Cyril Dauzac

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.

Individual probability of allogeneic erythrocyte transfusion in elective spine surgery: the predictive model of transfusion in spine surgery.

Background:The aim of this study was to generate a score based on preoperative characteristics and predictive of the individual probability of allogeneic erythrocyte transfusion in patients undergoing elective thoracolumbar spine surgery. Methods:Two hundred thirty consecutive patients were retrospectively included over a 15-month period (derivation set). Preoperative independent predictors of erythrocyte transfusion from the day of surgery until postoperative day 5 were determined by multivariable analysis, from which a model of individual probability of transfusion was derived and prospectively validated in 125 additional patients (validation set). Results:Four preoperative independent predictors were associated with transfusion: age older than 50 yr (adjusted odds ratio = 4.9 [2–13.5]), preoperative hemoglobin level less than 12 g/dl (adjusted odds ratio = 6.9 [3.1–17.2]), fusion of more than two levels (adjusted odds ratio = 6.7 [3.1–15.2]), and transpedicular osteotomy (adjusted odds ratio = 19.9 [5.6–98.2]). A 0–4 score (0 = no risk, 4 = maximum risk) predictive of allogeneic transfusion was derived by weighting estimate parameters for each variable in a multivariable logistic regression model. Discriminating capacity of the score was 0.86 [0.81–0.92] in the receiver operating characteristics in the derivation sample and 0.83 [0.75–0.91] in the validation sample. The observed transfusion rates in the validation set and the individual probabilities of erythrocyte transfusion from the score were well correlated (y = 0.98x + 0.04; P < 0.0001), and the observed differences were not statistically different (goodness-of-fit chi-square, P = 0.125). The score was also correlated with the number of erythrocyte units transfused (Spearman &rgr; = 0.61; P < 0.0001). Conclusion:The Predictive Model of Transfusion in Spine Surgery may be useful in clinical practice to identify patients undergoing spine surgery at risk of massive bleeding and encourage erythrocyte-saving strategies in these patients.

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.

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.

Radiological assessment of lumbosacral dystrophic changes in high-grade spondylolisthesis

ObjectiveTo analyse radiographic correlates for the clinical status of patients and the deformation reducibility of high-grade lumbosacral spondylolisthesis. We also clarify the clinical and radiographic correlates of a new parameter for S1 dystrophy, the “S1 index”.Design and patientsOne hundred cases of high-grade isthmic lumbosacral spondylolisthesis were reviewed. We noted the dystrophic changes in the cranial sacral endplate, and the caudal endplate of L5. The severity of the spondylolisthesis was evaluated by measuring the lumbosacral kyphosis. The clinical status and the deformation reducibility (dependent on the stiffness of the deformation) were compared with these dystrophic patterns, the sagittal slope of S1 and S2 endplates and a sacral morphological marker, the S1 index.ResultsLumbosacral kyphosis was less severe in cases with dystrophic changes of the posterior cranial edge of S1 and/or of the posterior caudal edge of L5 but its reducibility was worse. These patients were more functionally impaired. We describe and analyse this situation as a partial lumbosacral disc failure responsible for the less severe L5 slipping. The S1 index was strongly correlated with the grade of slipping, the lumbosacral kyphosis and its reducibility. We noted the same configuration among patients with a smaller S1 index, i.e. vertical S1 and S2 vertebral bodies associated with more severe but more reducible lumbosacral kyphosis.ConclusionAnalysing specific criteria, we think it is possible to note progressive dystrophic changes according to the natural history of lumbosacral spondylolisthesis. We think that repeated measurements of these morphological parameters in patients diagnosed with a low-grade lumbosacral spondylolisthesis could be helpful in the early detection of evolving lumbosacral kyphosis and L5 slipping.

CT evaluation of torsional malalignment after intertrochanteric fracture fixation.

INTRODUCTION Trochanteric fractures are commonly stabilized either by intramedullary nailing or plate and screw fixation after reduction on the orthopaedic surgical table under radiological guidance. HYPOTHESIS Closed trochanteric fracture anatomic reduction is difficult in the transversal plane. OBJECTIVES The objective of this prospective study was to assess the rotational malalignment induced after reduction and osteosynthesis of trochanteric fractures. PATIENTS AND METHODS Prospective study including 40 patients (mean age, 78 years; range, 51-90 years) operated for a trochanteric fracture between January 2007 and September 2008. Fourteen fractures were treated using DHS™ (Synthes™) plate and screw fixation and 26 with intramedullary nailing (trochanteric nail™, Stryker™). All these patients underwent postoperative CT of the pelvis during their hospitalization with measurement of anteversion of the operated and healthy femoral necks at the posterior condyles. The evaluation criterion was whether or not there was malalignment greater than 15° on the operated side compared to the healthy side. RESULTS The mean anteversion was 14.2° for the healthy side and 23° for the operated side. The mean rotational malalignment was 15.3°. Forty percent of the rotational malalignments were greater than 15°, with a majority of cases showing excess internal rotation (35%) of the distal fragment. CONCLUSION AND DISCUSSION The rate of internal rotational malalignment of the distal fragment greater than 15° was high (40% of this series). This should encourage surgeons to reduce the excess internal rotation that tends to be attributed to the distal fragment during preoperative reduction of these fractures. LEVEL OF EVIDENCE Level III. Prospective diagnostic study with no control group.

[Superior mesenteric artery syndrome following correction of spinal deformity: case report and review of the literature].

Superior mesenteric artery syndrome is a rare complication which can develop after surgical correction of a spinal deformity. The syndrome is caused by an extrinsic compression on the third portion of the duodenum by the aorta posteriorly and the mesenteric artery anteriorly. We report here a case of aortomesenteric compression of the duodenum secondary to surgical correction of lower thoracic scoliosis in a 19-year-old female. The patient presented vomiting and intestinal obstruction ten days after spinal surgery. Treatment consisted in exclusive parenteral nutrition followed by careful surveillance and progressive reintroduction of oral food intake to avoid unnecessary surgery. Young thin subjects are predominantly exposed to this type of complication. The body mass index is a good indication to identify subjects at risk. Symptoms of upper gastrointestinal obstruction develop seven to ten days after surgery. Diagnosis is based on transit studies using a hydroluble contrast agent which reveals major gastric dilation and a clear interruption of the transit at the level of the third duodenum as well as retrograde peristaltism. Medical treatment should be undertaken first and is effective in the large majority of cases. Surgery may be proposed only in the event of failure. Recurrence is exceptional. Early diagnosis, delivery of clear information for the patient and family and multidisciplinary management are important points to consider for proper care for this complication which if neglected can become life-threatening.

Hydatid disease drug therapy primarily to reconstruction of a multilevel thoracolumbar vertebral lesion

We report, a very unusual case of multilevel vertebral hydatidosis adjacent to the thoracolumbar junction, without concomitant chord compression. Two months after initiating oral antiparasite treatment, the patient underwent resection of the lesion using a posterior approach, medullary decompression, and a T11-L3 instrumented arthrodesis. Arthrodesis via the anterior approach was performed at a later stage. In addition to its diagnostic value, this case raises renewed discussion about single-level lesions given their rarity: their indication for preoperative medullary angiography, their indication for circumferential surgery, the timing of medical treatment, and the strategy to implement for the residual lesions.

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

PURPOSE OF THE STUDY Experimentally, 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. MATERIALS AND METHODS In 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. RESULTS At 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 . DISCUSSION In 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.

Un cas d’hémangiome épithélioïde du rachis

Epithelioid hemangioma is a rare and benign vascular tumor, most often occurring in the skin. Numerous other localizations, including bones, have been reported. The overall favorable clinical outcome of cutaneous epithelioid hemangioma is now well documented, but it still remains debated in osseous localization, as local recurrences and metastases have been described. We report a case of epithelioid hemangioma of the spine occurring in a 25-year-old male, and discuss main differential diagnoses. Recent studies tend to demonstrate that osseous epithelioid hemangioma, as cutaneous epithelioid hemangioma, should be considered as a benign tumor. Histologically, epithelioid hemangioma consists of a vascular proliferation with diffuse or lobular pattern and features vascular spaces lined by epitheliod endothelial cells with numerous lymphocytes and eosinophils. The main differential diagnosis is represented by epithelioid hemangioendothelioma, the surgical treatment of which must be more aggressive. Precise histological diagnosis is essential for accurate clinical management and to avoid overtreatment.