Intramedullary Spinal Tumors

Intramedullary spinal tumors are uncommon intra-axial lesions, which can be either primary or metastatic. Primary tumors arise from cell of spinal cord and account for 2–4% of all intrinsic tumors of the central nervous system, being much less common of brain tumors. They are slow-growing tumors, so symptoms precede diagnosis by an average of 2 years. Metastatic lesions usually originate from lung and breast tumors and are usually diagnosed within 1 month from symptom onset. Pain and weakness are the most common presenting symptoms. Magnetic resonance imaging represents the gold standard technique to study the spinal cord tumors, and first-line treatment is surgical resection, but it is not always curative. In selected situations, watchful waiting can be considered. Chemotherapy and radiation are considered, but controversy exists. Novel treatment options must be developed to supplement partial resection and recurrence

Long term recurrence of solitary fibrous tumor involving vertebral body in thoracic spine. A case report

Solitary fibrous tumor (SFT) represents only 0.08% of all primary bone tumors and 0.1% of primary malignant bone tumors and rarely occurs in the spine. We present the case of a 56-year-old woman with long term recurrence (11 years) of spinal SFT involving T8 vertebral body. We performed a total resection of the lesion and spinal fusion T6-T11 with T8 titanium mesh and placement of pedicle screws in T6-T7 and T10-T11 connected by rods. Microscopic examination confirmed the recurrence of the WHO grade II solitary fibrous tumor. SFT is known for a late but common recurrence and uncertain behaviour. Gold standard treatment is Gross Total Resection. We believe that when vertebral bone is involved it is essential to perform a total excision with "supracomplete" resection if possible in order to avoid local recurrence, more difficult to treat due to an higher rate of perioperative complications. Periodical long-term follow-up is essential to allow early detection of relapses and to allow long-term survival

Relevance of using a compressive preload in the cervical spine : an experimental and numerical simulating investigation

Simulating compressive action of muscles, a follower load attends to reproduce a more physiological biomechanical behaviour of the cervical spine. Only few experimental studies reported its influence on kinematics and intradiscal pressure in the cervical spine. STUDY DESIGN: In vitro human cadaveric and numerical simulating evaluation of a compressive preload in the cervical spine. OBJECTIVES: To analyse the influence of a compressive follower preload on the biomechanical behaviour of the cervical spine. METHODS: The present study was divided into two parts: part 1: in vitro investigation; part 2: numerical simulating analysis. Part 1: Twelve human cadaveric spines from C2 to T2 were evaluated intact and after application of a 50-N follower load. All tests were performed under load control by applying pure moments loading of 2 Nm in flexion/extension (FE), axial rotation (AR) and lateral bending (LB). Three-dimensional displacements were measured using an optoelectronic system, and intradiscal pressures were measured at two levels. Part 2: Using a 3D finite element model, we evaluated the influence of a 50- and 100-N compressive preload on intradiscal loads, facets forces and ranges of motion. Different positions of the follower load along the anteroposterior axis (±5 mm) were also simulated. RESULTS: Part 1: Mean variation of cervical lordosis was 5° ± 3°. The ROM slightly increased in FE, whereas it consistently decreased in AR and LB. Coupled lateral bending during AR was also reduced. Increase in hysteresis was observed on load-displacement curves only for AR and LB. Intradiscal pressures increased, but the aspect of load-pressure curves was altered in AR and LB. Part 2: Using the FE model, only minimal changes in ROM were noted following the simulation of a 50-N compressive load for the three loading conditions. Compared to intact condition, <10% variation was observed with regard to the different magnitude and positioning simulated. Intradiscal loads and facets forces were systematically increased by applying compressive preload. CONCLUSIONS: Although the follower load represents an attractive option to apply compressive preload during experimental tests, we found that this method could affect the native biomechanical behaviour of spine specimen depending on which movement was considered. Only minimal effects were observed in FE, whereas significant changes in kinematics and intradiscal pressures were observed for AR and LB

Short isthmic versus long trans-isthmic C2 screw: anatomical and biomechanical evaluation

INTRODUCTION: The Harms technique is now considered as the gold standard to stabilize C1-C2 cervical spine. It has been reported to decrease the risk of vertebral artery injury. However, the risk of vascular injury does not totally disappear, particularly due to the proximity of the trans-isthmic C2 screw with the foramen transversarium of C2. In order to decrease this risk of vertebral artery injury, it has been proposed to use a shorter screw which stops before the foramen transversarium. OBJECT: The main objective was to compare the pull-out strength of long trans-isthmic screw (LS) versus short isthmic screw (SS) C2 screw. An additional morphological study was also performed. METHOD: Thirteen fresh-frozen human cadaveric cervical spines were included in the study. Orientation, width and height of the isthmus of C2 were measured on CT scan. Then, 3.5-mm titanium screws were inserted in C2 isthmus according to the Harms technique. Each specimen received a LS and a SS. The side and the order of placement were determined with a randomization table. Pull-out strengths and stiffness were evaluated with a testing machine, and paired samples were compared using Wilcoxon signed-rank test and also the Kaplan-Meier method. RESULTS: The mean isthmus transversal orientation was 20° ± 6°. The mean width of C2 isthmus was less than 3.5 mm in 35 % of the cases. The mean pull-out strength for LS was 340 ± 85 versus 213 ± 104 N for SS (p = 0.004). The mean stiffness for the LS was 144 ± 40 and 97 ± 54 N/mm for the SS (p = 0.02). DISCUSSION: The pull-out strength of trans-isthmic C2 screws was significantly higher (60 % additional pull-out resistance) than SSs. Although associated with an inferior resistance, SSs may be used in case of narrow isthmus which contraindicates 3.5-mm screw insertion but does not represent the first option for C2 instrumentation. LEVEL OF EVIDENCE: Level V

Pertinence du neuromonitoring multimodal dans les lesions doubles : A propos de la prise en charge, a l’hopital neurologique de lyon, d’une scoliose congenitale avec deficit neurologique rapide

Nous rapportons un cas illustrant qu’une évaluation clinique, radiologique et neurophysiologique exhaustive est obligatoire avant une chirurgie de scoliose sévère. Une patiente a été référée pour bénéficier d’une correction chirurgicale d’une scoliose congénitale malformative. L’examen clinique à l’admission a révélé une tétraparésie qui a imposé un changement urgent de stratégie chirurgicale. L’imagerie par résonance magnétique a objectivé un neurofibrome C2-C3. Les potentiels évoqués somesthésiques (PES) des membres supérieurs et inférieurs étaient normaux mais les potentiels évoqués moteurs (PEM) étaient abolis. Leur réapparition peropératoire lors de la résection du neurofibrome a précédé une amélioration clinique progressive. La récupération spectaculaire des PEM a permis une correction de la déformation de la colonne vertébrale sous surveillance peropératoire plusieurs mois plus tard. &nbsp; French title: Relevance of multimodal neuromonitoring in dual lesions: About the management, in lyon neurological hospital, of congenital scoliosis with rapid neurological deficit We report a case illustrating that exhaustive clinical, radiological and neurophysiological assessment is mandatory before severe scoliosis surgery. A patient was referred for surgical correction of congenital malformative scoliosis. Clinical examination admission revealed a tetraparesis that enforced an urgent change in surgical strategy. Magnetic Resonance Imaging disclosed a C2-C3 neurofibroma. Upper and lower limbs somatosensory evoked potentials were normal but motor evoked potentials (MEPs) were abolished. Their intra-operative reappearance at the time of neurofibroma resection preceded a progressive clinical improvement. The spectacular MEPs recovery allowed correction of the spinal deformity under intraoperative monitoring several months later

Spinopelvic sagittal alignment of patients with transfemoral amputation

This study aims to describe the spinopelvic sagittal alignment in transfemoral amputees (TFAs) from a radiologic study of the spine with a postural approach to better understand the high prevalence of low back pain (LBP) in this population. METHODS: TFAs underwent X-rays with 3-D reconstructions of the full spine and pelvis. Sagittal parameters were analyzed and compared to the literature. Differences between TFAs with and without LBP were also observed. RESULTS: Twelve subjects have been prospectively included (TFA-LBP group (n = 5) and TFA-NoP group (n = 7)). Four of the five subjects of the TFA-LBP group and two of the seven in TFAs-NoP group had an imbalanced sagittal posture, especially regarding the T9-tilt, significantly higher in the TFA-LBP group than in the TFA-NoP (p = 0.046). Eight subjects (6 TFA-NoP and 2 TFA-LBP) had abnormal low value of thoracic kyphosis (TK). Moreover, the mean angle of TK in the TFA-NoP group was lower than in the TFA-LBP group (p = 0.0511). CONCLUSION: In the considered sample, TFAs often present a sagittal imbalance. A low TK angle seems to be associated with the absence of LBP. It can be hypothesized that this compensatory mechanism of the sagittal imbalance is the most accessible in this population. This study emphasizes the importance of considering the sagittal balance of the pelvis and the spine in patients with a TFA to better understand the high prevalence of LBP in this population. It should be completed by the analysis of the spinopelvic balance and the lower limbs in 3D. These slides can be retrieved under Electronic Supplementary Material

A new quasi-invariant parameter characterizing the postural alignment of young asymptomatic adults

Purpose Our study aims to describe the postural alignment of young asymptomatic subjects from head to feet from bi-planar standing full-body X-rays, providing database to compare to aging adults. Novelty resides in the inclusion of the head and lower limbs in the erected posture’s analysis. Methods For 69 young asymptomatic subjects (18–40 years old) 3D reconstructions of the head, spine, pelvis and lower limbs segments were performed from biplanar full-body X-rays. Usual studied spinal, pelvic and lower limbs’ parameters were computed in 3D, sagittal and frontal planes of the patient. Relationships between these parameters were investigated. Inclinations of different lines were studied to characterize the erected posture. Results Values found for spinal curvatures, pelvic parameters and lower limbs geometrical parameters agreed with the literature: thoracic kyphosis, lumbar lordosis, pelvic incidence, pelvic tilt and sagittal vertical axis were respectively in average of 26.9 (SD 7.2 ), 30.5 (SD 7.5 ), 51.0 (SD 9.4 ), 11.1 (SD 5.6 ) and -8.9 mm (SD 21.6 mm). The angle between the vertical and the line joining the most superior point of dentiform apophyse of C2 (OD) and the center of the bi-coxofemoral axis (HA) was the less variable one (SD 1.6 ). Conclusions This study on 3D postural alignment reports the geometry of the spine, pelvis and lower limbs, of the young asymptomatic adult. The less variable angle is the one of the line OD–HA with the vertical, highlighting the vertical alignment of the head above the pelvis. This study provides a basis for future comparisons when investigating aging populations.Authors thank the ParisTech BiomecAM chair program on subject-specific musculoskeletal modeling, and in particular COVEA and Société Générale

The efficacy of multimodal treatment for symptomatic vertebral hemangiomas: A report of 27 cases and a review of the literature

INTRODUCTION: Vertebral hemangiomas (VH) represent the most common primary bone tumor of the spine and are rarely symptomatic. Currently, there is no consensus for treatment and many therapeutic options are available, alone or in combination including cementoplasty, sclerotherapy, surgery, embolization and/or radiotherapy. OBJECTIVE: To evaluate the clinical and radiological outcome of a multimodal management for symptomatic VH. METHODS: A consecutive prospective and retrospective multicenter study was conducted to review cases of symptomatic VHs between 2005 and 2015. Clinical and radiological aspects, treatment modalities and complications were evaluated preoperatively; postoperatively and at last follow-up. We also reviewed the literature of studies concerning case series of VH, published after 1990 and involving more than 10 patients. RESULTS: Twenty-seven VHs were included in our series (mean age at diagnosis: 47.9 years), out of which 26 were symptomatic. Ten presented with neurologic deficit (37%). An epidural extension was noted in 13 patients (48%). Eleven patients (41%) underwent multimodal treatments. In the multimodal group, eradication was observed in 6 patients (54%), stable residue in 5 cases (46%) with no recurrence versus 3 eradication (23%), 9 stable residue (69%) and no recurrence in the monomodal group, (P>0.05). The literature comprised 14 studies including 458 patients. Only 4 studies were focused on multimodal treatments. CONCLUSION: Based on this study, the multimodal management of symptomatic VHs appeared safe and effective. Finally, we propose an algorithm for symptomatic VHS management based on the severity of epidural extension and fracture risk.Les auteurs n'ont aucun support financier à déclare

A continuous series of 27 adult patients treated for L5-S1 isthmic spondylolisthesis by combined approach: Clinical and radiological outcomes at 1 year follow-up

Through this single-center consecutive prospective study, we evaluated the results of a combinedapproach for L5-S1 isthmic spondylolisthesis, using a polyetheretherketone (PEEK) interbody lordoticcage during anterior approach and pedicle screw-based posterior fixation. Between 2010 and 2014,27 adult patients were treated for L5-S1 isthmic spondylolisthesis (high and low grades) by a combi-ned approach with a minimum follow-up of one year. Clinical outcome was assessed before surgicaltreatment and at four months and one year after surgery by: VAS, Oswestry Index (ODI) and Rolland-Morris scores. Two observers evaluated the following radiological parameters: pelvic incidence, pelvictilt, lumbar lordosis, segmental lordosis L5-S1, anterior and posterior disc height, spinal vertical axis(SVA), SVA/sacro-femoral distance (SFD) ratio. Fusion was evaluated on the CT scan at one-year follow-up. Blood loss, surgery time and complications were also collected. The mean age was 47.7 years (± 16.9).The VAS, ODI and Rolland-Morris scores were significantly improved postoperatively, decreased from 7.5(± 1.45); 48 (± 19.25); 15.3 (± 4.67) before the surgery to 3.8 (± 2.55); 28.7 (± 19.58) and 7.76 (± 7.21)respectively at one year after the surgery (P = 0.05). The mean follow-up was 3.3 years. Mean surgery timewas 193.7 min (± 37). Fusion was obtained in 100% of cases. Segmental lordosis L5-S1, pelvic tilt, slip-page, anterior and posterior L5-S1 disc height were significantly improved postoperatively, they passedfrom 20.1; 22.6; 35.3%; 26.4%; 17.9% to 29.5; 20.6; 20.3%; 64.4%; 36.3% respectively. Combined surgicalprocedure meets the required goals of surgery in the treatment of adults L5-S1 isthmic spondylolisthesis

Evaluation biomécanique d'une prothèse discale cervicale : analyses in vitro et in vivo

Through this thesis, we evaluated the In Vitro and In Vivo biomechanical behavior of a ball-and-socket cervical disc prosthesis. In Vitro tests on human cadaveric cervical spines permitted to assess segmental 3D kinematics at instrumented and adjacent levels. The measurement of the intradiscal pressure provided us data on changes of loads transmission at adjacent discs following arthroplasty. Different testing conditions were evaluated: 1 and 2-levels arthrodesis, 1 and 2-levels arthroplasty, hybrid constructs. In addition, using a finite element model of the cervical spine, we investigated the relevance of applying a follower preload during In vitro experiments. Through a prospective and multicentre study, including 32 patients operated with cervical total disc replacement, In Vivo assessment of spine kinematics allowed for measurement of ranges of motion and location of mean center of rotation at instrumented and adjacent levels. Finally, using the EOSTM bi-planar stereo-radiographic system, we could achieve In Vivo three-dimensional motion analysis of instrumented segments.Dans cette thèse, nous avons analysé le comportement biomécanique In Vitro et In Vivo d'une prothèse discale cervicale à articulation sphérique. Les expérimentations In Vitro nous ont permis d'étudier la cinématique segmentaire dans les trois plans de l'espace au niveau instrumenté et aux niveaux adjacents. La mesure de la pression intradiscale a apporté des informations sur les variations de contraintes après arthroplastie au niveau des disques adjacents. Différentes configurations ont ainsi été évaluées : arthroplastie et arthrodèse à 1 et 2 niveaux, montage hybride. L'influence de la précharge sur le comportement biomécanique du rachis cervical a fait l'objet d'un travail spécifique en se basant sur les essais In Vitro et sur la simulation numérique. Les analyses In Vivo 2D ont été effectuées sur des clichés dynamiques en flexion-extension et ont permis le calcul des amplitudes de mobilité et de la position des centres moyens de rotation dans une population de patients opérés (n=32). Celles-ci ont intéressé le niveau opéré mais également les niveaux adjacents à court et moyen terme. Grâce au système stéréo-radiographique EOSTM, nous avons pu compléter l'analyse cinématique In Vivo par la mesure des amplitudes de mobilité des segments instrumentés dans les trois plans de l'espace