PubMed Health⌕ Search

Biomedical subjects

J J Abitbol

Publications and source records attributed to J J Abitbol.

At least 19 recordsLinked to original sources
PubMed1994

Preventing postlaminectomy adhesion. A new experimental model.

STUDY DESIGN: The efficacy of various interpositional membranes for prevention of extradural adhesion was investigated by a new animal model that quantified the biomechanical effect of scar formation. Twenty-one dogs were treated with autologous free fat graft, hyaluronic acid or no interpositional membrane after undergoing two-level laminotomy, nerve root exploration, and disk injury. An additional 11 dogs that did not undergo spine surgeries served as control animals. OBJECTIVES: Inter-animal variability in inherent propensity to form scar was first measured before any spine surgery. Twelve weeks after spine surgery, the lumbosacral spine of each dog was harvested en bloc for biomechanical testing of extradural adhesion ultimate load. Scar stiffness coefficient was also calculated. SUMMARY OF BACKGROUND DATA: Adhesion ultimate load was significantly less in the nonoperative control group when compared with the fat graft and no interpositional membrane group, but not when compared with the hyaluronic acid group. A beneficial effect of hyaluronic acid in lowering adhesion ultimate load was demonstrated, although a statistically significant difference from the fat graft and no interpositional membrane groups was not reached. No difference in scar stiffness coefficient was found between the four groups. METHODS: A new experimental model allowing objective biomechanical quantification of the effect of postoperative scar was described. Ultimate load of adhesions to both nerve roots and dura was measured. A biochemical assay that determined collagen content was also used to assess inter-animal propensity to form scar after a standardized surgical insult. Results were compared with other relevant studies. RESULTS: Findings suggest a beneficial effect of hyaluronic acid in decreasing the biomechanical strength of extradural adhesions following laminotomy, nerve root exploration, and disk injury when compared with use of fat graft or no interpositional membrane. These results support other recent investigations that study the use of hyaluronic acid treatment in a laminectomy model. The adverse consequence of intraoperative epidural bleeding was also demonstrated. CONCLUSIONS: The new experimental model described in the current study was reproducible and permitted objective quantification of the effect of postoperative adhesion rather than measuring its mere presence. A beneficial effect of hyaluronic acid treatment and a lack of such beneficial effect of free fat graft interpositional membrane was suggested. The importance of avoiding active epidural bleeding was also evident.

Adipose Tissue↗
PubMed1993

Cervical stability after sequential capsule resection.

A portion of the cervical facet joint must be resected to expose and decompress cervical nerve roots from a posterior approach. When posterior fusion is performed, it is common to remove the facet capsule only for the joints being fused. This study was performed to examine the effect of resection of the facet capsule alone, without disruption of the bony facet to determine what degree of facet-capsule resection leads to acute instability. Seven human cervical cadaveric spines were used in the experiment. Nondestructive biomechanical testing was performed in axial load, flexion, extension, and torsion. Each specimen was tested intact and after sequential resection of 25%, 50%, 75%, and 100% of the C5-6 facet capsules. Axial stiffness changed very little during the experiment. In torsion, the displacement increased 1% after a 25% capsule resection, 19% after a 50% resection, and 25% after a 75% or 100% resection. No gross subluxation was seen during the torsional test. In the flexion test, posterior displacement increased 4% after a 25% resection, 5% after a 50% resection, 32% after a 75% resection, and 22% after a 100% resection. There was a statistically increased displacement seen during the flexion test after 75% or 100% of capsule resection. Thus, significant hypermobility did occur during both torsion and flexion testing with greater than 50% resection of the facet capsules. Great care should be taken when exposing an unfused facet to limit facet-capsule resection to less than 50%. With resection of greater than 50% of the capsule, postoperative hypermobility can occur and may require stabilization.

Biomechanical Phenomena↗
PubMed1993

The effects of depth of penetration, screw orientation, and bone density on sacral screw fixation.

Obtaining adequate sacral fixation is an important and challenging clinical problem. Bicortical screw fixation has been used to provide improved mechanical strength. The goal of this study was to evaluate the effects of depth of penetration (unicortical versus bicortical), orientation (medial versus lateral), and bone density on the strength of the bone-screw interface. Seven-millimeter Steffee screws (Acromed, Cleveland, Ohio) were placed in human cadaveric sacra. The screws were placed either medially into the centrum of the S1 body or laterally into the sacral ala. The fixation systems used, either bicortical or unicortical, were tested on a Universal testing machine. The specimens were loaded to failure and biomechanical parameters were measured. Medially oriented screws sustained the highest load to failure. In an older population, unicortical fixation sustained load to failure and initial compliance findings were similar to those for bicortical fixation. The regional bone density in the centrum of the first sacral body was denser than that in the lateral alar region, and also provided more rigid bone screw fixation.

Aged↗
PubMed1993

Anterior spinal fixators. A biomechanical in vitro study.

In vitro calf spine testing was performed in flexion, rotation, and axial load, using a vertebral body corpectomy and anterior iliac crest bone grafting model. Anterior spinal fixation devices then were sequentially tested, and axial stiffness, torsional stiffness, and flexural strain determined. The constructs tested were the Contoured Anterior Spinal Plate (CASP), the Kaneda device, the Kostuik-Harrington device (KH), and the Texas Scottish Rite Hospital (TSRH) vertebral body screw construct. In torsion, the Kaneda device returned spinal stability to that of the intact spine. The Kostuik-Harrington device was unstable in torsion. In axial loading and flexion, the Kaneda device and the TSRH construct proved the most stiff, with the KH and CASP systems significantly lower in stiffness. The authors believe that the Kaneda device and the TSRH vertebral body screw construct are effective in restoring acute stability to the lumbar spine after corpectomy.

Animals↗
PubMed1993

Vertebral collapse with quadraparesis due to metastatic gliobla multiforme: case report and review of the literature.

A case is reported of a patient rendered quadraparetic following collapse of a cervical vertebra due to neoplastic invasion by metastatic glioblastoma multiforme. The case is discussed in light of a review of the world literature regarding the clinical incidence and significance of metastasis of glial tumors. It is recommended that all patients with high grade glial tumors who complain of back pain be evaluated with plain radiographs and MRI of the spine or 99Tc bone scan. The management of pathologic spine fractures from metastatic glial tumors with accompanying spinal instability or spinal cord compression due to intracanalicular bone should aim for immediate surgical decompression and stabilization followed by involved field irradiation.

Adult↗
PubMed1992

Screw fixation in the human sacrum. An in vitro study of the biomechanics of fixation.

A load-to-failure test was used to study the biomechanical properties of sacral screw fixation in human cadaveric specimens. The goals of this study were 1) to determine the effects of the two commonly chosen sacral screw orientations of fixation characteristics; 2) to determine the effects of selected screw-instrumentation linkages on the biomechanics of sacral screw fixation; 3) to correlate the biomechanical properties with a noninvasive assessment of sacral bone density; and 4) to correlate the torque during screw insertion with these biomechanical properties. The bone density of each specimen was measured with quantitative computed tomography. A screw was inserted from the dorsal surface either anteromedially or anterolaterally into the body of S1, and the torque needed to insert each screw was measured. The screw head was attached to a constrained or semiconstrained loading linkage. Force was applied to the screw in an inferior direction until the maximum load was achieved. The maximum load, screw translation, rotation at maximum load, and initial compliance of the bone-screw interface were determined. It was found that the anteromedial screw orientation, combined with a rigidly constrained loading linkage, resulted in the greatest maximum load to failure, the least screw rotation, and the least initial compliance of the four groups studied. The maximum load and the initial stiffness of bone-screw fixation increased significantly with bone density. Torque measurements correlated significantly with maximum load to failure, initial interface stiffness, and bone density. It was therefore concluded that bone density and torque measurements can be useful in assessing sacral screw fixation.

Aged↗
PubMed1992

Can burst fractures be predicted from plain radiographs?

Plain radiographs of 67 acute spinal compression fractures in 49 patients were analysed by subjective and objective criteria, using CT scans as the diagnostic standard for the diagnosis of burst fracture. Discriminant analysis correctly predicted the type of fracture in 88% of cases. Burst fractures, however, were almost as frequently misdiagnosed as being wedge compression fractures using this technique, compared with the reading of 25 films from patients without previous information. A quarter of the injuries would have been misdiagnosed had reliance been placed solely on the plain radiographs. CT scans of all patients with acute spinal compression fractures should be considered to decrease this potentially serious diagnostic error.

Diagnosis, Differential↗
PubMed1992

Complications of anterior intervertebral grafting.

Reconstruction of the spine after anterior decompression is essential to restore stability and function. A variety of materials and methods are available to reconstitute the vertebral column. Numerous complications of anterior grafting have been identified, and include failure of the graft, graft extrusion, nonunion, and infection. The clinical severity of these complications vary. The use of spinal instrumentation has helped to address some of these problems. Although certain problems are the result of faulty decision making or technical error, others are related to the severity of the patient's disease and the limitations of grafting materials. Some complications can be avoided while others can be anticipated and perhaps corrected early.

Bone Transplantation↗
PubMed1992

Disk herniations associated with compression instrumentation of lumbar flexion-distraction injuries.

Flexion-distraction injuries are often treated by open reduction and fusion using compression instrumentation. Three cases that were complicated by disk herniation at the injured level, with an acquired neurologic deficit, are reported. Middle-column failure through the annulus fibrosis (Gertzbein and Court-Brown Type A) appeared to be a common feature. This may be a permissive condition for this complication as compression is applied across the torn annulus. Preoperative magnetic resonance imaging and postreduction myelography may identify such herniations. Acquired neurologic deficits after reduction and instrumentation demand emergent evaluation and treatment.

Adolescent↗
PubMed1992

Postoperative posterior spinal wound infections.

The incidence of postoperative spinal infections increases with the complexity of the procedure. Diskectomy is associated with less than a 1% risk of infection; spinal fusion without instrumentation is associated with a 1%-5% risk; and fusion with instrumentation may be associated with a risk of 6% or more. Twenty-two postoperative posterior spinal infections that occurred during a three-year period were reviewed for this report. Staphylococcus aureus was the most frequent organism cultured (more than 50% of the cases). Other recurring organisms were Staphylococcus epidermis, Peptococcus, Enterobacter cloacae, and Bacteroides. Many patients had multiple organisms. Risk factors appeared to include advanced age, prolonged hospital bed rest, obesity, diabetes, immunosuppression, and infection at remote sites. Operative factors included prolonged surgery (greater than five hours), high volume of personnel moving through the operating room, and instrumentation. Postoperative contamination may occur and may be related to prolonged postoperative bed rest, skin maceration (thoracolumbosacral orthoses), and drainage tubes exiting distally from lumbar wounds (toward the rectum). Effective treatment includes early diagnosis, surgical debridement and irrigation, and parenteral antibiotics. Superficial infections were treated successfully with wound closure over outflow tubes, and deep infections with inflow-outflow systems. Maintaining the instrumentation in place was possible in most cases. Parenteral antibiotics were maintained for six weeks in every case.

Anti-Bacterial Agents↗
PubMed1992

Surgical management of cervical radiculopathy. Indication, techniques, and results.

Cervical radiculopathy can be surgically approached either posteriorly or anteriorly and the anterior approach has been described with or without fusion. The choice of approach and technique must be based upon anatomic, pathophysiologic, and biomechanical principles in addition to the familiarity of the surgeon with the procedures. The authors discuss the use of the posterior approach for lateral soft-disk disease because it minimizes disruption of soft and bony tissues and does not markedly disrupt the biomechanics of the cervical spine. The anterior approach is preferred for radiculopathy involving osteophytic hard-disk disease, and when properly and carefully performed, the addition of an interbody fusion holds significant advantages over diskectomy without fusion.

Cervical Vertebrae↗
PubMed1991

Blunt injuries to the extracranial cerebral vessels associated with spine fractures.

Injury of the extracranial carotid or vertebral artery with associated spine fractures is a rare but documented entity. In this article, four cases are examined in which patients suffered axial fractures after motor vehicle accidents and subsequently were found to have pathology in one or more of the extracranial arteries. Misdiagnosis is a common complication because symptoms from this are often attributable to closed head injury. Early detection and treatment, however, are essential. As many as 40% of the cases reported have permanent neurologic deficit. Although cerebral angiography remains the diagnostic gold standard, other modalities (eg, transcranial doppler and magnetic resonance angiography) continue to be examined. The treatment of these lesions remains controversial. A variety of surgical procedures may be applicable depending on the time between the injury and the onset of symptoms, the location of the vascular injury, and the rapidity of diagnosis. Anticoagulation therapy appears to play a large role in the management of patients with injury of the extracranial carotid or vertebral artery.

Adult↗
PubMed1991

Anatomic comparison of the Roy-Camille and Magerl techniques for screw placement in the lower cervical spine.

The Roy-Camille and Magerl techniques for screw placement in the lower cervical spine were compared under simulated operating room conditions. Three surgeons with varying years of spine surgery experience participated. The anatomic morbidity risks of each screw insertion technique were evaluated by anatomic dissection and radiographic examination. The spinal cord and vertebral arteries were not threatened by either method. Analysis of the pooled data revealed that the Roy-Camille technique had less risk of nerve root injury, nerve roots placed "at risk" for injury, and errors in "zone" of placement. The Magerl technique had less risk of facet joint violation. A learning curve was observed. Once the surgeons gained experience with the two techniques, there were no longer any statistically significant differences among them. The number of years of spine surgery practice did not influence the morbidity risk of either technique. The surgeons' ability to aim the screws was identical in the axial plane, but consistently less accurate in the sagittal plane for the Magerl screws because of the normal prominence of the cervicothoracic junction. Thorough familiarity with the regional anatomy and practice in the anatomy laboratory are recommended before performing these techniques in patients.

Bone Screws↗
PubMed1991

The anatomy of the cauda equina on CT scans and MRI.

The nerve roots of the cauda equina may be visualised by contrast-enhanced CT scans and by surface-coil MRI. We have identified the pattern of anatomy from L2-L3 to L5-S1 in 10 human cadaver specimens and correlated this with anatomical dissections. Individual roots are slightly more distinct on contrast-enhanced CT than on surface-coil MRI. There is a crescentic oblique pattern of nerve roots at the lower lumbar levels which is still apparent in the more crowded proximal sections. In all cases, the axial images correlated precisely with the dissections. Current imaging modalities can help the clinical understanding and management of abnormalities in this region of the spine.

Adult↗
PubMed1991

Prevention of complications in surgical management of back pain and sciatica.

Accurate diagnosis of lumbar disc disease requires a thorough examination. Appropriate neurodiagnostic studies are required to confirm the suspected diagnosis. Other diagnoses should be considered prior to surgery, especially when there is a lack of correlation between the history, physical examination, or radiologic investigation. Proper surgical techniques should also help in preventing complications and are further discussed in this article.

Back Pain↗
PubMed1991

Anatomic consideration for sacral screw placement.

Instrumentation of the lumbosacral spine increasingly involves screw fixation to the sacrum. Recommended locations and techniques for screw placement vary, particularly when bicortical purchase of the sacrum is performed. The purpose of this study was to describe the critical anatomy and potential injuries to neurovascular and visceral structures anterior to the sacrum. Lack of awareness can lead to life-threatening complications. The study included 22 fresh human cadavers with no prior spinal surgery. Specimens were placed in a prone position, and the lumbosacral spine was exposed. Two 6.5-mm screws were inserted using one of two techniques, respectively: Starting just inferior to the S1 facet one screw was angled 25 degrees caudally and 30 degrees laterally; in the second technique, lateral inclination was increased to 45 degrees. In addition, all specimens had screws placed in the S2 pedicles. An anterior dissection was performed to allow evaluation of the neurovascular and visceral structures at risk for injury by, or adjacent to, the screw tips. All significant neurovascular structures in the area of concern were constant in position. The internal iliac vein and the lumbosacral nerve trunk were most at risk for injury by the 30 and 45 degrees laterally directed screws. The sigmoid colon, though close to the S2 screw, was protected by its mesentery. Screws placed in the S1 pedicle were least likely to injure the neurovascular bundle. A lateral and a midline safe zone were identified.

Aged↗
PubMed1990

Gluteal nerve damage following total hip arthroplasty. A prospective analysis.

Injuries to the peroneal or tobial divisions of the sciatic nerve occur in approximately 0.7-7.6% of patients undergoing total hip arthroplasty. No prior studies have investigated the incidence of injury to the superior or inferior gluteal nerves during hip surgery. This study evaluates the incidence of injury to the superior and inferior gluteal nerves in 55 patients undergoing total hip arthroplasty using a newly devised EMG scoring system. Subclinical gluteal nerve injury was documented in over 77% of patients, whether a posterior or a lateral approach to the hip was used.

Adult↗