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

Do Rib-Based Anchors Impair Chest Wall Motion in Early Onset Scoliosis (EOS)?

Purpose

There is a concern in pediatric surgery practice that rib-based fixation may limit chest wall motion in early onset scoliosis (EOS). The purpose of this study is to address the above concern by assessing the contribution of chest wall excursion to respiration before and after surgery.

Methods

Quantitative dynamic magnetic resonance imaging (QdMRI) is performed on EOS patients (before and after surgery) and normal children in this retrospective study. QdMRI is purely an image-based approach and allows free breathing image acquisition. Tidal volume parameters for chest walls (CWtv) and hemi-diaphragms (Dtv) were analyzed on concave and convex sides of the spinal curve. EOS patients (1-14 years) and normal children (5-18 years) were enrolled, with an average interval of two years for dMRI acquisition before and after surgery.

Results

CWtv significantly increased after surgery in the global comparison including all EOS patients (p < 0.05). For main thoracic curve (MTC) EOS patients, CWtv significantly improved by 50.24% (concave side) and 35.17% (convex side) after age correction (p < 0.05) after surgery. The average ratio of Dtv to CWtv on the convex side in MTC EOS patients was not significantly different from that in normal children (p=0.78), although the concave side showed the difference to be significant.

Conclusion

Chest wall component tidal volumes in EOS patients measured via QdMRI did not decrease after rib-based surgery, suggesting that rib-based fixation does not impair chest wall motion in pediatric patients with EOS.

Diagnostic and therapeutic strategies in early onset scoliosis: A current concept review

Substantial advances in the treatment of early onset scoliosis (EOS) over the past two to three decades have resulted in significant improvements in health-related quality of life of affected children. In addition to classifications that address the marked heterogeneity of this patient population, increasing understanding of the natural history of the disease, and new implants and treatment techniques have resulted in innovations unlike any other area of pediatric orthopedics. The growing understanding of the interaction between spinal and thoracic growth, as well as dependent lung maturation, has had a lasting impact on the treatment strategy of this potentially life-threatening disease. The previous treatment approach with early corrective fusion gave way to a growth-friendly concept. Despite the steady development of new growth-friendly surgical treatment options, whose efficacy still needs to be validated, as well as a revival of conservative growth control with serial casts and/or braces, the psychosocial burden of the long lasting and complication-prone treatments remains high. As a consequence, EOS still represents one of the greatest pediatric orthopedic challenges.

An initial effort to define an early onset scoliosis "graduate"-The Pediatric Spine Study Group experience

PURPOSE

Increasingly, patients with early onset scoliosis (EOS) are completing a growth friendly surgical program followed by observation, removal of implants or a definitive spinal fusion. These patients are colloquially referred to as "graduates". A standardized definition of a graduate is needed for research and comparing the outcomes, family counseling, and a better understanding of the population.

METHODS

A 15-question electronic survey was completed by 39 experienced pediatric spine surgeons to identify factors salient to the definition of a graduate of EOS surgical programs. A Delphi/Nominal group technique session with nine questions was then performed face-to-face with 21 members of the Pediatric Spine Study Group to discuss and refine the definition. A follow-up electronic survey was then distributed to these same 21 members to gain consensus on the final definition.

RESULTS

From the initial survey, it was identified that a graduate did not require definitive spinal fusion after a growing program. From the Delphi session, it was determined that skeletal maturity was the most important factor in defining a graduate. A strictly defined minimum length of follow-up was not felt to be a prerequisite for qualification of graduation. After the final electronic version was distributed, > 80% of respondents agreed upon the final definition, thereby achieving consensus.

CONCLUSION

The Pediatric Spine Study Group recommends adoption of the following definition: a "graduate" is a patient who has undergone any surgical program to treat early onset scoliosis, and has reached skeletal maturity and does not have a planned surgical intervention for EOS in the future.

LEVEL OF EVIDENCE

V.

Minimum 5-Year Follow-up on Graduates of Growing Spine Surgery for Early Onset Scoliosis

INTRODUCTION

After discontinuation of growth friendly (GF) surgery for early onset scoliosis, patients undergo spinal fusion or continued observation. This last planned treatment is colloquially called "definitive" treatment, conferring these patients as "graduates" of a growing program. The 5-year radiographic and clinical outcomes of this cohort are unknown.

METHODS

An international pediatric spine database was queried for patients from a GF program (spine or rib-based) with minimum 5-year follow-up from last planned surgery (GF or spinal fusion). Radiographs and charts were reviewed for main coronal curve angle and maximum kyphosis as well as occurrence of secondary surgery.

RESULTS

Of 580 graduates, 170 (29%) had minimum 5-year follow-up (37% male). Scoliosis etiology was congenital in 41 (24%), idiopathic 36 (21%), neuromuscular 51 (30%), and syndromic 42 (25%). Index surgery consisted of spine-based growing rods in 122 (71%) and rib-based distraction in 48 (29%). Mean age at index surgery was 6.8 years, and patients underwent an average of 5.4 lengthenings over an average of 4.9 years (range, 6 mo to 11 y). Last planned treatment was at an average age of 11.8 years (range, 7 to 17 years). Last planned treatment consisted of spinal fusion in 114 patients, 47 had growing implants maintained, 9 had implants removed. Average follow-up was 7.3 years (range, 5 to 13 y).When compared from postdefinitive treatment to 2-year follow-up, there was noted progression of the coronal curve angle (46±19 to 51±21 degrees, P=0.046) and kyphosis (48±20 to 57±25 degrees, P=0.03). However, between 2 and 5 years, no further progression occurred in the coronal (51±21 to 53±21 degrees, P=0.26) or sagittal (57±25 to 54±28 degrees, P=0.93) planes. When stratified based on etiology, there was no significant coronal curve progression between 2- and 5-year follow-up. When comparing spinal fusion patients to those who had maintenance of their growing construct, there was also no significant curve progression.Thirty-seven (21%) underwent at least 1 (average, 1.7; range, 1 to 7) revision surgery following graduation, and 15 of 37 (41%) underwent 2 or more revision surgeries. Reason for revision was implant revision (either GF or spinal fusion) in 34 patients, and implant removal in 3. On an average, the first revision was 2.5 years after the definitive treatment plan (range, 0.02 to 7.4 y). In total, 15 of 37 (41%) revisions occurred over 2 years following the final decision for treatment plan, and 7 of 37 (19%) occurred 5 or more years after the definitive treatment.Patients who underwent spinal fusion as a definitive treatment strategy were more likely to undergo revision surgery (27%) than patients who had their GF implants maintained (11%) (P=0.04).

CONCLUSIONS

Five years following "graduation" from growing surgery for early onset scoliosis, there is progression of curve magnitude in both the coronal and sagittal planes up to 2 years, with no further progression at 5 years. A total of 21% of patients undergo at least 1 revision surgery, and average time to revision surgery is over 2 years from last planned surgery. Risk of revision surgery was higher in patients who underwent a spinal fusion as their definitive treatment strategy.

LEVEL EVIDENCE

Level III-retrospective comparative.

TYPE OF EVIDENCE

Therapeutic.

The Association Between the Utilization of Traction and Postoperative Complications Following Growing Rod Instrumentation for Early-onset Scoliosis

BACKGROUND

Preoperative and/or intraoperative traction have been proposed as adjunctive methods to limit complications associated with growth-friendly instrumentation for early-onset scoliosis (EOS). By gradually correcting the deformity before instrumentation, traction can, theoretically, allow for better overall correction without the complications associated with the immediate intraoperative correction. The purpose of this multicenter study was to investigate the association between preoperative/intraoperative traction and complications following growth-friendly instrumentation for EOS.

METHODS

Patients with EOS who underwent growth rod instrumentation before 2017 were identified from 2 registries. Patients were divided into 2 groups: preoperative traction group versus no preoperative traction group. A subgroup analysis was done to compare intraoperative traction only versus no traction. Data was collected on any postoperative complication from implantation to up to 2 years postimplantation.

RESULTS

Of 381 patients identified, 57 (15%) and 69 (18%) patients received preoperative and intraoperative traction, respectively. After adjusting for etiology and degree of kyphosis, there was no evidence to suggest that preoperative halo traction reduced the risk of any complication following surgical intervention. Although not statistically significant, a subgroup analysis of patients with severe curves demonstrated a trend toward a markedly reduced hardware failure rate in patients undergoing preoperative halo traction [preoperative traction: 1 (3.1%) vs. no preoperative traction: 11 (14.7%), P=0.083]. Nonidiopathic, hyperkyphotic patients treated with intraoperative traction were 61% less likely to experience any postoperative complication (P=0.067) and were 74% (P=0.091) less likely to experience an unplanned return to the operating room when compared with patients treated without traction.

CONCLUSIONS

This multicenter study with a large sample size provides the best evidence to date of the association between the use of traction and postoperative complications. Our results justify the need for future Level I studies aimed at characterizing the complete benefit and risk profile for the use of traction in surgical intervention for EOS.

LEVEL OF EVIDENCE

Level III.

Vertical Expandable Rib-based Distraction Device for Correction of Congenital Scoliosis in Children of 3 Years of Age or Younger: A Preliminary Report

BACKGROUND

This study was designed to evaluate the treatment outcome of very young children with congenital scoliosis aged 3 years or under after surgery with a vertical expandable prosthetic titanium rib (VEPTR)-based distraction device.

METHODS

A retrospective study of 13 children undergoing implantation of a vertical expandable rib-based distraction device. From September 2007 to June 2018, 13 children (7 male and 6 female patients) with congenital scoliosis were followed after treatment with a VEPTR. The outcome parameters were complications, thoracic height, kyphosis, lordosis, and coronal major scoliosis curve. In addition, the American Society of Anaesthesiologists (ASA) score, assisted ventilation rating, and hemoglobin and body mass index were analyzed. Data were examined separately by 2 investigators.

RESULTS

The mean age at initial surgical treatment was 24.4±10.6 months, follow-up was 91.5±23.1 months. The mean number of surgical procedures per patient was 14±3.9 (total 182 operations). Apart from planned operations every 6 months, 5 unplanned operations (2.7%) were performed. The major scoliosis curve improved significantly from 55.2±21.9 degrees to 40.5±18.7 degrees, thoracic spine height T1-T12 significantly from 111±12 mm to 137±23 mm, T1-S1 height significantly from 211±13 mm to 252±36 mm and space available for the lung from 80.9%±11.3% to 84.4%±8.8% (preoperatively and at 5-y follow-up, respectively). Kyphosis increased significantly from 30±21.4 degrees to 42.6±23.5 degrees and lordosis from 32.4±20.9 degrees to 37.6±10.4 degrees. Hemoglobin levels were virtually unchanged. Weight increased from 10.6±2.8 kg to 20.2±5.0 kg at final follow-up, but body mass index decreased from 16.6±3.7 kg/m² to 15.7±2.9 kg/m².

CONCLUSIONS

The expandable rib-based distraction device is an effective method to treat severe congenital scoliosis in very young children. It can control the deformity and promotes spinal and thoracic growth.

LEVEL OF EVIDENCE

Level IV.

Early Results of a Management Algorithm for Collapsing Spine Deformity in Young Children (Below 10-Year Old) With Spinal Muscular Atrophy Type II

BACKGROUND

Progressive C-shaped scoliosis with marked pelvic obliquity is common to spinal muscular atrophy (SMA). Reducing the number of procedures with effective deformity control is critical to minimize the risk of pulmonary complications. This study reports the preliminary results of magnetically controlled growing rods (MCGR) in SMA-related collapsing spine deformity.

METHODS

Inclusion criteria for this retrospective review were: (1) SMA type 2 patients, (2) early onset scoliosis (below 10 y), (3) collapsing spine deformity with pelvic obliquity, (4) growth-friendly scoliosis treatment with MCGR, (5) in between 2014 and 2017. Extracted data included demographic and clinical information, radiologic parameters, surgical details, and final status of the patients.

RESULTS

A total of 11 patients (7 boys, 4 girls) were included. The average age at index surgery was 8.2 (6 to 10) years. Dual MCGR was implanted in 8 patients. In 3 patients, because of curve rigidity and inability of apex to be brought into the stable zone, apical fusion with gliding connectors (convexity) and a single MCGR (concavity) was preferred. Instrumentation included the pelvis in 9 and stopped at the lumbar spine (L3) in 2 patients at the index procedure. Average preoperative deformity of 81.8 degrees (66 to 115) decreased to 29 degrees (11 to 57) postoperatively and was 26 degrees at average 35 months (16 to 59). Pelvic obliquity of 20.9 degrees (11 to 30) decreased to 4.9 degrees (2 to 8) after index surgery and was 6.5 degrees (2 to 16) at the last follow-up. T1-S1 height of 329 mm (280 to 376) after index surgery increased to 356 mm (312 to 390) after 9.2 (4 to 20) outpatient lengthening. No neurologic, infectious, or implant-related complication was recorded. Distal adding-on deformity occurred in 2 patients without initial pelvic fixation.One patient deceased secondary to pneumonia at 16 months after surgery.

CONCLUSIONS

Short-term results indicate that MCGR may be a good option in SMA-associated collapsing spine deformity to reduce the burden of repetitive lengthening procedures. The authors recommend apical deformity control in the convex side in case of curve rigidity. In addition, including the pelvis in the instrumentation at index surgery is critical to prevent distal adding-on.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Functional outcomes in bilateral upper limb Amelia patient with scoliosis post vertical expandable prosthetic titanium rib (VEPTR) application: A case report

INTRODUCTION

Congenital upper limb Amelia is one of the extremely rare conditions in the world. Defined as complete absence of a limb which may present as isolated defect or as a part of syndrome with associated anomalies.

PRESENTATION OF THE CASE

We report a case of a medically free 6-year-old boy with bilateral upper limb Amelia associated with right thoracolumbar idiopathic Scoliosis.

DISCUSSION

Treatment for early onset scoliosis includes either posterior spinal fusion and instrumentation, or Vertical Expandable Prosthetic Titanium Rib (VEPTR). The choice of care for our patient was decided to be VEPTR alone as definitive management. Up to our knowledge, there are very scanty articles published regarding treatment for such cases.

CONCLUSION

Patient underwent vertical expandable prosthetic titanium rib (VEPTR) application for his large 45-degree curve as a definitive treatment and still have his preoperative physical functions, in terms of using lower limbs in daily living activities.

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.