Ruptured abdominal aortic aneurysm associated with a psoas abscess.

A case of abdominal aortic aneurysm infected by Salmonella dublin is presented. Computed tomography (CT) revealed an abdominal aortic rupture associated with a psoas abscess. An axillo-femoral bypass was performed. The aneurysm and the psoas abscess were resected.

The effect of age on inflammatory responses and nerve root injuries after lumbar disc herniation: an experimental study in a canine model.

STUDY DESIGN: An experimental investigation on the effect of age on pathologic events surrounding the herniated disc and at the adjacent nerve root. OBJECTIVES: To investigate the role of age on the inflammatory responses and nerve root damage surrounding a sequestered lumbar disc fragment using a dog model. SUMMARY OF BACKGROUND DATA: Lumbar disc herniation is manifested in patients by variable clinical findings, natural history, and resorption phenomena in which the variability is particularly noted among patients with different ages. There are no previous reports on the effect of age on pathologic events induced by the herniated disc. METHODS: Six beagle dogs, including two animals of each age group of 6, 12, and 24 months (human equivalent ages of 10, 15, and 24 years), were used in this study. The dogs underwent L4-L5, L5-L6, and L6-L7 laminotomy and discectomy under general anesthesia. An autologous intervertebral disc from the tail was divided into anulus fibrosus and nucleus pulposus fragments. The anulus fibrosus and nucleus pulposus fragments were placed in the anterolateral epidural space of L5-L6 and L6-L7, respectively. The L4-L5 discectomy site served as a control. Dogs were killed at 12 weeks after surgery. The lumbar spine was removed en bloc, and histologic sections were prepared consecutively and examined. RESULTS: In the nucleus pulposus group at L6-L7, neovascularity, and intensive infiltration of lymphocytes, macrophages, and fibroblasts were observed surrounding the nucleus pulposus fragment in the 24-month-old group only. Degenerative changes of the nerve root fibers were observed in the 24-month-old group only. In the control and anulus fibrosus groups at L4-L5 and L5-L6, there were no marked inflammatory reactions in all age groups. The nerve root fibers around the anulus fibrosus were normal in all age groups. CONCLUSIONS: There is an effect of age on the inflammatory response and nerve root injury caused by the herniated disc. The apparent neuroprotective mechanism in the young animal, and the apparent inflammatory and resorption changes of the nucleus pulposus fragment in the older animal are quite intriguing.

Anatomic changes of the spinal canal and intervertebral foramen associated with flexion-extension movement.

STUDY DESIGN: A cadaveric study was done to analyze the dimensional changes in the spinal canal and intervertebral foramen of the lumber spine with flexion and extension movements. OBJECTIVES: To investigate the relationship between flexion and extension movements and morphologic changes in the spinal canal and the intervertebral foramen. SUMMARY OF BACKGROUND DATA: Previous studies have reported that the dimensions of the spinal canal and the intervertebral foramen may change significantly with motion. The purpose of this study was to assess the quantitative changes in the spinal canal and the intervertebral foramen with segmental flexion-extension movements. METHODS: Nineteen fresh cadaveric spines yielding 25 motion segments were used. The lumbar motion segments were frozen and then imaged in axial and sagittal projections by a computed tomography scanner. They were thawed then, and the motion segments were loaded to 5.7 Nm in flexion (13 motion segments) and in extension (12 motion segments) specimens. While in flexion or extension, the specimens again were frozen and imaged by computed tomography scan. The frozen specimens than were sliced using a cryomicrotome in the sagittal plane to study the dimensions of the intervertebral foramen. Eighteen other fresh cadaveric spines were sliced sagittally for study in the neutral position. RESULTS: The axial computed tomography scans showed that extension significantly decreased the canal area, midsagittal diameter, and subarticular sagittal diameter, whereas flexion had the opposite effects. The sagittal computed tomography scans showed that extension decreased all the foraminal dimensions significantly, whereas flexion increased all the foraminal dimensions significantly. The translational changes were associated with the bulging of the disc and the presence of traction spurs. The cryomicrotome sections showed the cross-sectional area of the foramen to be 12% greater for the flexion group and 15% smaller for the extension group than the cross-sectional area of the neutral group. Nerve root compression in the foramen was found to be 21.0% in neutral, 15.4% in flexion, and 33.3% in extension groups. CONCLUSIONS: The study supports the concept of dynamic spinal stenosis. In addition to static anatomic changes, careful dynamic studies may be required to evaluate better the central canal and the foramen.

Postoperative osteomyelitis due to Mycobacterium fortuitum. A case report.

A rare case of osteomyelitis of the tibia caused by Mycobacterium fortuitum which developed after closed intramedullary Küntscher nail fixation is reported. After extraction of the nail, combination therapy with antituberculous drugs, ofloxacin, and interleukin 2 was undertaken and bony union was achieved. Since a bone cyst formed during union, curettage and conventional cancellous bone grafting were performed. The patient is now pain-free even with prolonged weight-bearing. The success of treatment in this case is in contrast to other reports of the disease.