Ludovic Rillardon

Is there a sagittal imbalance of the spine in isthmic spondylolisthesis? A correlation study

Recent studies suggested a predominant role of spinopelvic parameters to explain lumbosacral spondylolisthesis pathogeny. We compare the pelvic incidence and other parameters of sagittal spinopelvic balance in adolescents and young adults with developmental spondylolisthesis to those parameters in a control group of healthy volunteers. We compared the angular parameters of the sagittal balance of the spine in a cohort of 244 patients with a developmental L5–S1 spondylolisthesis with those of a control cohort of 300 healthy volunteers. A descriptive and correlation study was performed. The L5 anterior slipping and lumbosacral kyphosis in spondylolisthesis patients was described using multiple regression analysis study. Our study demonstrates that the related measures of sagittal spinopelvic alignment are disturbed in adolescents and young adults with developmental spondylolisthesis. These subjects stand with an increased sacral slope, pelvic tilt and lumbar lordosis but with a decreased thoracic kyphosis. Pelvic incidence was significantly higher in spondylolisthesis patients as compared with controls but was not clearly correlated with the grade of slipping. We showed the same “sagittal balance strategy” in spondylolisthesis patients as in the control group regarding correlations between pelvic incidence, sacral slope, pelvic tilt and lumbar lordosis. We believe that the lumbosacral kyphosis is a stronger factor than pelvic incidence which need to be taken into account as a predominant factor in theories of pathogenesis of lumbosacral spondylolithesis. We thus believe that increased lumbar lordosis associated with L5–S1 spondylolisthesis is secondary to the high pelvic incidence and is an important factor causing high shear stresses at the L5–S1 pars interarticularis. However, the “local” sagittal imbalance of the lumbosacral junction is compensated by adjacent mobile segments in the upper lumbar spine, the pelvis orientation and the thoracic spine. The result is not optimal but a satisfactory global sagittal balance of the trunk, even in the most severe grade of slipping.

Paraplégie secondaire à une infiltration épidurale interlamaire lombaire, à propos d'un cas

We report the first case of paraplegia observed after epidural steroid injection in the upper spine. The patient was a 42-year-old male who underwent surgery two years earlier for stenosis of the lumbar spine from L2 to the sacrum leading to early manifestations of an equina cauda syndrome. This first operation provided satisfactory function with complete resolution of the objective neurological symptoms. The patient later developed bilateral radiculalgia involving the L3 and L4 territories and was treated by radio-guided epidural steroid injection (125 mg hydrocortancyl) delivered in the L1-L2 interlaminar space. The injection was achieved with no technical difficulty and there was no injury to the dural sac. Immediately after the injection, the patient developed complete motor and sensorial paraplegia from T12. CT and MRI performed 30 min and 4h, respectively, after the accident revealed a medium-sized discal herniation behind the L2 body. No other lesion was observed. Emergency surgery was performed for radicular release but to no avail. The patients neurological status remained unchanged and four days later the T2 MRI sequence revealed a high-intensity intramedullar signal in the cone. The diagnosis of ischemia of the medullary cone was retained, hypothetically by injury to the dominant radiculomedullary artery via an undetermined mechanism. This complication has been previously described after upper foraminal steroid injections but not after intralaminar epidural steroid injection.

Analyse de l’équilibre sagittal du rachis dans les spondylolisthésis dégénératifs

Resume Les objectifs de ce travail ont ete de determiner les parametres caracterisant la statique rachidienne dans le plan sagittal d’un groupe de 70 patients operes pour spondylolisthesis degeneratif et de les comparer avec ceux d’une population de 250 temoins. Les parametres suivants ont ete pris en compte : incidence et version pelvienne, pente sacree, lordose lombaire, cyphose thoracique, gite sagittale T9 et angulation S1-S2. A partir de ces valeurs ont ete effectuees : une analyse univariee afin de preciser les principales caracteristiques de distribution des parametres pris en compte ; une etude multivariee afin d’etudier les variations de ces parametres les uns par rapport aux autres et ainsi de mieux definir les perturbations de l’equilibre sagittal de ces patients ; une comparaison des parametres etudies a ceux d’une population temoin. L’une des caracteristiques essentielles de la cohorte analysee etait la presence d’une forte incidence pelvienne (62,6 versus 54,7). La valeur elevee de ce parametre pourrait etre, par l’intermediaire de l’hyperlordose et de l’augmentation de la version pelvienne qu’elle induit, l’un des facteurs de degenerescence d’une unite fonctionnelle rachidienne et a terme d’un glissement degeneratif. Les determinants les plus significatifs de la gite sagittale T9 etaient : la version pelvienne, l’incidence pelvienne, la lordose lombaire et la lordose locale L4-S1. Un tiers de nos patients etait en situation de gite anterieure essentiellement en raison d’une importante cyphose lombosacree, un tiers avait une gite sagittale T9 normale et un tiers etait en situation de gite posterieure en raison d’une forte cyphose thoracique associee. Ce travail nous a permis de mieux caracteriser les parametres de l’equilibre sagittal du spondylolisthesis degeneratif, d’emettre quelques hypotheses vis-a-vis du mecanisme constitutif de tels glissements degeneratifs et de souligner la diversite des situations d’equilibre de ces patients avec les implications therapeutiques que cela comporte.

Fracture « tear-drop » en extension de l'axis : À propos d'un cas traité chirurgicalement

Tear-drop fracture of the axis is an exceptional spinal fracture which generally occurs after high-energy trauma with hyper-extension of the cervical spine. Purely anterior fracture can occur with no real impact on stability. Orthopedic treatment provides good results in this situation. If the fracture is posterior, it continues into the C2-C3 intervertebral disc and the common posterior vertebral ligament, leading to C2C3 instability and possible retrolisthesis of C2 over C3 and neurological involvement. We report a case of tear-drop fracture of C2 with C3 instability without neurological involvement. This patient underwent posterior fixation with C2C3 arthrodesis which provided good quality bone fusion without secondary displacement or clinical aggravation.Resume La fracture « tear-drop » de l’axis est une lesion rare du rachis qui survient le plus souvent du fait d’un traumatisme violent en hyper-extension du rachis cervical. La lesion peut etre uniquement anterieure, sans reelle instabilite. Le traitement orthopedique donne alors de bons resultats. Lorsque le trait de fracture se poursuit en arriere dans le disque inter-vertebral C2C3 et le ligament vertebral commun posterieur, l’instabilite C2C3 peut etre responsable d’un retrolisthesis de C2 par rapport a C3 et de troubles neurologiques. Nous rapportons un cas de fracture « tear-drop » de C2 avec instabilite C2C3 sans troubles neurologiques. Nous avons realise une fixation posterieure avec une arthrodese C2C3 qui a obtenu une fusion de bonne qualite sans deplacement secondaire ni aggravation clinique.

Influence de la hauteur discale sur le devenir d’une arthrodèse postérolaterale

PURPOSE OF THE STUDYnExperimentally, posterolateral fusion only provides incomplete control of flexion-extension, rotation and lateral inclination forces. The stability deficit increases with increasing height of the anterior intervertebral space, which for some warrants the adjunction of an intersomatic arthrodesis in addition to the posterolateral graft. Few studies have been devoted to the impact of disc height on the outcome of posterolateral fusion. The purpose of this work was to investigate the spinal segment immobilized by the posterolateral fusion: height of the anterior intervertebral space, the clinical and radiographic impact of changes in disc height, and the short- and long-term impact of disc height measured preoperatively on clinical and radiographic outcome.nnnMATERIALS AND METHODSnIn order to obtain a homogeneous group of patients, the series was limited to patients undergoing posterolateral arthrodesis for degenerative spondylolisthesis, in combination with radicular release. This was a retrospective analysis of a consecutive series of 66 patients with mean 52 months follow-up (range 3-63 months). A dedicated self-administered questionnaire was used to collect data on pre- and postoperative function, the SF-36 quality of life score, and patient satisfaction. Pre- and postoperative (early, one year, last follow-up) radiographic data were recorded: olisthesic level, disc height, intervertebral angle, intervertebral mobility (angular, anteroposterior), and global measures of sagittal balance (thoracic kyphosis, lumbar lordosis, T9 sagittal tilt, pelvic version, pelvic incidence, sacral slope). SpineView was used for all measures. Univariate analysis searched for correlations between variation in disc height and early postoperative function and quality of fusion at last follow-up. Multivariate analysis was applied to the following preoperative parameters: intervertebral angle, disc height, intervertebral mobility, sagittal balance parameters, use of osteosynthesis or not.nnnRESULTSnAt the olisthesic level, there was a 30% mean decrease in disc height and intervertebral angle. These variations were not correlated with functional outcome or quality of fusion observed at last follow-up. Disc height preoperatively did not affect these variations. The only factor correlated with decreased disc height was T9 sagittal tilt: disc height decreased more when T9 sagittal tilt approached 0 degrees .nnnDISCUSSIONnIn this very restricted context (retrospective study, short arthrodesis for degenerative spondylolisthesis), we were unable to find any evidence supporting the notion that high disc height is an argument which should favor complementary intersomatic arthrodesis in combination with posterolateral fusion. Analysis of the spinal balance in the sagittal plane would probably allow a more pertinent assessment of the specific needs of individual patients.

Thoracolumbar junction lateral spine dislocation.

The authors describe a case of traumatic lateral spine dislocation at the thoracolumbar junction level, without fracture, in a healthy young adult, complicated by a complete neurological deficit. The main aspects of surgical management are discussed based on a review of the literature. Control of the spinal cord is a mandatory first step, before reduction, independently of neurological deficits considerations. Instrumented stabilization and fusion are achieved thereafter; levels selection for instrumentation and fusion depends on the injury location.

An unusual Hangman's fracture: description and surgical management.

C2 pedicles, or Hangmans fracture and Tear-Drop fracture, have until now been described as two distinct entities, the former caused by extension-distraction and the latter by compression-flexion mechanisms. The present clinical case combined these two fracture types of the second cervical vertebra (C2), without neurologic complication. Surgical management reduced and stabilized the lesions of the bone and of the mobile segment between C2 and C3. A right-side subhyoid presternocleidomastoid approach was selected, the main deformity lying between the body of the second and third cervical vertebrae.