A comparison of idiopathic scoliosis surgery between teenage years and adulthood.

PURPOSE: Idiopathic scoliosis is an evolutive deformity during patient's life. In case of moderate deformity in a well aligned adolescent, it's a big concern to decide when to do the surgery. Objective of this work was to evaluate and compare clinical, radiological and surgical data of patients with adolescent idiopathic scoliosis operated in childhood (before 20 years) and those operated adults (after 35 years). METHODS: In this retrospective multicenter study, inclusion period extended from 2008 to 2018. Two groups were defined, those operated on before the age of 20 (YAIS), and those operated on after 35 years (OAIS). Demographic, radiographic and surgical data were collected. At follow-up, radiographic data and functional outcomes (VAS, SRS, SF12, Oswestry) were analyzed. Minimum FU was 5 years for young and 2 years for old patients. RESULTS: YAIS group included 364 patients, and OAIS group, 131 patients. In both groups, deformity was important (mean Cobb 63°). Vertebral osteotomies were significantly more frequent, fusions and length of stays were longer for old than young patients. Main Cobb correction was better in young than old (37 ± 10° vs 2 ± 13°, p = 0.03). Functional outcomes were better for young, operated patients than for operated groups after 35 years (SF12 PCS 50 ± 7 vs 39 ± 6, p = 0.02). The same trends were observed at longer follow-up. CONCLUSION: Surgery for idiopathic scoliosis seems to offer a better quality of life and deformity correction when it is performed at adolescence. After 35 years, surgery remains an acceptable therapeutic option, despite higher complication rate.

Digital vs Conventional OSCE in Orthopedic Surgery: A Feasibility Cross-Sectional Study.

OBJECTIVE: Remote OSCEs (Objective Structured Clinical Examination) are an alternative evaluation method during pandemic periods but they have never been evaluated in orthopedic surgery. We aimed to evaluate whether remote OSCEs would be feasible, and efficient for assessment of undergraduate medical students. METHODS: A cross-sectional study was performed. Thirty-four students were randomly assigned into 2 equal groups, either the conventional OSCE group or the digital OSCE group. Three types of skills were assessed: technical procedure, clinical examination, and radiographic analysis. Students were graded and they filled in a satisfaction questionnaire for both types of OSCEs. RESULTS: The mean score, out of 20, was 14.3 ± 2.5 (range 9.3-19) for the digital sessions, versus 14.4 ± 2.3 (range 10-18.6) for conventional sessions (p = 0.81). Bland Altman Plot showed that 88% of students scored within agreement. The average global feedback was different for item repeatability, relevance, and OSCEs preference (p < 0.0001, p = 0.0001, and p < 0.0001 respectively). However, they did not report differences for the item concerning the organization (p = 0.2). CONCLUSION: The results of this comparative study between digital and conventional OSCEs showed comparable distance learning scores between the 2 groups, whatever the skill assessed. However, the student's evaluation showed some reticence to conduct again OSCEs remotely.

Defining threshold for sagittal correction in lumbar fractures.

PURPOSE: Surgical indications for thoraco-lumbar fractures are driven both by neurological status, fractures instability and kyphotic deformity. Regarding kyphotic deformity, an angulation superior to 20° is considered by many surgeons as a surgical indication to reduce the disability induced by post-traumatic kyphosis. However, there is a lack of data reporting the ideal or theoretical lordosis that one must have in a particular lumbar segment on CT-scan. The main goal of this study was to determine the mean value for segmental lumbar lordosis according to pelvic incidence (PI) on a cohort of normal subjects. METHODS: The consecutive CT-scan of 171 normal adult subjects were retrospectively analyzed. The PI and the segmental lordosis (L4S1, L3L5, L2L4, L3L1, L2T12 and T11-L1) were measured on all CT-scan. The mean values were calculated for the global cohort and a sub-group analysis according to IP ranges (< 45°, 45 < IP < 60° and > 60°) was performed. RESULTS: The mean angular values for the whole cohort were IP: 54, 9°; L4S1: - 38, 1°; L3L5: - 30, 6°; L2L4: - 14, 1°; L1L3: - 4, 9°; T12L2: + 1, 9° and T11L1: + 5, 4°. The segmental values vary significatively with PI ranges, as for L3L5: - 26, 8° (PI < 45°); - 30° (45 < PI < 60°) and - 35, 1° (PI > 60°). CONCLUSION: These results provide a referential of theoretical values of segmental lordosis according to PI. This abacus may help spinal surgeon in their decision-making process regarding lumbar fractures, to determine the amount of sagittal correction needed, according to the PI range, to be adapted to the sagittal morphology of the patient. LEVEL OF EVIDENCE: III.

Does Spinal Surgery in Elderly Patients (Over 80 Years-Old) Lead to More Early Post-Operative Complications Than Lower Limb Prosthetic Surgery?

Purpose: Patients and surgeons may be reluctant on spinal surgery over 80 years old, fearing medical complications despite the possible improvement on quality of life. However, fewer reservations for lower limb prosthetic surgery (LLPS) seem to be arisen in this population. Is spinal surgery after 80 years-old responsible of more complications than lower limb surgery? Methods: The consecutive files of 164 patients over 80 years that had spinal surgery or LLPS were analyzed. The data collected pre-operatively were demographic, clinical and post-operatively the number and types of medical complications and length of stay. Results: The mean number of medical complications was 1.11 ± 0.6 [0-6] for spinal surgery and 1.09 ± 1.0 [0-3] for LLPS, (p = 0,87). The length of stay in orthopedic unit was comparable between the two groups: 10.7 ± 4.9 days [2-36] for SS and 10.7 ± 3.0 days [5-11] for LLPS (p = 0,96). Conclusion: The global rate of peri-operative complications and the length of hospital stay were similar between spinal surgery and lower limb prosthetic surgery. These results may be explained by the rising cooperation between geriatric specialist and surgeons and the development of mini-invasive surgical technics, diminishing the early post-operative complication rates.

The Whole-Exome Sequencing of a Cohort of 19 Families with Adolescent Idiopathic Scoliosis (AIS): Candidate Pathways.

A significant genetic involvement has been known for decades to exist in adolescent idiopathic scoliosis (AIS), a spine deformity affecting 1-3% of the world population. However, though biomechanical and endocrinological theories have emerged, no clear pathophysiological explanation has been found. Data from the whole-exome sequencing performed on 113 individuals in 19 multi-generational families with AIS have been filtered and analyzed via interaction pathways and functional category analysis (Varaft, Bingo and Panther). The subsequent list of 2566 variants has been compared to the variants already described in the literature, with an 18% match rate. The familial analysis in two families reveals mutations in the BICD2 gene, supporting the involvement of the muscular system in AIS etiology. The cellular component analysis revealed significant enrichment in myosin-related and neuronal activity-related categories. All together, these results reinforce the suspected role of the neuronal and muscular systems, highlighting the calmodulin pathway and suggesting a role of DNA-binding activities in AIS physiopathology.

Pregnancy and childbirth after adolescent idiopathic scoliosis surgery: A study of 80 pregnancies.

BACKGROUND: Adolescent idiopathic scoliosis (AIS) is a common spinal disease affecting 2% of adolescents, and women in 90% of the cases. When a surgical treatment is opted for, many questions are frequently asked by families and patients about the course of pregnancy and childbirth after the spinal fusion. This subject remains little studied in the literature, especially with modern instrumentation techniques. HYPOTHESIS: The goal was to describe pregnancy and childbirth after AIS surgery in terms of access to epidural analgesia, need for cesarean section (c-section), and low back pain during and after pregnancy. We thus hypothesized that women undergoing spinal surgery for AIS have subsequently uncomplicated pregnancies and childbirths, and have access to epidural analgesia as women without AIS do. PATIENTS AND METHODS: In this retrospective multicenter study, 198 women who underwent surgery between 1984 and 2014 were reviewed from two university hospitals. Among them, 50 women became pregnant, for a total of 80 pregnancies. Surgical data were collected [approach, uppermost and lowermost instrumented vertebra (UIV, LIV)]. Pregnancy characteristics were evaluated: time between surgery and pregnancy, number of births, mode of analgesia, type of delivery, weight gain. Occurrence of low back pain during pregnancy and at follow-up was recorded using ODI. RESULTS: Of the 50 women, 34 had posterior surgery and 16 had anterior surgery. Deliveries took place from 1988 to 2018. Of the 80 pregnancies, 81% were delivered by vaginal route (n=65/80), and an effective epidural anesthesia was performed for 49% of them (n=39/80). Epidural analgesia failed in 9% of pregnancies (n=7/80), and was denied in 35% of cases (n=28/80), half of the time by anesthesiologists (n=15/80). Patients refused epidural in 13 pregnancies (16%, n=13/80). A general anesthesia was used in six pregnancies (8%, n=6/80), for c-sections only. Back pain was reported in 48% of the pregnancies (n=38/80). The level of fusion was correlated with c-section, and conversely with epidural anesthesia. DISCUSSION: A normal pregnancy with vaginal delivery seems to be the rule for women undergoing spinal fusion for AIS. The c-section rate in AIS women was similar to the general population (19%). Yet, access to epidural anesthesia still seems problematic with only 49% of births in this series, compared with 81% in the French population. LEVEL OF EVIDENCE: IV, retrospective cohort.

Multiple Myeloma Spinal Lesion Care: Management of a Primary Bone Malignancy Rather Than a Spinal Metastasis.

OBJECTIVE: Multiple myeloma (MM) is too often wrongly categorized as a spinal metastasis (SpM), although it is distinguishable from SpM in many aspects, such as its earlier natural history at the time of diagnosis, its increased overall survival (OS), and its response to therapeutic modalities. The characterization of these 2 different spine lesions remains a main challenge. METHODS: This study compares 2 consecutive prospective oncologic populations of patients with spine lesions: 361 patients treated for MM spine lesions and 660 patients treated for SpM between January 2014 and 2017. RESULTS: The mean time between the tumor/MM diagnosis and spine lesions was respectively 0.3 (standard deviation [SD] 4.1) and 35.1 months (SD 21.2) for the MM and SpM groups. The median OS for the MM group was 59.6 months (SD 6.0) versus 13.5 months (SD 1.3) for the SpM group (P < 0.0001). Regardless of Eastern Cooperative Oncology Group (ECOG) performance status, patients with MM always have a significantly better median OS than do patients with SpM: ECOG 0, 75.3 versus 38.7 months; ECOG 1, 74.3 versus 24.7 months; ECOG 2, 34.6 versus 8.1 months; ECOG 3, 13.5 versus 3.2 months and ECOG 4, 7.3 versus 1.3 months (P < 0.0001). The patients with MM had more diffuse spinal involvement (mean, 7.8 lesions; SD 4.7) than did patients with SpM (mean, 3.9; SD 3.5) (P < 0.0001). CONCLUSIONS: MM must be considered as a primary bone tumor, not as SpM. The strategic position of the spine in the natural course of cancer (i.e., nurturing cradle of birth for MM vs. systemic metastases spreading for SpM) explains the differences in OS and outcome.

Loss of CSF-contacting neuron sensory function is associated with a hyper-kyphosis of the spine reminiscent of Scheuermann's disease.

Scheuermann's disease, also referred to as Scheuermann's kyphosis, is the second most frequent spine deformity occurring in humans after adolescent idiopathic scoliosis (AIS), both with an unclear etiology. Recent genetic studies in zebrafish unraveled new mechanisms linked to AIS, highlighting the role of the Reissner fiber, an acellular polymer bathing in the cerebrospinal fluid (CSF) in close proximity with ciliated cells and mechanosensory neurons lining the central canal of the spinal cord (CSF-cNs). However, while the Reissner fiber and ciliary beating have been linked to AIS-like phenotypes in zebrafish, the relevance of the sensory functions of CSF-cNs for human spine disorders remains unknown. Here, we show that the thoracic hyper-kyphosis of the spine previously reported in adult pkd2l1 mutant zebrafish, in which the mechanosensory function of CSF-cNs is likely defective, is restricted to the sagittal plane and is not associated with vertebral malformations. By applying orthopedic criteria to analyze the amplitude of the curvature at the apex of the kyphosis, the curve pattern, the sagittal balance and sex bias, we demonstrate that pkd2l1 knock-outs develop a phenotype reminiscent of Scheuermann's disease. Altogether our work consolidates the benefit of combining genetics and analysis of spine deformities in zebrafish to model idiopathic spine disorders in humans.

Lumbar scoliosis and stenosis: What outcomes for which treatment? Analysis of three surgical techniques in 154 patients with minimum two-year follow-up.

STUDY DESIGN: Prospective multicentric study. OBJECTIVE: This study goal was to analyze the clinical and radiographic outcomes of lumbar stenosis and scoliosis (LSS) patients, treated with lumbar decompression (LD), short fusion and decompression (SF) or long fusion with deformity correction (LF). HYPOTHESIS: Procedures without correction lead to poorer long-term outcomes. METHODS: Consecutive patients with two-year minimum follow-up, older than 50, with lumbar scoliosis (Cobb angle>15°), and symptomatic lumbar stenosis were included. Age, gender, Lumbar and Radicular Visual Analog Scale, ODI, SF12 and SRS30 were collected. Main and adjacent curves Cobb angles, C7 coronal tilt (C7CT), spinopelvic parameters, and spino-sacral angle (SSA) were measured preoperatively, at one and two years. Patients were sorted into surgery type groups. RESULTS: In total, 154 patients were included, with respectively 18, 58 and 78 patients in LD, SF and LF groups. Mean age was 69, 85% were women. Clinical scores improved in each group at one year, but only LF group exhibited persistent improvement at 2years. A significant fractional Cobb angle increase was noted in the SF group at 2years (from 12±11° to 18±14°). C7CT significantly increased in the LD group at 2years (from 2.5±1.3° to 5.1±3.5°). LF group presented the highest complication rate (45%, 19% for SF and 0% for LD). The overall revision rate was 14% in SF group and 30% in LF group. CONCLUSION: LSS is a complex pathology requiring custom-made surgical treatment. LD, SF and LF allow satisfactory clinical outcome, with a better and more sustained clinical improvement for LF despite higher complication and revision rates. LEVEL OF EVIDENCE: IV.

Spine Metastasis: Patients With Poor Performance Status (ECOG) Could benefit From Palliative Surgical Care! A Prospective Cohort Study.

STUDY DESIGN: This study used a French prospective national multi-center database of patients with spine metastasis (SpM). OBJECTIVE: The main challenge was to clarify if SpM patients presenting poor ECOG-PS could benefit from a surgical intervention. BACKGROUND: Spine metastases (SpM) are debilitating lesions commonly found in the evolution of cancer. At present, patients with poor ECOG-PS do not benefit from surgical care. MATERIALS AND METHODS: Between 2014 and 2017, 176 SpM patients with poor initial ECOG-PS (3 or 4) were identified. RESULTS: The median overall survival of patients was 2.1 months (SD 0.2). Seventy-one patients (40.3%) underwent surgery: for 49 patients (27.8%) the intervention consisted of a simple decompression and for 22 patients (12.5%) the previous was associated with an osteosynthesis. Patients who underwent surgery demonstrated significantly longer median overall survival than those who did not: 3.5 months (SD 0.4) versus 1.6 (SD 0.2) ( P <0.0001). No significant differences between operated/nonoperated patients were noted concerning median age (66.4 vs. 64.2 y, P =0.897), the median number of SpM (4.1 vs. 4.2, P =0.374), ECOG-PS 4 ratio (41.6 vs. 39.3%, P =0.616), or for primary tumors ( P =0.103). Patients who underwent surgery statistically improved their neurological impairment according to the Frankel score: 5/11 (45.4%) from A to C, 5/17 (29.4%) from B to C or D, 6/11 (54.5%) from C to D and 2/4 (50%). Twelve patients (16.9%) presented a postoperative complication. CONCLUSION: Patients with poor ECOG-PS could benefit from surgery. Even though survival gain is small, it permits the preservation of their neurological function. By making ambulation possible, pain is decreased during the last months of their lives.

Pre- and postoperative MRI analysis of central decompression in MIS fusion with lumbar stenosis.

OBJECTIVES: Mini-invasive approaches have grown substantially these last decades in spinal surgery, notably for lumbar decompressions and fusion, with advantages over open approaches in terms of morbidity reduction. However, to our knowledge, no study has measured on MRI the amount of central decompression obtained by MIS approach. The goal of this study was to precisely measure the decompression of central stenosis by unilateral MIS approaches. METHODS: The files of 42 patients that had a MIS lumbar fusion with central decompression for central stenosis were reviewed. All patients had a pre- and postoperative MRI that allowed on T2 axial images to classify the central stenosis, according to Schizas' classification, and measure the dural sac cross-sectional area (DSCA) and the anteroposterior diameter (DAP). The statistical analysis was made with paired t-test. RESULTS: Fifty-six levels were analyzed, mostly L4L5 (58%). The mean preoperative DSCA was 70.53mm2 and the mean postoperative DSCA was 172.2mm2. The mean preoperative DAP was 6.15mm and postoperative was 10.68mm. Preoperatively, the levels analyzed were rated B, C or D according to Schizas for 53 out of 56 levels and A1-4 for 51 out of 56 levels in postoperative. All the results were statistically significant (p<0.001). CONCLUSION: Decompression, assessed by MRI, seems to be equivalent by MIS approach to open laminarthrectomy. MIS approaches have been studied clinically in these indications with very satisfying results. As a conclusion, MIS approaches seems to be a relevant and efficient option in the treatment of lumbar degenerative stenosis. LEVEL OF EVIDENCE: IV, retrospective study.

Validation of the Total Disability Index (TDI) in French Version.

INTRODUCTION: The Total Disability Index (TDI) questionnaire has been developed to provide a more complete assessment of low back and neck pain, as they frequently co-occur. This study aimed at validating the TDI questionnaire in French, to determine if it could be used in France. HYPOTHESIS: The TDI French version is valid, reproducible and comparable to the English version. METHODS: This multicentric study prospectively included French-speaking volunteers, both patients admitted for spine surgery in two specialized spine centers and healthy individuals. Healthy subjects were recruited among students of an engineering school and medical staff. A booklet was given to the participants containing a Lumbar and Cervical Visual Analog Scale (respectively LVAS and CVAS), and the French versions of Oswestry Disability Index (ODI), Neck Disability Index (NDI) and TDI questionnaires. Statistical analysis included Cronbach's α calculation for internal consistency assessment, correlation analysis with ODI and NDI items for convergent validity, principal component analyses and factor analysis. Discriminant validity was assessed by comparing healthy subjects and patients using Student's t tests, and floor and ceiling effects search. RESULTS: 71 participants were included, with 34 (48%) healthy volunteers and 37 (52%) patients. Mean age was 45.2±19.6 years and 57% of the cohort were males. Internal consistency was good: Cronbach's α was calculated at 0.96 (95%CI: [0.95-0.98]). For each TDI item, a high correlation was found with ODI corresponding items, between 0.81 and 0.97 (p<0.001), and good correlation with NDI items, ranging from 0.65 to 0.96 (p<0.001). TDI correlated also with LVAS and CVAS (respectively 0.70 and 0.65, p<0.001). Principal component analyses indicated good correlation between the TDI items and between each item and TDI total score. Factor analysis indicated two main factors explaining 77% of TDI variance, constituted by all TDI items. Regarding discriminative validity, healthy subjects and patients presented significantly different TDI scores (p-values ≤0.01 for each item). Barplot representations of each TDI item revealed no major floor nor ceiling effects. CONCLUSION: This study confirms the reliability, feasibility and validity of the Total Disability Index questionnaire in its French version. Its validation allows its use in France. LEVEL OF EVIDENCE: II.

Efficiency of a novel vertebral body augmentation system (Tektona™) in non-osteoporotic spinal fractures.

BACKGROUND: The restauration of the local kyphosis is crucial to thoracolumbar fractures outcomes. Recently, the Tektona™ (Spine Art) system, constituted by a flexible lamella for corporeal reduction has emerged as a promising solution for osteoporotic fractures. However, no study has yet focused on its results on traumatic fractures. METHODS: A retrospective longitudinal study on prospectively collected data was conducted on 53 patients that had a kyphoplasty by Tektona™, associated or not to percutaneous fixation. The data collected were clinical, surgical and scannographic (measurement of AVH, MVH and PVH (anterior/medium/posterior vertebral height), and RTA (regional traumatic angle) in°), preoperatively, post-operatively and at last follow-up. RESULTS: Fractures were mainly located at the upper lumbar spine and were AOSpine A3 type for 74%. The mean RTA was 12° in pre-operative, 4° in post-operative (p = 2e- 9), and 8° at the last follow-up (p = 0,01). The mean correction of RTA for the fixation group was - 10 ± 6° versus - 7 ± 4° for the kyphobroplasty alone group (p = 0,006). The mean correction for fractures located at T10-T12 was - 9 ± 3°, - 9 ± 5° for L1, - 8 ± 3° for L2 and - 5 ± 3° for L3-L5 (p = 0,045). CONCLUSIONS: The Tektona® system appears to be efficient for acute thoraco-lumbar fractures, comparable to other available systems, allowing a real intracorporeal reduction work. Its relevance, especially in the long term needs further investigation. The association of a percutaneous fixation allow to obtain a better correction of the RTA but did not seem to prevent the loss of correction at follow-up.

Does the Distal Level Really Matter in the Setting of Health-Related Quality of Life? Assessment of a Series of Adolescent Idiopathic Scoliosis Patients at More Than 7 Years Following Surgery.

STUDY DESIGN: Retrospective longitudinal study. OBJECTIVE: The main goal of this study was to measure the disability after AIS correction, according to the LIV. SUMMARY OF BACKGROUND DATA: Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine that may require surgical correction. If the upper and lower instrumented levels (UIV and LIV) of these fusions are defined by the characteristics of the curve, the long-term consequences of the LIV choices are still partially unknown. METHODS: This retrospective longitudinal study collected demographic, radiologic (Lenke classification, Cobb angle), and surgical data (approach, LIV, UIV) on 116 patients operated for AIS fusion on a specialized pediatric spine center were collected. All participants answered SRS30, SF12, lumbar and leg pain Visual Analogue Scales (VAS) at last follow-up. Statistical analysis between LIV (T12L1, L2, L3 or L4L5) and clinical data at last follow-up was realized. RESULTS: The mean follow-up was 87months. The mean increase of back pain VAS per UIV level was 9 mm. No statistically significant difference between the different LIV was found, for SRS30 or SF12 MCS (mental component scale). There was a statistically significant difference between L3 UIV and L4L5 UIV for SF-12 PCS (physical component scale); ( P = 0.03). CONCLUSION: The long-term consequences of LIV choice mostly affect levels distal to L3. If the LIV is mostly defined by the characteristics of the curve, one level caudally corresponds to +9 mm of back pain VAS at 7 years of follow-up. Surgeons may be aware of the long-term consequence of LIV choice and patients be informed.

[Aging of an already pathological spine and its evaluation]. / Vieillissement d'un rachis déjà pathologique et évaluation.

Aging of an already pathological spine and its evaluation. The spine can be subject to different pathologies, starting from the beginning of its growth. Among these, scoliosis is relatively frequent and the question of what happens to unoperated scoliosis patients as they get older and are added to an already patho¬logical spine disc degeneration, posterior osteoarthritis or yellow ligament hypertrophy. The question also arises for other spinal pathologies, such as kyphosis or ankylosing spondylitis: what follow-up should be provided to these patients? What clinical and radiological assessment should be performed?

Vieillissement d'un rachis déjà pathologique et évaluation. Le rachis peut être sujet à différentes pathologies, à partir du début de sa croissance. Parmi celles-ci, la scoliose est relativement fréquente, et la question du devenir des patients scoliotiques non opérés lorsqu'ils avancent en âge et que s'ajoutent sur un rachis déjà pathologique la dégénérescence discale, l'arthrose postérieure ou l'hyper¬trophie du ligament jaune. La question se pose également pour d'autres pathologies rachidiennes, telles que les cyphoses, ou les spondylarthrites ankylosantes : quel suivi faut-il apporter à ces patients ? Quel bilan réaliser ?

The orthopedic characterization of cfap298tm304 mutants validate zebrafish to faithfully model human AIS.

Cerebrospinal fluid (CSF) circulation relies on the beating of motile cilia projecting in the lumen of the brain and spinal cord cavities Mutations in genes involved in cilia motility disturb cerebrospinal fluid circulation and result in scoliosis-like deformities of the spine in juvenile zebrafish. However, these defects in spine alignment have not been validated with clinical criteria used to diagnose adolescent idiopathic scoliosis (AIS). The aim of this study was to describe, using orthopaedic criteria the spinal deformities of a zebrafish mutant model of AIS targeting a gene involved in cilia polarity and motility, cfap298tm304. The zebrafish mutant line cfap298tm304, exhibiting alteration of CSF flow due to defective cilia motility, was raised to the juvenile stage. The analysis of mutant animals was based on micro-computed tomography (micro-CT), which was conducted in a QUANTUM FX CALIPER, with a 59 µm-30 mm protocol. 63% of the cfap298tm304 zebrafish analyzed presented a three-dimensional deformity of the spine, that was evolutive during the juvenile phase, more frequent in females, with a right convexity, a rotational component and involving at least one dislocation. We confirm here that cfap298tm304 scoliotic individuals display a typical AIS phenotype, with orthopedic criteria mirroring patient's diagnosis.

Evaluation of disc degeneration adjacent to AOspine A fractures: pre- and post-operative MRI analysis.

INTRODUCTION: The management of type A thoracolumbar fractures varies from conservative treatment to multiple level fusion. Indeed, although Magerl defined the type A fracture as a strictly bone injury, several authors suggested associated disc lesions or degeneration after trauma. However, the preservation of mobility of the adjacent discs should be a major issue. This study was conducted to analyze the presence of immediate post-traumatic disc injuries and to know if discs degenerate after receiving treatment. METHODS: We retrospectively reviewed the files of 27 patients with an AOspine A fracture, corresponding to 34 fractures (64 discs) with pre and post-operative MRI (mean follow-up: 32.4 months). Based on Pfirrmann's and Oner's classifications of disc injuries, two observers analyzed independently the type of lesion in the discs adjacent to the fractured vertebra in immediate post-trauma and at the last follow-up. RESULTS: The immediate post-traumatic analysis according to Pfirrmann's classification found 97% of the cranial adjacent discs and 100% of the caudal discs classified Pfirrmann 3 or less. The analysis on the secondary MRI revealed that 78% of cranial adjacent discs and 88% of caudal adjacent discs still were classified Pfirrmann 3 or less. CONCLUSIONS: Since, the great majority of type A fractures does not cause immediate disc injuries, these fractures are, as described by Magerl, strictly bony injuries. The quality of the body reduction seems to prevent secondary degeneration. These results may encourage surgeons not to perform arthrodesis on type A fractures even for A3 and A4.

Management of thoracolumbar fracture in France. Analysis of practices and radiologic results of a cohort of 407 thoracolumbar fractures.

BACKGROUND: Thoracolumbar fractures are a public health issue due to their severity and frequency. Management varies according to demographic, clinical and radiologic features, from non-operative treatment to extensive fusion. In the two last decades, improvements and new techniques have emerged, such as kyphoplasty and percutaneous approaches. The main goal of this study was to describe the management of thoracolumbar fractures in France in 2018. HYPOTHESIS: The study hypothesis was that management of thoracolumbar fractures in France has progressed in recent decades. MATERIAL AND METHODS: The files of 407 adult patients operated on between January 1, 2015 and December 31, 2016 for T4-L5 thoracolumbar fracture in 6 French teaching hospitals were retrospectively reviewed, at a mean follow-up at 10.2±8.2 [1; 42] months. Demographic, surgical and postoperative radiological data were collected. p-values<0.05 on Student test were considered significant. RESULTS: Five hundred and thirty-one fractures were analyzed (27% of patients presented more than one fracture). Surgery consisted in internal fixation for 56% of patients, including 17% with associated kyphoplasty; 29% had fusion, and 15% stand-alone kyphoplasty. Surgery used an open posterior approach in 54% of cases, and a percutaneous approach in 46%. Initial sagittal angulation was not a significant decision criterion for screwing (p=0.8) or for a secondary anterior approach in case of fusion (p=0.6). Immediate postoperative sagittal correction was significantly better with an open than a percutaneous approach (p=0.004), but without significant difference at last follow-up (p=0.8). Correction at last follow-up was significantly better with anterior associated to posterior fusion (p=0.003). DISCUSSION: Management of the thoracolumbar fractures has progressed in France in recent years: 46% of surgeries used a percutaneous approach, compared to 28% in 2013; 90% used a posterior approach only, compared to 83% in 2013; rates of combined approach were unchanged, at 6%. Twenty-five percent of burst fractures were treated by fusion, possibly due to lack of preoperative MRI in 79% of cases. LEVEL OF EVIDENCE: IV, retrospective cohort study.

Screw Loosening in Posterior Spine Fusion: Prevalence and Risk Factors.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Screw loosening in spinal fusion is poorly defined. Accordingly, its prevalence rates range from 1% to 60%, and its risk factors remain undefined. The goal of this study was to assess the prevalence of screw loosening, according to precise definitions, and to identify factors associated with it. METHODS: We retrospectively reviewed records for 166 patients who underwent a posterior spinal fusion in our institution between 2011 and 2016. We recorded demographic data, osteoporosis, pelvic balance, surgery-related information, and postoperative radiographic data at a minimum follow-up of 6 months. Univariable and multivariable logistic regression models were used. Significance was defined by P < .05. RESULTS: When loosening was defined by partial pull-out, its prevalence was 9.6% (95% CI 5.6-15); thoracic localization, the use of CrCo (chromium-cobalt) rods, osteoporosis, PI/LL (pelvic incidence/lumbar lordosis) mismatch (preoperative), and frontal imbalance (preoperative) were significant risk factors. When loosening was defined by osteolysis (radiolucent rim) >1 mm around at least 1 screw, its prevalence was 40.4% (95% CI 33-48) and age, scoliosis as indication for fusion, ASA (American Society of Anesthesiologists) 2 or 3, the use of CrCo rods, more than 5 levels fused, no circumferential arthrodesis, postoperative bracing, and sacrum or ilium as the inferior level of instrumentation were also significant risk factors. CONCLUSIONS: A clear definition of screw loosening seems essential for a useful analysis of the literature. Osteoporosis, sagittal imbalance, and rigid material appear to be risk factors, regardless of the definition.