Pierre Guigui

Radiographic analysis of the sagittal alignment and balance of the spine in asymptomatic subjects

BACKGROUND There is an increasing recognition of the clinical importance of the sagittal plane alignment of the spine. A prospective study of several radiographic parameters of the sagittal profile of the spine was conducted to determine the physiological values of these parameters, to calculate the variations of these parameters according to epidemiological and morphological data, and to study the relationships among all of these parameters. METHODS Sagittal radiographs of the head, spine, and pelvis of 300 asymptomatic volunteers, made with the subject standing, were evaluated. The following parameters were measured: lumbar lordosis, thoracic kyphosis, T9 sagittal offset, sacral slope, pelvic incidence, pelvic tilt, intervertebral angulation, and vertebral wedging angle from T9 to S1. The radiographs were digitized, and all measurements were performed with use of a software program. Two different analyses, a descriptive analysis characterizing these parameters and a multivariate analysis, were performed in order to study the relationships among all of them. RESULTS The mean values (and standard deviations) were 60 degrees 10 degrees for maximum lumbar lordosis, 41 degrees +/- 8.4 degrees for sacral slope, 13 degrees +/- 6 degrees for pelvic tilt, 55 degrees +/-10.6 degrees for pelvic incidence, and 10.3 degrees +/- 3.1 degrees for T9 sagittal offset. A strong correlation was found between the sacral slope and the pelvic incidence (r = 0.8); between maximum lumbar lordosis and sacral slope (r = 0.86); between pelvic incidence and pelvic tilt (r = 0.66); between maximum lumbar lordosis and pelvic incidence, pelvic tilt, and maximum thoracic kyphosis (r = 0.9); and, finally, between pelvic incidence and T9 sagittal offset, sacral slope, pelvic tilt, maximum lumbar lordosis, and thoracic kyphosis (r = 0.98). The T9 sagittal offset, reflecting the sagittal balance of the spine, was dependent on three separate factors: a linear combination of the pelvic incidence, maximum lumbar lordosis, and sacral slope; the pelvic tilt; and the thoracic kyphosis. CONCLUSIONS AND CLINICAL RELEVANCE This description of the physiological spinal sagittal balance should serve as a baseline in the evaluation of pathological conditions associated with abnormal angular parameter values. Before a patient with spinal sagittal imbalance is treated, the reciprocal balance between various spinal angular parameters needs to be taken into account. The correlations between angular parameters may also be useful in calculating the corrections to be obtained during treatment.

Complications and risk factors of primary adult scoliosis surgery: a multicenter study of 306 patients.

Study Design. A multicentric retrospective study on primary adult scoliosis patients operated on between 2002 and 2007. A 3-step statistical analysis was performed to describe the incidence of complications, the risk factors, and the reoperation risk with survival curves for the entire cohort. Objective. To describe complication rate and risk factors as well as survival curves associated with adult primary scoliosis surgery in patients aged 50 years or older. Summary of Background Data. Adult deformity surgery is classically associated with a high rate of complications. The identification of risk factors for developing such complications is consequently of major interest as well as survival curves that can provide useful information on reoperation risks. Although many reports exist in the literature, the cohorts analyzed are often heterogeneous and the actual prevalence of complications varies widely. This study represents to our knowledge the largest series on adult patients aged 50 years or older operated for the first time for lumbar or thoracolumbar scoliosis and excluding every other possible diagnosis. Methods. A retrospective review of prospectively collected data from 6 centers in France. A total of 306 primary lumbar adult or degenerative scoliosis patients older than 50 years undergoing surgery between 2002 and 2007 were included. Demographics, comorbidities, x-ray parameters, surgical data, and complications were analyzed. Statistical analysis was performed to obtain correlations and risk factors for developing complications. Reoperation risk was calculated with Kaplan-Meier survival curves. Results. A total of 306 patients aged 63 years (range, 50–83), with 83% women. Mean follow-up was 54 months. Mean Cumulative Illness Rating Scale score was 5 (range, 0–26). Main curve was 50° (range, 4–96) with apex between T12 and L2. Ten percent of patients had anterior surgery only, 18% had double anteroposterior approach, and 72% had posterior surgery only. Seventy-four percent (226 patients) had long fusions of 3 or more levels and 44% (134 patients) were fused to the sacrum. Forty percent (122 patients) had a decompression performed and 18% had an osteotomy. There were 175 complications for 119 patients (39%). No cases of death or blindness were reported. General complication rate was 13.7%, early infection occurred in 4% (12 patients), and late infection occurred in 1.2%. Neurological complications were present in 7% with 2 cases (0.6%) of late cord-level deficits and 12 reoperations (4%). Prevalence of mechanical complications was 24% (73 patients), with 58 patients (19%) needing a reoperation. Risk factors for mechanical or neurological complications were number of instrumented vertebra (P ⩽ 0.01) fusion to the sacrum (P ⩽ 0.001), pedicle subtraction osteotomy (PSO) (P = 0.01), and a high preoperative pelvic tilt of 26° or more (P ⩽ 0.05). Kaplan-Meier survival curves showed reoperation risk of 44% at 70 months. Long fusion risk was 40% at 50 months and fusions to the sacrum reoperation risk was 48% at 49 months. Conclusion. Overall complication rate was 39%, and 26% of the patients were reoperated for mechanical or neurological complications. Risk factors include number of instrumented vertebra, fusion to the sacrum, PSO, and preoperative pelvic tilt of 26° or more. There is a 44% risk of a new operation in the 6-year-period after the primary procedure.

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.

Camptocormia: the bent spine syndrome, an update

Camptocormia, also referred to as bent spine syndrome (BSS) is defined as an abnormal flexion of the trunk, appearing in standing position, increasing during walking and abating in supine position. BSS was initially considered, especially in wartime, as a psychogenic disorder. It is now recognized that in addition to psychiatric syndromes, many cases of reducible BSS have a somatic origin related to a number of musculo-skeletal or neurological disorders. The majority of BSS of muscular origin is related to a primary idiopathic axial myopathy of late onset, appearing progressively in elderly patients. Diagnosis of axial myopathy first described by Laroche et al. is based upon CT/MRI examination demonstrating massive fatty infiltration of paravertebral muscles. The non-specific histological aspect includes an extensive endomysial fibrosis and fat tissue with irregular degenerated fibers. Weakness of the paravertebral muscles can be secondary to a wide variety of diseases generating diffuse pathologic changes in the muscular tissue. BSS can be the predominant and sometimes revealing symptom of a more generalized muscular disorder. Causes of secondary BSS are numerous. They must be carefully assessed and ruled out before considering the diagnosis of primary axial myopathy. The principal etiologies include on the one hand inflammatory myopathies, muscular dystrophies of late onset, myotonic myopathies, endocrine and metabolic myopathies, and on the other hand neurological disorders, principally Parkinson’s disease. Camptocormia in Parkinsonism is caused by axial dystonia, which is the hallmark of Parkinson’s disease. There is no specific pharmacologic treatment for primary axial myopathy. General activity, walking with a cane, physiotherapy, and exercises should be encouraged. Treatment of secondary forms of BSS is dependent upon the variety of the disorder generating the muscular pathology. Pharmacologic and general management of camptocormia in Parkinson’s disease merge with that of Parkinsonism. Levodopa treatment, usually active on tumor rigidity and akinesia, has poor or negative effect on BSS.

Experimental model of posterolateral spinal arthrodesis in sheep. Part 2. Application of the model : evaluation of vertebral fusion obtained with coral (Porites) or with a biphasic ceramic (Triosite)

Objectives The authors evaluated two bone substitutes in a posterolateral spinal arthrodesis (PSA) model in sheep: coral porites (99% calcium carbonate, Biocoral@, Inoteb, France) and a biphasic ceramic (BCP) (65% hydroxyapatite and 35% B tricalcium phosphate, Triosite@, Zimmer International). Summary of Background Data Bone substitutes would be of great interest for PSA. Previous trials began with two kinds of biomaterials: natural coralline calcium carbonate, and phosphate calcium ceramic, Methods A lumbar PSA was performed in 11 sheep (coral group) and in 9 sheep (BCP group). Sacrifice and biomechanical tests were performed after 1 year. Results A large decrease of flexibility in all directions was obtained with both coral PSA and BCP PSA similarly to autologous graft. No nonfusion case was observed. Conclusion In conditions close to the human surgery, a PSA can be obtained using either coral porites or BCP as bone substitutes.

Acute spontaneous spinal epidural hematoma: an important differential diagnosis in patients under clopidogrel therapy

BACKGROUND CONTEXT Spontaneous spinal epidural hematoma (SSEH) is an infrequent spinal pathology. Although it is related to numerous risk factors, its etiology remains unclear. PURPOSE The aim of this article was to review the most important data in the literature about SSEH and to propose clopidogrel (Plavix) therapy as a risk factor. STUDY DESIGN Case report. METHODS A 79-year-old woman was hospitalized in our unit with posterior thoracic pain and urinary retention of 72 hours duration. A clinical history was taken, and laboratory and imaging tests were performed. Urgent surgical decompression was performed, showing an epidural hematoma. Postoperative bacteriological cultures were negative, and microscopic analysis confirmed the diagnosis. RESULTS For this patient, clopidogrel (Plavix) therapy was the only risk factor related to SSEH. CONCLUSIONS In any patient under clopidogrel (Plavix): Sanofi-Synthelabo, Bristol-Myers Squibb/Sanofi Pharmaceuticals) therapy and with a typical clinical presentation, SSEH should be suspected and quickly diagnosed, regardless of hemostatic status or the absence of other major risk factors.

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.

Traumatic atlantooccipital dislocation with survival: case report and review of the literature.

SummaryWe present the case of a patient with traumatic atlantooccipital dislocation. The initial neurological examination showed no abnormalities. Dislocation was the result of rapid deceleration in a motor vehicle accident. The mechanism of injury was hyperextension/rotation, probably combined with a distraction force. Only a few cases of atlantooccipital dislocation without neurological involvement have been reported. Every report pointed out difficulties of initial diagnosis. Special attention should be directed toward the atlanto-odontoid-basion relationships as seen on lateral radiographs. Prompt recognition and surgical stabilization are essential to avoid further neurological injury.

Early surgical site infections in adult spinal trauma: a prospective, multicentre study of infection rates and risk factors.

INTRODUCTION Spine surgery is known to have a high risk of surgical site infection (SSI). Multiple studies have looked into the risk factors and incidence of SSI during elective surgery, but only two retrospective studies have specifically evaluated SSI during surgery following spine trauma. MATERIALS AND METHODS This work was based on a prospective cohort study that included all the patients operated on for spinal trauma at 13 French hospitals over a three-month period. The main endpoint was the occurrence of a SSI during the three-month period. Patients with multiple trauma or open fractures were excluded from the study. RESULTS Of the 169 patients re-examined after a minimum of three months, six had had an acute SSI (3.55%). The following factors were significantly related to a SSI: age, ASA score, diabetes, procedure duration, delay elapsed between accident and procedure, number of levels fused, bleeding and prolonged presence of urinary catheter. DISCUSSION Our results were consistent with the published infection rates of 2 to 10%. The risk factors identified have all been described in previous studies on elective spine surgery. LEVEL OF EVIDENCE Level IV, prospective cohort study.