Difference in stretching of sarcomeres between medial gastrocnemius and tibialis anterior by tibial lengthening: an experiment in rabbits.

PURPOSE: To compare the degree of stretching of sarcomeres--in the medial gastrocnemius versus the tibialis anterior--acutely extended by tibial lengthening. METHODS: The right lower legs of 6 New Zealand White rabbits were acutely distracted by 6.3 mm using an external fixator, whereas the left lower legs served as controls. Immediately after distraction, the ankle was dorsiflexed at 50 degrees and the knee flexed at 140 degrees, with respect to the posture of resting on the ground. Both legs were immersed in 10% buffered formalin for fixation, and the medial gastrocnemius and tibialis anterior were removed. Length of the 2 sarcomeres was measured by a laser diffraction technique using isolated muscle fibre bundles. RESULTS: The mean lengths of sarcomeres in the medial gastrocnemius and tibialis anterior were 3.0 microm and 2.3 microm in the lengthened legs, and 2.4 microm and 2.1 microm in control legs, respectively. The degree of stretching of corresponding sarcomeres was therefore 25% and 10%, this difference being significant (p<0.01). CONCLUSION: Sarcomeres of the medial gastrocnemius are more stretchable than those of the tibialis anterior following tibial lengthening.

Perinuclear-antineutrophil cytoplasmic antibodies are associated with vasculitis.

We describe a 62-year-old man with perinuclear-antineutrophil cytoplasmic antibodies-associated vasculitis, which involved the heart, lung, and kidneys. The patient's care was complicated by total occlusions of the brachiocephalic and right renal arteries and a stenosis of the left renal artery. Involvement of large-sized vessels has not been reported in patients with perinuclear-antineutrophil cytoplasmic antibodies-associated vasculitis.

Orientation and osteoarthritis of the lumbar facet joint.

Several studies have shown an association between sagittal orientation of the facet joint and degenerative spondylolisthesis. There is currently no information available on the association between orientation of the facet joint and osteoarthritis. This study examined the association between orientation and osteoarthritis of the lumbar facet joints. One hundred eleven consecutive patients underwent plain radiography and magnetic resonance imaging. These patients were divided into two groups: No Degenerative Spondylolisthesis Group (98 patients) and Degenerative Spondylolisthesis Group (13 patients). In the No Degenerative Spondylolisthesis Group, segments with higher grades of osteoarthritis showed more sagittal orientation of the facetjoints at the L3-L4 and L4-L5 levels. The facet joint was oriented significantly more sagittally in the Degenerative Spondylolisthesis Group than in the No Degenerative Spondylolisthesis Group at the L4-L5 and L5-S1 levels. The severity of facet joint osteoarthritis was significantly higher in the Degenerative Spondylolisthesis Group than in the No Degenerative Spondylolisthesis Group at the L3-L4, L4-L5, and L5-S1 levels. A significant association was found between sagittal orientation and osteoarthritis of the lumbar facet joints, even in patients without degenerative spondylolisthesis. Facet joint osteoarthritis, rather than spondylolisthesis, is the pathoanatomic feature that is associated with sagittal orientation of the facet joints in patients with degenerative spondylolisthesis.

Anatomy of the iliolumbar ligament.

Information is lacking in the literature on the precise anatomy of the iliolumbar ligament and its individual differences. The morphologic pattern, length, and width of the iliolumbar ligament were determined in 56 embalmed lumbosacral spines from human cadavers. It was possible to classify the iliolumbar ligament into two groups: Type A (74 ligaments), in which anterior and posterior ligaments had separate courses; and Type B (32 ligaments), in which anterior and posterior ligaments moved together as one band. The angle of the posterior iliolumbar ligament in Type A was oriented significantly more posteriorly than that in Type B. The posterior iliolumbar ligament was significantly shorter and oriented more posteriorly in male anatomic specimens than in female ones.

Recurrent pulmonary adenoid cystic carcinoma presenting as a cardiac tumor.

A 58-year-old patient is presented who had a pulmonary adenoid cystic carcinoma which recurred 10 years after sleeve left pneumonectomy. The patient developed acute heart failure because the lesion obstructed blood flow by compressing the left atrium. Transesophageal echocardiography and magnetic resonance imaging demonstrated a solid mass arising from the pericardium which displaced the posterior wall of the left atrium. The mass was resected. Postoperative radiation was not performed.

The relationship between facet joint osteoarthritis and disc degeneration of the lumbar spine: an MRI study.

The role of MRI in assessing facet joint osteoarthritis is unclear. By developing a grading system for severity of facet joint osteoarthritis on MRI, the relationship between disc degeneration and facet joint osteoarthritis was determined. The accuracy of MRI in assessing facet joint osteoarthritis against CT was 94%. Under 40 years of age, the degree of disc degeneration varied among individuals. Over the age of 60, most of the discs were markedly degenerated. Under 40 years of age osteoarthritic changes in facet joints were minimal. Over the age of 60, variable degrees of facet joint osteoarthritis were observed but some facets did not show osteoarthritis. No facet joint osteoarthritis was found in the absence of disc degeneration and most facet joint osteoarthritis appeared at the intervertebral levels with advanced disc degeneration. Disc degeneration is more closely associated with aging than with facet joint osteoarthritis. The present study supports the hypothesis that "disc degeneration precedes facet joint osteoarthritis", and also supports the concept that it may take 20 or more years to develop facet joint osteoarthritis following the onset of disc degeneration.

Rheumatoid arthritis and simultaneous aortic, mitral, and tricuspid valve incompetence.

We describe a 72-year-old woman with aortic, mitral, and tricuspid valve incompetence secondary to a rheumatoid granulomata. The cardiac valvular lesions developed simultaneously and deteriorated rapidly. The patient died after a transient relief of symptoms by high dose steroid therapy.

Relationship between morphology of iliolumbar ligament and lower lumbar disc degeneration.

Previous imaging studies have shown little difference in the degree of disc degeneration between L4-L5 and L5-S1. We hypothesized that because the morphology of the iliolumbar ligament affects the stability of the lumbosacral junction, then it could determine the lower lumbar disc degeneration. Fifty-three male and 47 female patients were classified into three groups according to their disc degeneration grade-those in whom the L5-S1 disc was less degenerated (group A), more degenerated (group B), and equally degenerated (group C) compared to the L4-L5 disc on T2-weighted magnetic resonance images. The length and direction of the anterior and posterior iliolumbar ligaments were measured on T1-weighted axial images. The iliolumbar ligament was shorter in group A than in group B or C, and was oriented significantly more posteriorly in group A than in groups B or C. The morphology of the iliolumbar ligament, especially its length and direction, can be a factor influencing the development of disc degeneration at L4-L5 and L5-S1.

Subdivided left atrium mimicking a cardiac tumor.

We describe a 25-year-old man with a subdivided left atrium. The lesion was misdiagnosed preoperatively as a cardiac tumor because echocardiographic and magnetic resonance imaging revealed a solid mass arising from the posterior wall of the left atrium. Cardiac surgery revealed a small accessory chamber draining the two left pulmonary veins. No membranous structure was evident between the chamber and the left atrium. The solid mass identified noninvasively was a hypertrophic muscle which formed a wall of the accessory chamber.

Multifocal Ewing's sarcoma and hypercalcemia. A case report.

An unusual case of Ewing's sarcoma in which the earliest sign of disease was the development of hypercalcemia is described. Radiologic examinations showed extensive osteolysis involving all of the trunk, and the proximal femora and humeri. An ill defined destruction of the left fibula was also noted. No definite primary site was found. The lungs and other visceral organs were free of metastasis. To the best of the author's knowledge, no comparable case has been reported in the literature.

Peroneal arteriovenous fistula and pseudoaneurysm formation after blunt trauma. A case report.

A 56-year-old man sustained blunt trauma to the right calf which, 15 months later, manifested as a painful soft tissue mass with aggressive destruction of the fibula. Contrast-enhanced computed tomography and popliteal arteriography disclosed a peroneal arteriovenous fistula and pseudoaneurysm. Five years after pseudoaneurysm repair and fistula ligation, the patient was free of symptoms and had no further bone destruction.