Synovial sarcoma of the knee: missed diagnosis despite biopsy and arthroscopic synovectomy. A case report.
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Adult↗
Biomedical subjects
J Buckwalter
Publications and source records attributed to J Buckwalter.
Torsional fatigue of the lumbar intervertebral joints.
The effect of cyclic torsional loads on the behavior of intact lumbar intervertebral joints was investigated. A total of 24 specimens, divided in two groups, were tested. In the first group, a specimen was subjected to a specified constant cyclic torque, and the resulting change in angular displacement with time was recorded. The specimens in the second group were subjected to a specified constant angular displacement and the resultant torque recorded. The results of the constant torque tests showed that fatigue failure was primarily a function of the averaged initial angular displacement and secondarily of the applied torque. The critical threshold values appear to be an initial angular displacement of +/- 1.5 degrees. All specimens, displaying an averaged initial angular displacement of less than +/- 1.5 degrees, did not fail in fatigue, while the others did. However, the specimens with angular displacements of less than +/- 1.5 degrees had lower applied torques (11.3 and 22.6 Nm), while specimens with higher applied torques (33.9 and 45.2 Nm) all exceeded the +/- 1.5 degrees threshold and failed in fatigue. Failure locations occurred in such diverse regions as end-plates, facets, laminae, capsular ligaments, etc. All specimens exhibited a synovial fluid discharge from the apophyseal joint capsule sometime during testing. Post-test examinations of all the cartilage surfaces showed fibrillation, whether or not the intervertebral joint failed.
Adult↗
Pectoralis major myocutaneous reconstruction of the anterior skull base.
It was once believed that prognosis for many patients with neoplasms of the anterior skull base was hopeless. Now, however, craniofacial resection of these lesions has been curative for many patients. Massive resections of the anterior skull base pose many potentially life-threatening complications. Cerebrospinal fluid leakage with meningitis is especially troublesome when previous radiation therapy compromises wound healing. In such circumstances local tissue flaps and skin grafting may not provide reliable separation of the brain from the nose. The pectoralis major flap was utilized in eight patients undergoing anterolateral resection of the skull base. Several major advantages of this technique include: 1. reliable closure of the subarachnoid space; 2. acceptable cosmesis; 3. rapid wound rehabilitation, allowing early postoperative radiation therapy when necessary.
Adenocarcinoma↗
Gout presenting as a femoral cyst. A case report.
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Adult↗
The presence of a cartilage-like proteoglycan in the adult human meniscus.
Proteoglycans were extracted from the adult human meniscus under dissociative conditions and purified by CsCl-density-gradient centrifugation. The preparations of highest density contained proteoglycan that possessed the ability to interact with hyaluronic acid, was of large subunit size and was composed of chondroitin sulphate, keratan sulphate and sialic acid-containing oligosaccharides. This 'cartilage-like' proteoglycan also exhibited subunit and aggregate structures analogous to those of hyaline-cartilage proteoglycans when examined by electron microscopy. However, the composition of this proteoglycan was more comparable with proteoglycans from immature cartilage than from age-matched cartilage. The preparations from lower density, which were enriched in dermatan sulphate, contained smaller proteoglycan that was not able to interact with hyaluronic acid. This non-aggregating proteoglycan may be structurally distinct from the 'cartilage-like' proteoglycan, which does not contain dermatan sulphate.
Aged↗
Fatigue response of lumbar intervertebral joints under axial cyclic loading.
A low-cycle fatigue of 11 lumbar intervertebral joints under axial compression is reported. The magnitude of the maximum compressive load ranged from 37 to 80% of the failure load. The maximum deformation, as a function of the number of cycles, showed two distinct results: one group showed a gradual, stable increase, and the other an abrupt, unstable increase. The before- and after-test radiographs showed a one-to-one correspondence between unstable specimens and generalized bony failure. The radiographs of 5-mm thick transverse endplate slices show crack propagation from the periphery of the subchondral bone inward. Removal of the organic matrix from the cracked specimens produced its physical disintegration into small particles, while normal controls and stable specimens retained their size and shape.
Adolescent↗
Aortic wheeze: intermittent tracheal obstruction caused by a rare aortic arch anomaly.
Cardiac and aortic arch anomalies are a well-known cause of tracheal and esophageal compression producing stridor and dysphagia. We present a rarely encountered aortic arch anomaly in a 12-month-old infant who suffered from intermittent pulmonary wheezing. A discussion of the subsequent evaluation including an esophageal contrast study, computed tomography, angiocardiography, and bronchoscopy, will emphasize the diagnostic importance of these examinations. Preoperatively, a variant of Celoria type B aortic arch interruption was established by cardiac catheterization. The ascending aorta solely supplied both carotid arteries. Both subclavian arteries arose from the descending aorta, and all flow to the descending aorta was supplied via bilateral markedly enlarged vertebral arteries as a bilateral subclavian steal. Three areas of tracheal compression were noted at bronchoscopy. The patient's anomalous circulation was improved by the placement of a Gore-Tex graft connecting the ascending and descending aorta. A right-sided arterial ligament was divided in order to further relieve tracheal compression.
Aortic Arch Syndromes↗