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Biomedical subjects

J B Renner

Publications and source records attributed to J B Renner.

13 recordsLinked to original sources
PubMed1992

Positional changes of the mandibular condyle assessed by three-dimensional computed tomography.

This investigation was designed to test the validity and reliability of three-dimensional computed tomography (3-D CT) for quantification of positional changes of the condyle in a laboratory model. The model consisted of a mounted dried human skull and a mandibular condyle attached to a micromanipulator. Controlled changes in condylar position were made and the condyle/fossa was imaged. Positional changes were measured by triangulation methods based on specific 3-D CT landmarks. The data were analyzed using descriptive statistics, analyses of variance to evaluate the sources of variability, and linear contrasts to evaluate the differences between observed and expected values. The results indicated that selection of appropriate anatomic landmarks for assessment of movement influences technique accuracy. The data also indicate that 3-D CT is most accurate in detecting inferior condylar movements. Lateral and posterior movements were assessed with less accuracy than the inferior positional changes. The clinical significance of these differences has yet to be determined.

Analysis of Variance↗
PubMed1992

Fracture-dislocation of the lumbosacral spine: case report and review of the literature.

This report describes an extensively comminuted fracture of the sacrum and the L-5 vertebral body with complete anterior dislocation of the lumbar spine on the sacrum that occurred in a 19-year-old man ejected from a motor vehicle. Lumbosacral dissociation was characterized by computed tomography with three-dimensional and multiplanar reconstruction, and definitively managed by posterior instrumentation using locking hook spinal rods attached to the pelvis with hockey stick attachments by the Galveston technique. Implications of this case and a review of the literature are presented.

Adult↗
PubMed1990

Massive florid reactive periostitis.

Florid reactive periostitis is a rare, benign process usually occurring in the small, tubular bones of the hands and feet. Typically the lesion occurs in an adolescent or young adult and presents as a small area of pain and erythema over the affected bone. Although the histologic features may suggest malignancy, there is usually little radiographic evidence to support such a diagnosis. In the following report an unusual example of this entity is described whose large size and relentless local progression led to initial diagnostic uncertainty and eventual aggressive management. This case suggests that a wide spectrum of radiologic and morphologic changes may be seen in this entity and that a seemingly unrelated genetic disease may alter the typical clinical course.

Adolescent↗
PubMed1990

Treatment of suppurative arthritis by percutaneous catheter drainage.

Percutaneous catheter drainage to treat suppurative arthritis was performed in five joints in five patients. Joints drained included the hip in two cases and one case each of a hip joint prosthesis, an ankle joint, and a glenohumeral joint. Organisms isolated from the joints included Staphylococcus aureus in one hip joint and the hip prosthesis, and Haemophilus influenzae in the ankle joint. Specific organisms were not isolated in the other hip joint or in the shoulder joint. Systemic antibiotic therapy was used in all five patients, and in two patients gentamicin was instilled through the catheters. Joint infection was managed successfully with catheter drainage and antibiotics in three patients. In all three cases, the range of motion was restored and the patients became free of pain after catheter drainage. These three patients remained asymptomatic at follow-up ranging from 3 weeks to 9 months. In two patients, percutaneous drainage failed. In one patient, the catheter positions could not be maintained and the catheters repeatedly became dislodged. In the other, superimposed osteomyelitis necessitated surgical debridement. No complications occurred. Our experience suggests that suppurative arthritis can be successfully treated with drainage of the joint via a percutaneous catheter in combination with antibiotic therapy.

Adult↗
PubMed1989

Kirschner wire migration from the pelvis to the heart and a new method of fixation of articular fracture fragments, acetabular reconstruction.

Fixation of comminuted, articular fracture fragments is frequently difficult. This can be accomplished with Kirschner wires (K-wires), but the risk of migration of smooth K-wires is well known. A case of migration of such a wire from the acetabulum, through the great vessels, and into the heart is presented. The Herbert screw is designed to be "buried" and, thus, allows firm fixation and congruent reduction of overlying fragments. The variation in thread pitch between the two ends of the Herbert screw should prevent migration once the screw is seated. A use of the Herbert screw in the fixation of articular fracture fragments in acetabular reconstruction is presented.

Acetabulum↗
PubMed1987

Epidermolysis bullosa: radiographic findings in 16 cases.

Epidermolysis bullosa is a group of dermatologic disorders with varied inheritance patterns having the common manifestation of blister or bulla formation after minor trauma. Sixteen patients with the disease had the following radiographic manifestations: esophageal stricture (16), fecal impaction (six), vaginal stenosis (one), epithelial bridging and fusion of the digits (six), and aspiration changes in the lungs (two). Esophageal strictures involved the pharynx or cervical esophagus in eight cases and were multiple in five; they ranged in length from 2 mm to 15 cm and tended to progress over time. The findings of esophageal stricture, particularly when multiple and involving the proximal esophagus, and/or the presence of distal phalangeal atrophy with soft-tissue webbing suggest the diagnosis of epidermolysis bullosa.

Adolescent↗
PubMedDate not supplied

Evaluation of magnetic resonance imaging in Legg-Perthes disease: a prospective, blinded study.

Twenty-two patients (24 hips) with Legg-Perthes disease received 49 magnetic resonance (MRI) scans. The scans and corresponding radiographs were independently evaluated in a blinded fashion to assess the capabilities of, and indications for, MRI in Legg-Perthes disease. Early in the disease process, MRI often more clearly delineated the extent and location of areas of involvement than did plain radiographs. In one patient, MRI failed to indicate necrosis early in the course of the disease, but it was detected on plain radiographs. MRI can also be used to give a rough estimate of sphericity, which in some phases of the disease process is better than plain radiographs. For serially following the disease process through the natural healing course, plain radiographs were as good or better than MRI and considerably less costly.

Adolescent↗
PubMedDate not supplied

Niobium/aluminum filters reduce patient exposure.

Reducing patient exposure while maintaining image quality is key to radiographers. In a comparison study of different filters, the authors found that a combined niobium/aluminum filter provides substantial reduction of entrance skin exposure with fairly small increases in tube loading and little loss of image contrast.

Aluminum↗