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Objective: To evaluate curve correctability, complications, and rate of growth following treatment. Background: Distraction-founded techniques such as traditionally growing rods or magnetically controlled growing rods are the almost globally accepted management patterns for early onset scoliosis. However, periodic lengthening operations are still needed. Moreover, an MCGR is difficult to contour, and implant-associated problems are common. We developed concave side apical control of the growing rod in which an additional anchor site is inserted at the apex to enhance stability and assist in the adjustment of axial deformity. Methods: Entirely skeletally immature early onset scoliosis (EOS) cases with a progressive curve of >40° and without bone or soft tissue weakness were appropriate for this study. Coronal Cobb angle, sagittal parameters, complications, spinal length, and reoperations were documented with at least a 3-year follow-up. Results: In this study, 15 patients were involved. The mean age was 7 years. The mean preoperative Cobb angle was 48°, which postoperatively became 12° with the percentage of coronal correction reaching 75.73%. The mean Cobb angle degrees of correction were 39°. T1-S1 height increased by 10 mm/year. Postoperative complications occurred in two cases with single rod technique and rod breakage. Conclusions: The concave side apical control of the growing rod seems to be a hopeful surgical procedure for the management of EOS. Curve correctability in patients was 60% and can be sustained for a minimum of 2 years. Reoperations and complications might not be constricted, but the complication frequency looks more reasonable than in the current systems.

Background: Spinal deformities in children and adolescents can be easily divided into those occurring and diagnosed before the age of 10—early-onset scoliosis—and those occurring and diagnosed after the age of 10—late-onset scoliosis. When the curvature continues to progress and exceeds a Cobb angle of more than 60–65 degrees, surgical treatment should be considered. The most common treatment procedure for EOS is the surgical correction of the deformity using standard growing rods (SGRs), and in the case of congenital defects with additional hemivertebrae, it is the resection of the hemivertebra and short fusion. Minimally invasive controlled growing rods (MICGRs) need to be distracted every 6–9 months through a minimally invasive approach that involves sedation and neuromonitoring to obtain the best possible correction while minimizing complications. The aim of our study is to present a less-invasive surgical technique for MICGR implantation based on a two-case presentation—early-onset idiopathic scoliosis and congenital kyphosis. The surgical technique is the less-invasive percutaneous and subfascial implantation of MICGRs without long incisions in the back. Conclusions: The use of MICGRs is an alternative and safe surgical technique for patients undergoing surgical treatment for EOS. Without the risk of metallosis, like in other implant systems, and the need for replacement after 2 years of use, like in using magnetically controlled growing rods (MCGRs), the MICGR system can be used as a less-invasive procedure, allowing for the avoidance of many periodic invasive procedures in children with a wider opening of the spine (like in using standard growing rods), minimizing the number of planned hospitalizations, reducing the length of hospital stays, and reducing the physical and mental burdens on young patients, parents, and families. [ABSTRACT FROM AUTHOR]

Study design: This was a retrospective cohort study. Objective: There are preoperative characteristics that predict rod lengthening of magnetically controlled growing rods (MCGR). The lengthening of MCGR will lead to increased kyphosis. Summary of background data: The amount of length gained by MCGR is variable, and predictors are lacking. Similarly, sagittal plane changes over the MCGR lengthening period have not been investigated. Materials and methods: Patients with MCGR and a minimum 2-year follow-up were identified and those with previous spine surgery were excluded. Preimplantation, postimplantation, and last follow-up postlengthening radiographs were examined. Multiple linear regression analyses were used for rod length gain predictors. Results: Fifty-six patients with early-onset scoliosis met inclusion criteria: nine idiopathic, five congenital, 14 neuromuscular, 20 syndromic, and eight skeletal dysplasia patients. No difference was seen between subtypes of early-onset scoliosis for rod length gain ( P =0.62). Shorter preoperative T1-T12 height and higher curve correction rate after implantation were significant predictors for rod length gain ( P <0.001). Preoperative major curve magnitude and kyphosis were not significant predictors. Flattening of the spine around the actuator and compensative increase in T1-T5 kyphosis were seen secondarily after MCGR implantation. Maximum sagittal kyphosis, T1-T5 kyphosis, and T5-T12 kyphosis did not change during lengthening. Lumbar lordosis significantly decreased postimplantation (first erect) but then increased during lengthening. Pelvic incidence and sacral slope both increased during lengthening, but this may be age related. Conclusion: Patients who gained the most rod length with MCGR were those with an initially shorter T1-T12 height and better initial curve correction at implantation, likely representing that implants work best in small patients with flexible curves. Diagnosis, preoperative curve magnitude, and thoracic kyphosis were not related to rod length gain. Thoracic kyphosis did not deteriorate over the lengthening phase. Level of evidence: Level III-retrospective cohort study. [ABSTRACT FROM AUTHOR]

Background: The posterior procedure utilizing growth-friendly techniques is the golden standard for patients with early-onset scoliosis combined with thoracic insufficiency syndrome (EOS + TIS). Pulmonary hypoplasia is the main cause of dying prematurely in the EOS + TIS. This study assessed the therapeutic impact of a novel growth-friendly system on the pulmonary development of piglet's EOS + TIS model. Methods: The animal procedure period lasts 12 weeks, of which the construction of the EOS + TIS was performed at 0–8 weeks, and implantation of a novel growth-friendly system was applied at 8–12 weeks. During the animal procedure, X-rays and CT were performed to observe scoliosis, thorax, and lungs. After 12 weeks, pathological changes in lung tissue were assessed using HE and IHC staining. RNA-seq characterized novel growth-friendly system-associated differentially expressed genes (DEGs) and validated using RT-qPCR, western blotting, and IHC. Results: Implantation of the novel growth-friendly system increased body weight, body length, and total lung volume, as well as decreased the coronal and sagittal Cobb angles for the EOS + TIS model. It also ameliorated EOS + TIS-induced thickening of the alveolar wall, increased alveolar spaces, and decreased alveolar number and diameter. In lung tissue, a total of 790 novel growth-friendly system-associated DEGs were identified, and they were mainly involved in the regulation of immune, inflammatory, calcium transport, and vascular development. Among these DEGs, BDKRB1, THBS1, DUSP1, IDO1, and SPINK5 were hub genes, and their differential expression was consistent with RNA-seq results in lung tissues. Conclusion: The novel growth-friendly system has mitigated scoliosis and pulmonary hypoplasia in the EOS + TIS model. We further elucidate the molecular mechanisms underlying the amelioration of pulmonary hypoplasia.

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

In this study, the focus is on an implant used in the treatment of early-onset scoliosis called magnetically controlled growing rods (MCGR). The primary goal of the study is to address and propose solutions for the mechanical problems reported in the literature concerning MCGR. The problems of the MCGR are mainly due to excessive stress and mechanical bearing problems. Therefore, an MCGR removed from a patient is teardown and geometrically modeled. Then, eleven design parameters are determined on the MCGR for the mechanical problems experienced and these are evaluated by mechanical analysis over 14 control points. In this study, analysis processes are carried out with L12 orthogonal array for eleven design parameters and 2 levels using Taguchi’s experimental design method (DoE). With the obtained data by analyzing the experiments in L12, the fitness functions depending on the design parameters are created for 14 control points. Since the problem is multi-objective, a non-dominated sorting genetic algorithm (NSGA II) and multi-objective particle swarm optimization (MOPSO) are used to minimize stress and displacement in existing mechanical problems using fitness functions. The obtained design models from NSGA II and MOPSO are analyzed and evaluated in comparison with the existing mechanical model obtained through pre-optimization teardown study of MCGR.

Purpose: This updated meta-analysis aimed to compare single and dual growing rods, including both traditional growing rod and magnetically controlled growing rod (MCGR) used in the treatment of early-onset scoliosis (EOS) with regard to deformity correction, spinal growth, and complications. Methods: This meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using articles extracted from PubMed, EMBASE databases, and Cochrane Library databases. Only articles reporting the complications and the imaging parameters before and after growing rods in the patients diagnosed with EOS were included. We extracted and statistically analyzed the data deemed relevant for this study, and used the Newcastle–Ottawa Scale to assess the risk of bias in each study. Data synthesis and statistical analyses were performed using R software. Results: Fifteen eligible articles containing 409 participants (n = 185, single growing rods; n = 224, dual growing rods) were identified. The meta-analysis found no significant differences in the preoperative and postoperative major Cobb angle, T1–S1 distance, thoracic kyphosis, and coronal balance between single and dual rods groups. The final follow-up major Cobb angle (P = 0.01; standardized mean difference, − 0.42 [95% confidence interval (CI), − 0.74 to − 0.10]; I2 = 23%) was significantly smaller in dual rods group than single-rod group. However, no significant differences in the correction rate of angle (major Cobb angle and kyphosis angle) and changes in the T1–S1 distance between the two groups were observed. Moreover, there were no significant differences in the metalwork failure, infection, or proximal junctional kyphosis between single and dual rods groups. However, total complications (P = 0.03; risk ratio (RR), 0.79 [95% CI, 0.63–0.98]; I2 = 29%) and distraction failure in MCGR (P = 0.04; RR, 0.38 [95% CI, 0.14–0.98]; I2 = 11%) were significantly lower in dual rods group than single-rod group. Conclusion: This updated meta-analysis found that patients with dual growing rods had fewer complications, especially distraction failure in MCGR, than those with single growing rod. However, none of deformity correction, spinal growth, or other complications differed between single and dual growing rods. Therefore, we believe that dual growing rods do not provide strong advantages over single growing rod in the treatment of EOS. [ABSTRACT FROM AUTHOR]

Abstract Background Obtaining and maintaining final shoulder balance after the entire treatment course is essential for early-onset scoliosis (EOS) patients. The relatively small number of growing-rod (GR) graduates who complete final fusion has resulted in an overall paucity of research on the GR treatment of EOS and a lack of research on the shoulder balance of EOS patients during GR treatment. Methods Twenty-four consecutive patients who underwent GR treatment until final fusion were included. Radiographic shoulder balance parameters, including the radiographic shoulder height (RSH), clavicle angle (CA), and T1 tilt angle (T1T), before and after each step of the entire treatment were measured. Shoulder balance changes from GR implantation to the last follow-up after final fusion were depicted and analysed. Demographic data, surgical-related factors, and radiographic parameters were analysed to identify risk factors for final shoulder imbalance. The shoulder balance of patients at different time points was further analysed to explore the potential effect of the series of GR treatment steps on shoulder balance. Results The RSH showed substantial improvement after GR implantation (P = 0.036), during the follow-up period after final fusion (P = 0.021) and throughout the entire treatment (P = 0.011). The trend of change in the CA was similar to that of the RSH, and the T1T improved immediately after GR implantation (P = 0.037). Further analysis indicated that patients with shoulder imbalance before final fusion showed significantly improved shoulder balance after fusion (P = 0.045), and their RSH values at early postfusion and the final follow-up did not show statistically significant differences from those in the prefusion shoulder balance group (P > 0.05). Early postfusion shoulder imbalance (odds ratio (OR): 19.500; 95% confidence interval (CI) = 1.777–213.949; P = 0.015) was identified as an independent risk factor for final shoulder imbalance. Conclusions Shoulder balance could be improved by GR implantation but often changes during the multistep lengthening process, and the final result is relatively unpredictable. Final fusion could further adjust the prefusion shoulder imbalance. Focusing on the prefusion shoulder balance of GR graduates and providing patients with early shoulder balance after fusion might be necessary.

Abstract Background Treatment of early-onset scoliosis (EOS) is still a challenge to patients, families, and surgeons. Previous studies have indicated that EOS patients are at high risk for complications following growth-friendly surgery. This study was performed to evaluate the results and complications of all-pedicle screw dual growing rod instrumentation in the treatment of EOS. Methods In an IRB-approved retrospective study, we searched the electronic medical records of our institution for all patients who underwent posterior spinal instrumentation for scoliosis between March 2014 and March 2017. Patients under the age of 10 at the time of surgery who were treated with a growth-friendly technique were then selected. Patients with incomplete records and less than 2 years of follow-up were excluded. Charts, operative notes, clinic visits, and radiographs were extracted. Radiographs were reviewed, and the main curve Cobb angle, thoracic kyphosis, pelvic tilt, pelvic incidence, sacral slope, and proximal junctional angles were measured. We specifically looked for any intra-operative or post-operative complications. Statistical analysis was performed to determine the risk factors of complications. Results A total of 42 patients with a mean age of 4.8 ± 2.1 years (range, 1.5–8 years) were included in the final analysis. Patients were followed for a median of 34 months (range, 24–55). The major curve was corrected from a mean of 42.9° ± 10.7° to 28.8° ± 9.6° at the latest follow-up. Proximal junctional angles and thoracic kyphosis increased significantly during the follow-up period (both P values < 0.001). A total of 7 complications (17%) were observed. Four patients (10%) developed superficial surgical site infections, all of which resolved with antibiotics and one round of surgical debridement. Three cases (7%) of proximal junctional kyphosis (PJK) were encountered during the study period, none of which required revision surgery. Pre-operative thoracic kyphosis was the only significant risk factor for the development of PJK. Conclusions Our findings suggest that in settings without access to magnetically controlled growing rods, dual growing rods with all-pedicle screw instrumentation is still a viable treatment strategy with comparable results and complications. The most common complications are infection and PJK, with the latter being associated with a larger pre-operative thoracic kyphosis.

Although several studies have been reported on early-onset scoliosis (EOS), a bibliometric analysis is still lacking. A systematic bibliometric analysis will enable researchers to understand the scope of the research topics, identify research focuses and key literature, and predict future research directions. Literature data were retrieved from the Web of Science Core Collection database. The Web of Science Results Analysis and Citation Report were used to analyze the reported studies in different views. CiteSpace and VOSviewer were used for further analysis, including a cooperation network analysis of the authors, institutions, countries and/or regions, discipline and journal analysis, reference co-citation analysis, and keyword co-occurrence analysis. The final analysis included 674 relevant studies reported from 2005 to 2020. During the study period, the field of EOS has expanded rapidly. Multiple cooperation was found among the authors, institutions, and countries and/or regions, with some making great contributions. The results of the reference co-citation analysis showed that the studies had several main focuses, including the growing rod (GR), magnetically controlled GR, an EOS 24-item questionnaire, and a growth evaluation. From 2005 to 2020, surgical treatment has remained the focus of research in the EOS field. The magnetically controlled GR is the latest research focus, which might become more comprehensive in the future. The Gr has remained the most popular topic, and potential new surgical techniques might require improvement to become the favored techniques. In addition, assessing the health-related quality of life and growth parameters of patients with EOS have become a popular topic. [ABSTRACT FROM AUTHOR]

Abstract Background Spinal deformities constitute one of the most common types of manifestations of neurofibromatosis type-1 (NF-1), which can lead to either dystrophic or non-dystrophic early-onset scoliosis (EOS). Surgical treatment for EOS with NF-1 is challenging, and the outcomes have rarely been reported. The anterior-posterior procedure is widely used, but posterior-only fusion is theoretically easier and safer to perform. Is it possible that a new surgery that accommodates growth is a better choice? A direct comparison between posterior fusion and growth-friendly surgery in terms of surgical outcomes has not yet been conducted in dystrophic EOS with NF-1 patients. Methods Baseline information was extracted from the NF-1 database at our institute with approval from the local ethics committee. All enrolled patients were diagnosed with NF-1. Clinical and radiographic data were recorded preoperatively, after the initial surgery, and at the final follow-up. Implant-related, alignment, neurological complication and unplanned revision surgery data were recorded. We compared the outcomes of these two groups in terms of curve correction, growth parameters, complications and unplanned revision surgeries. Results There were eight patients in the PF group and eight patients in the GR group, with a mean follow-up of 51.0 ± 17.5 months. The main curve size was similar (PF 67.38° ± 17.43° versus GR 75.1° ± 26.43°, P = 0.501), and there were no significant differences in the initial surgery correction rate or the rate of correction. However, the patients in the GR group exhibited more T1-S1 growth during the follow-up overall and per year than did those in the PF group. The operative time was significantly longer for the PF group than for the GR group (PF, 4.39 ± 1.38 vs. GR, 3.00 ± 0.42 h; p = 0.008). Significantly fewer segments were involved in the PF group (8.25 ± 3.20) than in the GR group (13.00 ± 1.60). Conclusion For the initial treatment of dystrophic EOS in patients with NF-1, the GR technique is possibly a more appropriate treatment than is the PF technique in terms of trunk growth. However, the repeated procedures required for GR may be a considerable disadvantage. More studies with direct measurement of pulmonary function must be conducted to determine the effect of GR on pulmonary development. More studies with larger sample sizes and longer follow-up periods are needed to fully assess the treatment strategies.

Purpose The purpose of this study was to investigate pulmonary function and health-related quality of life after traditional growing rod (TGR) procedures. Methods Between January 2006 and December 2017, a retrospective observational study of 17 early onset scoliosis (EOS) patients with a mean follow-up of 6.2 years (2.3 to 10.4) was conducted. The forced expiratory volume in one second (FEV1), expiratory forced vital capacity (FVC) and 24-Item Early Onset Scoliosis Questionnaire (EOSQ-24) score before the index surgery and at last follow-up were investigated. Results The mean percentage of predicted FEV1 improved from 50% (20% to 86%) to 53% (15% to 80%; p = 0.08); and the mean percentage of predicted FVC improved from 51% (24% to 81%) to 55% (25% to 89%; p = 0.06). The mean EOSQ-24 score was 78.2 (58 to 90) preoperatively and 77.2 (55 to 88) at last follow-up, there was no statistical difference (p = 0.70). The subdomain scores of pulmonary function (p < 0.01) and daily living (p < 0.01) significantly improved, whereas the subdomain scores of pain (p < 0.01), emotion (p < 0.01) and satisfaction (p = 0.02) significantly declined at last follow-up. Conclusion The TGR procedure was associated with stable pulmonary function and decline in EOSQ-24 pain, emotion and satisfaction scores. [ABSTRACT FROM AUTHOR]

Purpose: Magnetically controlled growing rods (MCGR) allow more frequent outpatient lengthenings to better mimic the physiological growth. The assessment of distractions with radiographs raised concerns regarding ionizing radiation exposure in growing children. The aim was to assess the necessity of radiographs after every lengthening of MCGR. Methods: A retrospective analysis of 30 consecutive patients (19F, 11 M) treated in a single institution between 2011 and 2017. Planned radiographs were taken based on a protocol, updated over the years to involve less frequent acquisitions. Unplanned radiographs were obtained after a patient complaint or a significant clinical examination finding. Outcome measures were preoperative and postoperative radiographic measurements, and complications such as proximal and distal junctional kyphosis and failure, rod or actuator breakage, collapse of previously achieved height or failure to lengthen and worsening of deformity. Results: Mean age at surgery was 7.5 (4–11) years. Mean follow-up was 45 (24–84) months. Mean number of lengthenings and radiographs per patient were 14.4 (8–23), and 13.2 (5–46), respectively. Nine patients (30%) experienced a total of 13 mechanical complications. Almost all complications were detected in unplanned radiographs. The probability of detecting a mechanical complication was significantly lower (p < 0.00001) in planned radiographs. Conclusions: Radiographs taken after routine lengthenings of MCGR are not likely to reveal any significant finding, since only 0.9% of planned radiographs displayed a mechanical complication. Exposing growing children to radiation with an intention of checking the MCGR device after every lengthening could not be justified. Obtaining post-lengthening radiographs with a decreased frequency and after a significant complaint or clinical finding may be considered. [ABSTRACT FROM AUTHOR]

Background: Obtaining and maintaining final shoulder balance after the entire treatment course is essential for early-onset scoliosis (EOS) patients. The relatively small number of growing-rod (GR) graduates who complete final fusion has resulted in an overall paucity of research on the GR treatment of EOS and a lack of research on the shoulder balance of EOS patients during GR treatment.Methods: Twenty-four consecutive patients who underwent GR treatment until final fusion were included. Radiographic shoulder balance parameters, including the radiographic shoulder height (RSH), clavicle angle (CA), and T1 tilt angle (T1T), before and after each step of the entire treatment were measured. Shoulder balance changes from GR implantation to the last follow-up after final fusion were depicted and analysed. Demographic data, surgical-related factors, and radiographic parameters were analysed to identify risk factors for final shoulder imbalance. The shoulder balance of patients at different time points was further analysed to explore the potential effect of the series of GR treatment steps on shoulder balance.Results: The RSH showed substantial improvement after GR implantation (P = 0.036), during the follow-up period after final fusion (P = 0.021) and throughout the entire treatment (P = 0.011). The trend of change in the CA was similar to that of the RSH, and the T1T improved immediately after GR implantation (P = 0.037). Further analysis indicated that patients with shoulder imbalance before final fusion showed significantly improved shoulder balance after fusion (P = 0.045), and their RSH values at early postfusion and the final follow-up did not show statistically significant differences from those in the prefusion shoulder balance group (P > 0.05). Early postfusion shoulder imbalance (odds ratio (OR): 19.500; 95% confidence interval (CI) = 1.777-213.949; P = 0.015) was identified as an independent risk factor for final shoulder imbalance.Conclusions: Shoulder balance could be improved by GR implantation but often changes during the multistep lengthening process, and the final result is relatively unpredictable. Final fusion could further adjust the prefusion shoulder imbalance. Focusing on the prefusion shoulder balance of GR graduates and providing patients with early shoulder balance after fusion might be necessary. [ABSTRACT FROM AUTHOR]

Background: Current surgical treatment options for early onset scoliosis (EOS), with distraction- or growth-guidance implants, show limited growth and high complication rates during follow-up. We developed a novel implant concept, which uses compressed helical springs positioned around the rods of a growth-guidance construct. This spring distraction system (SDS) provides continuous corrective force to stimulate spinal growth, can be easily contoured, and can be used with all standard spinal instrumentation systems.Purpose: To assess curve correction and -maintenance, spinal growth, complication rate, and health-related quality of life following SDS treatment.Study Design: Prospective cohort study.Patient Sample: All skeletally immature EOS patients with an indication for growth-friendly surgery and without bone- or soft tissue weakness were eligible to receive SDS. For this study, all included patients with at least 2-year follow-up were analyzed.Outcome Measures: Coronal Cobb angle, sagittal parameters, T1-T12, T1-S1, and instrumented (ie, bridged segment) spinal height and freehand length, complications and re-operations, and the 24-Item Early Onset Scoliosis Questionnaires (EOSQ-24) score.Methods: All primary- and conversion patients (conversion from failed other systems) with SDS and ≥2 years follow-up were included. Radiographic parameters were compared preoperatively, postoperatively and at latest follow-up. Spinal length increase was expressed as mm/year.Results: Twenty-four skeletally immature EOS patients (18 primary and 6 conversion cases) were included. There were five idiopathic, seven congenital, three syndromic, and nine neuromuscular EOS patients. Mean age at implantation was 9.1 years (primary: 8.4; conversion: 11.2). Major curve improved from 60.3° to 35.3°, and was maintained at 40.6° at latest follow-up. Mean spring length increase during follow-up was 10.4 mm/year. T1-S1 height increased 9.9mm/year and the instrumented segment height showed a mean increase of 0.7 mm/segment/year. EOSQ-24 scores dropped after surgery from 75.6 to 67.4 but recovered to 75.0 at latest follow-up. In total, 17 reoperations were performed. Ten reoperations were performed to treat 9 implant-related complications. In addition, 7 patients showed spinal growth that exceeded expected growth velocity; their springs were retensioned during a small reoperation.Conclusion: The 2-year follow-up results from this prospective cohort study indicate that the concept of spring distraction may be feasible as an alternative to current growing spine solutions. Curve correction and growth could be maintained satisfactory without the need for repetitive lengthening procedures. However, as in all growth-friendly implants, complications and reoperations could not be prevented, which emphasizes the need for further improvement. [ABSTRACT FROM AUTHOR]

Purpose: Patients with spinal muscular atrophy (SMA) are often treated with growth friendly devices such as vertical expandable prosthetic titanium rib(VEPTR) and magnetically controlled growing rods(MCGR) to correct spinal deformity and improve pulmonary function. There is limited data on this topic, and the purpose of this study was to assess the effect of these constructs and the addition of chest wall support (CWS) on spinal deformity, thorax morphology and pulmonary outcomes. Methods: This is a retrospective analysis of prospectively collected data. We included patients with chest wall deformity and scoliosis secondary to SMA who were treated with growth friendly interventions and had two-year follow-up. Descriptive statistics and univariate analyses were performed. Results: This study included 66 patients (25% MCGR, 73% VEPTR, 2% unknown). Approximately 23% of constructs included CWS. The average Cobb angle improved from 67° (SD: 27°) to 50° (SD: 26°) at 2 years in patients with CWS (p = 0.02), and from 59° (SD: 20°) to 46° (SD: 15°) at 2 years in patients without CWS (p < 0.01). Hemithorax height improved in patients treated with and without CWS (p = 0.01), but hemithorax width only improved in patients with CWS (p = 0.01). One patient with CWS and two patients without CWS required additional respiratory support at 2 years. The rates of postoperative complications were not significantly different in patients treated with and without CWS (p = 0.31). Conclusions: Growth friendly constructs improve spinal deformity and may be effective in altering the progression toward respiratory failure in patients with SMA. Patients treated with CWS have significant improvements in thorax morphology compared to patients without CWS. [ABSTRACT FROM AUTHOR]

Background: Treatment of early-onset scoliosis (EOS) is still a challenge to patients, families, and surgeons. Previous studies have indicated that EOS patients are at high risk for complications following growth-friendly surgery. This study was performed to evaluate the results and complications of all-pedicle screw dual growing rod instrumentation in the treatment of EOS. Methods: In an IRB-approved retrospective study, we searched the electronic medical records of our institution for all patients who underwent posterior spinal instrumentation for scoliosis between March 2014 and March 2017. Patients under the age of 10 at the time of surgery who were treated with a growth-friendly technique were then selected. Patients with incomplete records and less than 2 years of follow-up were excluded. Charts, operative notes, clinic visits, and radiographs were extracted. Radiographs were reviewed, and the main curve Cobb angle, thoracic kyphosis, pelvic tilt, pelvic incidence, sacral slope, and proximal junctional angles were measured. We specifically looked for any intra-operative or post-operative complications. Statistical analysis was performed to determine the risk factors of complications. Results: A total of 42 patients with a mean age of 4.8 ± 2.1 years (range, 1.5–8 years) were included in the final analysis. Patients were followed for a median of 34 months (range, 24–55). The major curve was corrected from a mean of 42.9° ± 10.7° to 28.8° ± 9.6° at the latest follow-up. Proximal junctional angles and thoracic kyphosis increased significantly during the follow-up period (both P values < 0.001). A total of 7 complications (17%) were observed. Four patients (10%) developed superficial surgical site infections, all of which resolved with antibiotics and one round of surgical debridement. Three cases (7%) of proximal junctional kyphosis (PJK) were encountered during the study period, none of which required revision surgery. Pre-operative thoracic kyphosis was the only significant risk factor for the development of PJK. Conclusions: Our findings suggest that in settings without access to magnetically controlled growing rods, dual growing rods with all-pedicle screw instrumentation is still a viable treatment strategy with comparable results and complications. The most common complications are infection and PJK, with the latter being associated with a larger pre-operative thoracic kyphosis. [ABSTRACT FROM AUTHOR]

Objective: To evaluate curve correctability, complications, and rate of growth following treatment., Background: Distraction-founded techniques such as traditionally growing rods or magnetically controlled growing rods are the almost globally accepted management patterns for early onset scoliosis. However, periodic lengthening operations are still needed. Moreover, an MCGR is difficult to contour, and implant-associated problems are common. We developed concave side apical control of the growing rod in which an additional anchor site is inserted at the apex to enhance stability and assist in the adjustment of axial deformity., Methods: Entirely skeletally immature early onset scoliosis (EOS) cases with a progressive curve of >40° and without bone or soft tissue weakness were appropriate for this study. Coronal Cobb angle, sagittal parameters, complications, spinal length, and reoperations were documented with at least a 3-year follow-up., Results: In this study, 15 patients were involved. The mean age was 7 years. The mean preoperative Cobb angle was 48°, which postoperatively became 12° with the percentage of coronal correction reaching 75.73%. The mean Cobb angle degrees of correction were 39°. T1-S1 height increased by 10 mm/year. Postoperative complications occurred in two cases with single rod technique and rod breakage., Conclusions: The concave side apical control of the growing rod seems to be a hopeful surgical procedure for the management of EOS. Curve correctability in patients was 60% and can be sustained for a minimum of 2 years. Reoperations and complications might not be constricted, but the complication frequency looks more reasonable than in the current systems., Competing Interests: Conflicts of Interest: The authors declare that there are no relevant conflicts of interest., (Copyright © 2024 The Japanese Society for Spine Surgery and Related Research.)

Osteogenesis imperfecta (OI) is characterized by bone fragility and is often accompanied by spinal deformity. Surgical treatment for early-onset scoliosis in patients with OI is hazardous and difficult due to the bone fragility and rigidity of the deformity. A case of early-onset scoliosis with OI that was treated using growing-rod surgery is presented. The patient was an 11-year-old girl with type 4 OI. At the age of 4 years, she was noted to have scoliosis. Preoperative radiographs showed that the Cobb angle, thoracic kyphosis angle, and T1-S1 height were 94°, 77°, and 258 mm, respectively. One year before the operation, she underwent cyclic intravenous pamidronate disodium treatment. Three months after the pedicle screws were inserted, the growing rods were placed with pedicle screws and sublaminar polyethylene tape. The patient had intraoperative traction for correction. At 13 years and 11 months, the patients underwent posterior instrumentation and spinal fusion. Postoperative radiographs showed that the Cobb angle, thoracic kyphosis angle, and T1-S1 height were 29°, 29°, and 405 mm, respectively. Three months after the operation, she was well, and there have been no spine-related problems. This case demonstrates the successful use of the growing rod for early-onset scoliosis in patients with OI. The treatment strategy, which included pedicle screw insertion as anchors to create the foundations in advance, sublaminar tape, intraoperative traction, and preoperative bisphosphonate administration, might have led to the good outcome. [ABSTRACT FROM AUTHOR]

Background: Spinal deformities constitute one of the most common types of manifestations of neurofibromatosis type-1 (NF-1), which can lead to either dystrophic or non-dystrophic early-onset scoliosis (EOS). Surgical treatment for EOS with NF-1 is challenging, and the outcomes have rarely been reported. The anterior-posterior procedure is widely used, but posterior-only fusion is theoretically easier and safer to perform. Is it possible that a new surgery that accommodates growth is a better choice? A direct comparison between posterior fusion and growth-friendly surgery in terms of surgical outcomes has not yet been conducted in dystrophic EOS with NF-1 patients.Methods: Baseline information was extracted from the NF-1 database at our institute with approval from the local ethics committee. All enrolled patients were diagnosed with NF-1. Clinical and radiographic data were recorded preoperatively, after the initial surgery, and at the final follow-up. Implant-related, alignment, neurological complication and unplanned revision surgery data were recorded. We compared the outcomes of these two groups in terms of curve correction, growth parameters, complications and unplanned revision surgeries.Results: There were eight patients in the PF group and eight patients in the GR group, with a mean follow-up of 51.0 ± 17.5 months. The main curve size was similar (PF 67.38° ± 17.43° versus GR 75.1° ± 26.43°, P = 0.501), and there were no significant differences in the initial surgery correction rate or the rate of correction. However, the patients in the GR group exhibited more T1-S1 growth during the follow-up overall and per year than did those in the PF group. The operative time was significantly longer for the PF group than for the GR group (PF, 4.39 ± 1.38 vs. GR, 3.00 ± 0.42 h; p = 0.008). Significantly fewer segments were involved in the PF group (8.25 ± 3.20) than in the GR group (13.00 ± 1.60).Conclusion: For the initial treatment of dystrophic EOS in patients with NF-1, the GR technique is possibly a more appropriate treatment than is the PF technique in terms of trunk growth. However, the repeated procedures required for GR may be a considerable disadvantage. More studies with direct measurement of pulmonary function must be conducted to determine the effect of GR on pulmonary development. More studies with larger sample sizes and longer follow-up periods are needed to fully assess the treatment strategies. [ABSTRACT FROM AUTHOR]

Study Design: Analysis of explanted MAGnetic Expansion Control (MAGEC) growing rods.Objective: The aim of this study was to quantify the rate of locking pin breakage in explanted MAGEC rods and compare with the manufacturer's data.Summary Of Background Data: On June 25, 2019, NuVasive released an Urgent Field Safety Notice stating that MAGEC rods manufactured before March 26, 2015 had a higher than expected locking pin breakage rate of 5%. For rods made on or after that date, no pin breakages had occurred.Methods: From our independent explant database of 139 explanted MAGEC rods supplied from 10 UK spinal centers (Belfast, Bristol, Birmingham, Edinburgh, Exeter, Leeds, Newcastle, Nottingham, Oxford, and Sheffield) and one Danish center (Aarhus), we divided the rods into those manufactured before March 26, 2015, and those manufactured on or after that date. MAGEC rods were cut open to fully assess internal components including locking pins. From each of the two cohorts, 10 locking pins were selected at random and their diameters were measured using a micrometer.Results: One hundred and five explanted MAGEC rods were made before March 26, 2015 and could be disassembled to allow the locking pin to be examined. Fifty-nine percent (62/105) of these locking pins had fractured. For the MAGEC rods manufactured on or after March 26, 2015, 21% (6/29) were found to have fractured locking pins. Locking pins in MAGEC rods made on or after March 26, 2015 were of a stronger material and a larger diameter.Conclusion: Fifty-nine percent of the locking pins in MAGEC rods manufactured before March 26, 2015 had fractured, far greater than the 5% stated in the Urgent Field Safety Notice. Locking pin fracture still occurred in MAGEC rods manufactured on or after that date, in 21% of cases. This contrasted with the 0% reported by the manufacturer.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Objective: It can be assumed that the progression of scoliosis in the juvenile period will increase the asymmetry in the rib cage, and thus will contribute to an increase in the breast asymmetry (BA) in the future. We are looking for answers to the questions; "How will the breasts look with respect to each other and what is the possibility of developing BA in the early follow-up period following the early surgical treatment and final fusion surgery of juvenile idiopathic scoliosis (JIS)?" For this reason, in this study, we aimed to evaluate the breast asymmetries of patients in the period after the final fusion. Methods: Following growing rod treatment, final fusion was achieved in 12 females with JIS. We used the anthropomorphic measurement of the modified BREAST-V formula to assess whether there was an asymmetry between the breasts after an average of 4.8 years (2-11) following final fusion. Results: In comparison, the mean volume of the left breast (222.4 mL [range, 104.1-330.2]) was larger than the mean volume of the right breast volume (214.5 mL [range, 95.2-326.7]) (p=0.034). The left breast was larger in 75% of the patients. BA was observed in 50% of the patients. No correlation was detected between the Cobb angle of the patient after final fusion and BA (p=0.688). Conclusion: In the late follow-up period, BA was detected in 50% of the patients with JIS who achieved final fusion after treatment with growing rod. In majority of the patients, left breast was larger. The patients with JIS and their families can be informed prior to the operation about the probability of BA seen in the follow-up period after fusion. [ABSTRACT FROM AUTHOR]

Background: The posterior procedure utilizing growth-friendly techniques is the golden standard for patients with early-onset scoliosis combined with thoracic insufficiency syndrome (EOS + TIS). Pulmonary hypoplasia is the main cause of dying prematurely in the EOS + TIS. This study assessed the therapeutic impact of a novel growth-friendly system on the pulmonary development of piglet's EOS + TIS model., Methods: The animal procedure period lasts 12 weeks, of which the construction of the EOS + TIS was performed at 0-8 weeks, and implantation of a novel growth-friendly system was applied at 8-12 weeks. During the animal procedure, X-rays and CT were performed to observe scoliosis, thorax, and lungs. After 12 weeks, pathological changes in lung tissue were assessed using HE and IHC staining. RNA-seq characterized novel growth-friendly system-associated differentially expressed genes (DEGs) and validated using RT-qPCR, western blotting, and IHC., Results: Implantation of the novel growth-friendly system increased body weight, body length, and total lung volume, as well as decreased the coronal and sagittal Cobb angles for the EOS + TIS model. It also ameliorated EOS + TIS-induced thickening of the alveolar wall, increased alveolar spaces, and decreased alveolar number and diameter. In lung tissue, a total of 790 novel growth-friendly system-associated DEGs were identified, and they were mainly involved in the regulation of immune, inflammatory, calcium transport, and vascular development. Among these DEGs, BDKRB1, THBS1, DUSP1, IDO1, and SPINK5 were hub genes, and their differential expression was consistent with RNA-seq results in lung tissues., Conclusion: The novel growth-friendly system has mitigated scoliosis and pulmonary hypoplasia in the EOS + TIS model. We further elucidate the molecular mechanisms underlying the amelioration of pulmonary hypoplasia., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Study Design: Retrospective cohort study., Objective: The orthopaedic ability of traditional GR for severe EOS is limited. The proximal upper thoracic curve may progress during the lengthening procedure, which may lead to coronal imbalance and inhibit the longitudinal growth of the spine. In this retrospective cohort study, we investigated the clinical outcome of tandem GR., Methods: We modified the traditional technique by using two groups of GR devices to control the major and the proximal upper thoracic curve, connected the two groups of GR in series, and named it tandem GR. The clinical and imaging outcomes of the new technique were evaluated and compared with traditional technique., Results: Twenty one patients were enrolled in the tandem GR group, and 30 patients were treated with traditional GR as the control. The baseline parameters were consistent between the two groups. In the tandem GR group, the secondary curve progressed from 24.9 ± 3.9° to 31.4 ± 3.2° ( P = .006) in the procedure with the traditional GR and improved to 18.4 ± 4.5° ( P = .001) after the switch. Meanwhile, the clavicular angle aggravated from 1.6 ± 1.0° to 2.6 ± .7° ( P = .041), and improved to 1.7 ± .8° after changed to the tandem GR ( P = .033). At the final of the follow-up, the secondary curve was higher in the control group (27.1 ± 8.3° vs 18.4 ± 4.5°, P = .034), the clavicle angle was 2.4 ± 1.1° in control and 1.7 ± .8° in the tandem GR group ( P = .028), the T1-S1 height was 28.2 ± 4.8 cm in the control and 33.3 ± 3.0 cm in the tandem GR group ( P = .027). The average growth rate was 1.0 ± .3 cm/year in the control and 1.2 ± .4 cm/year in the tandem GR group ( P = .046)., Conclusion: Tandem GR can effectively improve the proximal upper thoracic curve progression during the treatment of EOS. Compared with the traditional GR, tandem GR can achieve better curve correction, better shoulder balance, and retains more capacity for longitudinal spine growth., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Study Design: Experimental and computational study of posterior spinal instrumentation and growing rod constructs per ASTM F1717-15 vertebrectomy methodology for static compressive bending.Objective: Assess mechanical performance of standard fusion instrumentation and growing rod constructs.Summary Of Background Data: Growing rod instrumentation utilizes fewer anchors and spans longer distances, increasing shared implant loads relative to fusion. There is a need to evaluate growing rod's mechanical performance. ASTM F1717-15 standard assesses performance of spinal instrumentation; however, effects of growing rods with side-by-side connectors have not been evaluated.Methods: Standard and growing rod constructs were tested per ASTM F1717-15 methodology; setup was modified for growing rod constructs to allow for connector offset. Three experimental groups (standard with active length 76 mm, and growing rods with active lengths 76 and 376 mm; n = 5/group) were tested; stiffness, yield load, and load at maximum displacement were calculated. Computational models were developed and used to locate stress concentrations.Results: For both constructs at 76 mm active length, growing rod stiffness (49 ± 0.8 N/mm) was significantly greater than standard (43 ± 0.4 N/mm); both were greater than growing rods at 376 mm (10 ± 0.3 N/mm). No significant difference in yield load was observed between growing rods (522 ± 12 N) and standard (457 ± 19 N) constructs of 76 mm. Growing rod constructs significantly decreased from 76 mm (522 ± 12 N) to 376 mm active length (200 ± 2 N). Maximum load of growing rods at 76 mm (1084 ± 11 N) was significantly greater than standard at 76 mm (1007 ± 7 N) and growing rods at 376 mm active length (392 ± 5 N). Simulations with active length of 76 mm were within 10% of experimental mechanical characteristics; stress concentrations were at the apex and cranial to connector-rod interaction for standard and growing rod models, respectively.Conclusion: Growing rod constructs are stronger and stiffer than spinal instrumentation constructs; with an increased length accompanied a decrease in strength. Growing rod construct stress concentration locations observed during computational simulation are consistent with clinically observed failure locations.Level Of Evidence: 5. [ABSTRACT FROM AUTHOR]

Objective: Comparing the effects of magnetically controlled growing rod (MCGR) and traditional growing rod (TGR) techniques on the sagittal plane in the treatment of early-onset scoliosis (EOS). Methods: Twelve patients were operated using dual MCGR technique in one center, while 15 patients were operated using dual TGR technique for EOS in another center. Patients' demographic characteristics, complications and radiological measurements such as cobb angle, thoracic kyphosis, lumbar lordosis, T1-S1 range (mm), proximal junctional angle, distal junctional angle, sagittal balance, coronal balance, pelvic incidence, sacral slope and pelvic tilt were assessed and compared in preoperative, postoperative and last follow-up period. Results: Age and sex distributions were similar in both groups. The mean number of lengthening in the MCGR group was 12 (8-15) and 4.8 (3-7) in the TGR group. Two techniques were shown to be effective in controlling the curvature and in the increase of T1-S1 distance. In TGR group, four patients had rod fractures, six patients had screw pull-out and four patients had an infection, whereas three patients had screw pull-out and one patient had infection complications in the MCGR group. Conclusion: There was no significant difference between the two groups in terms of cobb angle, coronal and sagittal balance and sagittal pelvic parameters. MCGR can cause hypokyphosis and proximal junctional kyphosis in a minimum 2-year follow-up period. The implant-related complications were less in the MCGR group. However, larger case groups and longer follow-up periods are required for the better understanding of the superiority of one method on other in terms of complications. [ABSTRACT FROM AUTHOR]

To determine the safety and effectiveness of the combined halo gravity traction and dual growing rod technique in achieving and maintaining scoliosis correction while allowing spinal growth. From January 2014 to July 2017, 11 patients with dystrophic neurofibromatosis type 1 (NF1)–associated scoliosis, including 7 men and 4 women, underwent combined halo gravity traction and dual growing rod technique procedures. Diagnoses were all dystrophic NF1-associated scoliosis. Patients with a Cobb angle of major curve >60° and flexibility of spine <30% were included in our research. Analysis included age at the time of treatment, levels of instrumentation, number and frequency of lengthening, lengthening distance, and complications. The changes in Cobb angle of scoliosis and T1-S1 length of spine over the treatment period were measured by radiographic evaluation. The average age of treated patients was 7.2 years (range, 5–9 years). Growing rods were lengthened every 6 months through exposure. The mean number of times of lengthening was 3.9 (range, 3–5). The distance of each extension was 1.6 cm (range, 1.0–2.0 cm). The Cobb angle was corrected 41.7% on average after traction, 48.4% after initial surgery, and 53.3% at the last follow-up. T1-S1 length increased 3.4 cm (range, 1.2–5.1 cm) on average over a mean treatment period of 2.2 years, with an average of 1.5 cm/y (range, 0.5–2.3 cm/y). During the treatment period, complication of hook dislodgement occurred in 1 of 11 patients (9.1%). The combined halo gravity traction and dual growing rod technique can safely and effectively correct NF1-associated scoliosis. This is an ongoing study that requires long-term follow-up. [ABSTRACT FROM AUTHOR]

Study Design: Cross-sectional case-control study.Objective: Compare psychosocial profile of magnetically-controlled growing rod (MCGR) patients to traditional-growing rod (TGR) with an array of psychiatric tools, expecting improvement in MCGR due to decreased number of surgical procedures.Summary Of Background Data: TGR treatment has had positive clinical and radiographic results; however, upward of 10 surgical sessions and high complication rates have called into question the quality of life of these children. Improvement with the introduction of the MCGR is expected.Methods: GR patients with minimum of 2-years follow-up were recruited. None had neurological conditions. All underwent testing with the Wechsler Intelligence Scale for Children-Revised, and only those in the normal range were included. Patients filled out questionnaires with mental health professionals to measure psychosocial status. MCGR patients' results were compared to TGR patients.Results: Twenty-seven patients met criteria (10 MCGR, 17 TGR): average age at enrollment 11.8 years (range 5.9-17). MCGR group was significantly younger (9.1 vs. 13.3 yr) and had significantly shorter follow-up (45.6 vs. 82.8 mo) (P < 0.05). TGR patients underwent an average of 16 surgical procedures, MCGR an average of 1.5 (including complications, P < 0.05). Age at index surgery (6 yr), preoperative and postoperative major curve magnitudes (60°, 40° respectively) were statistically similar.There was no difference in current psychiatric diagnoses between the groups. MCGR patients scored worse than TGR patients in general functionality domains. TGR patients showed increased functionality and prosocial scores with increased number of procedures. This effect was not observed in MCGR.Conclusions: The expected improvement in psychosocial status with the MCGR was not observed at a 31.6-month-follow-up. It appears that provided the patient spends enough time in the treatment process to notice benefit and does not experience major complications, noninvasiveness of lengthening procedures does not show up as an advantage with the psychosocial tools utilized in this study.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective study.Objective: The current study aimed to evaluate the effectiveness of the hybrid growing rod (GR) technique for the treatment of young children with congenital scoliosis (CS).Summary Of Background Data: Congenital vertebral anomalies within long-spanned kyphoscoliosis were difficult to be managed by either definitive spinal fusion or standard GR technique. Hybrid technique of one-stage posterior osteotomy with short fusion and GR distraction was proposed in previous studies. There is, however, paucity of data regarding its effectiveness.Methods: Thirteen patients (mean age, 5.4 ± 2.0 yr) who had undergone hybrid GR treatment were retrospectively reviewed, including 8 patients treated with single GR and 5 patients with dual GR. All of their radiographic data were measured, and surgical complications were recorded.Results: On average, the current cohort had 4.1 ± 1.7 lengthening procedures. After the index surgery, the major curve improved remarkably from 86.4° ± 11.9° to 37.3° ± 12.4° (P < 0.001). The global kyphosis significantly decreased from 66.8° ± 16.1° to 33.3° ± 3.5° postoperatively. Both value remained steady during follow-up. There were no significant difference between single GR and dual GR groups in terms of the coronal deformity correction, whereas correction loss of global kyphosis in single GR group was significantly higher than that in dual GR group (P = 0.039). After the index surgery, T1-S1 height averagely gained 4.4 ± 0.8 cm and it grew at an average rate of 1.31 ± 0.24 cm/yr during the follow-up. Two complications were identified in two patients, including one with rod fracture and one with proximal junctional kyphosis.Conclusion: The hybrid GR technique was effective in correcting spinal deformity and allowing continuous spinal growth. The optimal indications were young children with apical vertebrae anomalies and a long-spanned kyphoscoliosis.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

Background: Growing rod constructs are an important contribution in the treatment of children with early onset scoliosis even though these devices experience high rates of rod fracture. The mechanical performance of traditional, distraction-based dual growing rod constructs is not well understood, and mechanical models for predicting device performance are limited.Purpose: Two mechanical models were developed and used to determine the mechanical performance of various growing rod configurations by increasing construct complexity.Study Design/setting: Mechanical bench testing and finite element (FE) analysis.Methods: Static and dynamic compression bending tests were based on an ASTM F1717 method modified to accommodate dual growing rod constructs. Six construct configurations were tested, mechanical properties were recorded, and statistical analyses were performed to determine significant differences between groups: (1) no connectors (rods only), (2) side-by-side connectors, (3) side-by-side connectors plus 4 crosslinks, (4) (40-mm long tandem connectors, (5) 80-mm long tandem connectors, and (6) 80-mm long tandem connectors plus 4 crosslinks. FE analysis was used to predict the stress distribution within the constructs.Results: The static results indicated greater stiffness, yield load, and peak load as the axial connector length increased (side-by-side to 40 mm tandem to 80 mm tandem). The dynamic results showed similar cycles to failure for side-by-side and tandem connector (40 and 80 mm) construct configurations without crosslinks. Crosslinks shifted the location of rod fracture observed experimentally and significantly reduced the fatigue life of the construct. The flexibility of the construct decreased significantly as the axial connector length increased. FE predictions were highly consistent with the experimentally measured values and provided information on stress distribution within the rod for comparison to experimental fracture locations.Conclusions: This is the first study to evaluate mechanical performance of various configurations of pediatric growing rod constructs using preclinical models. The current study is consistent with a previous retrieval study in that rigid constructs lacking flexibility (ie, higher stiffness and lower displacement), such as those with 80-mm tandem connectors and multiple crosslinks, demonstrated decreased mechanical performance as shown through both experimental and computational models. Additionally, the experimental and computational findings suggest that surgeons should strategically consider the number of interconnecting components and subsequent stress concentrations along the posterior side of the rod. For example, changing the placement of crosslinks to low stress regions of the construct or not using crosslinks in the construct are options. [ABSTRACT FROM AUTHOR]

Growing rod implantation, a surgery treatment for EOS (early onset scoliosis), may cause a kind of chronic inflammation called metalosis and all other implant-related complications because of the metal debris released by the implants as a result of fraction and corrosion. There is no complete explanation of immunologic mechanisms of metalosis up to now. This review demonstrates the researches on metalosis from the clinical issues down to basic immunologic mechanisms. Adverse reactions of metal implants are mainly the formation of NLRP3 (nod-like receptor protein 3) inflammasome, primed by TLR4 (toll-like receptor protein 4), activated by phagocytosis and often accompanied by type Ⅳ hypersensitive reaction. Recent studies found that TNF-α (tumor necrosis factor α) also participates in priming, and activation of inflammasome requires disturbance of lysosome and release of cathepsin B. Ca-074Me and MCC950 are therapeutic interventions worth exploring in aseptic loosening of orthopedic implants., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Zhang, Han, Li, Zhao, Du, Yang, Wang and Zhang.)

Study Design: Retrospective cohort study.Objective: To assess the incidence and risk factors of instrumentation-related complication (IRC) in pediatric patients surgically treated for neurofibromatosis type 1 (NF-1) dystrophic scoliosis.Summary Of Background Data: Surgical management including growing rods technique and early definitive fusion has been recommended to avoid progression of NF-1 scoliosis. However, no study has yet investigated the incidence and risk factors of IRC in these surgical interventions.Methods: Data of 59 pediatric NF-1 patients who had been surgically treated for dystrophic scoliosis were retrospectively reviewed. All of their clinical and radiographic data were collected. We evaluated potential risk factors, including age, sex, curve type, preoperative Cobb angle, kyphosis angle and spinal length, and surgical procedure. The univariate analysis and multivariate logistic regression analysis were performed to identify the risk factors associated with IRC.Results: Seventeen (28.8%) patients suffered 19 IRCs, including seven cases of curve progression, three cases of screw dislodgement, three cases of adding-on phenomenon, two cases of rod breakage, two cases of proximal junctional kyphosis, one case of cap loosing, and one case of pedicle cutting. The univariate logistic regression analysis revealed age<9, kyphosis≥50°, and growing-rod techniques the significant risk factors (P < 0.05). Binomial logistic regression analysis demonstrated two independent risk factors of IRC, including kyphosis≥50° (OR: 8.23; P = 0.025) and application of growing-rod technique (OR: 8.75; P = 0.032).Conclusion: 17/59 (28.8%) patients suffered IRCs and age less than 9 years, kyphosis more than 50° and application of growing-rod are three risk factors for IRC after surgical treatment of NF-1 dystrophic scoliosis. Identification of these risk factors aids in stratifying preoperative risk to reduce IRC incidence. In addition, the results could be used in counseling patients and their families during the consent process.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

Background: Growing rods are increasingly used for treatment of early onset scoliosis (EOS) worldwide. Beside promising outcomes, some authors are concerned about high rates of complications. In the current clinical trial, complications of EOS surgery using dual growing rods were investigated. Methods: Between June 2006 and February 2017, twenty-two consecutive patients with a coronal curve >45 degrees underwent serial surgical correction using dual growing rods at Shafa Orthopedic hospital, Tehran, I.R. Iran. The rods were secured using hooks or screws or both. The patients were followed for 5.2 ± 1.7 years on average. Wilcoxon test was utilized to compare the pre- and post-operative values. P < 0.05 was considered significant. Results: The scoliotic and kyphotic curves decreased significantly from 52 ± 24° to 38 ± 19° and from 78 ± 22° to 60 ± 17°, respectively (P < 0.001). Total rate of implant-related complications (IRCs) and surgical site complications (SSCs) were 54.5% (12 patients) and 22.7% (5 patients), respectively. Malpositioned pedicular screw was found in 2 patients. Conclusion: EOS can be effectively corrected using dual growing rods, however, considerable rates of IRC are of concern (54.5%). It seems necessary to compare the efficacy and complication rate of newer devices with those of growing rods in future studies. [ABSTRACT FROM AUTHOR]

This paper describes the development of a dynamic implant designed to correct three dimensional spinal deformities in children with Early Onset Scoliosis (EOS). The device is a distraction-based implant that provides two innovative features: (1) a dynamic-viscoelastic system, which gives some flexibility to the implant, to avoid potential device fractures; and (2) a lengthening mechanism that allows minimally invasive elongation surgery to reduce infection. The novel device was designed and evaluated with finite element analysis. Five working prototypes were produced and mechanically tested according to a modified version of the ASTM F1717 Standard. Results demonstrated that the maximum load achieving run-out at 5 million cycles was 180 N. One prototype withstood almost two tests in a row (9 million cycles) with the peak load of 180 N and showed no sign of failure. Three tests performed with higher loads (190 and 200 N) did not achieve full runout due to pedicle screw fracture with only one device fracture along the weld. These results demonstrated an improved fatigue performance in comparison with data from the commercially available VEPTR I device (Depuy Synthes Spine, Raynham, USA). Therefore, the novel device proposed has the clinical potential to improve the surgical treatment of EOS. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the first results of surgical treatment using newly developed magnetically controlled growing rods (MCGR) for early onset scoliosis (EOS). Materials and Methods: From January 2013 to January 2017, 5 patients, who underwent surgical treatment with MCGR for EOS and were followed for more than one year, were analyzed retrospectively. The demographic and radiology data, including age at surgery, diagnosis, number of lengthening, Cobb angle, T1-S1 length, T1-T12 length, and complications, were analyzed. Results: The mean age of the patients was 6.0±2.7 years old. The subjects were 3 males and 2 females: 2 with neuromuscular scoliosis, 1 with syndromic scoliosis, 1 with idiopathic scoliosis, and 1 with congenital scoliosis. The mean number of lengthening was 9.8±2.9 times and the follow-up was 21.6±5.7 months. The Cobb angle improved from 82.0°±28.5° to 48.3°±28.8° at the last follow-up. The T1-S1 length increased from 283.1±72.7 mm to 342.6±86.3 mm at the last follow-up. The T1-T12 length increased from 163.1±50.5 mm to 202.3±65.5 mm at the last follow-up. One screw loosening complication was encountered and there were no neurological complications. Conclusion: The treatment using MCGR for EOS is effective and useful. [ABSTRACT FROM AUTHOR]

Study Design: Analysis of explanted MAGnetic Expansion Control (MAGEC) growing rods.Objective: To analyze explanted MAGEC rods used in management of early onset scoliosis and identify the mode of failure in such cases.Summary Of Background Data: Magnetically controlled growing rods are increasingly used as the option of choice for early onset scoliosis. However, being more complex than conventional growing rods they are perhaps more likely to succumb to multifarious failure modes. In addition, metallosis has been reported around failed MAGEC rods.Methods: Explanted MAGEC rods from seven UK spinal centers were obtained for independent analysis. Thirty-four MAGEC rods, from 18 children, explanted for reasons including failure of rod lengthening and maximum rod distraction reached, were cut open to allow internal components to be evaluated and assessed.Results: Externally, all MAGEC rods showed localized marks, which were termed "growth marks" as they indicated growth of the rod in vivo, on the extending bar component. After cutting open, titanium wear debris was found inside all 34 (100%) MAGEC rods. Ninety-one percent (31/34) of MAGEC rods showed measurable wear of the extending bar, towards the magnet end. Substantial damage to the radial bearing was seen inside 74% (25/34) of MAGEC rods while O-ring seal failure was seen in 53% (18/34) of cases. In 44% (15/34) of MAGEC rods the drive pin was fractured but this was felt to be an effect of rod failure, not a cause.Conclusion: The combination of high volumes of titanium wear debris alongside O-ring seal damage likely accounts for the metallosis reported clinically around some MAGEC rods. Based on this explant data, a failure mechanism in MAGEC rods due to the natural off axis loading in the spine was proposed. This is the largest data set reporting a complete analysis of explanted MAGEC rods to date.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]