A Preclinical Pilot Study on the Effects of Thermal Ablation on Lamb Growth Plates.

(1) Background: Thermal ablation has been demonstrated to affect the bone growth of osteoid osteoma in adolescents. Growth modulation due to thermal heat in children is conceivable, but has not yet been established. We used lamb extremities as a preclinical model to examine the effect of thermal ablation on growth plates in order to evaluate its potential for axial or longitudinal growth modulation in pediatric patients. (2) Methods: Thermal ablation was performed by electrocautery on eight different growth plates of the legs and distal radii of a stillborn lamb. After treatment, target hits and the physical extent of the growth plate lesions were monitored using micro-computed tomography (micro-CT) and histology. (3) Results: Lesions and their physical extent could be quantified in 75% of the treated extremities. The histological analysis revealed that the disruption of tissue was confined to a small area and the applied heat did not cause the entire growth plate to be disrupted or obviously damaged. (4) Conclusions: Thermal ablation by electrocautery is minimally invasive and can be used for targeted disruption of small areas in growth plates in the animal model. The results suggest that thermal ablation can be developed into a suitable method to influence epiphyseal growth in children.

Limited trunk motion and posterior pelvic tilting in ambulatory children treated with bilateral rib to pelvis implants for spinal deformity control.

In young children, growth-friendly spinal implants with bilateral rib to pelvis fixation are used to control progressive spinal deformity. Whereas curve progression, complications and side-effects have been extensively studied in this patient population, no data are available on gait pattern changes and postural body adjustments. Our study evaluates whether gait pattern changed for ambulatory children treated with bilateral rib to pelvis implants compared to age-matched healthy children. In this small cohort study, gait analysis was performed using spatiotemporal and kinematic parameters of four ambulatory children with severe scoliosis and growth-friendly spinal implants using the bilateral rib to pelvis fixation. Data were statistically analyzed and compared to seven healthy age-matched children. Between both groups, no differences were seen in walking speed, cadence and stride length. The treated patients showed a lower range of motion of the pelvic obliquity and of the trunk obliquity and rotation, but a higher knee flexion. Growth-friendly spinal implants with bilateral rib to pelvis fixation are commonly used in wheelchair children and rarely indicated in ambulatory patients. The presented data show reduced trunk and pelvis motion using this implant construct. These findings help to understand body postural adjustments and add valuable information for families and care providers when considering this surgery. Level of evidence: Therapeutic level IV.

Foot Typology, Dynamic and Static Weight Distribution, and Radiographic Changes After Subtalar Arthroereisis in Juvenile Symptomatic Flexible Flat Feet.

Flexible flatfoot is among the most common skeletal disorders in childhood. This study describes the dynamic and static correction effects of subtalar arthroereisis in adolescents with flexible symptomatic flatfeet in comparison to normal subjects as well as to results before and after removal of metal. Eighteen adolescents with 25 symptomatic flexible flatfeet were treated surgically with a subtalar arthroereisis at a mean of 12.5 (10-16) years. At follow-up (mean 3.9 years, range 0.4-8), patients filled out the American Orthopaedic Foot and Ankle Society questionnaire, received radiographs and were examined using dynamic and static pedobarography as well as static hindfoot axis examination. Results were compared to healthy controls (n = 13; 26 feet). Surgically treated feet (n = 25) had better questionnaire results after surgery than before, but lower scores than healthy feet. Radiological parameters improved significantly after surgery. Removal of metal did not influence post-surgical results (follow-up 2.8 years). Surgically treated feet had larger contact areas than normal feet with predominance to the midfoot region. The relative maximum force, relative peak pressure and contact time were higher in the midfoot of treated feet compared to controls. When comparing pedobarography data of treated versus untreated feet of the same patients (subgroup n = 11 feet), there were no differences. Subtalar arthroereisis was able to effectively treat symptomatic flexible flatfeet in this population. Results improved significantly evaluating a questionnaire, radiographs, dynamic and static weight distribution, but were still worse than results of healthy feet. There was no relapse after removal of metal.

[Congenital pseudarthrosis of the tibia : A rare often underestimated disorder]. / Kongenitale Pseudarthrose der Tibia : Ein seltenes, oft unterschätztes Krankheitsbild.

Congenital pseudarthrosis of the tibia (CPT) is a rare disease that has challenged trauma and orthopedic surgeons for a long time. Clinically CPT mostly presents with progressive varus and antecurvation malformation of the tibia in infancy and childhood. In many cases CPT is associated with neurofibromatosis or fibrous dysplasia. Without knowledge of the clinical picture a discontinuity of the tibia and/or fibula visible on an X­ray can be misinterpreted as a simple fracture. Histopathological investigations have revealed that a pathological alteration of the periosteum in the region of the pseudarthrosis, a hamartoma, may be essentially responsible for this disorder. Consequently, to treat the CPT a resection of the hamartoma must also be carried out. Multimodal treatment approaches combining pharmacological and surgical treatment, such as the cross-union technique of Paley, seem to have improved the prognosis of CPT.

Vertebral body changes after continuous spinal distraction in scoliotic children.

PURPOSE: Growth-friendly spinal implants (GFSI) were established for scoliotic children as an interim solution until definite spinal fusion could be performed during puberty. While deformity control was clearly proven, the effects on vertebral shape and morphology are still unclear. Our prospective study assesses the effect of GFSI with continuous distraction on vertebral body shape and volume in SMA children in comparison with previously untreated age-matched SMA patients. METHODS: Cohort I (n = 19, age 13.2 years) were SMA patients without prior surgical scoliosis treatment. Cohort II (n = 24, age 12.4 years) were children, who had continuous spinal distraction with GFSI for 4.5 years. Radiographic measurements and computed tomography (CT) 3D volume rendering were performed before definite spinal fusion. For cohort II, additional radiographs were analyzed before the first surgical implantation of GFSI, after surgery and every year thereafter. RESULTS: Our analysis revealed decreased depth and volume in scoliotic patients with prior GFSI compared to scoliotic patients without prior implants. This difference was significant for the lower thoracic and entire lumbar spine. Vertebral body height and pedicle size were unchanged between the two cohorts. CONCLUSION: CT data showed volume reduction in the vertebral body in scoliotic children after GFSI treatment. This effect was more severe in the lumbar and lower thoracic area. While vertebral height was identical in both groups, vertebral depth was reduced in the GFSI-treated group. Reduced vertebral depth and altered vertebral morphology should be considered before instrumenting the spine in previously treated scoliotic SMA children. LEVEL OF EVIDENCE III: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Spinal Deformities after Childhood Tumors.

Childhood tumors of the central nervous system (CNS) and other entities affecting the spine are rare. Treatment options vary from surgical biopsy to partial, subtotal, and total resection, to radiation, to chemotherapy. The aim of this study is to investigate spinal deformity and subsequent surgical interventions in this patient cohort. A retrospective review at our institution identified children with CNS tumors, spinal tumors, and juxta-spinal tumors, as well as spinal deformities. Tumor entity, treatment, mobilization, and radiographic images were analyzed relative to the spinal deformity, using curve angles in two planes. Conservative or surgical interventions such as orthotic braces, growth-friendly spinal implants, and spinal fusions were evaluated and analyzed with respect to treatment results. Tumor entities in the 76 patients of this study included CNS tumors (n = 41), neurofibromatosis with spinal or paraspinal tumors (n = 14), bone tumors (n = 12), embryonal tumors (n = 7), and others (n = 2). The initial treatment consisted of surgical biopsy (n = 5), partial, subtotal, or total surgical resection (n = 59), or none (n = 12), followed by chemotherapy, radiotherapy, or both (n = 40). Out of 65 evaluated patients, 25 revealed a moderate or severe scoliotic deformity of 71° (range 21-116°), pathological thoracic kyphosis of 66° (range 50-130°), and lordosis of 61° (range 41-97°). Surgical treatment was performed on 21 patients with implantation of growth-friendly spinal implants (n = 9) as well as twelve dorsal spinal fusions (two with prior halo distraction). Surgical interventions significantly improved spinal deformities without additional neurological impairment. With the increasing number of children surviving rare tumors, attention should be focused on long-term problems such as spinal deformities and consequent disabilities. A significant number of children with CNS tumors, spinal tumors or juxta-spinal tumors required surgical intervention. Early information about spinal deformities and a close follow-up are mandatory for this patient group.

Children With Spinal Muscular Atrophy With Prior Growth-Friendly Spinal Implants Have Better Results After Definite Spinal Fusion in Comparison to Untreated Patients.

BACKGROUND: Almost all children with spinal muscular atrophy (SMA) develop a scoliosis during childhood and adolescence. In the last decades, growth-friendly spinal implants have been established as an interim solution for these patients until definite spinal fusion can be performed. The effect of those implants on the final outcome has yet to be described. OBJECTIVE: To assess the effect of prior growth-friendly spinal surgical treatment on the outcome after spinal fusion in SMA children in comparison to untreated SMA patients through the prospective study. METHODS: A total of 28 SMA patients with (n = 14) and without (n = 14) prior surgical treatment with growth-friendly implants were included. Average surgical treatment prior to definite spinal fusion was 4.9 yr. Scoliotic curve angle, pelvic obliquity, spinal length, kyphosis, and lordosis were evaluated for children with prior treatment and before and after dorsal spondylodesis for all children. RESULTS: The curve angle before definite spinal fusion averaged at 104° for SMA patients without prior treatment and 71° for patients with prior treatment. Spondylodesis reduced the scoliotic curve to 50° and 33°, respectively, which equals a correction of 52% vs 54%. Pelvic obliquity could be improved by spinal fusion in all patients with better results in the pretreated group. Results for spinal length, kyphosis, and lordosis were similar in both groups. CONCLUSION: These data show the positive effect of prior growth-friendly surgical treatment on radiographic results of spinal fusion in children with SMA. Both scoliotic curve angles and pelvic obliquity showed significantly better values when patients had growth-friendly implants before definite spinal fusion.

Health-related quality of life in early-onset-scoliosis patients treated with growth-friendly implants is influenced by etiology, complication rate and ambulatory ability.

BACKGROUND: Progressive Early-Onset Scoliosis (EOS) in children may lead to surgical interventions with growth-friendly implants, which require repeated lengthening procedures in order to allow adequate growth. Quality of life was studied using the validated German version of the EOS-Questionnaire (EOSQ-24-G) in surgically treated EOS children with different lengthening modalities. METHODS: EOSQ-24-G and the KINDLR questionnaire were given to families with EOS children who had been treated by either vertical expandable prosthetic titanium rib implants and repetitive lengthening surgeries every 6 months or children who had received a magnetically expansion controlled implant, which was externally lengthened every 3 months. Results were compared according to differences between the two tests, and with possible influencing factors such as surgical method, severity of scoliosis, relative improvement of curvature, etiology, weight, age, travelling distance, complications, ambulatory ability and others. RESULTS: 56 children with an average curve angle of 69° corrected to 33° (52%; average age 5.6 yrs) answered the EOSQ-24-G and the KINDLR after an average follow-up of 3.9 years. Health-related quality of life (HRQoL) was not affected by the initial scoliosis correction, the number of surgeries or the implant type. However, there was a negative correlation with non-ambulatory status, complications during treatment and for children with a neuromuscular scoliosis. CONCLUSION: Using the validated EOSQ-24-G, no statistically significant differences were found between the group of children receiving repetitive surgeries and children with external lengthening procedures without surgery. However, results were influenced by the etiology, complication rate or ambulatory ability. LEVEL OF EVIDENCE/CLINICAL RELEVANCE: Therapeutic Level IV.

High Correlation Between Achieved and Expected Distraction Using Magnetically Controlled Growth Rods (MCGR) With Rib to Pelvis Fixation in Pediatric Spine Deformity.

PURPOSE: Magnetically controlled implant systems have been established to treat severe progressive spinal deformity in children. The purpose of this study was to evaluate (1) the ratio between achieved and expected distraction length, (2) the complication rate and its risk factors as well as (3) the correlation of the distraction length and the length of the spine. METHODS: A total of 40 patients with an average follow-up of 34 (14 to 57) months were prospectively included in the study. Children underwent lengthening procedures every three months. The ratio between the distraction lengths was determined by comparing the measured distraction length of the rod on radiographs with the distraction length displayed on the external remote controller for the magnetically controlled growing rod (MCGR). Age, weight, height, and complications were repeatedly recorded. RESULTS: The analysis of 746 procedures showed the actual distraction to be 94.4% of the expected one. No difference between implants on the concave and convex spinal side was observed. The overall complication rate was 4.6% mainly because of failure of the implant or lack of implant extension, which was directly related to an increased BMI. There was also a strong correlation between achieved implant distraction length and gain in spinal length. CONCLUSIONS: Our study demonstrates a high ratio (0.94) between achieved and expected distraction length of magnetically controlled spinal rods. The complication rate was low (4.6%) and correlated to a high BMI. The correlation between the achieved implant distraction length and spinal length indicates the efficiency of the MCGR therapy. LEVEL OF EVIDENCE: Therapeutic Level IV.

Combining Bilateral Magnetically Controlled Implants Inserted Parallel to the Spine With Rib to Pelvis Fixation: Surgical Technique and Early Results.

Spine-based fixation of magnetically controlled lengthening devices has been successfully performed for children with early-onset scoliosis. However, spinal manipulation may lead to ossifications, stiffness, and autofusion as previously described. To avoid these problems, a surgical technique combining bilateral externally controlled magnetic device implantation with a rib cradle and pelvic hook fixation was introduced by us in 2011. By using a bilateral single-rib or double-rib cradle fixation and a pelvic hook, the magnetic device is percutaneously inserted. The spine corrects indirectly without further manipulation. In small rib diameter or severe osteoporosis, double-rib cradles are used. Our introduced technique enables modification of the rib vertebral angle, which may be beneficial in children with spinal muscular atrophy and rib-cage deformity. This nonrandomized prospective study describes 18 children with neuromuscular scoliosis treated first by this method. All patients followed the same protocol, with expansion procedures being performed 5 months after surgery and every 3 months thereafter. Clinical, radiologic, and complication data were analyzed, showing a significant reduction in scoliosis and pelvic obliquity and an increase in spinal length, which could be maintained over a follow-up period of 1.2 years. The overall complication rate was lower than previously described, with 8%, 2 of them requiring surgery.

Spinal deformity changes in children with long-term vertical expandable prosthetic titanium rib treatment.

BACKGROUND CONTEXT: In several studies, vertical expandable prosthetic titanium rib (VEPTR) implants have shown good scoliosis control in children with the longest reported follow-up of 3.6 years. For growing rods, recent studies suggest a decreased efficiency of correction starting just after that time. To our knowledge, no long-term results of children with VEPTR treatment are available. PURPOSE: This study aimed to evaluate spinal deformity in scoliotic children and to investigate correction potential of VEPTR implants at several time points of treatment, particularly after long-term follow-up. STUDY DESIGN/SETTING: We performed a retrospective case series of 32 children with spinal deformity and VEPTR treatment with analysis of clinical and radiological data pre- and post-VEPTR implantation and every 2 years during the follow-up period. PATIENT SAMPLE: Thirty-two patients with spinal deformity and VEPTR treatment comprised the patient sample. OUTCOME MEASURES: Patients had a primary VEPTR implantation due to spinal deformity and thoracic insufficiency syndrome and repeated lengthening procedures every 6 months. Clinical data were assessed and radiological parameters were analyzed. The main thoracic scoliotic curve and associated curves as well as kyphosis, lordosis, pelvic obliquity, and spinal length were measured in all radiographs until the end of VEPTR treatment or the last available examination. METHODS: Development of the different parameters during follow-up was evaluated and statistical analysis was performed with Statistica version 13.0. No funding was obtained for this study. The authors have no conflicts of interest to declare. RESULTS: Directly after VEPTR implantation, thoracic and lumbar curves corrected significantly, were stable at 2.8-year follow-up, and increased at 5.5-year follow-up, whereas cervical scoliosis was not affected by the treatment. The sagittal profile was initially improved both in kyphosis and lordosis. However, at 5.5-year follow-up, hyperkyphosis had deteriorated beyond the initial deformity. Pelvic obliquity was significantly restored especially in neuromuscular patients, and increasing spinal length was achieved within the 5.5-year follow-up. CONCLUSION: In children with spinal deformity, implantation of the VEPTR device sufficiently corrected the deformity in all planes. During long-term follow-up, scoliosis increased slightly and was rather well controlled, whereas the implant system was not able to prevent deterioration of hyperkyphosis. Pelvic obliquity was well balanced and spinal lengthening was achieved during long-term follow-up.

Magnetically Controlled Devices Parallel to the Spine in Children with Spinal Muscular Atrophy.

BACKGROUND: Children with severe spinal deformity frequently are managed with growth-friendly implants. After initial surgery, externally controlled magnetic rods allow spinal deformity correction during growth without further surgical intervention. The ability to lengthen the spine without additional surgical procedures is especially beneficial in high-risk children, such as those with spinal muscular atrophy (SMA). The purpose of the present study was to assess the level of control of spinal deformity in a homogeneous group of patients with SMA who were managed with magnetically controlled implants for 2 years. METHODS: This prospective, nonrandomized study included 21 non-ambulatory children with type-II SMA and progressive scoliosis who were managed bilaterally with a magnetically controlled implant that was inserted parallel to the spine with use of rib-to-pelvis hook fixation. Radiographic measurements of scoliotic curves, kyphosis, lordosis, pelvic obliquity, and spinal length were performed before and after implantation of the magnetically controlled device and during external lengthening. The mean duration of follow-up was 2 years. RESULTS: The mean main curve of patients without prior vertical expandable prosthetic titanium rib (VEPTR) treatment decreased from 70° before implantation of the magnetically controlled device to 30° after implantation of the device. Correction was maintained during the follow-up period, with a mean curve of 31° at the time of the latest follow-up at 2.2 years. Pelvic obliquity was surgically corrected by 76% (from 17° to 4°) and remained stable during follow-up. Thoracic kyphosis could not be corrected within the follow-up period. Spinal length of children without prior spinal surgery increased by >50 mm immediately after device implantation and steadily increased at a rate of 13.5 mm/yr over the course of treatment. During treatment, 4 general complications occurred and 6 lengthening procedures failed, with 3 patients requiring surgical revision. CONCLUSIONS: Bilateral implantation of an externally controlled magnetic rod with rib-to-pelvis fixation represents a safe and efficient method to control spinal deformity in children with SMA, achieving sufficient and stable curve correction as well as increased spinal length. The complication rate was lower than those that have been described for VEPTR and other growing rod instrumentation strategies. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Treatment of Early-Onset Spinal Deformity (EOSD) With VEPTR: A Challenge for the Final Correction Spondylodesis-A Case Series.

STUDY DESIGN: Case Series. OBJECTIVE: To describe the post-VEPTR (vertical expandable prosthetic titanium rib) treatment changes in early-onset spinal deformity (EOSD), which may influence the final correction spondylodesis. SUMMARY OF BACKGROUND DATA: The VEPTR device, originally developed for the treatment of congenital rib cage malformation, is nowadays more widely used in the treatment of EOSD. At present, only a few reports describe the possible complications that may occur with repeated lengthening procedures of the VEPTR, thereby making the final spondylodesis more complicated and less satisfactory. METHODS: X-rays of 5 children treated for EOSD with 2 unilateral VEPTR (each rib to rib and rib to lumbar lamina) were analyzed for curve patterns and Cobb angles before, during, and at the end of VEPTR treatment, and after the final spondylodesis. Intraoperative observations during the spondylodesis, which influenced the possibilities of the curve correction, were documented. RESULTS: All patients showed a marked decompensation of the frontal balance and a high degree of rigidity of the main curve and the compensatory curves after treatment with the VEPTR device. Because of this spontaneous autofusion of spinal segments, migration of the rib cradles and/or the laminar hook, and a change in the curve patterns, the final fusion had to be longer in all patients than the primary deformity would have intended. CONCLUSIONS: If an EOSD is treated with VEPTR, the curve progression and, in particular, the development of a high thoracic hyperkyphosis or rotation of the main curve should be critically observed. Autofusion of ribs and vertebral bodies may make the final correction spondylodesis even more challenging and risky for the patient and the end result less satisfactory.

Ossifications after vertical expandable prosthetic titanium rib treatment in children with thoracic insufficiency syndrome and scoliosis.

STUDY DESIGN: Retrospective analysis of 1328 spinal radiographs of 57 patients after vertical expandable prosthetic titanium rib (VEPTR) implantation with an average follow-up of 30 months. OBJECTIVE: To evaluate the incidence, time of onset, as well as the underlying factors influencing the occurrence of ossifications in children treated with VEPTR. SUMMARY OF BACKGROUND DATA: Spontaneous spinal fusions and ossifications are well known in children treated with spinal implants. In theory, children with spinal deformity and VEPTR implantation are less likely to develop these complications because of either little or no implant contact to the spine. METHODS: Fifty-seven patients had a primary VEPTR implantation due to spinal deformity and thoracic insufficiency syndrome and repeated lengthening procedures. The mean age at the time of primary surgery was 7.7 years, the mean duration of follow-up was 29.8 months, and the mean number of operations was 5.9. A total of 1328 spinal radiographs were analyzed with respect to the occurrence and growth of ossifications, implant migration, and other complications. RESULTS: Overall, 24% of the patients (n = 13) had ossifications, which affected in 92% the main load sharing VEPTR implant. The fusions involved in 54% of cases the lumbar spine and in each 23% the ribs and the iliac crest. Ossifications developed in 11% of children within the first year of treatment and increased by about the same rate per annum. After 53 months, 48% of the radiographs showed some ossifications. There was a significant correlation to the stiffness of the deformity and the number of surgical procedures. CONCLUSION: Contrary to previous assumptions, it was shown that in children treated with the VEPTR system, 48% of children showed ossifications after 53 months. Ossifications were observed significantly more often in children with stiff deformities and after multiple surgical procedures. It is a much more common problem than previously thought. LEVEL OF EVIDENCE: 3.