Aims. Magnetically controlled growing rods (MCGR) have been gaining popularity in the management of early-onset scoliosis (EOS) over the past decade. We present our experience with the first 44 MCGR consecutive cases treated at our institution. Methods. This is a retrospective review of consecutive cases of MCGR performed in our institution between 2012 and 2018. This cohort consisted of 44 children (25 females and 19 males), with a mean age of 7.9 years (3.7 to 13.6). There were 41 primary cases and three revisions from other rod systems. The majority (38 children) had dual rods. The group represents a mixed aetiology including idiopathic (20), neuromuscular (13), syndromic (9), and congenital (2). The mean follow-up was 4.1 years, with a minimum of two years. Nine children graduated to definitive fusion. We evaluated radiological parameters of deformity correction (Cobb angle), and spinal growth (T1-T12 and T1-S1 heights), as well as complications during the course of treatment. Results. The mean Cobb angles pre-operatively, postoperatively, and at last follow-up were 70° (53 to 103), 35° (15 to 71) and 39° (15 to 65) respectively (p < 0.001). Further, there was a mean of 14° (-6 to 27) of additional Cobb angle correction upon graduation from MCGR to definitive fusion. Both T1-T12 and T1-S1 showed significant increase in heights of 27 mm and 45 mm respectively at last follow-up (p < 0.001). Ten children (23%) developed 18 complications requiring 21 unplanned operations. Independent risk factors for developing a complication were single rod constructs and previous revision surgery. Conclusion. MCGR has the benefit of avoiding multiple surgeries, and is an effective tool in treatment of early-onset scoliosis. It also maintains the flexibility of the spine, allowing further correction at the time of definitive fusion. Cite this article: Bone Joint Open 2020;1-7:405–414

Introduction. Growing rods are used in the treatment of early-onset scoliosis. The aim of this technique is to achieve deformity correction while maintaining spinal growth. Gradual stiffening or spontaneous fusion of the spine can interfere with the ability to lengthen. Furthermore, diminished acquired length with serial distraction is common and needs to be evaluated and quantified. The purpose of this prospective study was to measure the forces and amount of distraction over time in patients with early-onset scoliosis treated with growing rods. Methods. Distraction forces were measured prospectively during 60 consecutive lengthening procedures in 26 patients. All patients had single submuscular rod constructs with side-to-side connectors. For every measurement, output from a transducer on a dedicated pair of distraction calipers was recorded at zero load status, and the force was then recorded at every 1 mm lengthening; length was obtained at each event and was recorded in millimeters. Results. The force required to distract the spine doubled at the fifth lengthening procedure (mean 368 N [SD 54]), and the distraction force was significantly higher at the fifth lengthening than at previous lengthening (p<0·01). Mean length achieved at each distraction decreased over time, such that by the fifth lengthening, 8mm or less was consistently achieved. Conclusions. Distraction forces increase significantly after repeated lengthening of growing rod constructs, and the length obtained at each procedure decreases

Introduction. Sparing of the spinal growth and scoliotic deformity control in patients with early-onset scoliosis is a challenge in spinal surgery. Loss of the surgical correction, implant breakage, and revision surgeries are the main disadvantages of present treatment methods. The purpose of this study is to investigate whether growing transpedicular instrumentation spares achieved surgical correction during patient's growth. Methods. This is a prospective study of 12 consecutive patients with early-onset scoliosis from one clinical centre. All patients underwent anterior convex growth arrest and posterior transpedicular instrumentation with growing construct. Spinal derotation was used for the correction of the deformity. The diagnoses were infantile idiopathic (n=10) and congenital (n=2) scoliosis (formation failure). Follow-up was 3 years. Mean age at the time of surgery was 9·1 years. Results. Preoperative major Cobb angle was 74·3° (range 52–100°), minor Cobb angle was 32·2° (5–50°), and average preoperative thoracic kyphosis was 27·2° (0–63°). Mean number of the instrumented levels was 12·2. Postoperative major Cobb angle was 22·4° (0–40°), minor Cobb angle was 5·7° (0–23·5°), and postoperative thoracic kyphosis was 26·2° (6–41°). After 3 years of follow-up, primary curve was an average of 22·7° (10–40°), secondary curve was 5·4° (0–25°), and mean thoracic kyphosis was 28° (12–40°). Mean growth of the instrumented spine was 18 mm. We did not observe any gross complications in the patients. Two patients had pleural effusion, and one needed rod exchange 15 months after primary surgery because of insufficient length. Conclusions. The results of this study show that anterior convex growth arrest and polysegmental transpedicular spinal instrumentation with growing construct save spinal growth and anatomical values achieved after surgical correction. Rod derotation for the deformity correction favours spinal growth in skeletally immature patients

SUMMARY. A retrospective cohort study of 19 patients of EOS who underwent MCGR rod instrumentation with subsequent serial distractions, measured using ultrasonography. The degree of distraction achieved during each session were analyzed and subgroup analysis done. HYPOTHESIS. The degree of distraction/ distractibility of the MCGR rod is closely linked to the etiology of EOS. The degree of distraction achieved at each session progressively diminishes with successive distractions. STUDY DESIGN. Retrospective cohort study. INTRODUCTION. MCGR rods have gained popularity as an alternative to traditional growing rods for the treatment of Early-onset scoliosis (EOS), serially distracting with an aim to mimic the normal spinal growth, which can be achieved in an outpatient setting using external remote controller. The use of ultrasound as a tool to measure the degree of distraction achieved has been validated previously. However the association between the etiological diagnosis of EOS and the degree of distraction achieved has not been studied previously. METHODS. We performed a retrospective cohort study of 19 patients with EOS of varying etiologies who underwent MCGR rod instrumentation at our institution since 2016. Their hospital records were analyzed to assess the demographics, distraction interval and the degree of distraction achieved at each session. RESULTS. 19 patients (12 females and 7 males) were included in the study. The average age of the study population was 7 years (4–13 years). The average follow up was 2.1 years (1–4). The following were the etiological diagnoses: Idiopathic EOS(8), Neuromuscular scoliosis(5), Syndromic(5), Congenital(1). The average interval between each distraction was 109.8days (88.2–140.6). The overall mean distraction was 1.66mm (0.6–3.427). The mean distraction achieved for the concave rod was 1.69mm (0.6–3.03) as against 1.59mm (0.2–3.427) for the convex rod. The degree of distraction achieved per session was the greatest in patients with neuromuscular scoliosis 2.79mm (0.94–4.62), while it was the least in Congenital scoliosis 0.99mm (0.8–2.93). The degree of distraction in Syndromic and Idiopathic scoliosis groups were 2.19mm (0.1–4.2) and 1.50mm (0.2–4.45) respectively. The mean distraction achieved during the first session after MCGR instrumentation was 2.82mm (0.4–9.8) as against 1.98mm (0.1–4.2) and 1.18mm (0.2–2.3), achieved during the 5. th. and 10. th. distractions respectively. CONCLUSIONS. The average distraction of the MCGR rod achieved per session depends upon the etiological diagnosis of EOS. Neuromuscular curves are the most amenable to MCGR distractions, while the congenital curves are the least. The degree of distraction achieved progressively diminishes with each successive distractions. The distraction achieved slumps to 70% of the initial distraction by the 5. th. session and further declines to 41% of the initial distraction by the 10. th. session. TAKE HOME MESSAGE. The distractibility of the MCGR rod is closely linked to the etiology of EOS. MCGR rods are most effective in cases of neuromuscular scoliosis, while least effective in congenital scoliosis. The law of diminishing returns holds true even with MCGR rods

Introduction. Many methods are available for distal anchoring of spine-based and rib-based growing rod systems for early-onset scoliosis. One of these methods, pelvic S-hooks, was initially recommended for patients with spina bifida or for those with severe thoracolumbar curves. No study has yet analysed the clinical and radiographic effects of S-hooks on patients with rib-based instrumentation. The purpose of this study is to retrospectively review the results of S-hook pelvic fixation in patients with rib-based instrumentation. Methods. A multicentre, retrospective study, approved by the institutional review board, was undetaken in all patients treated with rib-based constructs using S-hooks for pelvic fixation. Preoperative and postoperative clinical variables, radiological measurements, and the incidence and management of complications were evaluated in patients with a minimum follow-up of 2 years. Results. 44 patients, 26 of whom were girls, were studied and had a mean age at surgery of 71 months. The most common surgical indication was progressive neuromuscular scoliosis. The average preoperative Cobb angle was 64° and at most recent follow-up (mean 45 months) was 53°. The most common construct was dual rods resting over the iliac crest without suture to the iliac crest extending from T3/T4 ribs to the pelvis using domino connectors. 45% of the patients had complications, of which S-hook migration after the initial procedures was the most common. S-hook migration was corrected at the next lengthening with repositioning of the hook to the iliac crest. No correlation was detected between the complication rates and the clinical, radiographic, and surgical technique variables evaluated. Conclusions. Control of spinal deformities without fusion presents several challenges. S-hooks can migrate off the iliac crest, requiring repositioning of implants during subsequent lengthening. This finding highlights the need to explore different fixation techniques with a stronger attachment to the iliac crest

Introduction. Spinopelvic parameters describe the orientation, shape, and morphology of the spine and pelvis. In children without spinal deformity, these parameters change during the first 10 years of life; however, spinopelvic parameters need to be defined in children with significant early-onset scoliosis (EOS). The purpose of this study is to examine the effects of EOS on sagittal spinopelvic alignment. We hypothesise that sagittal spinopelvic parameters for patients with EOS will differ from age-matched children without spinal deformity. These values will act as a baseline for future studies and may predict postoperative complications such as proximal junctional kyphosis and implant failure in children being treated with growing systems. Methods. Standing, lateral radiographs of 82 untreated patients with EOS with Cobb angle greater than 50° were evaluated. Sagittal spine parameters (sagittal balance, thoracic kyphosis [TK], lumbar lordosis [LL]) and sagittal pelvic parameters (pelvic incidence [PI], pelvic tilt [PT], sacral slope [SS], and modified pelvic radius angle [PR]) were measured. These results were compared with those reported by Mac-Thiong and colleagues (Spine, 2004) for a group of similar aged children without spinal deformity. Results. Patients had a mean age of 5·17 years and mean Cobb angle of 73·3° (□}17·3°). Mean sagittal spine parameters were: sagittal balance (+2·4 cm [□}4·03]), TK (38·2° [□}20·8°]), and LL (47·8° [□}17·7°]). These values were similar to those reported for asymptomatic patients (table). Mean sagittal pelvic parameters were: PI (47·1° [□}15·6°]), PT (10·3° [□}10·7°]), SS (35·5° [□}12·2°]), and PR (57·1° [□}21·2°]). Although PI was similar to age-matched controls, PT was significantly higher and there was a trend for lower SS in the study population. Conclusions. Sagittal plane spine parameters in children with EOS were similar to those in children without spinal deformity. Pelvic parameters (PI, SS, PR) were similar between groups; however, children with EOS had signs of pelvic retroversion (increased pelvic tilt)

Introduction. Spinopelvic parameters describe the orientation, shape, and morphology of the spine and pelvis. These parameters change during the first 10 years of life in children without spinal deformity; however, spinopelvic parameters have yet to be defined in children with significant early-onset scoliosis (EOS). Sagittal plane alignment could affect the natural history and outcome of interventions for EOS. As a result, spinopelvic parameters are being defined for this population. On the basis of the landmarks used for measurement of these parameters, there may be inherent error in performing these measurements on the immature pelvis. The purpose of this study is to define the variability associatedwith the measurement of spinopelvic parameters in children with EOS. Methods. Standing, lateral radiographs of 11 patients with untreated EOS were evaluated. Sagittal spinopelvic parameters (pelvic incidence [PI], pelvic tilt [PT], sacral slope [SS], and modified pelvic radius angle [PR]) were measured. To assess intraobserver reliability, these measurements were repeated 15 days apart. To define interobserver reliability, radiographs were measured by 2 independent observers. Results. Average age was 5·7 years and average Cobb angle was 80·8°. Repeated measurements by one observer showed no significant differences for any of the parameters. Paired samples correlations showed a moderate correlation between measurements of PI (0·564), whereas stronger correlations were demonstrated for measurements of PT (0·816), SS (0·947), and PR (0·789). Interobserver analysis showed a significant difference in measurement of SS (p=0·003), whereasmeasurements of PI, PT, and PR did not differ significantly between independent observers. Conclusions. Intraobserver variabilty yielded acceptable correlations for PT, SS, and PR; however, we noted only a moderate correlation for PI. Interobserver analysis showed a significant difference only in SS. The intraobserver and interobserver variablity of measurements for PT and PR were superior than were those for PI and SS. This finding may be related to difficulties in determining the orientation of the sacral endplate in the immature pelvis when measuring PI and SS

Introduction. Children with early-onset scoliosis (EOS) with rib hump chest-wall distortion or fused/absent ribs have thoracic insufficiency syndrome (TIS). Commonly, respiration is adversely affected by loss of lung volume from chest-wall constriction and clinical loss of active rib cage expansion. The dynamic thoracic components of diaphragm or rib cage lung expansion during respiration is poorly characterised by radiograph or CT scan. Pulmonary function tests indicate only hemithorax performance. Dynamic lung MRI, however, can visualise both chest-wall and diaphragm motion, allowing assessment of each individual hemithorax performance, so that a dynamic classification system of the thoracic function can be developed. Methods. Ten patients with TIS underwent dynamic lung MRI testing as part of the routine clinical preoperative work-up. Each hemithorax was graded: 1=intact motion of both chest wall and diaphragm; 2=primarily loss of chest-wall motion with minimal diaphragm abnormality; 3=substantial loss of diaphragm excursion with minimal loss or compensatory hyperkinesis of chest wall; and 4=substantial loss of both diaphragm and chest-wall motion. The grades for each hemithorax were added and averaged to form the thoracic function score. Ranges of scores were grouped into levels of clinical thoracic performance: level I (score 1–1·5); level II (>1·5–2·5); level III (>2·5–3·5); and level IV(>3·5–4·0). Results. Of nine patients with EOS, two were level I, three were level II, and four were level III. In four patients there was marked posterior obstruction of diaphragmatic excursion by soft-tissue organs. One patient with hypoplastic thorax without scoliosis was level II. Conclusions. Thoracic function index is a new thoracic performance approach based on dynamic lung MRI that has potential to identify biomechanical abnormalities of the thorax in EOS that cause restrictive lung disease. This index could provide insight into how to reverse the abnormality with new types of surgeries. Posterior obstructive blockade of the diaphragm is identified as a new cause for restrictive lung disease in EOS

Introduction. The change of position of the distal pedicle screws with growing rods in relation to vertebral bodies was described as pedicle screws migration. Pedicle screws are subjected to serial distractive forces pushing them down with every distraction; additionally there is continuous growth of the vertebral bodies during the treatment period. These two factors can affect the change of position of the pedicle screws in relation to the vertebrae during the use of growing rods. To our knowledge, this finding has never been studied, confirmed, or quantified. Methods. This is a retrospective review of the radiographs and operative notes of 23 consecutive cases of early-onset scoliosis treated with single growing rods. Age at index surgery ranged from 4 years 2 months to 8 years 9 months, and the number of distractions was four to 11 per patient. Measurements were done on post-index and latest follow-up true lateral radiographs. With optimum initial position of the screws in the pedicle, we calculated the distance between the upper end plate and the pedicle screw (distance superior to the screw [SS]) and the distance between the screw and lower-end plate (distance inferior to the screw [IS]). We expressed this ratio as a percentage: SS/IS x 100%. Any increase in this percentage with time denoted a more caudal position; however, a change in the percentage of less than 10% was regarded as insignificant. Results. Seven cases were excluded because of inadequate radiographs for measurements. Within the distal construct, measurements of the upper pedicle screw showed that six cases had a change of less than 10% and were regarded as insignificant. Ten cases had changes of more than 10%, five had changes between 10% and 50%, three between 50% and 100%, and two more than 100%. We identified two types of migration: the first within the pedicle with pedicle elongation, and the second through and distal to the pedicle. None of the patients had adverse clinical consequences related to this change. Conclusions. Change of screw position with time is a frequent occurrence in the distal pedicle screws with single growing rods. Two different types were identified. With growing rods some degree of distal pedicle screw migration in this paediatric age group may not be regarded as a complication of treatment

Objective: To assess the treatment outcome at a minimum age of 15 years in patients who had presented with idiopathic scoliosis in infancy. Design: Patients were recalled for full pulmonary function testing (spirometry, lung volumes and gas diffusion) and surface topography. Results were correlated with history and clinical radiographs. Subjects: The records showed 32 patients, of whom 23 could be contacted and agreed to take part in the study. Thirteen had no other abnormality, and 9 had a variety of additional problems not thought to directly precipitate their spinal deformity. There were 13 female and 9 male and age at testing ranged from 15.2 to 30.2 years. Outcome measures: Spirometry (forced vital capacity (FVC), forced expiratory volume in one minute (FEV. 1. )), lung volumes ( total lung capacity (TLC), residual volume (RV)) and gas diffusion (carbon monoxide diffusion (DLCO), and alveolar volume (VA)) were correlated with the most recent Cobb angle, surface topography and age at surgery where applicable. Results: Those who were successfully managed without recourse to surgery (N=6) had normal cosmesis and pulmonary function (mean FEV. 1. = 98.7%, mean FVC = 96.6%). When surgery had been postponed until after age 10 (N=6, mean age at surgery 12.9 years) pulmonary function showed some restriction (mean FEV. 1. = 79%, mean FVC = 68.3%). Those who underwent corrective surgery before age 10 years (N=11, mean age at surgery 4.1 years) had significant recurrence of deformity and diminished respiratory function (mean FEV. 1. = 41%, range 14 – 72%, mean FVC = 40.8%, range 12 – 67%). There was statistically significant correlation (p< 0.01 or less) between respiratory measures on the one hand and age at surgery (where applicable), surface topography measures and latest Cobb angle. Conclusions: It has been reported that only in early-onset scoliosis is the growth of lung tissue and the multiplication of alveoli impeded[. 1. ,. 2. ] and treatment is directed at preserving both pulmonary function and cosmesis. Early surgery is recommended on the assumption that the Cobb angle can be controlled and normal pulmonary development enabled in those whose scoliosis did not respond to conservative methods. Methods have changed since the earlier cases in this series were treated, and it is hoped that later results will be different. However, caution requires that, in monitoring these patients, cosmesis and, more importantly, respiratory function be considered before a conclusion is drawn

Aims

This study aims to enhance understanding of clinical and radiological consequences and involved mechanisms that led to corrosion of the Precice Stryde (Stryde) intramedullary lengthening nail in the post market surveillance era of the device. Between 2018 and 2021 more than 2,000 Stryde nails have been implanted worldwide. However, the outcome of treatment with the Stryde system is insufficiently reported.

Objectives

The Precice nail is the latest intramedullary lengthening nail with excellent early outcomes. Implant complications have led to modification of the nail design. The aim of this study was to perform a retrieval study of Precice nails following lower-limb lengthening and to assess macroscopical and microscopical changes to the implants and evaluate differences following design modification, with the aim of identifying potential surgical, implant, and patient risk factors.

The June 2012 Children’s orthopaedics Roundup³⁶⁰ looks at; open reduction for DDH; growing rod instrumentation for scoliosis; acute patellar dislocation; management of the relapsed clubfoot; clubfoot in Iran; laughing gas and fracture manipulation; vascularised periosteal fibular grafting for nonunion; slipped upper femoral epiphysis; intramedullary leg lengthening and orthopaedic imaging and defensive medicine.