Introduction. Pedicle subtraction osteotomy is a powerful technique for correcting sagittal imbalance in ankylosing spondylitis. There has been significant perioperative morbidity associated with this technique in the peer review literature. We present the Royal National Orthopaedic Hospital experience with a single surgeon retrospective study that was conducted to evaluate the outcomes in patients who underwent lumbar pedicle subtraction osteotomy for the correction of thoracolumbar kyphotic deformity in ankylosing spondylitis. Method. Twenty seven patients underwent a lumbar pedicle subtraction osteotomy and adjacent level posterior instrumentation between 1995 and 2010. There were 18 males and 9 females in the study. Events during the peri-operative course and post-operative complications were recorded. The radiological outcome and patient satisfaction were analysed with mean follow-up of one and a half years. Results. The mean operative time was three and half hours and the mean blood loss was 2290mls. Final follow-up radiograph showed an increase in lumbar lordosis angle from 17 degrees to 45 degrees. The sagittal imbalance improved by 85mm with the operation. Complications included loosening in two patients, one transient neurologic deficit and one infective non-union occurred overall. There were no mortalities from the surgery. Two patients developed junctional kyphosis and required a repeat operation. There was an improvement in the Oswestry Disability Score from a mean of 29 to 16 after the surgey. All (100%) of the patients were satisfied with the results of the procedure and would recommend the surgey to others. Conclusion. The study shows that pedicle subtraction extension osteotomy is effective for the correction of kyphotic deformity in ankylosing spondylitis

Study Design. Retrospective review. Objective. To report the technique and results of vertebral column decancellation (VCD) for the management of sharp angular spinal deformity. Summary of Background Data. The goal of management of sharp angular spinal deformity is to realign the spinal deformity and safely decompress the neurological elements. However, some shortcomings related to current osteotomy treatment for these deformities are still evident. Methods. From January 2004 to March 2007, 45 patients (27 males/18 females) with severe sharp angular spinal deformities at our institution underwent VCD. The diagnoses included 29 congenital kyphoscoliosis and 16 Pott's deformity. The operative technique included multilevel VCD, disc removal, osteoclasis of the concave cortex, compression of the convex cortex accompanied by posterior instrumentation with pedicle screws. Preoperative and postoperative radiographic evaluation was performed. Intraoperative, postoperative and general complications were noted. Results. For a kyphosis type deformity, an average of 2.2 vertebrae was decancellated (range, 2to 4 vertebrae). The mean preoperative kyphosis was +98.6° (range, 82° to 138°), and the meankyphosis in the immediate postoperative period was +16.4° (range, 4° to 30°) with an averagepostoperative correction of +82.2° (range, 61° to 124°). For a kyphoscoliosis type deformity, thecorrection rate was 64% in the coronal plane (from 83.4° to 30.0°) postoperatively and 32.5°(61% correction) at 2 years follow-up. In the sagittal plane, the average preoperative curve of88.5° corrected to 28.6° immediately after surgery and to 31.0° at 2 years follow-up. All patientshad solid fusion at latest follow-up. Complications were encountered in 8 patients (17.8%) andincluded transient neurological deficit and complete paralysis (n = 1). Conclusion. Single stage posterior vertebral column decancellation (VCD) is an effective option to manage severe sharp angular spinal deformities

Clinically significant proximal junctional kyphosis (PJK) occurs in 20% of children treated with posterior distraction-based growth friendly surgery. In an effort to identify modifiable risk factors, it has been theorized biomechanically that low radius of curvature (ROC) implants (i.e., more curved rods) may increase post-operative thoracic kyphosis, and thus may pose a higher risk of developing PJK. We sought to test the hypothesis that EOS patients treated with low ROC (more curved rods) distraction-based treatment will have a greater risk of developing PJK as compared to those treated with high ROC (straighter) implants. This is a retrospective review of prospectively collected data obtained from a multi-centre EOS database on children treated with rib-based distraction with minimum 2-year follow-up. Variables of interest included: implant ROC at index (220 mm or 500 mm), patient age, pre-operative scoliosis, pre-operative kyphosis, and scoliosis etiology. In the literature, PJK has been defined as clinically significant if revision surgery with superior extension of the upper instrumented vertebrae was performed. In 148 scoliosis patients, there was a higher risk of clinically significant PJK with low ROC (more curved) rods (OR: 2.6 (95%CI 1.09-5.99), χ2 (1, n=148) = 4.8, p = 0.03). Patients had a mean pre-operative age of 5.3 years (4.6y 220 mm vs 6.2y 500 mm, p = 0.002). A logistic regression model was created with age as a confounding variable, but it was determined to be not significant (p = 0.6). Scoliosis etiologies included 52 neuromuscular, 52 congenital, 27 idiopathic, 17 syndromic with no significant differences in PJK risk between etiologies (p = 0.07). Overall, patients had pre-op scoliosis of 69° (67° 220mm vs 72° 500mm, p = 0.2), and kyphosis of 48° (45° 220mm vs 51° 500mm, p = 0.1). The change in thoracic kyphosis pre-operatively to final follow up (mean 4.0 ± 0.2 years) was higher in patients treated with 220 mm implants compared to 500 mm implants (220 mm: 7.5 ± 2.6° vs 500 mm: −4.0 ± 3.0°, p = 0.004). Use of low ROC (more curved) posterior distraction implants is associated with a significantly greater increase in thoracic kyphosis which likely led to a higher risk of developing clinically-significant PJK in EOS patients

Introduction and Objective. Pectus carinatum is a common congenital anterior chest wall deformity, characterized by outward protrusion of sternum and ribcage resulted from rib cartilage overgrowth. The protrusion may be symmetrical or asymmetrical. Pectus carinatum association with mitral valve diseases, Marfan's syndrome, and scoliosis enforces that poor connective tissue development as possible etiological factor. Despite the coexistence of pectus carinatum and scoliosis has attracted the attention of some researchers, the association between pectus carinatum and the other spinal deformities has not been studied comprehensively. The frequency of spinal deformity in patients with pectus carinatum and the mutual relationships of their subtypes are needed to be studied to determine the epidemiological character of the combined deformity and to plan patient evaluation and management. Our study aimed to investigate the association, define the incidence and evaluate the characteristics between different types of spinal deformities and Pectus carinatum. Materials and Methods. Radiological and physical examinations were performed for 117 pectus carinatum patients in Marmara university hospital/Turkey in the years between 2006 and 2013. The incidence of spinal deformity was calculated. Spinal deformities were classified as scoliosis, kyphosis, kyphoscoliosis, and spinal asymmetry, whereas pectus carinatum were subdivided into symmetric and asymmetric subgroups. The relationship between spinal deformities and the symmetrical-asymmetric subtype of pectus excavatum was statistically analyzed, Pearson chi-square test was used to compare the association of qualitative data. The significance level was accepted as p <0.05. Lastly, the angular values of the deformities of scoliosis and kyphosis patients were measured using the Cobb method. In this way, the magnitude of the deformity was given as a numerical value. Results. Spinal deformity was detected in 23 (17 symmetrical PE and 6 asymmetrical PE) of 117 pectus excavatum patients. Scoliosis and kyphosis were seen equally in symmetrical pectus carinatum, whereas scoliosis was seen in 33.3% and kyphosis in 50% in asymmetric pectus carinatum patients, respectively. However, there were no statistically significant differences in the distribution of scoliosis and kyphosis in patients with symmetrical and asymmetrical PE. Idiopathic scoliosis constituted the most common scoliosis group. Congenital kyphosis was not found in any kyphosis patient. The average Cobb angle of scoliosis patients was 32°, and the mean T2-T12 kyphosis angle of these patients was 55.5°, while the average kyphosis angle of those with kyphosis deformity was 71°. Conclusions. Patients with Pectus carinatum have a higher incidence of spinal deformities than the normal population. Such high concomitant incidence should be taken under consideration in evaluating and treating patients presenting with either deformity

Aims. The aim of this study was to evaluate the reliability and validity of a patient-specific algorithm which we developed for predicting changes in sagittal pelvic tilt after total hip arthroplasty (THA). Methods. This retrospective study included 143 patients who underwent 171 THAs between April 2019 and October 2020 and had full-body lateral radiographs preoperatively and at one year postoperatively. We measured the pelvic incidence (PI), the sagittal vertical axis (SVA), pelvic tilt, sacral slope (SS), lumbar lordosis (LL), and thoracic kyphosis to classify patients into types A, B1, B2, B3, and C. The change of pelvic tilt was predicted according to the normal range of SVA (0 mm to 50 mm) for types A, B1, B2, and B3, and based on the absolute value of one-third of the PI-LL mismatch for type C patients. The reliability of the classification of the patients and the prediction of the change of pelvic tilt were assessed using kappa values and intraclass correlation coefficients (ICCs), respectively. Validity was assessed using the overall mean error and mean absolute error (MAE) for the prediction of the change of pelvic tilt. Results. The kappa values were 0.927 (95% confidence interval (CI) 0.861 to 0.992) and 0.945 (95% CI 0.903 to 0.988) for the inter- and intraobserver reliabilities, respectively, and the ICCs ranged from 0.919 to 0.997. The overall mean error and MAE for the prediction of the change of pelvic tilt were -0.3° (SD 3.6°) and 2.8° (SD 2.4°), respectively. The overall absolute change of pelvic tilt was 5.0° (SD 4.1°). Pre- and postoperative values and changes in pelvic tilt, SVA, SS, and LL varied significantly among the five types of patient. Conclusion. We found that the proposed algorithm was reliable and valid for predicting the standing pelvic tilt after THA. Cite this article: Bone Joint J 2024;106-B(1):19–27

Aims. This systematic review aims to identify 3D predictors derived from biplanar reconstruction, and to describe current methods for improving curve prediction in patients with mild adolescent idiopathic scoliosis. Methods. A comprehensive search was conducted by three independent investigators on MEDLINE, PubMed, Web of Science, and Cochrane Library. Search terms included “adolescent idiopathic scoliosis”,“3D”, and “progression”. The inclusion and exclusion criteria were carefully defined to include clinical studies. Risk of bias was assessed with the Quality in Prognostic Studies tool (QUIPS) and Appraisal tool for Cross-Sectional Studies (AXIS), and level of evidence for each predictor was rated with the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. In all, 915 publications were identified, with 377 articles subjected to full-text screening; overall, 31 articles were included. Results. Torsion index (TI) and apical vertebral rotation (AVR) were identified as accurate predictors of curve progression in early visits. Initial TI > 3.7° and AVR > 5.8° were predictive of curve progression. Thoracic hypokyphosis was inconsistently observed in progressive curves with weak evidence. While sagittal wedging was observed in mild curves, there is insufficient evidence for its correlation with curve progression. In curves with initial Cobb angle < 25°, Cobb angle was a poor predictor for future curve progression. Prediction accuracy was improved by incorporating serial reconstructions in stepwise layers. However, a lack of post-hoc analysis was identified in studies involving geometrical models. Conclusion. For patients with mild curves, TI and AVR were identified as predictors of curve progression, with TI > 3.7° and AVR > 5.8° found to be important thresholds. Cobb angle acts as a poor predictor in mild curves, and more investigations are required to assess thoracic kyphosis and wedging as predictors. Cumulative reconstruction of radiographs improves prediction accuracy. Comprehensive analysis between progressive and non-progressive curves is recommended to extract meaningful thresholds for clinical prognostication. Cite this article: Bone Jt Open 2024;5(3):243–251

Aims. This study aimed to evaluate sagittal spinopelvic alignment (SSPA) in the early stage of rapidly destructive coxopathy (RDC) compared with hip osteoarthritis (HOA), and to identify risk factors of SSPA for destruction of the femoral head within 12 months after the disease onset. Methods. This study enrolled 34 RDC patients with joint space narrowing > 2 mm within 12 months after the onset of hip pain and 25 HOA patients showing femoral head destruction. Sharp angle was measured for acetabular coverage evaluation. Femoral head collapse ratio was calculated for assessment of the extent of femoral head collapse by RDC. The following parameters of SSPA were evaluated using the whole spinopelvic radiograph: pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), sagittal vertical axis (SVA), thoracic kyphosis angle (TK), lumbar lordosis angle (LL), and PI-LL. Results. The HOA group showed higher Sharp angles compared with the RDC group. PT and PI-LL were higher in the RDC group than the HOA group. SS and LL were lower in the RDC group than the HOA group. No difference was found in PI, SVA, or TK between the groups. Femoral head collapse ratio was associated with PT, SS, SVA, LL, and PI-LL. A PI-LL > 20° and a PT > 30° correlated with greater extent of femoral head destruction by RDC. From regression analysis, SS and SVA were significantly associated with the femoral head collapse ratio within 12 months after disease onset. Conclusion. Compared with HOA, RDC in the early stage correlated with sagittal spinopelvic malalignment. SS and SVA may partially contribute to the extent of femoral head destruction by RDC within 12 months after the onset of hip pain. The present study indicates a potential role of SSPA assessment in identification of RDC patients at risk for subsequent bone destruction. Cite this article: Bone Jt Open 2022;3(1):77–84

Proximal junctional kyphosis (PJK) is defined as adjacent segment kyphosis >10° between the upper instrumented vertebrae and the vertebrae 2 levels above following scoliosis surgery. There are few studies investigating the predictors and clinical sequelae involved with this relatively common complication. Our purpose was to determine the radiographic predictors of post-op PJK and to examine the association between PJK and pain/HRQOL following surgery for AIS. The Post-Operative Recovery after Scoliosis Correction: Home Experience (PORSCHE) study was a prospective multicenter cohort of AIS patients undergoing spinal fusion surgery. Pre-op and minimum 2 year f/u scoliosis and sagittal spinopelvic parameters (thoracic kyphosis–TK, lordosis–LL, pelvic tilt-PT, sacral slope-SS, pelvic incidence-PI) were measured and compared to numeric rating scale for pain (NRS) score, SRS-30 HRQOL and to the presence or absence of PJK (proximal junctional angle >100). Continuous and categorical variables were assessed using logistic regression and binomial variables were compared to binomial outcomes using chi-square. 163 (137 females) patients from 8 Canadian centers met inclusion criteria. At final f/u, PJK was present in 27 patients (17%). Pre-op means for PJK vs No PJK: Age 14.1 vs 14.7yr; females 85 vs 86%; scoliosis 57±22 vs 62±15deg; TK 28±18 vs 19±16deg ∗, LL 62±11 vs 60±12deg, PT 8±12 vs 10±10deg, SS 39±8 vs 41±9deg, PI 47±14 vs 52±13deg, SVA −9±30 vs −7±31mm. Final f/u for PJK vs No PJK: Scoliosis 20±11 vs 18±8deg, final TK 26±12 vs 19±10deg∗, LL 60±11 vs 57±12deg, PT 9±12 vs 12±13deg, SS 39±9 vs 41±9deg, PI 48±17 vs 52±14deg, SVA −23±26 vs −9±32mm∗. Significant findings: Pre-op kyphosis >40deg has an odds ratio (OR) of 4.41 (1.50–12.92) for developing PJK∗. The presence of PJK was not associated with any significant differences in NRS or SRS-30. ∗denotes p<0.05. This prospective multicenter cohort of AIS patients demonstrated a 17% risk of developing PJK. Pre-op thoracic kyphosis >40deg was associated with the development of PJK; however, the presence of PJK was not associated with increased pain or decreased HRQOL

Aging impairs the regenerative capacity of musculoskeletal tissues and is associated with poor healing outcomes. PolgA. D257A/D257A. (PolgA) mice present a premature aging phenotype due to the accumulation of mitochondrial DNA (mtDNA) point mutations at rates 3 – 5 fold higher compared to wild type mice. Consequently, PolgA mice exhibit the premature onset of clinically-relevant musculoskeletal aging characteristics including frailty, osteo-sarcopenia, and kyphosis. I will present our recent findings on the use of PolgA mice to investigate the effects of aging on the regenerative capacity of bone. In particular, I will focus on the mechano-sensitivity of the regenerative process in aged bone environments and the opportunities it presents for clinical translation of mechanical intervention therapies

The aim of this study was to report the restauration of the normal vertebral morphology and the absence of curve progression after removal the instrumentation in AIS patients that underwent posterior correction of the deformity by common all screws construct whitout fusion. A series of 36 AIS immature patients (Risser 3 or less) were include in the study. Instrumentation was removed once the maturity stage was complete (Risser 5). Curve correction was assessed at pre and postoperative, before instrumentation removal, just post removal, and more than two years after instrumentation removal. Epiphyseal vertebral growth modulation was assessed by a coronal wedging ratio (WR) at the apical level of the main curve (MC). The mean preoperative coronal Cobb was corrected from 53.7°±7.5 to 5.5º±7.5º (89.7%) at the immediate postop. After implants removal (31.0±5.8 months) the MC was 13.1º. T5–T12 kyphosis showed a significant improvement from 19.0º before curve correction to 27.1º after implants removal (p<0.05). Before surgery, WR was 0.71±0.06, and after removal WR was 0.98±0.08 (p<0.001). At the end of follow-up, the mean sagittal range of motion (ROM) of the T12-S1 segment was 51.2±21.0º. SRS-22 scores improved from 3.31±0.25 preoperatively to 3.68±0.25 at final assessment (p<0.001). In conclusion, fusionless posterior approach using a common all pedicle screws construct correct satisfactory scoliotic main curves and permits removal of the instrumentation once the bone maturity is reached. The final correction was highly satisfactory and an acceptable ROM of the previously lower instrumented segments was observed

In healthy subjects, respiratory maximal volumes are highly dependent on the sagittal range of motion of the T7-T10 segment. In AIS, the abolition of T7-T10 dynamics related to the stiffness induced by the apex region in Lenke IA curves could harm ventilation during maximal breathing. The aim of this study was to analyze the dynamics of the thoracic spine during deep breathing in AIS patients and in healthy matched controls. This is a cross-sectional, case-control study. 20 AIS patients (18 girls, Cobb angle, 54.7±7.9°; Risser 1.35±1.2) and 15 healthy volunteers (11 girls) matched in age (12.5 versus 15.8 yr. mean age) were included. In AIS curves, the apex was located at T8 (14) and T9 (6). Conventional sagittal radiographs of the whole spine were performed at maximal inspiration and exhalation. The ROM of each spinal thoracic functional segment (T1-T7, T7-T10, T10-T12) and the global T1-T12 ROM were measured. In healthy subjects, the mean T1-T12 ROM during forced breathing was 16.7±3.8. AIS patients showed a T1-T12 ROM of 1.1±1.5 (p<0.05), indicating a sagittal stiffness of the thoracic spine. A wide T7-T10 ROM (15.3±3.0) was found in healthy controls (91.6% of the T1–T12 ROM). AIS patients showed only 0.4±1.4 ROM at T7-T10 (36.4% of the T1-T12 ROM) (p<0.001). There was a significant positive correlation between the magnitude of T7-T10 kyphosis in maximal exhalation and both FVC (% of predicted FVC) and FEV1. In conclusion, Lenke 1A AIS patients show a restriction of the thoracic spine motion with an almost complete abolition of T7-T10 ROM, a crucial segment for deep breathing. T7-T10 stiffness could explain the ventilatory limitations found in AIS patients

Less invasive single-rod fusion technique may be indicated in the management of NMS to minimise operative time, blood loss and wound-related complications. This retrospective 12-year cohort study (2008–2020) aims to evaluate and compare the outcomes of this technique to the current standard dual rod technique to determine their safety and efficacy. 28 patients in the single rod group (Mean age = 16.4 [SD ±4.0]) and 30 in the double rod group (Mean age = 16.3 [SD±3.5]). Indications included a minimum 2 year follow period, detailed information on the type of implant and a complete pre- and post-operative imaging and medical records. Baseline demographics, comorbidities, and surgical characteristics were collected. Outcomes assessed included the immediate post-op and final follow up angles and general complications. All outcome analysis was performed using a regression approach. Angles at final follow-up: lumbar (Difference ratio (DR)= 2.60 [95% CI 0.37 – 18.4], p=0.25), thoracic (DR= 1.08 [95% CI 0.19 – 6.28], p=0.92), thoracolumbar (major curve angle) (DR 1.35 [95% CI 0.60 – 3.06], p=0.46) and kyphosis (DR = 0.97 [0.66, 1.42] p=0.86). There was no statistically significant difference, between the two groups, for any of the above angle outcomes as well as for length of surgery, blood loss and complication outcomes. Both single and double rod instrumentation achieves satisfactory and safe deformity correction which is maintained at final follow up. A larger scale study is warranted to further assess these techniques while also conducting a cost-benefit analysis between them

Spinal deformations are posture dependent. Official data from the Netherlands show that youth are encountering increasing problems with the musculoskeletal system (>40% back pain, and sport injury proneness). Prolonged sloth and slumped sitting postures are causative factors. Dutch youth are “champion sitting” in Europe. The effects of sitting on the development of posture and function of locomotion (stiffness) during growth have only been reported clearly in classic textbooks (in German) of practical anatomy and orthopaedics. Research with relevant clinical examinations is being done to understand epidemiological data on the increasing posture-dependent problems. A cohort of adolescents (15–18 years) in secondary school was assessed for sagittal postural deviations while bending. 248 children completed a questionnaire, and tests were done on neuromuscular tightness. The femorotibial angle was used to measure hamstring tightness. Measurement of the dorsiflexion of the foot was used to assess the tightness of calf muscles and Achilles tendons. All adolescents were photographed laterally while performing the finger–floor test (used to test flexibility), assessed as a knockout test: “Can you reach the floor or not?” The spinal profiles while bending were classified as abnormal arcuate or angular kyphosis. Hamstring tightness was present in 62.1% of the cohort in both legs, and in 18.2% unilaterally. Achilles tendon tightness was present bilaterally in 59.3%, and unilaterally in 19.4%. Activities with presence of stiffness (finger–floor distance), in descending order, were football, running, no sports, field hockey, tennis, dance, and gymnastics. 93.5% of the soccer players had tight hamstrings in both legs compared with none of those performing gymnastics. The correlation of the finger–floor test with tight hamstrings was 73.2%. For sagittal bending deformities, the correlation between form and function deficits cannot be made yet. 80 of 248 spines were rated by the examiners as having deformed flexion. Since Andry (1741) and at the zenith of continental orthopaedics and anatomy around 1900, the prolonged flexed positions of a young spine were indicated as being the main cause of deformity by overload and shear loads on immature discs and cartilage, preventing normal development of the discs. Nachemson proved that the intradiscal pressure in sitting adults was extremely high, so it follows that children must also be at risk. Evidence suggests that youth, generally because of their sedentary and “screenful lifestyle”, will encounter serious problems in growth, manifesting as incongruent neuro-osseous growth (Roth), serious neuromuscular tightness (being prone to injury), and spinal deformations, leading to pain

Neuromuscular scoliosis patients face rates of major complications of up to 49%. Along with pre-operative risk reduction strategies (including nutritional and bone health optimization), intra-operative strategies to decrease blood loss and decrease surgical time may help mitigate these risks. A major contributor to blood loss and surgical time is the insertion of instrumentation which is challenging in neuromuscular patient given their abnormal vertebral and pelvic anatomy. Standard pre-operative radiographs provide minimal information regarding pedicle diameter, length, blocks to pedicle entry (e.g. iliac crest overhang), or iliac crest orientation. To minimize blood loss and surgical time, we developed an “ultra-low dose” CT protocol without sedation for neuromuscular patients. Our prospective quality improvement study aimed to determine: if ultra-low dose CT without sedation was feasible given the movement disorders in this population; what the radiation exposure was compared to standard pre-operative imaging; whether the images allowed accurate assessment of the anatomy and intra-operative navigation given the ultra-low dose and potential movement during the scan. Fifteen non-ambulatory surgical patients with neuromuscular scoliosis received the standard spine XR and an ultra-low dose CT scan. Charts were reviewed for etiology of neuromuscular scoliosis and medical co-morbidities. The CT protocol was a high-speed, high-pitch, tube-current modulated acquisition at a fixed tube voltage. Adaptive statistical iterative reconstruction was applied to soft-tissue and bone kernels to mitigate noise. Radiation dose was quantified using reported dose indices (computed tomography dose index (CTDIvol) and dose-length product (DLP)) and effective dose (E), calculated through Monte-Carlo simulation. Statistical analysis was completed using a paired student's T-test (α = 0.05). CT image quality was assessed for its use in preoperative planning and intraoperative navigation using 7D Surgical System Spine Module (7D Surgical, Toronto, Canada). Eight males and seven females were included in the study. Their average age (14±2 years old), preoperative Cobb angle (95±21 degrees), and kyphosis (60±18 degrees) were recorded. One patient was unable to undergo the ultra-low dose CT protocol without sedation due to a co-diagnosis of severe autism. The average XR radiation dose was 0.5±0.3 mSv. Variability in radiographic dose was due to a wide range in patient size, positioning (supine, sitting), number of views, imaging technique and body habitus. Associated CT radiation metrics were CTDIvol = 0.46±0.14 mGy, DLP = 26.2±8.1 mGy.cm and E = 0.6±0.2 mSv. CT radiation variability was due to body habitus and arm orientation. The radiation dose differences between radiographic and CT imaging were not statistically significant. All CT scans had adequate quality for preoperative assessment of pedicle diameter and orientation, obstacles impeding pedicle entry, S2-Alar screw orientation, and intra-operative navigation. “Ultra-low dose” CT scans without sedation were feasible in paediatric patients with neuromuscular scoliosis. The effective dose was similar between the standard preoperative spinal XR and “ultra-low dose” CT scans. The “ultra-low dose” CT scan allowed accurate assessment of the anatomy, aided in pre-operative planning, and allowed intra-operative navigation despite the movement disorders in this patient population

Neuromuscular scoliosis patients face rates of major complications of up to 49%. Along with pre-operative risk reduction strategies (including nutritional and bone health optimization), intra-operative strategies to decrease blood loss and decrease surgical time may help mitigate these risks. A major contributor to blood loss and surgical time is the insertion of instrumentation which is challenging in neuromuscular patient given their abnormal vertebral and pelvic anatomy. Standard pre-operative radiographs provide minimal information regarding pedicle diameter, length, blocks to pedicle entry (e.g. iliac crest overhang), or iliac crest orientation. To minimize blood loss and surgical time, we developed an “ultra-low dose” CT protocol without sedation for neuromuscular patients. Our prospective quality improvement study aimed to determine:. if ultra-low dose CT without sedation was feasible given the movement disorders in this population;. what the radiation exposure was compared to standard pre-operative imaging;. whether the images allowed accurate assessment of the anatomy and intra-operative navigation given the ultra-low dose and potential movement during the scan. Fifteen non-ambulatory surgical patients with neuromuscular scoliosis received the standard spine XR and an ultra-low dose CT scan. Charts were reviewed for etiology of neuromuscular scoliosis and medical co-morbidities. The CT protocol was a high-speed, high-pitch, tube-current modulated acquisition at a fixed tube voltage. Adaptive statistical iterative reconstruction was applied to soft-tissue and bone kernels to mitigate noise. Radiation dose was quantified using reported dose indices (computed tomography dose index (CTDIvol) and dose-length product (DLP)) and effective dose (E), calculated through Monte-Carlo simulation. Statistical analysis was completed using a paired student's T-test (α= 0.05). CT image quality was assessed for its use in preoperative planning and intraoperative navigation using 7D Surgical System Spine Module (7D Surgical, Toronto, Canada). Eight males and seven females were included in the study. Their average age (14±2 years old), preoperative Cobb angle (95±21 degrees), and kyphosis (60±18 degrees) were recorded. One patient was unable to undergo the ultra-low dose CT protocol without sedation due to a co-diagnosis of severe autism. The average XR radiation dose was 0.5±0.3 mSv. Variability in radiographic dose was due to a wide range in patient size, positioning (supine, sitting), number of views, imaging technique and body habitus. Associated CT radiation metrics were CTDIvol = 0.46±0.14 mGy, DLP = 26.2±8.1 mGy.cm and E = 0.6±0.2 mSv. CT radiation variability was due to body habitus and arm orientation. The radiation dose differences between radiographic and CT imaging were not statistically significant. All CT scans had adequate quality for preoperative assessment of pedicle diameter and orientation, obstacles impeding pedicle entry, S2-Alar screw orientation, and intra-operative navigation. “Ultra-low dose” CT scans without sedation were feasible in paediatric patients with neuromuscular scoliosis. The effective dose was similar between the standard preoperative spinal XR and “ultra-low dose” CT scans. The “ultra-low dose” CT scan allowed accurate assessment of the anatomy, aided in pre-operative planning, and allowed intra-operative navigation despite the movement disorders in this patient population

Aims. Severe spinal deformity in growing patients often requires surgical management. We describe the incidence of spinal deformity surgery in a National Health Service. Methods. Descriptive study of prospectively collected data. Clinical data of all patients undergoing surgery for spinal deformity between 2005 and 2018 was collected, compared to the demographics of the national population, and analyzed by underlying aetiology. Results. Our cohort comprised 2,205 patients; this represents an incidence of 14 per 100,000 individuals among the national population aged between zero and 18 years. There was an increase in mean annual incidence of spinal deformity surgery across the study period from 9.6 (7.2 to 11.7) per 100,000 individuals in 2005 to 2008, to 17.9 (16.1 to 21.5) per 100,000 individuals in 2015 to 2018 (p = 0.001). The most common cause of spinal deformity was idiopathic scoliosis accounting for 56.7% of patients. There was an increase in mean incidence of surgery for adolescent idiopathic scoliosis (AIS) (from 4.4 (3.1 to 5.9) to 9.8 (9.1 to 10.8) per 100,000 individuals; p < 0.001), juvenile idiopathic scoliosis (JIS) (from 0.2 (0.1 to 0.4) to one (0.5 to 1.3) per 100,000 individuals; p = 0.009), syndromic scoliosis (from 0.7 (0.3 to 0.9) to 1.7 (1.2 to 2.4) per 100,000 individuals; p = 0.044), Scheuermann’s kyphosis (SK) (from 0.2 (0 to 0.7) to 1.2 (1.1 to 1.3) per 100,000 individuals; p = 0.001), and scoliosis with intraspinal abnormalities (from 0.04 (0 to 0.08) to 0.6 (0.5 to 0.8) per 100,000 individuals; p = 0.008) across the study period. There was an increase in mean number of posterior spinal fusions performed each year from mean 84.5 (51 to 108) in 2005 to 2008 to 182.5 (170 to 210) in 2015 to 2018 (p < 0.001) and a reduction in mean number of growing rod procedures from 45.5 (18 to 66) in 2005 to 2008 to 16.8 (11 to 24) in 2015 to 2018 (p = 0.046). Conclusion. The incidence of patients with spinal deformity undergoing surgery increased from 2005 to 2018. This was largely attributable to an increase in surgical patients with adolescent idiopathic scoliosis. Paediatric spinal deformity was increasingly treated by posterior spinal fusion, coinciding with a decrease in the number of growing rod procedures. These results can be used to plan paediatric spinal deformity services but also evaluate preventative strategies and research, including population screening

Purpose of the study. Two patients with very severe thoracolumbar Scheuermann's kyphosis who developed spontaneous bony fusion across the apex of the deformity are presented and their treatment, as well as surgical outcome is discussed. Summary of Background Data. Considerable debate exists regarding the pathogenesis, natural history and treatment of Scheuermann's kyphosis. Surgical correction is indicated in the presence of severe kyphosis which carries the risk of neurological complications, persistent back pain and significant cosmetic deformity. Methods. We reviewed the medical notes and radiographs of 2 adolescent patients with severe thoracolumbar Scheuermann's kyphosis who developed spontaneous posterior and anteroposterior fusion across the apex of the deformity. Results. Patient 1. A male patient aged 17 years and 11 months underwent kyphosis correction when the deformity measured 115o and only corrected to 100o on supine hyperextension radiograph against the bolster; he had a small associated scoliosis. The surgery involved a combined single-stage anterior and posterior spinal arthrodesis T4-L3 with the use of posterior pedicle hook/screw/rod instrumentation and autologous rib graft. The anterior longitudinal ligament was ossified from T10 to L1 with bridging osteophytes extending circumferentially from T11 to T12 at the apex of kyphosis and displacing the major vessels anteriorly. The intervertebral discs from T9 to T12 were very stenotic and immobile. The osteophytes were excised both on the convexity and concavity of the associated thoracolumbar scoliosis. The anterior longitudinal ligament was released and complete discectomies back to the posterior longitudinal ligament were performed from T7 to L1. During the posterior exposure, the spine was found to be spontaneously fused across the apex of the kyphosis from T9 to L1. There were no congenital vertebral anomalies. Extensive posterior apical closing wedge osteotomies were performed from T7 to T12. The fused facets and ossified ligamentum flavum were excised and the spine was mobilised at completion of the anterior and posterior osteotomies. The kyphosis was corrected using a cantilever maneuver from proximal to distal under spinal cord monitoring. Excellent correction to 58o was achieved and maintained at follow-up. Autologous rib graft was used to enhance a solid bony fusion. Patient 2. A female patient aged 18 years and one month underwent kyphosis correction when the deformity measured 115o and only corrected to 86o on supine hyperextension radiograph against the bolster; she had a small thoracolumbar scoliosis. The surgery involved a single-stage posterior spinal arthrodesis T2-L4 with the use of posterior pedicle hook/screw/rod instrumentation and autologous iliac crest bone. The spine was spontaneously fused across the apex of kyphosis from T9 to L1. There were no congenital vertebral anomalies. Extensive posterior apical closing wedge osteotomies were performed from T6 to T12. The fused facets and ossified ligamentum flavum were excised and the spine was mobilised at completion of the osteotomies. The kyphosis was corrected using a cantilever maneuver from proximal to distal under spinal cord monitoring. Excellent correction to 60o was achieved and maintained at follow-up. Autologous iliac crest graft was used to achieve a solid bony fusion. In both patients the preoperative MRI assessed the intraspinal structures but failed to diagnose the solid fusion across the posterior bony elements at the apex of kyphosis. A CT scan with 3D reconstruction would have illustrated the bony anatomy across the kyphosis giving valuable information to assist surgical planning. This is recommended in the presence of rigid thoracolumbar Scheuermann's kyphosis which does not correct in hyperextension, especially if the plain radiograph shows anterior bridging osteophytes. Conclusion. Spontaneous posterior or anteroposterior fusion can occur across the apex of severe thoracolumbar Scheuermann's kyphosis; this should be taken into account when surgical correction is anticipated. The bony ankylosis may represent the natural history of an extreme deformity as an attempt of the spine to auto-stabilise. A combination of factors including a rigid deformity, which limits significantly active movement of the spine, as well as anterior vertebral body wedging with severe adjacent disc stenosis which induces bridging osteophyte formation may result in the development of spontaneous fusion across the apex of the kyphosis either posteriorly or anteroposteriorly. In the presence of an isolated posterior fusion, segmental posterior closing wedge osteotomies with complete excision of the ossified ligamentum flavum and fused facets should mobilise the thoracolumbar spine and allow for kyphosis correction. An additional anterior spinal release including complete discectomies, resection of the anterior longitudinal ligament and osteophytes is required if the bony fusion extends anteroposteriorly. Patients with Scheuermann's kyphosis should be ideally treated at an earlier stage and with a lesser degree of deformity so that this ossification process is prevented

Background. Improvement of Scheuermann's thoracic kyphosis in the growing spine with Milwaukee brace treatment has been reported. However, the role of brace treatment in Mb. Scheuermann is controversial. We report results of brace treatment by low profile scoliosis module with sternal shield. Indication. Thoracic kyphosis >55° or back pain and kyphosis >50°. Material. 21 consecutive patients (17 boys, 4 girls) referred to the Orton Orthopaedic Hospital between 2000-2007. One boy interrupted treatment and the follow-up of two boys was carried out at another hospital. The data of 18 patients are reported. Results. The mean age of patients at the beginning of treatment was 14 years (11-17) and the average thoracic kyphosis was 71° (50-94). On extension radiographs, the kyphosis decreased to 43°(16-66) with a mean correction of 38%. The average time of brace treatment was 2,5 (1-7) years. The final follow- up visit was at the age of 19 (15-21) years. At the final follow-up, the mean thoracic kyphosis was 59° (30-78). Permanent correction of thoracic kyphosis was achieved in 15 patients (83%) with a mean correction of 15 degrees. In two patients no correction was achieved and in one patient the kyphosis increased 9°. No patient required operative treatment. Discussion and conclusion. The efficiency of brace treatment is difficult to prove because natural history of Scheuermann's kyphosis is not fully known. Our material is too small for any final conclusions. However, treatment of the growing spine with modified low profile brace seem to decrease progression of kyphosis in most cases and operative treatment may be avoided

The aim of this study was to compare the treatment ouctomes of severe idiopathic scoliosis (IS) (>90 degrees) using the staged surgery with initial limited internal distraction and typical IS treated using segmental pedicle screw instrumentation. We hypothesized that staged surgical treatment of severe scoliosis would improve more HRQoL and pulmonary function (PF) as compared with posterior spinal fusion (PSF) for typical IS curves. It was a retrospective review of a consecutive series of 60 IS, severe group (SG) vs. moderate group (MG) with min. 2 years of follow up (FU). The mean preoperative major curve (MC) was 120° and thoracic kyphosis (TK) was 80° for the SG and 54° and 17° for the MG, respectively (p<0.001). The MC was corrected to 58° and TK to 32° for the SG; the MC to 26° and TK to 14°, for the MG, respectively (p<0.001). The mean preoperative AVT was 8.9 cm and improved to 2.8 cm at the final FU for the SG and from 6.5 cm to 2.2 cm at the final FU for the MG (p<0.001). At baseline, the FVC% & FEV1% values were significant different between the two groups (41.5% vs. 83%, p <0.001) & (41.6% vs. 77%, p <0.001). Compared the baseline for SG vs. the values at 2-year FU the FVC % values were (41.5% vs. 66.5%, p <0.001), and the baseline for MG vs. the values at 2-year FU, the FEV1 values were (77% vs. 81%, NS). At last FU, no complications were reported. Gradual traction with complicity of multilevel Ponte's osteotomies and neuromonitoring followed by staged pedicle screws instrumentation in severe IS proved to be a safe and effective method improving spinal deformity (52% correction), PF (improved percentage of predicted forced vital capacity by 49%), and health-related quality and allows to achieve progressive curve correction with no neurologic complications associated to more aggressive one-stage surgeries

Scheuermann's kyphosis is a structural deformity of the thoracic or thoracolumbar spine, which can result in severe pain, neurological compromise and cosmetic dissatisfaction. Modern surgical techniques have improved correction through a posterior-only or antero-posterior approach but can result in significant morbidity. We present our results of the surgical management of severe Scheuermann's kyphosis by a single surgeon with respect to deformity correction, global balance parameters, functional outcomes and complications at latest follow-up. We included 49 patients, of which 46 had thoracic and 3 had thoracolumbar kyphosis. Surgical indications included persistent back pain, progressive deformity, neurological compromise and poor self-image. Fourty-seven patients underwent posterior-only and 2 antero-posterior spinal arthrodesis utilising Chevron-type osteotomies and hybrid instrumentation. Mean age at surgery was 16.0 years with mean postoperative follow-up of 4.5 years. Mean kyphosis corrected from 92.1o to 46.9o (p<0.001). Concomitant scoliosis was eliminated in all of the 28 affected patients. Coronal and sagittal balance was corrected in all patients. Mean blood loss was 24% total blood volume. Mean operation time was 4.3 hours with mean inpatient stay of 9 days. SRS-22 questionnaire improved from a mean preoperative score of 3.4 to 4.6 at 2 years, with high treatment satisfaction rates. Complications included one toxic septicaemia episode but otherwise no wound infections, no junctional deformity, no loss of correction and no requirement for re-operation. Posterior spinal arthrodesis with the use of hybrid instrumentation can safely achieve excellent correction of severe Scheuermann's kyphosis helping to relieve back pain, improve functional outcomes and enhance self-image