Definitive Fusion Research Articles

Osteotomies At The Time of Graduation Surgery: How Much Do We Get from Them?

Retrospective, Multicenter. Determine if posterior column osteotomies (PCO) at time of conversion from growth friendly instrumentation (GFI) to definitive fusion in early onset scoliosis (EOS) graduates impacts outcomes. Increasing spinal rigidity following treatment of EOS with GFI can limit curve correction at time of conversion to definitive spinal fusion. PCO are often employed at the time of fusion to improve flexibility. This technique's efficacy has not been studied. EOS patients with GFI undergoing conversion to fusion were grouped by those that did or did not have PCO. Patients with inadequate radiographs, <2 years follow-up, or three-column osteotomies at time of fusion were excluded. 832 patients met inclusion criteria. 175 (21%) patients had PCO. Age at index surgery was younger (6.6 vs. 7.4y, P =0.0009) and the mean duration of GFI was greater (6.2 vs. 5.5y, P =0.009) in the PCO group. Prior to fusion, curve magnitude was similar between the groups (PCO=61.9 degrees, no PCO=59.3 degrees, P=0.18). On average 4.4 osteotomies (range: 1 - 12) were performed for the PCO group and EBL (PCO=820cc vs no PCO=752cc, P<0.01) and surgical time (PCO=403min vs no PCO=349min, P<0.01) were greater. Postoperatively, mean curve correction (PCO=16.6, no PCO=14.4 degrees, P=0.18) was similar. Accounting for preoperative curve magnitude, there was a relationship between number of PCOs and curve correction (P=0.04). There was no relationship between degrees of correction per osteotomy and duration of GFI (P=0.12). Postoperative complications at 2 years were similar (PCO=25% vs no PCO=27%, P=0.63). EOS graduates achieve minimal correction at time of conversion regardless of whether PCOs are performed. PCOs increase EBL and operative time but have a similar complication rate. More PCOs resulted in more correction, though less than that anticipated in a previously uninstrumented spine. III.

Prospective Assessment of Transforaminal Lumbar Interbody Fusion (TLIF) in Spondylolisthesis: A Radiological and Functional Outcome Study in an Indian Population.

Spondylolisthesis is a common spinal condition in which one vertebra slips over another, leading to pain and disability. Transforaminal lumbar interbody fusion (TLIF) has emerged as a surgical option for addressing spondylolisthesis; however, limited research exists, especially in the Indian context, evaluating its radiological and functional outcomes. The study aimed to evaluate the radiological and functional outcomes of TLIF in spondylolisthesis using standardized scoring systems, to evaluate the sagittal balance of the spine radiologically in patients who have undergone TLIF for spondylolisthesis, and to evaluate the correlation between the functional and radiological outcomes after TLIF. This prospective observational study included spondylolisthesis patients undergoing TLIF at SRM Medical College Hospital and Research Centre from August 2022 to August 2024. Criteria included Meyerding grade 1-4 spondylolisthesis, single-segment fusion, and willingness for 12-month follow-up. Forty-five patients were included with age 36.6 ± 12.2 years, with 73.3% being female. L4-L5 is the most common level affected in 21 patients (46.7%). Significant improvements were observed in pelvic tilt 19.07 ± 2.05, sacral slope 30.6 ± 4.4, segmental lordosis 18.4 ± 1.4, lumbar lordosis 57.1 ± 1.8, sagittal vertical axis (SVA) 2.5 ± 0.3, Visual Analog Scale for pain 0.4 ± 0.5, and Oswestry Disability Index (ODI) scores 5.23 ± 2.6 postoperatively (p < 0.05). At one-year follow-up, 84.4% of patients had good-to-excellent outcomes, and 44.4% had definitive fusion according to modified Lee criteria. However, there was no correlation between ODI score and grade of listhesis, pelvic incidence (PI), or SVA of the spine (p > 0.05). This study provides valuable insights into the effectiveness of TLIF surgery in addressing spondylolisthesis, both in terms of radiological and functional outcomes. However, there was no correlation between improvement in functional and radiological parameters (PI vs. ODI, SVA vs. ODI). TLIF appears to offer significant improvements in patient well-being and quality of life. These findings contribute to understanding TLIF's suitability as a treatment for spondylolisthesis and can inform clinical practice, ultimately benefiting patients suffering from this condition.

Cerebellar Haemorrhage After Corrective Surgery for Scoliosis in a Girl with Arrested Hydrocephalus.

A 14-year-old girl with congenital hydrocephalus and early-onset scoliosis presented with sudden onset of severe headache on the fourth postoperative day of scoliosis correction (definitive fusion). On evaluation, she was found to have cerebellar haemorrhage on computed tomography scan with the findings of obstructive hydrocephalus. Posterior fossa bleed with hydrocephalus contributing to raised ICP was suspected initially. Headache persisted despite treating the patient with analgesics and antioedema measures. There was no history of postural variation of headache. As the drain output was not coming down, even by the sixth postoperative day, low cerebrospinal fluid pressure headache was considered and the drain was removed, which resulted in marked improvement of headache. Subsequent wound exploration revealed grade III dural tear at D10 level, which was repaired and the headache subsided completely. The linear pattern of haemorrhage in the cerebellum is classical of remote cerebellar haemorrhage, which is seen rarely following spinal surgeries with associated dural tear.

Impact of Spinal Surgery on Intrathecal Nusinersen Injections in Pediatric Spinal Muscular Atrophy.

Complex spinal deformities necessitate surgical interventions that may intervene with intrathecal injections in patients with spinal muscular atrophy (SMA). This study aimed to determine the effect of spinal deformity correction surgery on nusinersen administration. Pediatric patients with SMA, operated by a single surgeon, either via magnetically controlled growing rod (MCGR) or definitive fusion (DF) with skip instrumentation, were evaluated retrospectively in terms of safety and feasibility of intrathecal injections. Patients' and their parents' perspectives were evaluated through a questionnaire regarding any shift in the setting of injections. Fourteen patients with 15 spinal surgeries (10 MCGR and 5 DF) were included. Eleven patients received intrathecal treatment both before and after the surgery. Preoperative (n=3) and postoperative (n=9) fluoroscopic guidance was required leading to a shift in the application settings in 6 patients. Of 106 preoperative injections, 15% required fluoroscopy and 2% required anesthesia. Postoperatively, of 88 injections, 73% required fluoroscopy and 26% required anesthesia. No patients discontinued intrathecal injections due to technical difficulties associated with the spinal surgery. This study demonstrates that spinal surgery does not prevent safe and successful intrathecal nusinersen injections. In the DF group, the skip instrumentation technique provided access to interlaminal space for intrathecal injections. In either surgical group, no further auxillary approach was required. Modifications in the injection technique require an institutional approach, and concerns of patients and their families should be addressed accordingly. IV.

How will early onset scoliosis surgery affect my child's future as a young adult? A follow-up study using patient-reported outcome measures.

Using patient-reported outcome measures (PROMs), this study was undertaken to determine how well patients with early onset scoliosis (EOS) fare in adulthood. Among eight healthcare centers, 272 patients (≥ 18years) surgically managed for EOS (≥ 5years) completed the Scoliosis Research Society (SRS)-22r, Functional Assessment of Chronic Illness Therapy-10 (FACIT-Dyspnea-10), and Short Form (SF)-12. Functional and demographic data were collected. The response rate was 40% (108/272). EOS etiologies were congenital (45%), neuromuscular (20%), idiopathic (20%) syndromic (11%), and unknown (4%). All patients scored within normal limits on the FACIT-Dyspnea-10 pulmonary (no breathing aids, 78%; no oxygen, 92%). SF-12 physical health scores and most SRS-22r domains were significantly decreased (p < 0.05 and p < 0.001, respectively) compared with normative values. SF-12 and SRS-22r mental health scores (MHS) were lower than normative values (p < 0.05 and p < 0.02, respectively). Physical health PROMs varied between etiologies. Treatment varied by etiology. Patients with congenital EOS were half as likely to undergo definitive fusion. There was no difference between EOS etiologies in SF-12 MHS, with t scores being slightly lower than normative peers. Good long-term physical and social function and patient-reported quality of life were noted in surgically managed patients. Patients with idiopathic EOS physically outperformed those with other etiologies in objective and PROM categories but had similar MHS PROMs. Compared to normative values, EOS patients demonstrated decreased long-term physical capacity, slightly lower MHS, and preserved cardiopulmonary function. Level IV Case Series.

Evaluation of crankshaft phenomenon after posterior fusion for early onset scoliosis using an inverse trigonometric function: a multicenter retrospective cohort study.

The crankshaft phenomenon (CSP) is a corrective loss after posterior surgery for early onset scoliosis (EOS). However, an accurate method for CSP evaluation has yet to be developed. In this study, we evaluated pedicle screw (PS) length and rotation angle using an inverse trigonometric function and investigated the prevalence of the CSP. Fifty patients from nine institutions (mean age 10.6years, male/female ratio 4:46) who underwent early definitive fusion surgery at ≤ 11years of age were included. The rotation angle was calculated as arctan (lateral/frontal PS length) using radiography. Measurements were taken at the apex and lower instrumented vertebra (LIV) immediate, 2-, and 5-year postoperatively. CSP was defined as a rotation angle progression ≥ 5°. We divided patients into CSP and non-CSP groups and measured the demographic parameters, Risser grade, state of the triradiate cartilage, major coronal Cobb angle, T1-T12 length, T1-S1 length, and presence of distal adding-on (DAO). We compared these variables between groups and investigated the correlation between the measured variables and vertebral rotation. Logistic regression analysis investigated factors associated with CSP. The rotation angle progressed by 2.4 and 1.3° over 5years for the apex and LIV, respectively. CSP occurred in 15 cases (30%), DAO in 11 cases (22%), and CSP and DAO overlapped in 4 cases (8%). In the CSP group, the T1-T12 length was low immediate postoperatively. The rotation angle was negatively correlated with preoperative height (r = -0.33), T1-T12 length (r = -0.35), and T1-S1 length (r = -0.30). A lower preoperative T1-T12 length was associated with CSP (odds ratio: 0.996, p = 0.048). CSP occurred in 30% of patients with EOS who underwent definitive fusion. The presence of CSP was associated with a lower preoperative T1-T12 length. Diagnosis, level IV.

Spinal height for growth guidance treatment in early onset idiopathic scoliosis: analysis through final surgical treatment.

The growth guidance (GG) method for treatment of early onset scoliosis has as its primary goal the restoration of apical spinal alignment, facilitating normal spinal growth to achieve a suitable adult thoracic height. To evaluate whether GG surgical treatment achieves comparable thoracic and spinal height to distraction-based treatment (DBT) in idiopathic early onset scoliosis (I-EOS) patients. We hypothesized that GG would prove superior to DBT at the time of definitive fusion surgery. All I-EOS patients who underwent GG at a single center were reviewed. T1-L1 and T1-S1 heights were measured using the traditional coronal method as well as the Halifax sagittal spinal length (SSL) technique. The same measurements were obtained from a comparable control group obtained from a multi-center pediatric early onset scoliosis database who underwent treatment with traditional growing rods (TGR) or magnetically controlled growing rods (MCGR). Of the I-EOS patients who underwent GG 2004-2019, 15 patients underwent final fusion after GG completion, with a mean 5.5years of GG treatment prior to fusion (range 2.0-11.4years). Mean age at GG implantation was 8.4years (range 2.0-11.7years); 7 were male and 8 female. GG patients experienced a mean coronal thoracic height increase of 6.2cm during treatment through final fusion, and a mean coronal spinal height increase of 8.8cm. At the time of final fusion, GG patients achieved greater significant mean increases than DBT patients by 2.9cm in coronal thoracic height (p = 0.0023), 4.5cm in coronal spinal height (p = 0.001), and 4.0cm in SSL spinal height (p = 0.01). No GG patient concluded treatment with a thoracic height less than 18cm in either coronal or sagittal plane. Not only did 100% of GG patients reach minimum thoracic height of 18cm at time of final fusion, but GG also proved to be superior to distraction-based constructs in a comparison cohort on 3 of 4 spinal elongation measures. 3.

Predicting early return to the operating room in early-onset scoliosis patients using machine learning techniques.

Surgical treatment of early-onset scoliosis (EOS) is associated with high rates of complications, often requiring unplanned return to the operating room (UPROR). The aim of this study was to create and validate a machine learning model to predict which EOS patients will go on to require an UPROR during their treatment course. A retrospective review was performed of all surgical EOS patients with at least 2 years follow-up. Patients were stratified based on whether they had experienced an UPROR. Ten machine learning algorithms were trained using tenfold cross-validation on an independent training set of patients. Model performance was evaluated on a separate testing set via their area under the receiver operating characteristic curve (AUC). Relative feature importance was calculated for the top-performing model. 257 patients were included in the study. 146 patients experienced at least one UPROR (57%). Five factors were identified as significant and included in model training: age at initial surgery, EOS etiology, initial construct type, and weight and height at initial surgery. The Gaussian naïve Bayes model demonstrated the best performance on the testing set (AUC: 0.79). Significant protective factors against experiencing an UPROR were weight at initial surgery, idiopathic etiology, initial definitive fusion construct, and height at initial surgery. The Gaussian naïve Bayes machine learning algorithm demonstrated the best performance for predicting UPROR in EOS patients. Heavier, taller, idiopathic patients with initial definitive fusion constructs experienced UPROR less frequently. This model can be used to better quantify risk, optimize patient factors, and choose surgical constructs. Prognostic: III.

Integrated analysis of transcriptome and genome variations in pediatric T cell acute lymphoblastic leukemia: data from north Indian tertiary care center

IntroductionT-cell acute lymphoblastic leukemia (T-ALL) is a genetically heterogeneous disease with poor prognosis and inferior outcome. Although multiple studies have been perform on genomics of T-ALL, data from Indian sub-continent is scarce.MethodsIn the current study we aimed to identify the genetic variability of T-ALL in an Indian cohort of pediatric (age ≤ 12 years) T-ALL patients (n = 25) by whole transcriptome sequencing along with whole exome sequencing and correlated the findings with clinical characteristics and disease outcome.ResultsThe median age was 7 years (range 3 -12 years). RNA sequencing revealed a definitive fusion event in 14 cases (56%) (including a novel fusions) with STIL::TAL1 in 4 (16%), followed by NUP21::ABL1, TCF7::SPI1, ETV6::HDAC8, LMO1::RIC3, DIAPH1::JAK2, SETD2::CCDC12 and RCBTB2::LPAR6 in 1 (4%) case each. Significant aberrant expression was noted in RAG1 (64%), RAG2 (80%), MYCN (52%), NKX3-1 (52%), NKX3-2 (32%), TLX3 (28%), LMO1 (20%) and MYB (16%) genes. WES data showed frequent mutations in NOTCH1 (35%) followed by WT1 (23%), FBXW7 (12%), KRAS (12%), PHF6 (12%) and JAK3 (12%). Nearly 88.2% of cases showed a deletion of CDKN2A/CDKN2B/MTAP genes. Clinically significant association of a better EFS and OS (p=0.01) was noted with RAG2 over-expression at a median follow up of 22 months, while a poor EFS (p=0.041) and high relapse rate (p=0.045) was observed with MYB over-expression.ConclusionOverall, the present study demonstrates the frequencies of transcriptomic and genetic alterations from Indian cohort of pediatric T-ALL and is a salient addition to current genomics data sets available in T-ALL.

Radiological Outcomes of Magnetically Controlled Growing Rods for the Treatment of Children with Various Etiologies of Early-Onset Scoliosis-A Multicenter Study.

Background: The management of spinal deformities diagnosed before the age of 10 is critical due to the child's development, skeletal system, and growth mechanism. Magnetically controlled growing rods (MCGRs) are a surgical treatment option for the growing spine. The aim of this study was to analyze the radiological findings of patients treated with MCGRs for early-onset scoliosis (EOS) of various etiologies. We hypothesized that the MCGRs could provide acceptable long-term radiographic results, such as an increase in the T1-T12 and T1-S1 height and significant overall deformity correction. Methods: We retrospectively reviewed 161 EOS patients with a combined total of 302 MCGRs inserted at five institutions between 2016 and 2022 with a mean follow-up of at least two years. The Cobb angle of the major curve (MC), thoracic kyphosis (TK), lumbar lordosis (LL), and T1-T12 and T1-S1 height measurements were assessed before, after, and during the follow-up. Results: Among the 90 female and 71 male patients, there were 51 neurological, 42 syndromic, 58 idiopathic, and ten congenital scoliosis etiologies. Of the patients, 73 were aged under six years old. The mean follow-up time was 32.8 months. The mean age at placement of the MCGRs was 7 years and that at the last follow-up after fusion surgery was 14.5 years. The mean MC before the initial surgery was 86.2°; following rod implantation, it was 46.9°, and at the last follow-up visit, it was 45.8°. The mean correction rate among the etiology subgroups was from 43% to 50% at follow-up. The mean TK was noted as 47.2° before MCGR implantation, 47.1° after MCGR placement, and 44.5° at the last follow-up visit. The mean T1-T12 height increased by 5.95 mm per year, with a mean T1-S1 height of 10.1 mm per year. Conclusions: MCGR treatment allowed for an average correction of the curvature by 50% during the period of lengthening, while controlling any deformity and growth of the spine, with a significant increase in the T1-T12 and T1-S1 values during the observation period. MCGR treatment in EOS carries a risk of complications. While congenital and syndromic EOS often have short and less flexible curves in those groups of patients, single rods can be as effective and safe. Definitive fusion results in the mean final coronal correction between the start of MCGR treatment and after undergoing PSF of approximately 70%. The mean T1-T12 spinal height increased by 75 mm, while the T1-S1 spinal height gained a mean of 97 mm.

Health-related quality of life and clinical outcomes for magnetically controlled growing rod patients after treatment termination.

To determine the health-related quality of life (HRQoL) and clinical outcomes of children with early onset scoliosis (EOS) treated with magnetically controlled growing rods (MCGR) followed to definitive fusion (DF). A retrospective review of EOS patients treated with MCGR and followed to DF was performed. Outcomes included HRQoL scores, radiographic, clinical, and unplanned returns to the operating room (UPROR) data collected at pre-MCGR implantation, immediately post-MCGR implantation, pre-DF, and post-DF. HRQoL scores were collected at least 6months post-DF. Twenty-eight patients (57.1% females, mean age at MCGR insertion 7.19 ± 1.5years, mean pre-MCGR Cobb 64.7° ± 17.6) met inclusion criteria. MCGR treatment resulted in an overall 30.2% improvement in coronal plane deformity following DF. The mean growth rates between MCGR implantation and pre-DF for T1-T12 height and T1-S1 length were 0.33 ± 0.23mm/month and 0.49 ± 0.28mm/month, respectively. Of the 28 included patients, 26 (92.9%) experienced at least one UPROR, with a total of 52 surgical complications occurring in the total cohort, representing 1.9 UPROR/patient. Interestingly, there was a decline in scores reported between post-MCGR implantation and the pre-DF time-point (N = 16, 78.2 ± 14.9 vs 69.7 ± 17.8, p = 0.02). These scores recovered post-DF, resulting in an overall unchanged HRQoL when comparing pre-MCGR to post-DF (N = 11, 79.9 ± 15.1 vs 76.7 ± 17.9, p = 0.44). While MCGR treatment achieves coronal plane deformity control and facilitates spinal growth, only 7.1% of children experienced a complication-free treatment course when followed to definitive fusion. Patients achieved modest curve correction and spinal growth, while maintaining stable HRQoL outcomes between pre-MCGR and post-DF.

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.

Fusion's Location and Quality within the Fixated Segment Following Transforaminal Interbody Fusion (TLIF).

Transforaminal interbody fusion (TLIF) has gained increased popularity over recent decades and is being employed as an established surgical treatment for several lumbar spine pathologies, including degenerative spondylosis, spondylolisthesis, infection, tumor and some cases of recurrent disc herniation. Despite the seemingly acceptable fusion rates after TLIF (up to 94%), the literature is still limited regarding the specific location and quality of fusion inside the fixated segment. In this single-institution, retrospective population-based study, we evaluated all post-operative computed tomography (CT) of patients who underwent TLIF surgery at a medium-sized medical center between 2010 and 2020. All CT studies were performed at a minimum of 1 year following the surgery, with a median of 2 years. Each CT study was evaluated for post-operative fusion, specifically in the posterolateral and intervertebral body areas. The fusion's quality was determined and classified in each area according to Lee's criteria, as follows: (1) definitive fusion: definitive bony trabecular bridging across the graft host interface; (2) probable fusion: no definitive bony trabecular crossing but with no gap at the graft host interface; (3) possible arthrosis: no bony trabecular crossing with identifiable gap at the graft host interface; (4) definite pseudarthrosis: no traversing trabecular bone with definitive gap. A total of 48 patients were included in this study. The median age was 55.6 years (SD ± 15.4). The median time from surgery to post-operative CT was 2 years (range: 1-10). Full definitive fusion in both posterolateral and intervertebral areas was observed in 48% of patients, and 92% showed definitive fusion in at least one area (either posterolateral or intervertebral body area). When comparing the posterolateral and the intervertebral area fusion rates, a significantly higher definitive fusion rate was observed in the posterolateral area as compared to the intervertebral body area in the long term follow-up (92% vs. 52%, p < 0.001). In the multivariable analysis, accounting for several confounding factors, including the number of fixated segments and cage size, the results remained statistically significant (p = 0.048). In conclusion, a significantly higher definitive fusion rate at the posterolateral area compared to the intervertebral body area following TLIF surgery was found. Surgeons are encouraged to employ bone augmentation material in the posterolateral area (as the primary site of fusion) when performing TLIF surgery.

Growing rods in meningomyelocele lead to increased risk for complications in comparison with fusion; a retrospective study of 30 patients treated for at the University Hospital of Uppsala

PurposeTo compare the complication rates of two different types of posterior instrumentation in patients with MMC, namely, definitive fusion and fusionless surgery (growing rods).MethodsSingle-center retrospective study of 30 MMC patients that underwent posterior instrumentation for deformity (scoliosis and/or kyphosis) treatment from 2008 until 2020. The patients were grouped based on whether they received definitive fusion or a growth-accommodating system, whether they had a complication that led to early surgery, osteotomy or non-osteotomy. Number of major operations, Cobb angle correction and perioperative blood loss were the outcomes.Results18 patients received a growing system and 12 were fused at index surgery. The growing system group underwent a mean of 2.38 (± 1.03) surgeries versus 1.91 (± 2.27) in the fusion group, p = 0.01. If an early revision was necessitated due to a complication, then the number of major surgeries per patient was 3.37 (± 2.44) versus 1.77 (± 0.97) in the group that did not undergo an early revision, p = 0.01. Four patients developed a superficial and six a deep wound infection, while loosening/breakage occurred in 10 patients. The Cobb angle was improved from a mean of 69 to 22 degrees postoperatively. Osteotomy did not lead to an increase in perioperative blood loss or number of major operations.ConclusionGrowing systems had more major operations in comparison with fusion surgery and early revision surgery led to higher numbers of major operations per patient; these differences were statistically significant. Definitive fusion at index surgery might be the better option in some MMC patients with a high-risk profile.

The Evaluation of Serum Metal Ion Levels and Metallosis in Graduated Patients With Magnetically Controlled Growing Rods.

Magnetically controlled growing rods (MCGR) aim to control curve progression while limiting surgical burden in children with early-onset scoliosis. Systemic and local distribution of metal debris has been documented in children with spinal implants. The aim of the study was to assess serum metal ion levels and local metal debris-related changes at the conclusion of MCGR treatment. Between February 2019 and September 2022, all patients who had a conversion to definitive fusion at the completion of MCGR treatment in our institution were invited to participate in this study. Consenting patients had serum metal ion levels drawn (titanium, cobalt, and chromium) and histologic analyses of peri-implant tissue samples. We enrolled 24 children who underwent definitive fusion post-MCGR treatment for early-onset scoliosis. The average age at definitive fusion was 13.3 years (range: 11 to 17 y). The average length of MCGR treatment was 4.8 years (range: 1.5 to 6.8 y). At the end of the MCGR treatment, 23 (96%) patients had elevated serum metal ion levels. Mean serum titanium levels were 165.4 nmol/L (range: 30 to 390 nmol/L), mean serum cobalt levels were 4.6 nmol/L (range: 1.2 to 14 nmol/L), and mean serum chromium levels were 14 nmol/L (range: 2.4 to 30 nmol/L). Peri-implant soft tissue histologic analysis demonstrated local metal debris and foreign body reactions in all patients. At the completion of MCGR treatment, the majority of patients demonstrate elevated serum metal ion levels and local metal debris-related peri-implant soft tissue changes. Although there is no current literature to suggest these findings are harmful, further research as to the clinical significance is required. Level IV.

Pilot Study on Percutaneous Delivery of Recombinant Human Bone Morphongenetic Protein-2 Augments Fusion in a Nicotine-impaired Rabbit Fusion Model.

A nicotine-impaired spinal fusion rabbit model. To examine whether controlled delivery of morselized absorbable collagen sponge recombinant human bone morphogenetic protein-2 (rhBMP2) in a delayed manner postsurgery would allow for improved bone healing. The current delivery method of rhBMP-2 during surgery causes a burst of rhBMP-2, which is not sustained. Given that bone morphogenetic protein 2 (BMP-2) expression peaks later in the fusion process, there may be the benefit of delivery of rhBMP-2 later in the healing process. Sixteen male 1-year-old rabbits underwent a posterolateral spinal fusion with iliac crest bone graft at L5-L6 while being given nicotine to prevent spinal fusion as previously published. Eight were controls, whereas 8 had morselized rhBMP-2 (4.2 mg) injected at the fusion site at 4 weeks postoperatively. Histologic, radiologic, and palpation examinations were performed at 12 weeks to determine fusion status and the volume of bone formed. Hematoxylin and eosin stains were used for histology. A Student t test was used to compare the computed tomography scan measured volume of bone created between the control cohort (CC) and rhBMP-2 delayed delivery cohort (BMP-DDC). Of the total, 7/8 rabbits in the BMP-DDC and 5/8 rabbits in the CC formed definitive fusion with a positive palpation examination, bridging bone between transverse processes on computed tomography scan, and an x-ray showing fusion. Histologic analysis revealed newly remodeled bone within the BMP-DDC. There was an increased average volume of bone formed within the BMP-DDC versus the CC (22.6 ± 13.1 vs 11.1 ± 3.6 cm 3 , P = 0.04). Our study shows that injectable morselized absorbable collagen sponge/rhBMP-2 can create twice as much bone within a nicotine-impaired rabbit spine fusion model when delivered 4 weeks out from the time of surgery.

Radiographic and clinical outcomes after definitive spine fusion for skeletally immature patients with idiopathic scoliosis.

To assess the intermediate-term radiographic and clinical outcomes of skeletally immature idiopathic scoliosis (IS) patients that underwent definitive fusion (DF). A retrospective review of patients with IS who were Risser 0 with open tri-radiate cartilages at the time of DF with minimum 5-year follow-up. Outcomes included Scoliosis Research Society (SRS)-30 scores, major Cobb angle, pulmonary function tests (PFTs), and unplanned returns to the operating room (UPROR). Adding-on was defined as progression of the major Cobb angle > 5° or tilt of the lowest instrumented vertebra > 5°. Thirty-two patients (78% female, mean age 12.2 ± 1.3years old, mean preoperative major Cobb 64.8° ± 15.9) were included. Of these patients, 20 (62.5%) experienced adding-on and 6 (18.8%) required a revision surgery to correct their progressive spinal deformity. Adding-on was associated with lower 5-year postoperative SRS scores for appearance (3.7 ± 0.7 vs 4.4 ± 0.3, p = 0.0126), mental health (4.2 ± 0.6 vs 4.6 ± 0.3, p = 0.0464), satisfaction with treatment (4.0 ± 0.8 vs 4.7 ± 0.4, p = 0.0140), and total score (4.0 ± 0.4 vs 4.4 ± 0.2, p = 0.0035). The results of the PFTs did not differ between groups. Patients experienced an average of 0.53 UPROR/patient. DF in skeletally immature patients results in a high rate of adding-on, which adversely affects Health-Related Quality of Life. However, reoperation rates, both planned and unplanned, remain lower when compared to patients undergoing growth-friendly treatment.

Radiation exposure in pediatric patients with early onset scoliosis: A longitudinal single-center study

BackgroundThere is no consensus regarding the acceptable level of medical radiation exposure in patients with early-onset scoliosis. This study aimed to quantify radiation exposure in these patients and investigate factors associated with high exposure. MethodsPatients with early-onset scoliosis who received care for their spine deformity and other comorbidities in our institution were retrospectively reviewed. Cumulative radiation exposure and total number of imaging studies were recorded. Patients with ≥30 mSv exposure were classified as high exposure and analyzed to clarify factors associated with high exposure. ResultsThirty-five patients were included for analysis. The etiology of scoliosis was idiopathic in 8 patients, congenital in 7, syndromic in 8, and neuromuscular in 12. Fifteen patients underwent 19 spinal surgeries. The types of operation performed were definitive fusion (n = 12), vertebrectomy for hemivertebra (n = 2), growing rod (n = 1), lengthening (n = 3), and revision/partial implant removal (n = 1). The mean cumulative radiation dose was 22.3 mSv (range, 2.5–94.5 mSv). Spine radiography and computed tomography combined accounted for 15.0 mSv (range, 2.4–52.5 mSv, 67.3% of the mean cumulative dose). The mean radiation dose was significantly higher in patients who underwent spinal surgery than in those who did not (31.2 mSv vs. 15.6 mSv). The high-exposure group comprised 10 patients (1 idiopathic, 1 congenital, 5 syndromic, and 3 neuromuscular scoliosis) and 8 underwent 11 spinal operations. Among 8 patients who underwent spinal surgery, the cumulative radiation dose for spine was ≥30 mSv and spine computed tomography was performed an average of 4.0 times. ConclusionsNearly one-third of patients with early-onset scoliosis and half of patients who underwent spinal surgery had >30 mSv radiation exposure due to multiple computed tomography. Medical radiation exposure and associated cancer risk should be considered when treating these patients.

Incidence and causes of instrument-related complications after primary definitive fusion for pediatric spine deformity.

Various complications have been reported in the treatment of pediatric spinal deformities. Among these, instrument-related complications could be critical concerns and risks of reoperation. This study aimed to identify the incidence and causes of complications after primary definitive fusion for pediatric spine deformities. The authors retrospectively collected data from 14 institutions about patients who underwent primary definitive fusion between 2015 and 2017. There were 1490 eligible patients (1184 female and 306 male), with a mean age of 13.9 years. The incidence, causes, and reoperation rates were analyzed according to 4 etiologies of pediatric spine deformity (congenital, neuromuscular, syndromic, idiopathic). The complications were also categorized as screw-, hook-, or rod-related complications, implant loosening or backout, and junctional problems. The incidence of overall instrument-related complications was 5.6% (84 cases). Regarding etiology, the incidence rates were 4.3% (idiopathic), 6.8% (syndromic), 7.9% (congenital), and 10.4% (neuromuscular) (p < 0.05). The most common causes were pedicle screw malposition (60.7%), followed by implant backout or loosening (15.4%), junctional problems (13.1%), rod breakage (4.8%), and other complications (6.0%). Univariate analysis showed that etiology, type of deformity (kyphosis), surgical procedure, operation time, and estimated blood loss were significant factors. Multivariate analysis revealed that etiology (neuromuscular), surgical procedure (combined approach), and operation time (> 5 hours) remained as significant risk factors. Among all patients with instrument-related complications, 45% (38/84) required revision surgery. Of these cases, > 50% were related to pedicle screw malposition. Medial breach was the most common complication regardless of location, from upper thoracic to lumbar spine. Pedicle screw malposition was the primary cause of overall complications and subsequent reoperation. In addition to more precise screw insertion techniques, meticulous confirmation of pedicle screw placement, especially of medial breach, may reduce the overall instrument-related complications and revision rates.

Maintenance of curve correction and unplanned return to the operating room with magnetically controlled growing rods: a cohort of 24 patients with follow-up between 2 and 7 years.

Early onset scoliosis (EOS) is defined as spinal curvature affecting children below 10years of age. Non-operative treatment can consist of casting and bracing. When curvature progresses despite these treatments, operative intervention is indicated. Traditional growing rods (TGR) have been a mainstay of treatment. Unfortunately, TGR's require planned return to the operating room every 6-9months. Magnetic controlled growing rods (MCGR) ideally provide curve correction and allow the spine to grow without frequent surgeries. However, the ability to correct and maintain correction after MCGR has not been well-characterized. The purpose of this study is to evaluate maintenance of curve correction in patients treated primarily with MCGR and analyze the rate of complications including unplanned return to the operating room (UPROR). 24 patients with EOS were retrospectively reviewed. These patients were subdivided into 4 subcategories: congenital, idiopathic, neuromuscular (NMS), and syndromic. The major curve correction (%) and T1-S1 distance were assessed utilizing scoliosis plain film radiographs over time. Complications and return to the operating room for any reason were recorded. Patients were followed until conversion to posterior spinal fusion (PSF) or most recent lengthening of MCGR. There were 11 male and 13 female patients averaging 8 years at the time of index surgery. The average preoperative curve angle was 61.1°. Initial curve correction with MCGR obtained at the index procedure was 46.2%, reducing the mean curve angle to 32.7° (p < 0.05). Curve correction at a mean 6.2years (2.4-7.4) follow-up was 36.1°, 40.9% curve correction. 75% of patients underwent conversion to PSF during the study period 4.8years (2.4-7.0) after initial MCGR surgery. 15% of patients were still undergoing MCGR lengthening after 6.1years. 54.2% of patients had at least one UPROR. For patients with EOS with curve progression, MCGRs can maintain curve correction well after 2years. Furthermore, MCGR allowed patients to grow over time to safely delay timing to definitive fusion. On average, patients underwent conversion to PSF after 4.7years at an average age of 13.5. Although the complication rate in the first 2years is relatively low, 54.2% of patients underwent an UPROR. As the use of MCGR increases, surgeons should be aware of possible complications associated with this technology and counsel patients accordingly. Further research is needed to continue to evaluate the efficacy and safety of MCGR in this challenging patient population.