Charles Court

The effect of static in vivo bending on the murine intervertebral disc

BACKGROUND CONTEXT Intervertebral disc cell function in vitro has been linked to features of the local environment that can be related to deformation of the extracellular matrix. Epidemiologic data suggest that certain regimens of spinal loading accelerate disc degeneration in vivo. Yet, the direct association between disc cell function, spinal loading and ultimately tissue degeneration is poorly characterized. PURPOSE To examine the relationships between tensile and compressive matrix strains, cell activity and annular degradation. STUDY DESIGN/SETTING An in vivo study of the biologic, morphologic and biomechanical consequences of static bending applied to the murine intervertebral disc. SUBJECT SAMPLE: Twenty-five skeletally mature Swiss Webster mice (12-week-old males) were used in this study. OUTCOME MEASURES Bending neutral zone, bending stiffness, yield point in bending, number of apoptotic cells, annular matrix organization, cell shape, aggrecan gene expression, and collagen II gene expression. METHODS Mouse tail discs were loaded for 1 week in vivo with an external device that applied bending stresses. Mid-sagittal sections of the discs were analyzed for cell death, collagen II and aggrecan gene expression, and tissue organization. Biomechanical testing was also performed to measure the bending stiffness and strength. RESULTS Forceful disc bending induced increased cell death, decreased aggrecan gene expression and decreased tissue organization preferentially on the concave side. By contrast, collagen II gene expression was symmetrically reduced. Asymmetric loading did not alter bending mechanical behavior of the discs. CONCLUSIONS In this model, annular cell death was related to excessive matrix compression (as opposed to tension). Collagen II gene expression was most negatively influenced by the static nature of the loading (immobilization), rather than the specific state of stress (tension or compression).

Surgical excision of bone sarcomas involving the sacroiliac joint.

Each author certifies that his institution has approved or waived approval for the human protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research. Correspondence to: Charles Court, MD, Hôpital Bicêtre, 78, rue du Général Leclerc, 94270 le Kremlin Bicêtre Cedex, France. Phone: 033-1-45-21-34-92; Fax: 033-1-45-21-22-50; E-mail: charles.court@bct.ap-hop-paris.fr. Adequate (wide or marginal and uncontaminated) margins and reconstruction are difficult to achieve when performing an internal hemipelvectomy for bone sarcomas involving the sacroiliac joint. We evaluated whether adequate surgical margins could be achieved and if functional outcomes could be predicted based on the type of resection and reconstruction. Forty patients had resections of the sacroiliac joint. Vertical sacral osteotomies were through the sacral wing (n = 2), ipsilateral sacral foramina (n = 27), sacral midline (n = 9), or contralateral foramina (n = 2). Iliac resections were Type I, Type I-II with partial or total acetabular re-section, or Type I-II-III. Surgical margins were adequate in 28 of 38 patients (74%), two (7%) of whom experienced local recurrence, compared with seven of 10 (70%) patients with inadequate margins. Reconstruction consisted of restoring continuity between the spine and pelvis. Resection of the entire acetabulum and removal of the lumbosacral trunk were the two main determinants of function, as assessed using the Musculoskeletal Tumor Society score. There were no life-threatening or function-threatening complications. Internal hemipelvectomy with a limb salvage procedure can be achieved with adequate surgical margins in selected patients. Functional outcomes can be predicted based on the type of resection and reconstruction, which helps the surgeon plan the procedure and inform the patient.Level of Evidence: Level IV Therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Minimally invasive posterior surgery for thoracolumbar fractures. New trends to decrease muscle damage

High-energy spine fractures mainly affect the thoracolumbar junction. Surgery helps restore spine stability and sagittal realignment and improves long-term outcomes of patients. Posterior instrumentation ensures stability in most cases, some patients with unstable fractures benefitting from an additional anterior approach. This article discusses the indications for surgery with a view to conservative treatment and presents the advantages of posterior and anterior approaches. It also describes posterior, minimally invasive surgical techniques that have been developed in the past decade. In the light of scientific arguments, posterior minimally invasive surgery, combined with balloon-assisted vertebroplasty (or kyphoplasty) when necessary, appears to be at least as efficient as other posterior techniques, including open surgery. It has the advantage of being less aggressive towards soft tissues and of generating fewer complications than open surgery. Minimally invasive surgery may have better long-term outcomes for patients and may be cost-effective for health budgets, but these points need to be confirmed by further investigations.

Real-time and Spatial Quantification Using Contrast-enhanced Ultrasonography of Spinal Cord Perfusion During Experimental Spinal Cord Injury

Study Design. Experimental study in male Wistar rats. Objective. To quantify temporal and spatial changes simultaneously in spinal cord blood flow and hemorrhage during the first hour after spinal cord injury (SCI), using contrast-enhanced ultrasonography (CEU). Summary of Background Data. Post-traumatic ischemia and hemorrhage worsen the primary lesions induced by SCI. Previous studies did not simultaneously assess temporal and spatial changes in spinal cord blood flow. Methods. SCI was induced at Th10 in 12 animals, which were compared with 11 sham-operated controls. Spinal cord blood flow was measured in 7 adjacent regions of interest and in the sum of these 7 regions. Blood flow was quantified using CEU with intravenous microbubble injection. Spinal cord hemorrhage was measured on conventional B-mode sonogram slices. Results. CEU allowed us to measure the temporal and spatial changes in spinal cord blood flow in both groups. In the SCI group, spinal cord blood flow was significantly decreased in the global region of interest (P = 0.0016), at the impact site (epicenter), and in the 4 regions surrounding the epicenter, compared with the sham group. The blood flow decrease was maximum at the epicenter. No statistically significant differences between the sham groups were found for the most rostral and caudal regions of interest. Hemorrhage size increased significantly with time (P < 0.0001), from 30.3 mm2 (±2) after 5 minutes to 39.6 mm2 (±2.3) after 60 minutes. Conclusion. CEU seems reliable for quantifying temporal and spatial changes in spinal cord blood flow. After SCI, bleeding occurs in the spinal cord parenchyma and increases significantly throughout the first hour.

Isolated thoracic spine lesion: is this the presentation of a SAPHO syndrome? A case report.

A case of an isolated lesion of the thoracic spine attributed to SAPHO syndrome is presented. A 51-year-old man was referred for inflammatory pain in the thoracic spine. The general examination was normal (especially cutaneous and rheumatologic examinations). Laboratory analysis showed only a mild inflammatory reaction. Standard radiographs showed partial condensation of T8. Computed tomography showed osteolysis of the anterior corner of T8, and MRI revealed an abnormal signal of T8, with enlargement of the prevertebral soft tissue. Percutaneous and thoracoscopic biopsies showed a nonspecific inflammatory process, and cultures were sterile. Initially, several diagnoses were advanced: infectious spondylitis, malignant tumor, lymphomas, Paget disease, seronegative spondyloarthropathies and finally atypical SAPHO syndrome. Three months later, the patient experienced more pain. General examination was still normal. The radiological findings worsened, while the inflammatory blood tests were normal. A new thoracoscopic biopsy revealed a nonspecific inflammatory process. A diagnosis of SAPHO syndrome was made, despite the lack of typical lesions. Dramatically improving with anti-inflammatory therapy, the patient’s condition was favorable at 3-year follow-up. This atypical presentation of an isolated lesion in the spine makes the diagnosis of a SAPHO syndrome difficult but possible. Spine surgeons must be aware of this rare entity, to avoid misdiagnosis and unnecessary repeated surgical biopsies.

Interest of Denosumab for the Treatment of Giant-cells Tumors and Aneurysmal Bone Cysts of the Spine. About Nine Cases.

Study Design. A prospective cohort study. Objective. The aim of this study was to evaluate the interest of denosumab in the treatment of spinal giant-cells tumors (GCTs) and aneurysmal bone cysts (ABCs). Summary of Background Data. To treat GCTs and ABCs, surgical resection remains the best treatment to limit local recurrence (LR) but constitutes an aggressive treatment with potential morbidity. Denosumab, a human antibody anti-RankL, inhibiting the differentiation of osteoclasts, could be an alternative treatment to avoid aggressive surgery. Methods. Patients suffering from GCTs and ABCs of the spine were included. Patients received a monthly subcutaneous injection of denosumab (120 mg) during a minimum of 6 months either as a neoadjuvant or as an adjuvant therapy. In association with denosumab, an osteosynthesis was added in case of vertebral fracture and a laminectomy in case of spinal cord compression. Clinical and computed tomography (CT)-scan outcomes were analyzed. Results. Eight GCTs and one ABC were included. The mean age was 35 years (range: 22–55 yr). Five patients had neurologic deficit. All patients were operated: six osteosynthesis, one “en bloc” resection, four curettages, and two of them associated with an osteosynthesis. Average duration of denosumab therapy was 12.9 months (range: 3.2–24 months). Among them, four patients began denosumab 6 months at least before the surgery. With a mean follow-up of 19.3 months (range: 3.2–52.4 months), back pain and neurologic deficit improved for all patients. Systematic CT-scan at 6 months showed decrease of tumor size and bone consolidation. Regarding patients treated by neoadjuvant denosumab treatment, intraoperative histologic analysis showed an absence of giant cells and a maximum of 10% of alive tumor cells. Conclusion. Denosumab allows bone formation and tumor regression with a maximum efficacy after 6 months of treatment without widely substituting surgery. Long-term results are mandatory to confirm the interest of denosumab and to evaluate LR when stopping denosumab. Level of Evidence: 3

Preoperative imaging study of the spinal cord vascularization: Interest and limits in spine resection for primary tumors

The necessicity to localize the anterior spinal arteries before anterior approach of the spine stays controversial by orthopaedic surgeons. On the other hand the surgical treatment of thoracoabdominal aneurisms routinely sacrifices many segmental arteries pairs without spinal arteries localization. This, associated with spinal cord protection, results to few neurological complication. However, during vertebrectomies, the roots ligation completely interrupts the spinal cord blood supply at this level. In our experience the spinal arteries localization was systematically done before ninety-eight spine resections. In five cases an anterior radiculomedullary artery was ligated (four anterior radiculomedullary and one great anterior radiculomedullary arteries) without neurological complication, in two cases of extended resection (more than four levels) a neurological complication occurred. No spinal artery was identified at the resection level and the neurological complications were resolutive and did not seem related to definitive vascular problem. These accomplishments lead to discuss the importance of spinal arteries localization and preservation in this surgery. The discovery of an anterior radiculomedullary artery is not a contraindication to en-bloc vertebrectomy at this level, nevertheless in the case of great anterior radiculomedullary artery (Adamkiewicz) the surgical indication must be seriously debated. In fact, this case and those where multilevel resections (more than three levels) are indicated seem the most dangerous situations and the use of the different means of spinal cord protection could be indicated to decrease neurological risk. So before spine resection the spinal arteries localization could improve patient information and give more deciding factors for planning treatment.

Interest of Laparoscopy for "En Bloc" Resection of Primary Malignant Sacral Tumors by Combined Approach: Comparative Study With Open Median Laparotomy.

Study Design. Retrospective case-control study. Objective. To compare laparoscopy with open median laparotomy for anterior approach in “en bloc” resection of primary malignant sacral tumors (PMST) in combined approach strategy. Summary of Background Data. Wide margin surgical resection is the “gold standard” treatment of PMST. Methods. Two groups of patients suffering from PMST and operated for “en bloc” resection by combined approach (anterior and posterior) only differencing for the anterior approach were constituted: “laparoscopy” group (n = 11) and “laparotomy” group (n = 22). Intraoperative morbidity (blood loss, red blood cell transfusion (RBC transfusion), surgical procedure duration) and postoperative morbidity (surgical-site infection (SSI), perineal dysfunctions, local recurrence) were analyzed. Surgical margins were studied. Data of both groups were compared using nonparametric Mann–Whitney test for continuous data and Fisher test for categorical data. Overall survival (OS) and Disease-free survival (DFS) were analyzed by Kaplan–Meier method. Results. Blood loss during anterior approach was less important in “laparoscopy” group 71.9 mL (range 0–400 mL) as compared with 2140 mL (range 0–9000 mL) for “laparotomy” group (P = 0.019). Blood loss during posterior approach was not different between the 2 groups. Total blood loss including anterior and posterior approach was inferior in “laparoscopy” group 2208 mL (range 230–4800 mL) versus 5385.7 mL (range 1400–11500 mL) for “laparotomy” group (P = 0.026). We reported significant difference on blood transfusion (3.7 RBC transfusions (range 0–8) for “laparoscopy group” versus 10.1 RBC transfusions (range 0–35) for “laparotomy” group (P = 0.025)). Surgical duration, quality of surgical margins, perineal dysfunctions and SSI were equivalent for both groups. At a follow-up of 36.6 months for “laparoscopy” group and 115.3 months for “laparotomy” group, OS and DFS were equivalent. Conclusion. Use of laparoscopy for anterior approach decreases intraoperative blood loss and intraoperative RBC transfusion without increasing surgical duration, without altering the quality of surgical margins and without impairing long-term outcomes. Level of Evidence: 4

Ligamentoplastie à double faisceau de la membrane interosseuse de l’avant-bras – évaluation anatomique et biomécanique

Introduction L’avant-bras est une structure mobile permettant le positionnement spatial de la main. Cette fonction implique que l’avant-bras soit a la fois mobile et stable. Or cette stabilite peut etre entierement compromise en cas de syndrome d’Essex-Lopresti associant une rupture de la membrane interosseuse et du complexe fibrocartilagineux triangulaire du poignet. Afin de restaurer la stabilite antebrachiale nous avions decrit une ligamentoplastie verticale de la MIO consistant a implanter un transplant unique entre le radius et l’ulna. L’application de cette technique en pratique clinique a montre un effet satisfaisant sur la stabilite longitudinale de l’avant-bras mais un effet mediocre sur la stabilite transversale. Nous avons donc fait l’hypothese que l’implantation d’un deuxieme transplant transversal (double ligamentoplastie) etait techniquement possible et permettait de restaurer a la fois les stabilites longitudinale (SL) et transversale (ST) des articulations radio-ulnaires proximale (RUP) et distale (RUD). L’objectif principal de ce travail etait de confirmer cette hypothese. Materiel Douze avant-bras de cadavres frais indemnes de lesions innees ou acquises. Methodes Dans la premiere partie biomecanique de l’etude nous avons isole l’avant-bras qui a ete installe dans un cadre specifique permettant de quantifier l’amplitude de prono-supination ainsi que d’evaluer la SL et les ST des RUP et RUD. Ces stabilites ont ete testees pour cinq configurations successives de l’avant-bras - intact, completement destabilise (equivalent de syndrome d’Essex-Lopresti), ligamentoplastie verticale unique, ligamentoplastie transversale unique, double ligamentoplastie. Dans la deuxieme partie anatomique de l’etude, la double ligamentoplastie etaient realisee en conditions similaires a une intervention realisee chez le patient. Ensuite, une dissection exhaustive des nerfs, vaisseaux et tendons de l’avant-bras etait effectuee a la recherche de lesions induites par la realisation de la double ligamentoplastie. Resultats La ligamentoplastie verticale unique restaurait la SL mais n’avait qu’un effet faible sur les ST des RUP et RUD. La double ligamentoplastie restaurait completement la SL ainsi que les ST des RUP et RUD sans reduction significative de l’amplitude de prono-supination. Aucune lesion neurovasculaire ou tendineuse n’a ete identifiee apres realisation de la double ligamentoplastie. Discussion Les lesions de type Essex-Lopresti representent encore un defi therapeutique aux consequences fonctionnelles souvent catastrophiques. La realisation de cette double ligamentoplastie est techniquement complexe mais offre la possibilite de traiter ces lesions. Conclusion Cette technique doit maintenant etre evaluee cliniquement. Un premier cas a pu etre effectue avec un resultat tres encourageant.

OUTCOMES OF EN BLOC RESECTION OF NON-SMALL CELL LUNG CANCER (NSCC) INVADING THE THORACIC INLET (TI) AND INTERVERTEBRAL FORAMINA (IF)

Background: NSCC invading the TI and IF have been considered surgically unresectable leading to a one-year mortality rate of 100% with chemotherapy and radiotherapy Purpose: To assess operative mortality, morbidity, and long-term results of patients with surgically resected NSCC invading the TI and IF. Methods: From 1981 to 2006, 28 patients had a two stage procedure.Through the transcervical approach, resectability was controlled and tumor-bearing structures were dissected, leaving tumor-free margins. Standard upper lobectomy was performed, leaving the lobe in place. Then, a posterior approach was used for spine instrumentation, multilevel unilateral laminectomy and vertebral body osteotomy. The tumor was removed en bloc with the spine, lung, ribs, and vessels through the posterior incision. Results: There were 17 men and 11 women with a mean age of 48.7 years (37–71). 14 patients underwent neoadjuvant therapy and 18 patients received adjuvant therapy. Upper lobectomy was performed in 25 cases, wedge resection in 2 and pneumonectomy in 1, combined with resections of the phrenic nerve in 7 cases and subclavian artery in 8 cases. Hemivertebrectomies at 3and 4-level were done in 17 and 7 cases, respectively; 2-and 3-level total vertebrectomies and 2-level hemivertebrectomies were done in 1 case each respectively. There were no perioperative deaths or neurologic complications. Postoperative complications were pneumonia (n 8), pulmonary edema (n 2), cerebrospinal fluid leakage (n 1), deep infection (n 1), empyema (n 2), paradoxical breathing requiring reintubation (n 2) and bleeding necessitating reoperation (n 3). Resection was complete in 25 (89.2%) patients. The overall 5-year survival was 27.2%. Recurrence was observed in 16 patients; systemic in 10, local in 5 and both in one. Conclusions: NSCC invading the TI and IF can be removed en bloc through a combined anterior transcervical and posterior midline approach, with superior survival rate than non surgical treatment. I N T E R N A T I O N A L S O C I E T Y F O R T H E S T U D Y O F L U M B A R S P I N E