Growing Rod Treatment Research Articles

Outcome of distraction-based growing rods at graduation: a comparison of traditional growing rods and magnetically controlled growing rods.

Distraction-based growing rods have been considered as an alternative surgical option for the operative treatment of EOS. TGR has been challenged by MCGR, which is reported to have the advantage of non-invasive lengthening with fewer planned returns to theatre. This study explores the radiographic outcomes, Unplanned Returns to the Operating Room (UPROR) and complication profile of both the procedures at the end of the planned growing rod treatment with either TGR or MCGR. We included all the EOS cases from the PSSG database that underwent either TGR or MCGR with spine-based proximal anchors, followed up to the time of graduation. Any crossover or hybrid procedures were excluded. 549 patients (409 TGR and 140 MCGR) were eligible for review. We measured the coronal curve magnitude, Kyphosis, T1-T12, T1-S1 and L1-S1 lengths at 4 time points (before and after the index surgery and before and after the definitive surgery). The TGR group were slightly younger at the time of the index procedure (7years for TGR vs. 8.5years for MCGR, p < 0.001). We noted an improvement in all radiological parameters after the growing rod implantation. The spinal lengths increased through the lengthening period, while the coronal curve magnitude and the kyphosis increased. The kyphosis normalized following the final fusion, the coronal curve magnitude reduced further with a further increase in spinal lengths. The final follow-up from the time of the index implantation to the definitive surgery was 5.1years (IQR 3.8) in TGR and 3.5years (IQR 1.65) in the MCGR groups. The total number of complications was fewer in the MCGR group. The overall risk of UPROR was lower in the MCGR group and implant breakage was less in the MCGR group by 4.7 times. This study confirms the equivalence of both the distraction-based growing rods systems from the radiological stand-point, during the lengthening phase and at the time of the definitive surgery. The TGR was more kyphogenic during the lengthening period. The complications and UPROR were fewer in the MCGR groups.

Optimal timing of starting growing rod treatment for early-onset scoliosis

BACKGROUND CONTEXTGrowing rod (GR) systems require periodical surgical intervention and may cause associated complications, as well as worsened sagittal plane deformity. Generally, the risk of complications decreases with an increment in age at the time of the index surgery with GR construct placement. However, the optimal timing to begin GR treatment has not reached a consensus yet. PURPOSEThis study was performed to investigate the effect of age at the index GR surgery on the complication rates and formulate clinical guidelines for the optimal timing to begin GR treatment for EOS patients. STUDY DESIGNKaplan-Meier analysis was used to determine complication occurrence as a function of the age at the index surgery and to determine the survival rates for the procedures. The receiver operator characteristic (ROC) curve was used to determine optimal cut-off values for the optimal timing of index surgery based on whether complications occurred or not. PATIENT SAMPLE54 patients who met the criteria were enrolled in this study. OUTCOME MEASURESThe following spinal parameters were measured: major coronal Cobb angle, global kyphosis (GK), and coronal balance (CB). CB was defined as the horizontal distance from the C7 plumb line to the center sacral vertical line. METHODSAll patients had completed GR treatment and had a minimum 1-year follow-up duration after the final surgical intervention. Patient data were collected as follows: age at the index surgery, gender, diagnosis, type of GR construct, and the number of lengthening procedures. The standing full-spine radiographs were obtained before and after the index surgery, before and after each lengthening procedure, before and after the final surgical intervention, and at the latest follow-up. Complications were categorized as implant, alignment, and general. RESULTSKaplan-Meier analysis of complications demonstrated a declining trend in complication rates with increasing age at the index surgery. The absence of perioperative complications was targeted, we constructed the ROC curve and the cut-off value was 71.0 months. Age at the index surgery was therefore categorized into two groups: younger-age group (≤ 71.0 months) and advanced-age group (> 71.0 months). There was a higher complication rate for the younger-age group than versus the advanced-age group (61.5% vs 22.0%, p=.011). PJK as a major alignment-related complication, was more frequent in the younger-age group than in the advanced-age group (30.8% vs 4.9%, p=.025). But the advanced-age group exhibited significantly more severe deformities before GR surgery compared to the younger-age group. CONCLUSIONSThis study shows that the elevated risk of complications observed in the younger-age group, which can be attributed to the younger age at the index surgery and the increased number of lengthening procedures during treatment. We suggest deferring the initiation of GR treatment until after the age of six years for EOS patients. We hope it will serve as a basis for GR technique in the treatment of EOS, with the ultimate goal of enhancing treatment outcomes for this challenging disorder.

Growing Rod versus Posterior Spinal Fusion Treatment of Juvenile Idiopathic Scoliosis: Unique Characteristics and Surgical Outcomes.

Progressive spinal curvature in juvenile idiopathic scoliosis (JIS) is challenging to treat. When conservative management fails, treatments include growing rods (GRs) or posterior spinal fusion (PSF). The purpose of this study is to compare the patient characteristics and outcomes of GR and PSF treatment of JIS. We performed a retrospective review of demographic, radiographic, and surgical data for all JIS patients requiring surgical treatment between 2012 and 2020. Patients who underwent any GR treatment were compared to PSF patients. A total of 36 patients (13 GR, 23 PSF) were reviewed. PSF patients had a larger pre-operative spinal height (p = 0.002), but similar pre-operative major curve magnitudes (p = 0.558). PSF treatment resulted in similar change in the T1-S1 length (p = 0.002), but a greater correction of the curve magnitude (p < 0.055) compared to GR patients. Eight patients initially treated with GRs later underwent definitive PSF treatment. This subset of patients had a greater spinal height before PSF (p = 0.006), but similar immediate post-PSF T1-S1 lengths (p = 0.437) and smaller changes in spinal height from PSF (p = 0.020) than primary PSF patients. At final follow-up, patients who underwent primary PSF versus PSF after GR had similar spinal heights (p = 0.842). The surgical intervention chosen to manage progressive JIS often differs based on patient characteristics. While this choice may impact immediate outcomes, the outcomes at final follow up are similar.

Autofusion in growing rod surgery for early onset scoliosis; what do we know so far?

The evolving landscape of early onset scoliosis management has shifted from the traditional paradigm of early definitive spinal fusion towards modern growth-friendly implants, particularly Growing Rods (GR). Despite the initial classification of GR treatment as a fusionless procedure, the phenomenon of autofusion has emerged as a critical consideration in understanding its outcomes. Studies have demonstrated the presence of autofusion since the early 1980s. The consequences of autofusion are extensive, impacting curve correction, diminishing trunk growth rate, and contributing to the "law of diminishing returns" in growing rod surgery. The literature suggests that autofusion may complicate definitive fusion surgery, leading to prolonged and intricate procedures involving multiple osteotomies. Additionally, it poses challenges in identifying anatomical landmarks during surgery, potentially increasing the risk of complications and revisions. While autofusion poses challenges to achieving optimal outcomes in growing rod treatment, it cannot be considered a standalone replacement for definitive fusion. Recent advances aim to limit autofusion and enhance treatment outcomes. In this review, we will delve into the existing literature on autofusion, examining studies that have documented its presence, probable causes, pathophysiology, potential implications for long-term patient outcomes, and possible new implants and techniques that decrease its incidence.

Halo-gravity traction combined with growing rod treatment: an effective preoperative management for severe early-onset scoliosis.

The aim of this study was to investigate the effectiveness of preoperative halo-gravity traction (HGT) with subsequent growing rod (GR) treatment in patients with severe early-onset scoliosis (EOS). The authors retrospectively reviewed a cohort of patients with severe EOS who had received preoperative HGT with subsequent GR treatment at their center between January 2008 and January 2020. Patients with a Cobb angle in the coronal or sagittal plane that was > 90° were included. All patients received at least 6 weeks of HGT before GR placement. Results of pulmonary function tests (PFTs) and blood gas tests were compared before and after HGT. Radiological parameters were compared pre-HGT, post-HGT, postindex surgery, and at the latest follow-up. A total of 28 patients (17 boys and 11 girls, mean age 6.1 ± 2.3 years) were included in this study. After a mean of 65.2 ± 22.9 days of traction, the Cobb angle decreased from 101.4° ± 12.5° to 74.5° ± 19.3° (change rate 26.5%), and the kyphosis angle decreased from 71.1° ± 21.2° to 42.7° ± 9.5° (change rate 39.9%). There was a significant improvement in BMI but a decrease in hemoglobin levels following HGT. No HGT-related complications were recorded except pin site infections in 2 patients. Statistically significant improvements in PFTs after HGT were observed in forced vital capacity (FVC) (p = 0.011), the percentage predicted FVC (p = 0.007), FEV1 (p = 0.015), and the percentage predicted forced expiratory volume in 1 second (FEV1) (p = 0.005). Fourteen patients received assisted ventilation due to preoperative hypoxia, alveolar hypoventilation, or hypercapnia. Significant improvement was seen in PaCO2 (p = 0.008), PaO2 (p = 0.005), actual bicarbonate (p = 0.005), and oxygen saturation (p = 0.012) in these patients. After the index surgery, the Cobb angle decreased to 49.5° ± 18.9° and the kyphosis angle decreased to 36.2° ± 25.8°. After a mean of 4.3 ± 1.4 lengthening procedures, the Cobb angle was 56.5° ± 15.8°, and the kyphosis angle was 38.8° ± 19.7°. Surgical complications occurred in 14 (50%) patients, but none of these patients required revision surgery at the latest follow-up. Preoperative HGT notably improved both spinal deformity and pulmonary function in patients with severe EOS. GR treatment after HGT is a safe and effective strategy for these patients.

Magnetically controlled growing rod treatment for early-onset scoliosis: analysis of 52 consecutive cases demonstrates improvement of coronal deformity.

The purpose of this study was to report the radiographic results and complications of magnetically controlled growing rod (MCGR) treatment in patients with early-onset scoliosis (EOS). Patient records and radiographs from a consecutive series of patients treated with MCGR for EOS at two Swedish institutions were reviewed retrospectively. Radiographic analysis included Cobb angle, T1-T12 height, T1-S1 height, thoracic kyphosis, and lung height. Subgroup analyses were performed on primary versus conversion cases and single versus dual rods using one-way analysis of variance (ANOVA) and independent samples t-test. Fifty-two cases treated with MCGR (24 single rods, 28 dual rods) were included from local surgical records into this cohort study, 32 primary and 20 converted from other growth friendly surgical treatment. Mean age at MCGR implantation was 7.4 (2.0-14.6) years old in the primary group and 9.3 (5.0-16.1) years old in the converted group. Mean follow-up time was 3.7 (2.0-7.6) years. Mean (standard deviation; SD) Cobb angle of the major curve changed from 62° (17°) preoperatively to 42° (16°) postoperatively to 46° (18°) at final follow-up (P<0.001). Mean (SD) overall thoracic kyphosis changed from 41° (19°) preoperatively to 32° (14°) postoperatively to 39° (17°) at final follow-up (P=0.018). Mean T1-T12 height was 177 mm (34 mm) preoperatively, 183 mm (35 mm) immediate postoperative and 199 mm (35 mm) at final follow-up (P=0.047). The mean T1-T12 height increased significantly in the primary group but not in the converted group. The number of surgeries was 114 (78 planned, 36 unplanned). The rate of unplanned surgeries did not differ significantly between single and dual rods. The total number of complications was 70 of which 38 were implant related. The overall mean complication rate was 1.4 (0-4). There were no significant differences in complication rates between subgroups. MCGR treatment enabled and maintained correction of spinal deformity while allowing spinal growth. There were no significant differences in complication rates or unplanned surgeries between the groups treated with single or dual rods.

Waiting for Change: Pulmonary Function Improves in a Delayed Fashion Following Dual Growing-Rod Surgery for Early-Onset Scoliosis: Commentary on an article by Yunsheng Wang, MD, et al.: "Long-Term Radiographic and Pulmonary Function Outcomes After Dual Growing-Rod Treatment for Severe Early-Onset Scoliosis".

Commentary Jess Lair, PhD, said, “Children are not things to be molded, but people to be unfolded.” He clearly understood the fine line that we walk when we treat children with early-onset scoliosis. We need to intervene in a way that helps the child to grow and maximizes lung capacity without doing so too early, too late, too aggressively, or not aggressively enough, with a limited fusion, but also just enough fusion to avoid progression. All the while, we wonder if these interventions really help children to live longer or better. Pulmonary function is a very objective way to evaluate our outcomes, but these data are difficult to obtain. Redding and Mayer have shown us that lung structure and function change with early-onset scoliosis and with early-onset scoliosis treatment1,2. We tend to rely on radiographs and patient-reported outcomes as our measures of success, with some good evidence that there is correlation3. This study by Wang et al. not only identifies successful improvement in children with severe early-onset scoliosis, but also goes a step further in describing the timeline of radiographic and respiratory changes. Notably, the pulmonary function at 1 year following original dual growing-rod surgery improved but was not significantly different from before the operation, although this was the time frame in which the radiographic parameters improved the most. The improvement in pulmonary function was delayed to the time between 1 year postoperatively and the final follow-up. The lungs may have taken a bit of time to grow or may have still been recovering from the surgical procedure, but improvement was ultimately seen: dual growing-rod surgery indeed resulted in improvements in lung function demonstrated by pulmonary function testing. One concern with regard to this study is the ability of children to participate in pulmonary function testing, and another concern is the flexibility of curves that improved from 104° to 38° following the index surgical procedure. Also, the cohort was heterogeneous, and these results cannot be universally applied to all children with early-onset scoliosis, as some diagnoses will not show the same response. Although we as pediatric orthopaedic surgeons do our best to let children “unfold” over their natural course, sometimes we do have to “mold” them a bit, and it is reassuring to know that we ultimately help create healthier adults with better lung function than they would have had without intervention.

Long-Term Radiographic and Pulmonary Function Outcomes After Dual Growing-Rod Treatment for Severe Early-Onset Scoliosis.

We evaluated long-term outcomes (radiographic parameters and pulmonary function) at a minimum follow-up of 5 years after use of dual growing rods (DGRs) to treat severe early-onset scoliosis (sEOS). Among a total of 112 patients who were diagnosed with early-onset scoliosis (EOS) and were treated with DGRs between 2006 and 2015, 52 patients had sEOS, with a major Cobb angle of >80°. Of these patients, 39 with a minimum follow-up of 5 years had complete radiographic and pulmonary function test results and were included. The Cobb angle of the major curve, T1-S1 height, T1-T12 height, and maximum kyphosis angle in the sagittal plane were measured on radiographs. Pulmonary function test results were collected in all patients before the initial operation (preoperatively), 12 months after the initial operation (postoperatively), and at the last follow-up. The changes in pulmonary function and complications during treatment were analyzed. The mean age of patients before the initial operation was 7.7 ± 1.2 years, and the mean follow-up period was 75.0 ± 14.1 months. The mean number of lengthenings was 4.5 ± 1.3, and the mean interval between lengthenings was 11.2 ± 2.1 months. The Cobb angle improved from 104.5° ± 18.2° preoperatively to 38.1° ± 10.1° after the initial surgical procedure (postoperatively) and 21.9° ± 8.6° at the final follow-up. The T1-S1 height increased from 25.1 ± 4.0 cm preoperatively to 32.4 ± 3.5 cm postoperatively and to 39.5 ± 4.0 cm at the final follow-up. However, no significant difference was detected between the increased pulmonary function parameters at 1 year and those before the operation (p > 0.05), except for residual volume, whereas pulmonary function parameters had significantly increased at the final follow-up (p < 0.05). During the treatment period, 17 complications occurred in 12 patients. DGRs are effective in treating sEOS in the long term. They allow longitudinal growth of the spine, and the correction of the spinal deformity can provide conditions that make improving pulmonary function possible in patients with sEOS. Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Efficacy of the growing rod technique on kyphotic early-onset scoliosis.

ObjectiveTo explore the application of the growing rod (GR) technique in the treatment of kyphotic early-onset scoliosis (KEOS) and analyze its surgical efficacy and safety.MethodsThe clinical data of 30 children with KEOS who received GR treatment at our department between January 2016 and December 2019 were analyzed retrospectively. There were 18 cases with normal kyphosis (normal kyphosis group) and 12 cases with excessive kyphosis (excessive kyphosis group). Both groups received GR treatment, and all patients received anteroposterior and lateral spine X-ray examinations before, after the initial surgery, and at the final follow-up. The surgical conditions and imaging parameters of the two groups were compared, and the complications were recorded.ResultsThere was no statistical difference in the Cobb angle of the major curve, apical vertebral translation (AVT), and trunk shift (TS) between the two groups before, after the first surgery, and at the final follow-up (P > 0.05). The Cobb angle of the major curve, the AVT, and the TS in both groups after the first surgery were lower than before the first surgery (P < 0.05), but there was no statistical difference between the two groups (P > 0.05). At the final follow-up, there were increases in both the Cobb angle and the AVT (P < 0.05), while the TS decreased in comparison with findings after the first surgery (P < 0.05). Before and after the first surgery and at the final follow-up appointment, there was a statistical difference in the degree of thoracic kyphosis (TK) between the two groups (P < 0.05), while there was no statistical difference in terms of lumbar lordosis (LL), the proximal junctional angle (PJA), and the distal junctional angle (DJA) (P > 0.05). After the first surgery, TK and LL showed a significant moderate response in both groups (P < 0.05), while there was no significant difference in TK, LL, PJA, and DJA compared with the results at the final follow-up (P > 0.05).ConclusionsThe use of the GR technique can improve kyphosis in KEOS treatment.

The application of finite element analysis to determine the optimal UIV of growing-rod treatment in early-onset scoliosis.

Objectives: To analyze the stress distribution in the proximal vertebral body and soft tissue of dual growing-rod (GR) with different upper instrumented vertebra (UIV) to determine the optimal UIV. Methods: A ten-year-old male EOS case treated with GR was selected. Based on spiral computed tomography (CT) scanning performed in 0.6 mm thick slices, a finite element model (FEM) of the preoperative state (M0, the original spine state) of the patient was created. Subsequently, four models with different UIV fixations were numerically analyzed by FEM, including M1 (UIV = T1, i.e., the upper-end vertebrae (UEV) of the upper thoracic curve), M2 (UIV = T2), M3 (UIV = T3) and M4 (UIV = T4, i.e., the lower end vertebrae (LEV) of the upper thoracic curve). Displacement and maximum stress in the proximal vertebral body and soft tissue were measured and compared among the five models. Results: The spine model was fixed with the sacrum, and the gravity conditions were imposed on each vertebral body according to the research of Clin and Pearsall. The results are as follows:M4 model has the largest overall displacement, while M1 has the least displacement among the four models. Except M2, the maximum normalized stress of UIV increases with the downward movement of UIV. M1 has the lowerest annulus fibrosus stress and highest joint capsule stress, which is characterized by the vertebrae backward leaning, while M4 is the opposite. The supraspinous ligament stress of M3 and M4 is significantly higher than that of M1 and M2. This suggests that UIV downshift increases the tendency of the proximal vertebral bodies to bend forward, thereby increasing the tension of the posterior ligaments (PL). Conclusion: The UIV of the GR is recommended to be close to the UEV of the upper thoracic curve, which can reduce the stress of the proximal PL, thereby reducing the occurrence of proximal junctional kyphosis (PJK).

Unmatched rod contouring at the proximal end predisposes to occurrence of junctional kyphosis in early-onset scoliosis patients undergoing traditional growing rods treatment

Study designA retrospective case series.ObjectiveTo investigate whether unmatched rod contouring at the proximal end predisposed to the occurrence of proximal junctional kyphosis (PJK) in early-onset scoliosis (EOS) patients after traditional growing rods (TGR) treatment.Summary of background dataTGR treatment has become a mainstay of treatment for EOS patients. PJK is one of the most common alignment-related complications.MethodsA consecutive series of EOS patients who had undergone TGR treatment were retrospectively reviewed. They were divided into PJK and non-PJK groups according to the occurrence of PJK or not. Demographic data, surgical strategies, and radiographic parameters were recorded and compared between groups. Proximal junctional angle (PJA) was defined as the angle between the caudal endplate of the UIV and the cephalad endplate of the second supradjacent vertebra above the UIV, while proximal rod contouring angle (PRCA) was defined as the angle of proximal rod contouring, which was represented by the angle between the cephalad endplate of the UIV and the caudal endplate of the second vertebra caudal to the UIV. Unmatched proximal rod contouring was regarded if the postoperative PRCA-PJA difference was greater than 5°.ResultsThis study finally included 73 patients. The mean age at the index surgery was 6.5 ± 2.2 years (range, 2–10 years). Mean follow-up lasted 5.0 ± 1.7 years (range, 2–9 years). They received mean 4.6 ± 1.6 lengthening procedures. There were 13 patients who were observed with PJK (18%). In comparison with the non-PJK group, the PJK group showed a larger preoperative major curve (82 ± 21° vs 70 ± 17°, P = 0.041) and global kyphosis (57 ± 6° vs. 44 ± 15°, P = 0.044). In addition, the PJK group had significantly larger postoperative PJA (10 ± 3 vs. 5 ± 3, P<0.001) and greater postoperative PJA-PRCA (6 ± 3 vs. 3 ± 3, P = 0.031). The proportion of patients with unmatched proximal rod contouring in PJK group was significantly higher than that in the non-PJK group (69% vs. 25%). Multiple logistic regression showed that preoperative GK>50°, postoperative PJA>10 and postoperative unmatched proximal rod contouring were the risk factors in predicting PJK after TGR treatment.ConclusionApproximately 18% EOS patients experienced PJK after TGR treatment. Unmatched proximal rod contouring may be an independent risk factor of PJK occurrence, in addition to greater preoperative GK and larger postoperative PJA.Level of evidence3.

Relook into the Risk Factors of Proximal Junctional Kyphosis in Early Onset Scoliosis Patients: Does the Location of Upper Instrumented Vertebra in Relation to the Sagittal Apex Matter?

ObjectiveGrowing rods surgery is the mainstay of treatment for early‐onset scoliosis (EOS) while proximal junctional kyphosis (PJK) is one of the most commonly reported postoperative complications. We sought to investigate the impact of the location of upper instrumented vertebra (UIV) in relation to the sagittal apex on proximal junctional kyphosis in EOS after traditional growing rods (GRs) treatment.MethodsA total of 102 EOS patients who received traditional growing rods treatment with a follow‐up of at least 2 years between 2009 and 2020 were retrospectively reviewed. Radiographic measurements were performed before and after the index surgery and at the latest follow‐up. We investigated the coronal Cobb angle and spinopelvic parameters of the whole spine. The location of the UIV, apex, lower instrumented vertebra (LIV), inflection vertebra (IV), the number and distance of UIV‐apex, LIV‐apex and IV‐apex were also recorded. Risk factors for PJK were analyzed by logistic regression analysis.ResultsPJK was observed in 21 patients (20.6%) during the follow‐up period. The PJK group showed a younger age at the index surgery (5.9 vs. 7.1 years, P = 0.042), more lengthening procedure times (5.0 vs. 4.0, P = 0.032), larger preoperative coronal Cobb angle (82.0 vs. 75.6°, P = 0.038), higher correction rate (51.2% vs. 44.4%, P = 0.047) and larger postoperative proximal junctional angle (PJA) (13.9 vs. 5.5°, P < 0.001) than the non‐PJK group. The ratio of the number and distance from UIV‐apex to IV‐apex also differed significantly between the two groups. The logistic regression revealed that age at the index surgery ≤ 7 years, the ratio of the number from UIV‐ apex to IV‐ apex ≤ 0.6 and the ratio of the distance from UIV‐ apex to IV‐ apex ≤ 0.6 were independent risk factors for postoperative PJK.ConclusionBesides younger age, a closer location of UIV relative to the sagittal apex is identified to be an independent risk factor of postoperative PJK. Selection of UIV at a relatively farther location away from the sagittal apex might help prevent occurrence of PJK.

The Effect of Apical Vertebra Position on Growing Rod Treatment: A Clinical and Finite Element Study.

Growing rods (GRs) is a commonly utilized technique for the management of early-onset scoliosis. The significance of the position of the apical vertebrae relative to the rods is not known. The purpose of this study is to analyze the potential effects of the position of the apical vertebrae in relation to the GRs on deformity control through plain radiographs and finite element analysis (FEA) modeling. We identified 140 patients treated with GR between 2000 and 2018. Patients who had a congenital vertebral anomaly or <2-year follow-up were excluded. Curve magnitude, traction radiograph under general anesthesia (TRUGA) flexibility, apical rotation, the lengths of T1-12, T1-S1, and the instrumented segments were recorded. Patients were divided into 3 groups according to the apical position on the postoperative radiographs: group 1 (both pedicles are between the rods), group 2 (convex rod is between the apical vertebra pedicles), group 3 (both pedicles are lateral to the convex rod). FEA models were created simulating the 3 groups. Both radiographic and FEA data were analyzed to compare the deformity control and growth in each group. Fifty-eight patients were included in the final analyses (mean age 84 mo; range: 38 to 148). Ten patients (17%) were in group 1, 34 (59%) in group 2, and 14 (24%) in group 3. Difference between TRUGA flexibilities was statistically insignificant. Group 3 was the least successful in terms of both height gain and rotational control. FEA showed a decrease in rotation and displacement for every group, however, the residual rotation and displacement was highest in group 3. Bringing the apex in line with the GR increases the capacity of growth preservation as it results in largest height gain and better deformity control. FEA model demonstrated that distraction alone is inadequate for controlling rotation, and with increasing apical translation, residual rotation after distraction also increases. Level III.

Clinical Outcomes of 3-column Osteotomy at Growing Rod Graduation.

Several different strategies were described on how to graduate a patient when skeletal maturity is reached after growing rod treatment. A final instrumentation and fusion is commonly performed, but the stiffness of the spine after numerous lenghthenings can be a major problem. When correction is needed in a severe and rigid curve, 3-column osteotomies (3CO) can be used as a method of bringing the spine back to a well-balanced position. This study aims to evaluate the clinical outcomes of 3CO osteotomies at growing rod graduation. A retrospective search of the database was performed between 1996 and 2018. Inclusion criteria were: diagnosis of early-onset scoliosis, underwent 3CO at the final fusion procedure, and ≥1 year of follow-up. Indications for this osteotomy were: significant sagittal and/or coronal off-balance or severe crankshaft deformity or significant distal and/or proximal adding-on. Clinical, radiographic, and operative data were analyzed. Complications were classified according to the modified Clavien-Dindo-Sink system. Eight patients were included in the study with a mean age of 13.5 at graduation (male/female: 2/6). The mean scoliosis angle significantly reduced from 65.6 to 39 degrees (P=0.012). Mean T1-T12 height increased from 19 to 20.5 (P=0.084) and T1-S1 from 29.6 to 31.6 (P=0.144). Five patients had a staged surgery. Average operative time was 338 minutes and blood loss was 1321 mL. Four grade 1, 1 grade 2, and 1 grade 3 complications occurred. This is the first case-series in the literature reporting on the use of 3CO at growing rod graduation. These procedures can be safely and effectively used to overcome significant multiplanar deformity and/or off-balance in the graduation of patients with early-onset scoliosis and significant correction can be achieved on these severe and rigid curves. Level IV-case series.

P81. The impact of growing rod surgery on cervical alignment during the treatment of early onset scoliosis: A case-control study based on machine learning algorithms

P81. The impact of growing rod surgery on cervical alignment during the treatment of early onset scoliosis: A case-control study based on machine learning algorithms

Traditional growing rod for early-onset scoliosis in high-altitude regions: a retrospective study

BackgroundChildren with early-onset scoliosis living in high-altitude areas have severe deformities and poor nutritional status. However, no reports on early-onset scoliosis treatment using traditional growing rods in such children exist. Thus, we analyzed the outcomes of traditional growing rods treatment in such patients and the effect of altitude on therapy.MethodsBetween September 2007 and December 2017, 59 consecutive patients with EOS underwent systematic surgical correction using traditional growing rods. They were divided into the high-altitude and low-altitude groups, and differences in surgical efficacy and complications between the groups were analyzed pre- and postoperatively. Radiographic measurements, including the Cobb angle, thoracic kyphosis, lumbar lordosis, T1–S1 and T1–T12 heights, sagittal and coronal balance, distance between C7PL and sagittal vertical axis, pelvic incidence, sacral slope, and pelvic tilt were assessed preoperatively, postoperatively, and at the last follow-up. Continuous data were analyzed using paired or independent Student’s t tests, and they were compared preoperatively, postoperatively, and at the last follow-up using a repeated measures analysis of variance. Enumerated data were analyzed using the χ2 test.ResultsThe mean patient age at the initial surgery and mean follow-up duration were 8.9 ± 2.4(5–14) years and 51.91 ± 25.23 months, respectively. Altogether, 234 operations were conducted for all patients with an average interval between operations of 11.4 ± 3.0 months. The average Cobb angle was similar in both groups preoperatively and at the last follow-up, it was significantly different postoperatively. TK was significantly different in all three periods. T1–S1 and T1–T12 heights were significantly different only during the preoperative period. The overall rates of complications and implant-related complications did not differ significantly between the groups.ConclusionsDeformity in patients with EOS in high-altitude areas was more severe, and treatment using TGRs yielded a satisfactory therapeutic effect.

Coronal imbalance after growing rod treatment in early-onset scoliosis: a minimum of 5 years' follow-up.

The objective of this study was to investigate the incidence and risk factors of coronal imbalance (CI) in patients with early-onset scoliosis (EOS) who underwent growing rod (GR) treatment. A consecutive series of 61 patients with EOS (25 boys and 36 girls, mean age 5.8 ± 1.7 years) who underwent GR treatment was retrospectively reviewed. Postoperative CI was defined as postoperative C7 translation on either side ≥ 20 mm. Patients were divided into an imbalanced and a balanced group. Coronal patterns were classified into three types: type A (C7 translation < 20 mm), type B (C7 translation ≥ 20 mm with C7 plumb line [C7PL] shifted to the concave side of the curve), and type C (C7 translation ≥ 20 mm and a C7PL shifted to the convex side of the curve). Each patient had an average of 5.3 ± 1.0 lengthening procedures and was followed for an average of 6.2 ± 1.3 years. Eleven patients (18%) were diagnosed with CI at the latest distraction, 5 of whom graduated from GRs and underwent definitive fusion. However, these patients continued to present with CI at the last follow-up evaluation. The proportion of preoperative type C pattern (54.5% vs 16.0%, p = 0.018), immediate postoperative apical vertebral translation (30.4 ± 13.5 mm vs 21.2 ± 11.7 mm, p = 0.025), lowest instrumented vertebra tilt (11.4° ± 8.2° vs 7.3° ± 3.3°, p = 0.008), and spanned obliquity angle (SOA) (9.7° ± 10.5° vs 4.1° ± 4.5°, p = 0.006) values in the imbalanced group were significantly higher than in the balanced group. Multiple logistic regression demonstrated that a preoperative type C pattern and immediate postoperative SOA > 11° were independent risk factors for postoperative CI. The incidence of CI in patients with EOS who underwent GR treatment was 18%. This complication could only be slightly improved after definitive spinal fusion because of the autofusion phenomenon. A preoperative type C pattern and immediate postoperative SOA > 11° were found to be the risk factors for CI occurrence at the latest follow-up.

Evaluation of changes in shoulder balance and prediction of final shoulder imbalance during growing-rod treatment for early-onset scoliosis

BackgroundObtaining 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.MethodsTwenty-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.ResultsThe 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.ConclusionsShoulder 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.

Growing-rod implantation improves nutrition status of early-onset scoliosis patients: a case series study of minimum 3-year follow-up

BackgroundEarly onset scoliosis (EOS) may cause malnutrition in affected patients. Growing-rod treatment has been an effective protocol for treating EOS. The objective of this study is to demonstrate whether growing-rod treatment improves nutritional status of EOS patients.MethodsFifty-two EOS patients who had dual growing-rod surgery was enrolled. The minimum follow-up was 3-years. Their body weights were normalized based on the data of two National Population Census of China. Z-scores were used to indicate the standard deviation from the median body weight-for-age.ResultsThe median follow-up time was 6 years. Preoperatively, the prevalence of malnutrition (Z < − 2) was 21.2%, and reduced to 9.6% at the end of the follow-up. Preoperatively, the average Z-score was − 0.94, and it increased to − 0.65 at the latest follow-up (p < 0.05). Patients with preoperative Z-score below − 1 had more significant increase of Z-scores (− 2.15 vs − 1.26, p < 0.001). A significant negative correlation between the change of Z-score and the preoperative Z-score (correlation coefficient − 0.65, p < 0.001).ConclusionsThe growing rod surgery and lengthening procedures significantly improves the nutrition status of EOS patients. The body weight gains are more significant in patients with lower body weights.

Outcomes of growing rods in a series of early-onset scoliosis patients with neurofibromatosis type 1.

Early-onset scoliosis (EOS) is not uncommon in patients with neurofibromatosis type 1 (NF1). Despite conservative treatment, spinal deformities progress and require early surgical intervention. To avoid potential interference with chest and trunk growth, growing rods (GRs) have been used effectively in EOS of various etiologies. In this study the authors sought to analyze the outcomes of GRs in EOS patients with NF1. This was a retrospective single-center cohort study that included consecutive EOS patients with NF1 who were treated with GRs and were followed up for a minimum of 2 years. Clinical and radiological analyses were performed preoperatively and until the last follow-up. From to 2008 to 2017, 18 patients (6 male, 12 female) underwent GR surgery (14 single GRs, 4 dual GRs) at a mean age of 8 ± 2.1 years. Mean follow-up was 5 ± 2.4 years. Fifty-five lengthenings were performed at a mean rate of 3 lengthenings per patient (range 0-7). Ten of 14 single GRs (71%) were converted into dual GRs during treatment. No patient underwent definitive posterior spinal fusion (PSF) at GR treatment completion. The mean initial and last follow-up major curves were 57° and 36°, respectively (p < 0.001, 37% correction). The average T1-S1 increase was 13 mm/yr. Six of 9 hyperkyphotic patients had normal kyphosis at last follow-up. There were 26 complications involving 13 patients (72%), with 1 patient who required unplanned revision. The primary complications were instrumentation related, consisting of 17 proximal hook dislodgments, 6 distal pedicle screw pullouts, and 2 rod fractures. Only 1 patient experienced a mechanical complication after dual GR implantation. There were no wound infections. The GR technique provided satisfactory spinal deformity control in EOS patients with NF1 while allowing substantial spinal growth. Adequately contoured dual GRs with proximal hooks placed in nondystrophic regions should be used to minimize implant-related complications. Surgeons should not attempt to correct kyphosis at GR implantation.