°(±11)/11°(±10) in IS patients. Whereas in NIS patients average CA/RVAD after the thrid cast was 28°(±12)/18°(±13). At latest follow-up the CA/RVAD was 16°(±7)/9°(±8) in IS patients and 31°(±11)/17° (±15) in NIS patients.

CONCLUSION

Syndromic etiology is not a contraindication for serial casting in EOS. Our results show a curve correction, measured in CA, of 65% in IS patients and 44% in NIS patients. Significant reduction in the morphologic deformity, measured in RVAD, was achieved in the IS cohort, but not in the NIS cohort. In all cases surgical treatment could be delayed.