To compare preoperative and postoperative Health Related Quality of Life (HRQoL) scores in operated Adolescent Idiopathic Scoliosis (AIS) patients with and without concomitant isthmic spondylolisthesis.

A retrospective study of a prospective cohort of 464 individuals undergoing AIS surgery between 2008 and 2018 was performed. All patients undergoing surgery for AIS with a minimum 2-year follow-up were included. We excluded patients with prior or concomitant surgery for spondylolisthesis. HRQoL scores were measured using the SRS-22 questionnaire. Comparisons were performed between AIS patients with vs. without concomitant spondylolisthesis treated non-surgically.

AIS surgery was performed for 36 patients (15.2 ±2.5 y.o) with concomitant isthmic spondylolisthesis, and 428 patients (15.5 ±2.4 y.o) without concomitant spondylolisthesis. The two groups were similar in terms of age, sex, preoperative and postoperative Cobb angles. Preoperative and postoperative HRQoL scores were similar between the two groups. HRQoL improved significantly for all domains in both groups, except for pain in patients with spondylolisthesis. There was no need for surgical treatment of the spondylolisthesis and no slip progression during the follow-up duration after AIS surgery.

Patients undergoing surgical treatment of AIS with non-surgical management of a concomitant isthmic spondylolisthesis can expect improvement in HRQoL scores, similar to that observed in patients without concomitant spondylolisthesis.

There is a significant positive association between hours of brace wear and rate of success in the treatment of Adolescent Idiopathic Scoliosis (AIS). The abandon rate reported in the literature averages 18%. In a recent randomized trial conducted at our center; the abandon rate was 4%. We aim to document the abandon rate towards brace treatment during the COVID-19 pandemic and its impact on AIS progression.

We reviewed a database of AIS patients recruited between March and September 2020. Inclusion criteria were patients with AIS under brace treatment according to SRS criteria. The patients were divided in 2 cohorts: those with a self-reported good adherence to treatment and those who voluntarily abandoned treatment during follow-up. Patients with irregular adherence were excluded. Data analysis included age, gender, Risser stage, type of brace, Cobb angles at first visit and last follow-up (mean 11 months) and % of progression. Unpaired student tests were used for comparison.

154 patients met inclusion criteria. 20 patients were excluded due to irregular adherence. 89 patients (age: 12.1 y.o. ±1.4) reported good adherence to treatment, while 45 patients (age: 12.6 y.o. ±1.5) abandoned treatment, an abandon rate of 29%. The cohort of compliant patients started treatment with a mean main thoracic (MT) curve of 26° and finished with 27°. The mean difference between measurements was +0.65°±7.5; mean progression rate was −4.6%. However, patients who abandoned treatment started with a mean MT curve of 28° and finished with 33°, with a mean increase of +5°±8 and a mean progression rate of −11%. The differences between the 2 cohorts were statistically significant (p=0.002). Five (5) patients from the abandon group were offered for surgery because of curve progression.

The abandon rate of brace treatment in AIS significantly increased during the first wave of COVID-19 pandemic. Patients who voluntarily discontinued treatment had significant increases in curve progression and surgical indication rates.

The aim of this study is to clarify the implication of ciliary pathway on the onset of the spinal curvature that occurs in Adolescent Idiopathic Scoliosis (AIS) patients through functional studies of two genes: POC5 and TTLL11. Since the genetic implication for AIS is accepted, many association and candidate gene analysis revealed the implication of ciliary genes.

The characterisation of these two proteins was assessed by qPCR, WB and immunofluorescence in vitro using control cells and cells derived from AIS patients. The impact of genetic modification of these genes on the functionality of the proteins in vitro and in vivo was analysed in zebrafish model created by CRISPR/Cas9 using microCT and histologic analysis.

Our study revealed that mutant cells, for both gene, were less ciliated and the primary cilia was significantly shorter compared to control cells. We also observed a default in cilia glutamylation by immunofluorescence and Western Blot. Moreover, we observed in both zebrafish model, a 3D spine curvature similar to the spinal deformation in AIS. Interestingly, our preliminary results of immunohistology showed a retinal defect, especially at the cone cell layer level.

This study strongly supports the implication of the ciliary pathway in the onset of AIS and this is the first time that a mechanism is described for AIS. Indeed, we show that shorter cilia could be less sensitive to environmental factors due to lower glutamylation and result in altered signalling pathway. Identifying the biological mechanism involved is crucial for elucidating AIS pathogenesis.

The etiology of adolescent idiopathic scoliosis (AIS) is largely unknown, but clinical observations revealed the role of hereditary and rapid growth in the development of this condition. More recently, several genes were suspected to cause or contribute to AIS. Our group identified gene variants of POC5 centriolar protein in a French and French-Canadian families with multiple members affected with AIS. We sought to expand on this study and to investigate for the role of POC5 gene and mutated protein. In this work, the potential pathogenic effect of mutated POC5 was investigated in vitro (human osteoblats cell culture) and in vivo in a zebrafish animal model.

To investigate the role of POC5 in AIS, we investigated subcellular localization of POC5 with respect to cilia in cells overexpressing wt or POC5 variants (C1286T, A429V) and in human osteoblasts from scoliotic patients carrying these POC5 variants and normal control cells (in vitro study). We also created a loss-of-function model in zebrafish (in vivo study). The role of POC5 was investigated by: 1) mass spectroscopy analysis and co-immunoprecipitation to identify differences in binding partners between the wild-type (wt POC5 and mut POC5 protein; 2) immunolocalization of POC5 wt and mut proteins at the cellular level; 3) histology and immunohistochemistry performed on tissues from wt (control) and scoliotic (poc5 mut) zebrafish.

Our work identified several interacting partners with POC5, and documented functional connections with respect to cilia and centrosome dysfunction. A number of ciliary proteins were identified to be interacting with wt POC5 but not mut POC5. At the cellular level, localization and co-localisation of wt POC5 and mut POC5 protein with alpha acetylated tubulin (cilia marker), confirmed the consequence of the mutation on subcellular location with respect to cilium structure, length and staining intensity of cilia. In vivo, several defects in the retina were identified in mut poc5 zebrafish compared wt zebrafish. Finally, using different markers for retinal layers and acetylated tubulin, the defects were localized in ganglion cell layer and cones of the retina.

Our findings confirm the involvement of POC5 in scoliosis. A role of POC5 with respect to the primary cilia was attributed. These findings open new avenues for the understanding the primary causes of AIS at the molecular and physiological levels.

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.

Aims

Spinal fusion remains the gold standard in the treatment of idiopathic scoliosis. However, anterior vertebral body tethering (AVBT) is gaining widespread interest, despite the limited data on its efficacy. The aim of our study was to determine the clinical efficacy of AVBT in skeletally immature patients with idiopathic scoliosis.

This study addresses a crucial gap in the knowledge of normative spinal growth in children. The objective of this study is to provide detailed and accurate 3D reference values for global and segmental spinal dimensions in healthy children under the age of 11.

Radiographic spine examinations of healthy children conducted to rule out scoliosis were reviewed in four scoliosis referral centers in North America. All consecutive children aged three to eleven years old with EOS biplanar good quality x-rays, but without diagnosed growth-affecting pathologies, were included. Postero-Anterior and Lateral calibrated x-rays were used for spine 3D reconstruction and computation of vertebral body height and spine length. Median and interquartile range were calculated from cross-sectional data. Smooth centiles growth curves for 3D True Spinal Length (3DTSL) between T1 and S1, as well as for mid-vertebral heights of T5, T12 and L3, where fit and calibrated from data using the Lambda-Mu-Sigma method (GAMLSS package for R). This method automatically selects the best performing distribution from a familly of choices. Tables of centiles were then predicted from the computed models for selected ages.

A total of 638 full spine examinations from asymptomatic patients were reconstructed in 3D, 397 in girls and 241 in boys. Medians and interquartile ranges were calculated for 3DTSL (T1-S1): 285 (24) mm, 314 (26) mm and 349 (31) mm, and for selected vertebral heights T5: 10 (1) mm, 11 (1) mm and 12 (1) mm, T12: 13 (2) mm, 14 (1) mm and 16 (2) mm, and L3: 14 (1) mm, 16 (2) mm and 18 (2) mm, respectively for the 3–6, 6–8 and 8–11 age groups. Centile curves ready for clinical use of the 3DTSL (T1-S1) and of the vertebral heights of T5, T12 and L3 as a function of age were derived for the 5, 10, 25, 50, 75, 90 and 95th centiles. In general, boys presented linear relationships between spinal dimensions and age, and girls presented more diverging trends with increased variance for older ages. Accordingly curves for boys follow the Normal distribution whereas those for girls follow the original Box-Cox-Cole-Green distribution. Model diagnostic tests (normally distributed residuals, adequate wormplots and |Z statistics| < 2) confirmed adequacy of the models and the absence of significant misfit.

Accurate reference values were derived for spinal dimensions in healthy children. Spinal dimension charts showed that the spinal lengths and vertebral heights changed relatively constantly across the age groups closely resembling WHO total body height charts. The reference values will help physicians better assess their patients' growth potential. It could also be used to predict expected spinal dimensions at maturity or changes in pathologic conditions as well as to assess the impact of growth friendly interventions in the correction of spinal deformities.

Treat to target is the use of a physiologic marker as a monitor of effectiveness or compliance to an intervention. A recent example has been the progressive use of CTX-1 (Marker of osteoclastic activity) as a surrogate of bone resorptive activity in osteoporosis treatment. CTX-1 levels were demonstrated to be inversely related to drug efficacy in the suppression of bone resorption. As far as fragility fractures are concerned, no reference value of CTX-1 for any index fracture sites was found in the literature. In order to prevent subsequent fractures, efforts to better manage this chronic disease are to be explored. The main objective of this study was to compare and validate the use of serum CTX-1 to the perceived compliance to treatment.

Five hundred and forty three patients (men and women) 40 years of age or older who had been treated for a fragility fracture were enrolled. The purpose of this study was to correlate the measurement of CTX-1 with the perceived compliance to treatment of patients at the time of fracture and at six, 12 and 18 months after initiation of treatment. Our secondary objectives were to evaluate two different CTX-1 suppression target levels (CTX-1< 0.3 ng/mL and CTX-1<0.2 ng/mL), to determine CTX-1 values according to fracture sites, and to explore the profile of patients with subsequent fractures.

Considering index fractures, compliant patients under treatment at baseline had lower CTX-1 levels than non-compliant patients (p=0.052). Patients who were compliant to treatment at six, 12 and 18 months also had lower CTX-1 levels than non-compliant patients (p=0.000). When index fractures were divided into fracture sites, regardless of CTX-1 suppression target level (i.e. CTX-1< 0.3 or 0.2 ng/mL), significant CTX-1 suppression was observed in non-hip and non-vertebral (NHNV) fractures at six, 12 and 18 months (p0.05). No clinically relevant difference was observed between the profile of patients with and without subsequent fractures.

The correlation between serum CTX-1 at the time of fracture and at six, 12, 18 months and the perceived compliance to treatment was validated for NHNV fractures supporting the concept of the available treatments and their effects on bone remodeling for this type of fracture. The correlation was not validated for hip neither for vertebral fracture. There was no correlation between CTX-1 levels and subsequent fracture risk.

Referral patterns in spine clinic of young patients with suspected scoliosis is suboptimal with 19% of late referrals and 42% of inappropriate referrals. Patients' triage and prioritisation in spine clinic is a strategy to ensure that health care allocation is done according to the level of health needs, favoring effective management and efficient use of health care resources use. The objective of the study is to elaborate a model for triage and prioritisation of young patients in spine clinic based on expert consensus and literature on best practices.

This projects was structured in three parts: 1)We documented best evidence. We conducted a review of empirical studies evaluating triage and prioritisation initiatives in order to identify key components for intervention success. 2)We elaborate a model of health care delivery with the professionals of a local paediatric spine clinic. In this model, the triage and prioritisation algorithm was developed from list of potential factors (demographics, signs and perceived symptoms, provisional diagnoses and known co-morbidities, results of preliminary physical examination and radiological findings) that was submitted to five paediatric orthopaedic surgeons for rating according to their potential relevance to orient prioritisation decisions. 3) We compared the professionals' model of health care delivery to the literature synthesis in order to propose the best model.

Seven key components of triage and prioritisation systems were identified: centralised review of referral requests, list of consensual objectives criteria for triage, fast track evaluation of urgent cases, selection of cases for management at point of triage, cases prioritisation to main consultant, multidisciplinary evaluation and alternatives pathways. The consensual decision algorithm confirmed that cases who should be seen in priority are immature patients presenting with a significant trunk deformity. In addition, presence of persisting neurological symptoms, severe incapacitating pain or night pain, as well as abnormal scan or MRI findings were considered as urgent/PI priority. Cases characteristics for evaluation by nurse practitioners as well as alternative pathways of management were defined. Acceptability, compatibility, clinical relevance and discriminant capacity of the new model of health care delivery were satisfactorily demonstrated.

Consensus was easily reached between the five respondents on factors supporting decisions to prioritise patients in spine clinic for suspected spinal deformity. Refinements to the initially proposed model according the identified key features from the literature, led to a final model of health care delivery that is evidence-base, feasible and coherent with the local context. Future implementation of this model should facilitate timely and appropriate health care delivery and best use of health care resources according to patients' needs.

Introduction

From the many human studies that attempt to identify genes for adolescent idiopathic scoliosis (AIS), the view emerging is that AIS is a complex genetic disorder with many predisposing genes exhibiting complex phenotypes through environmental interactions. Although advancements in genomic technology are transforming how we undertake genetic and genomic studies, only some success has been reached in deciphering complex diseases such as AIS. Moreover, the present challenge in AIS research is to understand the causative and correlative effects of discovered genetic perturbations. An important limitation to such investigations has been the absence of a method that can easily stratify patients with AIS.

To overcome these challenges, we have developed a functional test that allows us to stratify patients with AIS into three functional subgroups, representing specific endophenotypes. Interestingly, in families with multiple cases of AIS, a specific endophenotype is shared among the affected family members, indicating that such a transmission is inherited. Moreover, increased vulnerability to AIS could be attributable to sustained exposure to osteopontin (OPN), a multifunctional cytokine that appears to be at the origin of the Gi-coupled receptor signalling dysfunction discovered in AIS. We examined the molecular expression profiles of patients with AIS and their response to OPN.

Introduction

Adolescent idiopathic scoliosis (AIS) is the most common form of spinal deformity. It occurs mainly in girls and progresses during pre-pubertal and pubertal growth, which is a crucial period for bone mass acquisition. The cause and molecular mechanisms of AIS are not clear; at present the consensus is that AIS has a multifactor cause, with many genetic factors. During the past 5 years, considerable effort has been devoted to identify a gene or genes that cause a predisposition to AIS. Many loci for this disorder have been mapped to different chromosome regions, but no genes have been clearly identified as being responsible for AIS, and, most importantly, the resulting protein defects remain to be shown. We aimed to identify the gene(s) that could be involved in AIS and to validate their involvement by both genetic and functional analyses.

Purpose: Prediction of progression is actually impossible in adolescent idiopathic scoliosis (AIS). Potential risk factor to consider at first visit might be morphologic parameters of the spine. The objective of this study was to compare 3D morphologic parameters of the spine in a non evolutive an in an evolutive group of AIS.

Method: A retrospective cohort study was done. Two groups were recruited with sample size based on a difference of 5 degrees for rotation parameters. First group were all surgical patients (n=19) and second group non evolutive patient (n=18). Inclusion criteria were

Risser sign of 0 or 1

Exclusion criteria were

limb length discrepancy

All spines were reconstructed in 3D with AP and lateral radiographs of the first visit and measurements were performed on the reconstruction. There were 4 categories of measurements done: Cobb angle, wedging, rotation, slenderness. Student t test were performed.

Results: There was no statistical difference between the two groups for Cobb angle in maximal plane, for lordosis and kyphosis. Differences were found for wedging of the apical disk in 3D plane (S=5,4° vs NE= 0,7° with p=0,04). For coronal orientation of the apex (S=7,8° vs NE=0,1° with p=0,01). For axial orientation of inferior junctional vertebrae (S=1,9° vs 0,1° with p=0,007). For torsion (S=−4,1° vs NE= – 1,2° with p=0,03). For ratio between height and width of T6 (S=51% vs NE=53,6% with p=0,04).

Conclusion: This study give for the first time some 3D morphologic parameters that could be use in the prediction of AIS. Some limitations exist such as the small sample size and the low level of significance. In the future those parameters will be used in the development of a prediction model base on those keys parameters that will confirm the actual findings.

Purpose of the study: Recent studies have shown that the incidence of certain cancers would be due to ionising radiation received during diagnostic radiological explorations. It is thus important to optimise dosimetry. In this context, slot scanners have demonstrated potential for generating images with a quality comparable with conventional systems but with a considerable reduction in dose. We wanted to verify this proposition.

Material and method: Radiographs were obtained in 50 scoliosis patients (posteroanterior and lateral incidences) using the slot scanner (EOS, Biospace) and with a conventional machine (FCR-7501S, Fuji). A dosimeter was placed on the patient after each exam. Phantoms were used to adjust radiographic parameters for each system in order to obtain comparable quality images. Patient images were then acquired ad the dose calculated at several entry points. These measures were used to compare skin radiation and to initialise a Monte-Carlo simulation calculating the effective dose. Two orthopaedic surgeons and two radiologists then evaluated the visibility of the structures of interest using a standard check list. They read the images in random order and were blinded to all information concerning the patient and the system used to acquire the images. Visibility was noted on a non-parametric scale with 4 levels. Wilcoxon’s test was used to compare the visibility scores.

Results: Mean radiation of the skin in the thoracoab-dominal region varied from 0.11 to 0.30 mGy (effective dose 0.057 mSv) for the EOS and 0.73 to 2.47 mGy (effective dose 0.460 mSv) for the FCR-7501S. EOS provided significantly superior visibility for all structures (frontal view, p< 0.006), lateral view p< 0.04) except for the posterior arch of the lumbar vertebrae in the lateral view for which visibility was superior for FCR-7501S (p< 0.003).

Discussion: Using the slot scanner, the patients received 6 to 9 times less radiation to the skin for the thoracoab-dominal region and an 8-fold reduction in effective dose than with the conventional system. In addition, the doses presented in the literature for the same exam are much higher than reported for EOS.

Conclusion: The EOS slot scanner offers image quality which is globally superior to conventional systems while considerably reducing radiation dose.

Purpose: In pediatric orthopedics, Risser sign is used to assess skeletal maturity. Two grading system exist for the Risser sign, one US and one European. In adolescent idiopathic scoliosis (AIS) the curve acceleration phase begin at a digital skeletal age (DSA) score between 400 – 425. The objective was to asses the disagreement between both grading system and evaluate the best estimator of the curve acceleration phase.

Method: One hundred twenty-one AIS patients had a PA and lateral X-rays of the spine and a left hand and wrist X-ray. Risser sign was measured according to both grading system and bone age was calculated according to Tanner-Whitehouse III method. Kappa statistics were done to evaluate concordance between US and Euro-pean grading system and 2 multiple linear regression models were performed to find which stage best predicts the beginning of the rapid acceleration phase.

Results: Kappa statistic between the US and European system was 0.517 (moderate agreement). US Risser 1 was the best predictor of the curve acceleration phase. DSA scores predicted with Risser 1 were 425 and 445 for US and European system respectively.

Conclusion: American and European Risser grading system use different criteria to define 6 stages of a same sign. This is reflected in our study with a moderate agreement between both grading systems. US Risser 1 is the stage that best predicts the beginning of the rapid acceleration phase and a close follow up should be made at the beginning of the iliac apophysis ossification.

Purpose: Musculoskeletal injuries affect up to 13% of adults annually. Despite this high incidence, quality of primary care, including analgesia, may be sub-optimal. The goal of this study is to describe the quality of primary care for ambulatory patients with isolated limb injury and to identify related factors.

Method: A cross sectional study was undertaken on 166 consecutive ambulatory adult patients with isolated limb injury who presented to orthopedics service in a Level one Trauma Centre. Quality of care was assessed by evaluating analgesia, walking aids, immobilization, and quality of referral diagnosis according to actual expert recommendations. Patient satisfaction was assessed by Visit Satisfaction Questionnaire.

Results: This study revealed low quality of primary care for more than 50% of injured patients. More than half the patients had pain level over 5/10 and more than a quarter had insufficient/absent analgesia prescriptions. A third had unacceptable immobilization and 36% of patients with a lower limb injury did not receive a walking aid prescription. A total of 37% had an absent or inadequate referral diagnosis. Factors associated with lower quality depended on the specific quality indicator and included: living further away from the hospital, younger age, initially consulting at another health care center, having a fracture, and being a smoker.

Conclusion: The high frequency of low quality of care underlines the necessity for orthopedic surgeons to be involved in primary care education. Identifying factors associated with lower quality of care will orient efforts to improve medical care of patients with isolated traumatic injury.

Object: Smoking is a negative prognostic factor in the outcome of some fractures. We evaluated whether smoking is associated with primary care quality and referral to orthopedic surgeons for an isolated injury.

Materials and Methods: We enrolled all new ambulatory cases with an isolated injury to an extremity referred to an orthopedic trauma clinic. Data were analyzed concerning: type of trauma, prior medical consultations, quality of initial management, patient characteristics and smoking status.

Results: Among 166 consecutive patients referred, 45 were smokers. Family income was under $30 000 for 44% of smokers compared to 27% for non-smokers (p< 0,05). Smokers were younger (43 y.o. vs 50 y.o.; p< 0,05) and used illegal drugs more often (16% vs 5%; p< 0,05). Smokers were more likely to have been injured at work while non -smokers reported their injury as a sport accident. Injury severity, type of injury and ethnic characteristics were not different. Smokers were twice as likely to receive an unacceptable immobilization for their injury than non-smokers (52% vs 25%; p< 0,05) and received inadequate walking aids (26% vs 9%;0< 0,05). Delay from first primary care consultation to orthopedic appointment was almost 2 times longer for smokers (93hrs vs 58hrs; p< 0,05).

Discussion and Conclusion: Injured smokers received a lower standard of care and had longer delays for orthopedic consultations. Primary care quality and efficiency were associated with smoking status, possibly due to medical bias or incorrect use of health service by patients. Relevance: Smoking is a risk factor for complications in orthopedic surgery. Our results suggest that biology may not be the only explanation.

Purpose: To determine the reliability of six measurement techniques for lumbosacral kyphosis.

Method: Using custom computer software, four raters evaluated 60 standing lateral radiographs of the lumbosacral spine during two sessions at a one week interval. The sample size consisted of 20 normal, 20 low and 20 high grade spondylolisthetic subjects. Six parameters were included for analysis: Boxall’s slip angle; Dubousset’s lumbosacral angle (LSA); the Spinal Deformity Study Group’s (SDSG) LSA; dysplastic SDSG LSA; sagittal rotation (SR); kyphotic Cobb angle (k-Cobb). Intra- and inter- rater reliability for all parameters was assessed using intra-class correlation coefficients (ICC). Correlations between parameters and slip percentage were evaluated with Pearson coefficients.

Results: The intra-rater ICC’s for all the parameters ranged between 0.81 and 0.97 and the inter-rater ICC’s were between 0.74 and 0.98. All parameters except sagittal rotation showed a medium to large correlation with slip percentage. Dubousset’s LSA and the kyphotic Cobb angle showed the largest correlations (r=−0.78 and r=−0.50, respectively). Sagittal rotation was associated with the weakest correlation (r=−0.10). All other parameters had medium correlations with percent slip (r=0.31 to 0.43).

Conclusion: All measurement techniques provided substantial to almost perfect inter- and intra- rater reliability. Dubousset’s LSA showed the strongest correlation with slip grade. However, this parameter does not reflect the local dysplastic changes that occur in lower L5 and upper S1 endplates. A longitudinal study evaluating the best suited parameter for predicting the risk of progression and response to surgical treatment is warranted.

Purpose: To determine the relationship between sacral morphology and developmental L5/S1 spondylolisthesis in children and adolescent.

Method: A radiographic study was conducted to investigate sacral morphology in developmental L5/S1 spondylolisthesis in a pediatric and adolescent population. The lateral standing radiographs of 131 subjects, aged 6 to 20 years old with developmental L5-S1 spondylolisthesis (91 low grade and 40 high grade) were analyzed with a dedicated software allowing to measure the following parameters, which were analyzed for each subject by the same individual and compared to an age and sex-matched cohort of 120 asymptomatic subjects: the sacral table index (STI), the sacral table angle (STA), the sacral kyphosis (SK), S1 superior angle, S2 inferior angle, and grade of spondylolisthesis. Student t tests were used to compare the parameters between the curve types.

Results: This study demonstrated that STA is significantly smaller (p< 0.01) in children and adolescents with L5-S1 spondylolisthesis compared to a similar control group. Furthermore, STA is significantly smaller in high grade spondylolisthesis when compared to subjects with low grade. There is also a significant difference in segmental sacral morphology (S1 and S2 anatomy) in the spondylolisthesis group. Increasing sacral kyphosis is also found to be significantly associated with spondylolisthesis.

Conclusion: The sagittal sacral morphology is a constant anatomic variable specific to each normal individual. The anatomy of the sacrum in children and aldolescentss with L5-S1 spondylolisthesis is particular and different from a control group. This study suggests that sacral anatomy may have a direct influence on the development of spondylolisthesis: a lower STA and higher sacral kyphosis may be two factors predisposing to vertebral slip in developmental spondylolisthesis.