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Biomedical subjects

S Stenzler

Publications and source records attributed to S Stenzler.

6 recordsLinked to original sources

Exposure of the orthopaedic surgeon to radiation.

A prospective study of sixty-five orthopaedic procedures performed with fluoroscopic assistance was undertaken to determine the risk to the primary orthopaedic surgeon with regard to radiation. Radiation was monitored with the use of a universal film badge placed outside the collar of a lead apron, and a gas-sterilized thermoluminescent dosimeter ring worn on each hand. The rings were changed with every operation, but the same film badge was transferred from surgeon to surgeon. The hand dominance of the surgeon, the duration of the operative procedure, the type of operation, and the total time that fluoroscopy had been used were noted. The study was conducted during twenty-one intramedullary nailing procedures (thirteen involving distal locking), forty open reductions with internal fixation (plates and screws), and four external-fixation procedures. All of the badges and rings were submitted for a report regarding radiation exposure. No relationship was found between a ring with a positive reading for exposure to radiation and the duration of the operation. Similarly, there was no correlation between a positive reading and the surgeon's hand dominance. The mean duration of the fluoroscopy was 2.3 minutes for the group for which the rings did not show a positive reading and 4.7 minutes for the group for which the rings did show a positive reading. This was a significant difference (p < 0.0001). There was no positive reading for exposure to radiation from any ring that had been worn during a procedure in which the fluoroscope had been used for less than 1.7 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Nails↗

Case report 650: Grade II chondrosarcoma of the proximal end of the right femur.

A case is presented in which the conventional radiograph was suggestive of avascular necrosis. This impression remained unchanged inspite of an MRI examination that was more suggestive or replacement of marrow. The diagnosis of ischemic necrosis was strongly supported by the patient having previously established avascular necrosis in the opposite hip. The gross pathologic specimen showed only necrotic tumor, which mimicked avascular necrosis on the plain film. The importance of placing proper confidence in the MRI findings is thus emphasized. A classification and brief description of the various types of chondrosarcoma are included in the Discussion.

Chondrosarcoma↗

Mathematical analysis of computed carpal models.

The computed carpal models from digital computed tomography (CT) data obtained in this study compare favorably to natural anatomy. A new application of algebraic analysis of this data provides mathematical markers from which to calculate the position and orientation of each carpal bone. When the origin of the spatial coordinates of a carpal bone is transferred to the centroid of the bone, the data can be treated as three-dimensional pattern vectors describing its surface. It is then possible to calculate vectors that are the principal axes of the geometry. These axes provided references that were used to calculate position and orientation of the carpal bones in three wrist specimens. Comparisons of volumes, surface areas, and sizes and proportions of five computed images of each carpal bone from two of these wrists demonstrate the reliability of the technique. The analysis of CT scans of ceramics with known boundaries allows an estimation of its accuracy. The technique is well suited to the future study of normal wrist kinematics and pathological conditions.

Carpal Bones↗

Scaphoid orientation and location from computed, three-dimensional carpal models.

Subtle subluxations within the carpus are often difficult to diagnose. Carpal orientation and location can now be quantified by mathematical analysis of computed, three-dimensional models produced from serial CT scans. The technique and its application in the analysis of scaphoid subluxation are described.

Biomechanical Phenomena↗

The prevalence of presumed tardive dyskinesia in psychiatric inpatients and outpatients.

Randomly selected psychiatric patients (271 total) were examined by raters blind to diagnosis and treatment history for the presence of abnormal movements. The prevalence of presumed tardive dyskinesia among neuroleptic-exposed patients was 4.6%. If minimal rating scale criteria were applied, 9% of those patients with no history of neuroleptic exposure might have been given 'presumptive' diagnoses of dyskinesia. Problems in establishing diagnostic criteria are discussed and a longitudinal approach toward validating diagnoses is recommended.

Adult↗

Progressive diaphyseal dysplasia presenting as neuromuscular disease.

Two children with progressive diaphyseal dysplasia (Engelmann's disease) were initially diagnosed as having a neuromuscular disorder because of their clinical presentations of muscle weakness, a waddling gait, and limb pain. Radiographs revealed the characteristic radiographic changes.

Camurati-Engelmann Syndrome↗