Radiographic Outcomes of Shilla Growth Guidance System and Traditional Growing Rods Through Definitive Treatment

A Novel growth guidance system for early onset scoliosis: a preliminary in vitro study

PURPOSE

The purpose of the study was to describe a novel growth guidance system, which can avoid metal debris and reduce the sliding friction forces, and test the durability and glidability of the system by in vitro test.

METHOD

Two major modifications were made to the traditional Shilla system, including the use of ultra-high molecular weight polyethylene (UHMWPE) gaskets to avoid direct contact between the screw and rod, and polishing the surface of the sliding part of the rod. We tested the durability of the system by a fatigue test, which the samples were test on the MTS system for a 10 million cycle of a constant displacement. Pre and post-testing involved weighing the UHMWPE gaskets and observing the wear conditions. The sliding ability were measured by a sliding displacement test. The maximum sliding displacement of the system was measured after a 300 cycles of dynamic compressive loads in a sinusoidal waveform.

RESULTS

After the fatigue test, all the UHMWPE gaskets samples showed some of the fretting on the edge of the inner sides, but its still isolated and avoided the friction between the screws and rods. There was no production of metallic fretting around the sliding screws and rods. The average wear mass of the UHMWPE gaskets was 0.002 ± 0.001 g, less than 1.7% of the original mass. In the sliding test, the novel growth guidance system demonstrated the best sliding ability, with an average maximum sliding distance(AMSD) of 35.75 ± 5.73 mm, significantly better than the group of the traditional Shilla technique(AMSD 3.65 ± 0.46 mm, P < 0.0001).

CONCLUSION

In conclusion, we modified the Shilla technique and designed a novel growth guidance system by changing the friction interface of sliding screw and rod, which may significantly reduce the metallic debris and promote spine growth. The fatigue test and sliding dislocation test demonstrated the better durability and glidability of the system. An in vivo animal experiment should be performed to further verify the system.

Changes in sagittal balance and pre-existing junctional angle influence development of proximal junctional kyphosis in growth guidance systems for early-onset scoliosis

PURPOSE

Proximal junctional kyphosis (PJK) has been reported to occur at a rate of about 30% in traditional growing rods (GR) and magnetically controlled growing rods (MCGR). Growth guidance systems (GGS) have non-rigid, gliding fixation along rods, which may mitigate PJK. There have been no studies done in shilla around PJK, hence this study aimed to assess the occurrence, risk factors, and timeline of PJK.

METHODS

A prospective, multicenter database was queried for EOS patients who underwent surgery utilizing GGS.

INCLUSION CRITERIA

< 10 years at index surgery and > 2 year follow-up.

RESULTS

Sixty-five patients (thirty-six female) met inclusion criteria. Mean age at index surgery was 6.2 y/o (2-9); mean follow-up was 66 m. Most common etiologies were syndromic (n = 23). Mean thoracic kyphosis at pre-op was 41.8°, post-op was 35.5°, and final was 42.2°. Mean PJA at pre-op was 6.15°, post-op 1 was 4.2°, and final was 15.6°. Incidence of PJK at post-op was 35% and final was 43%. Pre-op sagittal balance and change in sagittal balance from pre-op to post-op were associated with post-op PJK (p = 0.05, 0.02). Change in spinal height from pre-op to post-op was associated with PJK at final (p = 0.04). Interestingly, increased PJA at pre-op was significantly associated with decreased PJK at post-op and final (p = 0.01, 0.03).

CONCLUSION

PJK was identified in 43% of patients post-operatively after GGS for EOS. Pre-op PJA was negatively correlated with an increased incidence of PJK. Changes in sagittal balance, in either direction, was the strongest predictor for development of PJK post-operatively.

Implant-Related Complications Do Not Interfere with Corrections with the Shilla Technique in Early Onset Scoliosis: Preliminary Results

Growth-preservation techniques are utilized in early onset scoliosis (EOS) cases requiring surgical intervention. The Shilla technique corrects the deformity by reducing additional surgeries with its growth-guidance effect. As with other techniques, various problems can be encountered following the administration of the Shilla technique. The aim of this study was to examine the effect of complications encountered with the Shilla treatment on correction and growth. Sixteen patients with a follow-up period of at least one year after receiving Shilla growth guidance for EOS were included in this retrospective study. No complications occurred, and no unplanned surgery was required in 50% of the cases. Of the remaining eight patients with postoperative implant-related complications (50%), six (37.5%) required unplanned surgery; this consequently caused implant failure in the proximal region in five cases (31.25%) and deep tissue infection around the implant in one case (6.25%). Deformity correction, spine length, and quality-of-life scores significantly improved in EOS through Shilla growth guidance. In terms of spinal growth and deformity correction, there were no significant differences between patients with implant-related problems and individuals without occurrences. Although implant-related problems were detected in our dataset and corresponding unexpected surgeries were necessary, these complications had no significant unfavorable influence on correction and spine growth.

Is Final Fusion Necessary for Growing-Rod Graduates: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

The need for definitive fusion for growing rod graduates is a controversial topic in the management of Early-onset scoliosis (EOS) patients. The authors performed a systematic review and meta-analysis on the available literature to evaluate the outcomes of growing rod graduates undergoing final fusion or observation with implants in-situ.

METHODS

An extensive literature search was carried out aimed at identifying articles reporting outcomes in growing rod graduates. Apart from the study characteristics and demographic details, the extracted data included Cobb's correction, trunk height parameters, and revision rate. The extracted data was analyzed and forest plots were generated to draw comparisons between the observation and fusion groups.

RESULTS

Of the 11 included studies, 6 were case-control and 5 were case series. The authors did not find any significant difference between the 2 groups with respect to the pre-index and final Cobb's correction, T1-T12 or T1-S1 height gain in either over-all, or sub-analysis with case-control studies. The meta-analysis showed a significantly higher revision rate in patients undergoing a definitive fusion procedure.

CONCLUSION

The current analysis revealed comparable outcomes in terms of correction rate and gain in the trunk height but a lesser need of revisions in observation sub-group. The lack of good quality evidence and the need for prospective and randomized trials was also propounded by this review.

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.

A comparison of the inflammatory host response to particulate debris adjacent to unlocked and locked screws of a growth guidance system for early onset scoliosis

PURPOSE

The SHILLA™ Growth Guidance system is a stainless-steel rod and screw system used for Early Onset Scoliosis which incorporates a unique flanged set screw designed to capture the rod, while allowing it to slide as the patient grows. Concomitant with this design is the potential for generation of wear debris and for an inflammatory host response. We hypothesized that the magnitude of the host response adjacent to the unlocked screws and rods would be greater than the host response to the locked rod/screws.

METHODS

Seven tissue samples adjacent to locked (3) and unlocked screws (4) from three SHILLA patients (mean implantation time of 19 post-operative months) with infantile idiopathic scoliosis were obtained as part of an explant analysis protocol during a PMDA-approved clinical trial in Japan. Gross appearance, high-resolution radiographs, and histology were assessed. ISO Standard 10993 Part 6 was used to assess the host response.

RESULTS

All three locked screw had no metallosis. In contrast, metallosis for unlocked screw tissue samples were rated as "ubiquitous" (2/4), "focal" (1/4), or "absent" (1/4). Microscopic metallic debris was found intracellularly and within interstices of fibrous connective tissues more frequently adjacent to unlocked screws compared to locked screws. Cell type and population scoring consistently showed a modestly larger inflammatory response (macrophages) in the unlocked tissue samples.

CONCLUSIONS

The peri-prosthetic tissue response to the unlocked rods/screws had a higher reactivity grade (slight reaction, Δ = 4.0) per ISO 10993 Part 6 compared to the locked screws in three patients with the SHILLA™ Growth Guidance scoliosis system.

The role of traditional growing rods in the era of magnetically controlled growing rods for the treatment of early-onset scoliosis

PURPOSE

To describe the clinical and radiographic profile of early-onset scoliosis (EOS) patients treated with traditional growing rods (TGR) during the magnetically-controlled growing rod (MCGR) era.

METHODS

A US multicenter EOS database was reviewed to identify (1) patients who underwent TGR after MCGR surgery was introduced at their institution, (2) patients who underwent MCGR during the same time period. Of 19 centers, 8 met criteria with all EOS etiologies represented. Clinical notes were reviewed to determine the indication for TGR. Patient demographics and pre-operative radiographs were compared between groups.

RESULTS

A total of 25 TGR and 127 MCGR patients were identified. The TGR patients were grouped by indication into the sagittal plane profile (n = 11), trunk height (n = 6), co-morbidities/need for MRI (n = 4), and other (ex: behavioral issues, remaining growth). Four patients had a combination of sagittal profile and short stature with sagittal profile listed as primary factor. The TGR short trunk group had a mean T1-S1 length of 192 mm vs 273 mm for the MCGR group (p = 0.0002). The TGR sagittal profile group, had a mean maximal kyphosis of 61° vs 55° for the MCGR group (p = 0.09).

CONCLUSION

TGR continues to have a role in the MCGR era. In this study, the most commonly reported indications for TGR were sagittal plane profile and trunk height. These results suggest that TGR is indicated in patients of short stature with stiff hyperkyphotic curves. As further experience is gained with MCGR, the indications for TGR will likely be refined.

Complications in growth-friendly spinal surgeries for early-onset scoliosis: Literature review

BACKGROUND

The treatments for early-onset scoliosis (EOS), defined as curvature of the spine with onset before 10 years of age, continue to pose a great challenge for pediatric orthopedics. The treatment goals for EOS include minimizing spinal deformity while maximizing thoracic volume and pulmonary function. Different surgical techniques have different advantages and drawbacks; however, the two major concerns in the management of EOS are repeated surgeries and complications.

AIM

To review the current literature to assess the safety of EOS surgical treatment in terms of the rate of complications and unplanned surgeries.

METHODS

In January 2021 two independent reviewers systematically searched three electronic medical databases (PubMed, the Cochrane Library, and Embase) for relevant articles. Every step of the review was done according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Due to the heterogeneity of articles and topics after data analysis, a descriptive (synthetic) analysis was performed.

RESULTS

A total of 2136 articles were found. Forty articles were included in this systematic review, after applying our inclusion and exclusion criteria. EOS surgery has a varying but high rate of complications. The most frequent complications were categorized as implant (54%), general (17%), wound (15%) and alignment (12%). The rate of complications might have been even higher than reported, as some authors do not report all types of complications. About 54% of patients required unplanned surgeries due to complications, which comprised 15% of all surgeries.

CONCLUSION

The literature concerning the definitions, collection, and interpretation of data regarding EOS surgery complications is often difficult to interpret. This creates problems in the comparison, analysis, and improvement of spine surgery practice. Additionally, this observation indicates that data on the incidence of complications can be underestimated, and should be interpreted with caution. Awareness of the high rate of complications of EOS surgery is crucial, and an optimal strategy for prevention should become a priority.

[Surgical strategies in the treatment of neuromuscular scoliosis]

As part of the underlying condition, neuromuscular scoliosis occurs in early childhood. Compared to idiopathic scoliosis, neuromuscular scoliosis shows a more rapid progress of deformity, which continues even after the end of growth. This progress and the associated complications can only be prevented by surgical treatment. Depending on the patient's age and the extent of the deformity, different strategies have been established: in early childhood, so-called "growing implants" are used, while between the ages of 10 to 12, definitive treatment by reposition and fusion of the deformity is the treatment of choice. In this review, we present different surgical strategies as well as indications for surgery and discuss challenges in the treatment of these complex deformities.

Understanding the implant performance of magnetically controlled growing spine rods: a review article

PURPOSE

Early-Onset Scoliosis (EOS) (defined as a curvature of the spine ≥ 10° with onset before 10 years of age) if not properly treated, can lead to increased morbidity and mortality. Traditionally Growing Rods (TGRs), implants fixated to the spine and extended every 6-8 months by surgery, are considered the gold standard, but Magnetically Controlled Growing Rods (MCGRs) avoid multiple surgeries. While the potential benefit of outpatient distraction procedure with MCGR is huge, concerns still remain about its risks, up to the release of a Medical Device Alert (MDA) by the Medicines and Healthcare Regulatory Agency (MHRA) advising not to implant MCGRs until further notice. The aim of this literature review is to (1) give an overview on the use of MCGRs and (2) identify what is currently understood about the surgical, implant and patient factors associated with the use of MCGRs.

METHODS

Systematic literature review.

RESULTS

Surgical factors such as use of single rod configuration or incorrect rod contouring might affect early failure of MCGRs. Patient's older age and higher BMI are correlated with rod slippage. Wear debris and distraction mechanism failure may result from implant design and iteration.

CONCLUSION

Despite the complications reported, this technology still offers one of the best solutions to spine surgeons dealing with severe EOS. Lowering the complication rate by identifying risk factors for failure is possible and further studies in this direction are required. Once the risk factors are well described, some of these can be addressed enabling a safer use of MCGRs.

Shilla Growth Guidance Compared With Magnetically Controlled Growing Rods in the Treatment of Neuromuscular and Syndromic Early-onset Scoliosis

STUDY DESIGN

Retrospective review of consecutive series of patients treated at two institutions.

OBJECTIVE

The aim of this study was to compare the health-related quality of life (HRQoL) and surgical outcomes of Shilla growth guidance and magnetically controlled growing rod (MCGR) treatment in patients with syndromic and neuromuscular early-onset scoliosis (EOS).

SUMMARY OF BACKGROUND DATA

Knowledge of the outcomes of Shilla instrumentation is limited.

METHODS

We identified 13 children treated with Shilla and 18 children treated with MCGR with syndromic or neuromuscular EOS (major curve ≥45 degree) before the age of 10 years with minimum 2-year follow-up. Outcome parameters included clinical data, radiographic as well as HRQoL outcomes (EOSQ-24 questionnaire).

RESULTS

Mean preoperative major curves were 64 degree (range, 45-108 degree) in the Shilla group and 58 degree (range, 45-85 degree) in the MCGR group (P = 0.151). At final follow-up, mean major curves were 31 degree (range, 9.4-54 degree ) and 30 degree (range, 16-53 degree), respectively (P = 0.392). The mean major curve correction was 45% in the Shilla group and 48% in the MCGR group during the follow-up (P = 0.383). Spinal (T1-S1) and T1-T12 growth were significantly better (P = 0.006 and 0.042) in the MCGR than in the Shilla group during the distraction period. At final follow-up, 11 (85%) children in the Shilla group and 17 (94%) in the MCGR group had achieved T1-T12 length of ≥18 cm (P = 0.202). There were significantly more surgical procedures in the MCGR group (mean 2.6 vs. 1.4, P = 0.034) with no difference in the number of complications (P = 0.768). EOSQ24 domains were similar at final follow-up.

CONCLUSION

Shilla growth guidance provided similar correction of spinal deformity, equal number of complications, but with significantly less surgical procedures in patients treated for EOS when compared with MCGR instrumentation. MCGR provided with slightly better spinal growth during the distraction period. There were no significant differences between the quality of life assessments.

LEVEL OF EVIDENCE

3.

Growth-preserving instrumentation in early-onset scoliosis patients with multi-level congenital anomalies

STUDY DESIGN

Retrospective.

OBJECTIVES

To assess final outcomes in patients with early-onset scoliosis (EOS) who underwent growth-preserving instrumentation (GPI). Various types of growth-preserving instrumentation (GPI) are frequently employed, but until recently had not been utilized long enough to assess final outcomes.

METHODS

GPI "graduates" with multi-level congenital curves were identified. Graduation was defined as a final fusion or 5 years of follow-up without planned future surgeries. Outcomes included radiographic parameters and complications.

RESULTS

26 patients were included. 11 had associated diagnoses; eight had fused ribs. 17 were treated with traditional growing rods, seven with vertically expandable prosthetic ribs, and two with Shilla procedures. The mean GPI spanned 12.3 levels including 10.7 motion segments, age at index surgery was 5.5 years, treatment spanned 7.5 years, and follow-up was 9.2 years. 24 patients underwent final fusion. Mean major curve decreased from 73° to 49° with index surgery (p < 0.01) and remained unchanged through a final follow-up. Final major curve was < 40° in 9 patients (35%), 40°-60° in 11 patients (42%), and > 60° in 6 patients (23%). None worsened throughout treatment. Mean T1-T12 height increased 2.4 cm with index surgery (p = 0.02) and 5.4 cm total (p < 0.01). T1-T12 height increased in all patients and was ultimately < 18 cm in 10 patients (38%), 18-22 cm in 10 patients (38%), and > 22 cm in 6 patients (23%). On average, there were 2.6 complications per patient, including 1.7 implant failures. 12 patients (46%) experienced ≥ 3 complications; four patients (15%) experienced none.

CONCLUSION

We observed successful prevention of deformity progression but substantial residual deformity among GPI graduates with multi-level congenital EOS. Most coronal curve correction was attained during GPI implantation; thoracic height improved throughout treatment. While some favorable results were found, treatment strategies allowing improved deformity correction would be valuable for this challenging population.

LEVEL OF EVIDENCE

Therapeutic-III.

Current status of the magnetically controlled growing rod in treatment of early-onset scoliosis: What we know after a decade of experience

The magnetically controlled growing rod (MCGR) has had approximately 10 years of clinical experience worldwide. Clinical effectiveness to control early-onset scoliosis is consistent even at final surgery. MCGRs have significantly lower relative percentage of infection or wound complications as compared to traditional growing rods. Most common complications include foundation failure and failure of distraction. Contouring of the rod especially at the proximal segment while accommodating for the straight actuator remains a difficult task and its failure may lead to proximal junctional kyphosis. Unique complications of MCGR include clunking, temporary diminishing distraction gains, and metallosis. Temporary reductions in distraction gains are observed as the MCGR lengthens but return to normal baseline distraction gains after rod exchange. Lack of standardization for rod configuration, distraction strategies and decisions of whether to keep the rods in situ, remove without fusion surgery or to perform spinal fusion at skeletal maturity will require further study.

Growth guidance constructs with apical fusion and sliding pedicle screws (SHILLA) results in approximately 1/3rd of normal T1-S1 growth

STUDY DESIGN

Retrospective, multicenter.

OBJECTIVE

To investigate clinical outcomes in particular T1-S1 growth in patients with SHILLA instrumentation independent of inventor's reports. Guided growth with apical fusion and sliding pedicle screws (GGC/SHILLA) is an alternative to distraction-based growing rods for the treatment of EOS. A recent report of patients treated with GGC primarily at the center where the procedure was invented reported surprisingly good spinal growth similar to normal growth.

METHODS

Retrospective review of EOS patients treated with GGC between 2007 and 2013 was performed from a multicenter database prior to final fusion. Inclusion criteria were < 10 years at index surgery and minimum 2-year follow-up. Patients with GGC performed at the inventor's institution or prior spinal instrumentation were excluded. Predicted normal T1-S1 change during the growth period was calculated for each patient based on Dimeglio's growth rates.

RESULTS

20 patients (mean age at surgery: 5.7 years) with the following diagnoses met inclusion criteria: syndromic (N = 9), neuromuscular (N = 5), idiopathic (N = 3) and congenital (N = 3). Preoperative mean Cobb was 77° (range 33°-111°). Mean increase in T1-S1 length from preoperative to postoperative was 51.5 mm, and change from postoperative to final follow-up was 21.8 mm (4.2 mm/year) which was 36% of predicted growth. 15/20 (75%) patients underwent 21 revision surgeries most commonly for implant complications (N = 26) and 8/20 (40%) underwent definitive fusion at a mean of 5.1 ± 1.2 years after guided growth surgery.

CONCLUSION

This study constitutes the largest case series of patients with EOS treated with GGC outside of the inventor's institution. The change in T1-S1 observed through the follow-up period in EOS patients treated with GGC was approximately 1/3rd of predicted normal growth, and less than 1/3rd of growth reported in previous reports. Similar curve correction and complication rates but less T1-S1 growth during the growth period were found compared to prior GGC (SHILLA) series.

Active Apex Correction (Modified SHILLA Technique) Versus Distraction-Based Growth Rod Fixation: What Do the Correction Parameters Say?

Introduction

SHILLA and growth rods are two main surgical correction techniques for patients with early-onset scoliosis. There have been some comparative studies between the two techniques, where a comparison was made between deformity identifying characteristics such as Cobb angle, apical vertebral translation, coronal balance, spinal length gain, etc. However, the SHILLA procedure experiences loss of correction or the reappearance of deformity through crankshafting or adding-on (e.g., distal migration). The current study identifies a solution with a modified approach to SHILLA (which could help in dynamically remodulating the apex of the deformity and mitigating loss of correction) and presents comparative correction data against the long-established traditional growth rod system.

Methods

The active apex correction (APC) group consisted of 20 patients and the growth rod group consisted of 26 patients, both with the same inclusion and exclusion criteria. The APC surgical procedure involved a modified SHILLA technique, that is, insertion of pedicle screws in the convex side of the vertebrae above and below the wedged one for compression and absence of apical fusion.

Results

There were no statistical differences between the various spinal parameters (namely, Cobb angle, apical vertebral translation, sagittal balance, and spinal length gain) of the two groups. However, significant differences existed for coronal balance, which in part may have been due to differences in its pre-op value between the two groups.

Conclusions

APC and the traditional growth rod system showed similar deformity correction parameters at current follow-ups; however, the latter requires multiple surgeries to regularly distract the spine.

Radiographic Outcome and Complication Rate of 34 Graduates After Treatment With Vertical Expandable Prosthetic Titanium Rib (VEPTR): A Single Center Report

BACKGROUND

The final strategy for graduates from growth-sparing surgery is challenging. The purpose of this study was to evaluate the radiographic outcome and complications of patients with early onset scoliosis (EOS) who have graduated from vertical expandable prosthetic titanium rib (VEPTR) treatment, either undergoing final fusion surgery or following a nonfusion approach.

METHODS

Final treatment for VEPTR graduates was divided in "VEPTR in situ without final fusion," "removal of VEPTR without final fusion," and "removal of VEPTR with instrumented final fusion." Radiographic evaluations included main coronal Cobb angle and main kyphosis pre and post VEPTR implantation, at the end of implant lengthening, after final fusion (if applicable), and at latest follow-up. Complications during VEPTR treatment and in case of final fusion were reported.

RESULTS

In total, 34 VEPTR graduates were included; 17 underwent final fusion surgery, and 17 followed a nonfusion strategy. Average coronal Cobb angle before VEPTR implantation was 70±23 degrees (range, 21 to 121 degrees), and 65±22 degrees (range, 17 to 119 degrees) at latest follow-up. Average main kyphosis angle was 53±27 degrees (range, 6 to 137 degrees) before VEPTR, and 69±34 degrees (range, 10 to 150 degrees) at latest follow-up. There was a 41% complication rate with final fusion surgery.

CONCLUSIONS

There is a high complication rate during VEPTR treatment and with final fusion surgery. The stiffness of the spine and thorax allow for only limited correction when performing a final instrumented spondylodesis. Avoiding final fusion may be a viable alternative in case of good coronal and sagittal alignment.

LEVEL OF EVIDENCE

Level IV-therapeutic.

Long term outcome of vertical expandable prosthetic titanium rib treatment in children with early onset scoliosis

The vertical expandable prosthetic titanium rib (VEPTR) device was originally developed for the treatment of thoracic insufficiency syndrome with the aim of improving respiratory function of affected patients. Although clinically obvious, the changes in pulmonary function of VEPTR-treated patients are difficult to assess when using common lung function tests, and newer techniques based on functional magnetic resonance imaging (MRI) are currently being evaluated. The potential of improving lung function and simultaneously controlling the spinal deformity has continuously broadened the spectrum of indications for VEPTR, not least due to the frequent reports of complications with spine-based traditional growing rods (tGR). However, the initial enthusiasm of spine-sparing deformity correction has progressively subsided with the increasing number of reports on complications, including the detection of extraspinal ossifications along the implants and across ribs. The avoidance of repetitive surgical implant lengthening with the availability of motorized distraction-based implants has further diminished the use of VEPTR, especially in the absence of volume-depletion deformities of the thorax. In view of the still scarce reporting on the ultimate strategy of VEPTR treatment and the lack of long-term follow-up of patients receiving growth-sparing surgery, only limited conclusions can be drawn so far. Based on the available reports, however, the intended deformity corrections with final fusion surgeries can be achieved to a rather limited extent, while the complication and reoperation rates are still very high.

An Overview of the Current State of Pediatric Scoliosis Management

Historically pediatric scoliosis represents a condition deeply rooted within the origins of orthopedic surgery. Today only a few subspecialized surgeons treat pediatric scoliosis patients. In severe cases surgery can hold progression of and correct pathologic spinal curvature. The goal of this article is to provide an overview of the current state of pediatric scoliosis management. It aims to increase the attention of general physicians and orthopedic surgeons to a niched but rather frequently encountered pediatric pathology to facilitate early recognition and diagnosis. A thorough research of literature was conducted to summarize the different scoliosis types, their etiology and presentation. Classification, normal human growth phases and curve progression risk have been further elaborated. Finally, current treatment options with their benefits, shortcomings and complications were laid out and discussed. Among the etiological groups a focus was put on idiopathic scoliosis, in particular adolescent idiopathic scoliosis as the most frequently encountered subtype.

Two-stage posterior spinal fusion for early-onset scoliosis: Two case reports

RATIONALE

Fusionless techniques for early-onset scoliosis (EOS) have evolved to allow near-normal growth while maintaining the correction achieved during the initial surgery. However, such procedures require repeated surgeries and have increased complication rates. We have developed a 2-stage fusion technique using pedicle screws for EOS to reduce patient burden and complication risk. This series describes the clinical and radiological features of 2 patients with EOS who received 2-stage posterior spinal fusion. This surgical method for EOS represents the first of its kind.

PATIENT CONCERNS

Case 1 was a 10-year-old girl who was diagnosed as having scoliosis with Prader Willi syndrome at the age of 2 years. Her preoperative major curve Cobb angle was 100 degrees at age 10 years. Case 2 was an 11-year-old boy who was found to have scoliosis with 22q11.2 deletion syndrome at the age of 4 years. His preoperative major curve Cobb angle was 77 degrees at age 11 years.

DIAGNOSIS

Whole-spine radiographs were performed to diagnose scoliosis.

INTERVENTIONS

Both patients received 2-stage posterior spinal fusion.

OUTCOMES

Postoperative Cobb angle of the major curve improved to 46 and 48 degrees, respectively. Thoracic height respectively improved from 160 and 148 mm before surgery to 206 and 211 mm at final follow-up. Surgical outcome as evaluated by Scoliosis Research Society-22 patient questionnaires revealed acceptable results without any severe complications.

LESSONS

Based on the present case report, 2-stage posterior spinal fusion for EOS achieves good radiological and clinical outcomes without severe complications.

Early-Onset Scoliosis: Updated Treatment Techniques and Results

STUDY DESIGN

This is a review of the current literature on early-onset scoliosis (EOS) techniques and treatment written by the Growing Spine Committee of the Scoliosis Research Society.

OBJECTIVES

The Growing Spine Committee of the Scoliosis Research Society sought to update the information available on the definition and treatment of EOS, including new information about existing techniques.

SUMMARY OF BACKGROUND DATA

EOS represents a diverse, heterogeneous, and clinically challenging group of spinal disorders occurring in children under the age of 10. Our understanding of EOS has changed dramatically in the last 15 years, and management of EOS has changed even more rapidly in the last five years.

METHODS

The Growing Spine Committee of the Scoliosis Research Society has embarked upon a review of the most current literature on EOS techniques and treatment.

RESULTS

This white paper provides recent updates on current techniques, including a summary of new modalities, indications, contraindications, and clinical results.

CONCLUSIONS

Although treatment of EOS is still challenging and complicated, the evolution of options and knowledge presents hope for better understanding and management in the future.

LEVEL OF EVIDENCE

Level V.

Spine Deformity With Fused Ribs Treated With Proximal Rib- Versus Spine-Based Growing Constructs

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To compare the use of spine-based versus rib-based implants for the treatment of early-onset scoliosis (EOS) in the setting of rib fusions.

SUMMARY OF BACKGROUND DATA

Treatment for severe early-onset spinal deformity with rib fusions includes growing spine devices with proximal rib or spine anchors. The results of treatment, however, have not been compared between spine-based versus rib-based proximal anchors.

METHODS

169 patients with rib fusions treated with rib-based or spine-based constructs and minimum two-year follow-up were included. Sixteen patients were treated with proximal spine-based anchors and 153 with proximal rib-based devices (VEPTRs). Overall, 104 of the patients with rib-based fixation underwent thoracoplasty at the index surgery. We evaluated change in T1-T12 and T1-S1 height, coronal Cobb angle, kyphosis, and number of lengthening/revision surgeries.

RESULTS

Kyphosis increased a mean of 7° in the rib-based group and decreased a mean of 20 degrees in the spine-based group (p = .002). Major Cobb angle decreased in both groups (p < .0001); however, the spine-based group had greater Cobb angle improvement (24 vs. 11 degrees, p = .04). From implant and lengthening of distraction devices, there was a mean 3.3-cm (22%) increase in T1-T12 height and a mean of 8.0 lengthenings in the rib-based group compared with a 5.7-cm increase and 6.3 lengthening surgeries in the spine-based group. Patients with rib-based constructs had a mean of 11 total procedures, whereas spine-based patients had a mean of 8.

CONCLUSIONS

Patients underwent a mean of eight lengthening surgeries before final fusion or cessation of lengthening with a modest 2.3-cm increase in T1-T12 height. Compared with proximal rib anchors, proximal spine anchors controlled kyphosis and improved Cobb angle correction for early-onset scoliosis with rib fusions.

Minimizing Spine Autofusion With the Use of Semiconstrained Growing Rods for Early Onset Scoliosis in Children

BACKGROUND

A new growing rod (GR) design, the semiconstrained growing rod (SCGR), with the added advantage of axial rotation freedom within the components, has been introduced at our center which has been shown to be growth friendly. We hypothesize that the SCGR system would reduce autofusion in vivo, thereby maximizing the coronal plane correction, T1-S1 growth, and the final correction achieved at definitive fusion for children with an early onset scoliosis.

METHODS

In total, 28 patients had either single or dual 5.5 mm diameter SCGR placed minimally invasively through a submuscular approach. Surgical lengthening procedures occurred approximately every 6 months until the definitive fusion procedure was performed for 18 patients. Scoliosis, kyphosis, and lordosis angles, T1-S1 trunk length, and any complications encountered were evaluated.

RESULTS

For the full cohort, before GR insertion, the mean major Cobb curve angle was 72.4 degrees (SD, 18.8; range, 45 to 120), mean T1-S1 trunk length was 282 mm (SD, 59; range, 129 to 365), and at the latest follow-up (mean 6.9 y, SD 3.3, range 2.0 to 13.0), 38.8 degrees (SD, 17.5; range 10 to 90) and 377 mm (SD, 62; range, 225 to 487), respectively. For the subset of 18 patients who have had their final instrumented fusion surgery, the definitive surgery procedure alone produced a correction of the major Cobb curve angle by mean 20.3 degrees (SD, 16.1; P<0.0001), and an increase in the T1-S1 trunk length of mean 31.7 mm (SD, 23.1; P<0.0001). There were 14 complications involving 11 of the 28 patients, giving rise to 5 unplanned surgical interventions and 1 case where GR treatment was abandoned.

CONCLUSIONS

SCGR patients exhibited statistically significant increase in T1-S1 trunk length and statistically significant decrease in the severity of scoliosis over the course of GR treatment and again, importantly, with the definitive fusion surgery, suggesting that autofusion had been minimized during GR treatment with relatively low complication rates.

LEVEL OF EVIDENCE

Level IV-case series.

A six-year observational study of 31 children with early-onset scoliosis treated using magnetically controlled growing rods with a minimum follow-up of two years

Aims

Magnetically controlled growing rod (MCGR) systems use non-invasive spinal lengthening for the surgical treatment of early-onset scoliosis (EOS). The primary aim of this study was to evaluate the performance of these devices in the prevention of progression of the deformity. A secondary aim was to record the rate of complications.

Patients and Methods

An observational study of 31 consecutive children with EOS, of whom 15 were male, who were treated between December 2011 and October 2017 was undertaken. Their mean age was 7.7 years (2 to 14). The mean follow-up was 47 months (24 to 69). Distractions were completed using the tailgating technique. The primary outcome measure was correction of the radiographic deformity. Secondary outcomes were growth, functional outcomes and complication rates.

Results

The mean Cobb angle was 54° (14° to 91°) preoperatively and 37° (11° to 69°) at the latest follow-up (p < 0.001). The mean thoracic kyphosis (TK) was 45° (10° to 89°) preoperatively and 42° (9° to 84°) at the latest follow-up. The mean T1-S1 height increased from 287 mm (209 to 378) to 338 mm (240 to 427) (p < 0.001) and the mean sagittal balance reduced from 68 mm (-76 to 1470) preoperatively to 18 mm (-32 to 166) at the latest follow-up. The mean coronal balance was 3 mm (-336 to 64) preoperatively and 8 mm (-144 to 64) at the latest follow-up. The mean increase in weight and sitting and standing height at the latest follow-up was 45%, 10% and 15%, respectively. The mean Activity Scale for Kids (ASKp) scores increased in all domains, with only personal care and standing skills being significant at the latest follow-up (p = 0.02, p = 0.03). The improvements in Cobb angle, TK and T1-S1 heights were not related to gender, the aetiology of the EOS, or whether the procedure was primary or conversion from a conventional growing rod system. A total of 21 children developed 23 complications at a rate of 0.23 per patient per year. Seven developed MCGR-specific complications. Complications developed at a mean of 38 months (3 to 67) after the initial surgery and required 22 further procedures. Children who developed a complication were more likely to be younger, have syndromic EOS, and have a single-rod construct (6.9 versus 9.3 years, p = 0.034).

Conclusion

The progression of EOS can be controlled using MCGRs allowing growth and improved function. Younger and syndromic children are more likely to develop complications following surgery. Cite this article: Bone Joint J 2018;100-B:1187-1200.

Current Use of Evidence-Based Medicine in Pediatric Spine Surgery

Evidence-based medicine (EBM) is a process of decision-making aimed at making the best clinical decisions as they relate to patients' health. The current use of EBM in pediatric spine surgery is varied, based mainly on the availability of high-quality data. The use of EBM is limited in idiopathic scoliosis, whereas EBM has been used to investigate the treatment of pediatric spondylolysis. Studies on early onset scoliosis are of low quality, making EBM difficult in this condition. Future focus and commitment to study quality in pediatric spinal surgery will likely increase the role of EBM in these conditions.

Cost analysis of a growth guidance system compared with traditional and magnetically controlled growing rods for early-onset scoliosis: a US-based integrated health care delivery system perspective

Purpose

Treating early-onset scoliosis (EOS) with traditional growing rods (TGR) is effective but requires periodic surgical lengthening, risking complications. Alternatives include magnetically controlled growing rods (MCGR) that lengthen noninvasively and the growth guidance system (GGS), which obviate the need for active, distractive lengthenings. Previous studies have reported promising clinical effectiveness for GGS; however the direct medical costs of GGS compared to TGR and MCGR have not yet been explored.

Methods

To estimate the cost of GGS compared with MCGR and TGR for EOS an economic model was developed from the perspective of a US integrated health care delivery system. Using dual-rod constructs, the model estimated the cumulative costs associated with initial implantation, rod lengthenings (TGR, MCGR), revisions due to device failure, surgical-site infections, device exchange, and final spinal fusion over a 6-year episode of care. Model parameters were from peer-reviewed, published literature. Medicare payments were used as a proxy for provider costs. Costs (2016 US$) were discounted 3% annually.

Results

Over a 6-year episode of care, GGS was associated with fewer invasive surgeries per patient than TGR (GGS: 3.4; TGR: 14.4) and lower cumulative costs than MCGR and TGR, saving $25,226 vs TGR. Sensitivity analyses showed that results were sensitive to changes in construct costs, rod breakage rates, months between lengthenings, and TGR lengthening setting of care.

Conclusion

Within the model, GGS resulted in fewer invasive surgeries and deep surgical site infections than TGR, and lower cumulative costs per patient than both MCGR and TGR, over a 6-year episode of care. The analysis did not account for family disruption, pain, psychological distress, or compromised health-related quality of life associated with invasive TGR lengthenings, nor for potential patient anxiety surrounding the frequent MCGR lengthenings. Further analyses focusing strictly on current generation technologies should be considered for future research.