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Biomedical subjects

R J Zehr

Publications and source records attributed to R J Zehr.

8 recordsLinked to original sources
PubMed1999

Treatment options for orthopaedic oncologic entities.

Over the past 2 decades, tremendous advancement in the understanding of tumor natural history and treatment has occurred. If the basic principles are followed, the evaluation and appropriate treatment of musculoskeletal tumors can be reproduced successfully by any conscientious surgeon. Many benign bone and soft-tissue tumors can and probably should be treated by the community orthopaedic surgeon, and this chapter is biased toward treatment of those lesions. The encounter of a malignant lesion is probably beyond the scope of practice of most practicing orthopaedic surgeons. The assessment of the patient and treatments rendered in the first meetings may well dictate the ultimate outcome of survival and limb preservation: thus, patients with such lesions should be treated by experienced orthopaedic oncologists. With the small numbers of these lesions and the extreme consequences of mishandling them, it would be imprudent to do otherwise.

Adult↗
PubMed1996

Allograft-prosthesis composite versus megaprosthesis in proximal femoral reconstruction.

A review of 33 patients who underwent proximal femoral resection for primary bone tumor and reconstruction with an allograft-prosthesis composite or a megaprosthesis is presented to consider the relative merits of the 2 procedures. Clinical function, reconstruction survival, and associated complications were analyzed. Eighteen composites in 16 patients and 18 megaprosthesis in 17 patients were analyzed. Infection in the composite group and instability in the megaprosthesis group were the common causes of failure and removal of reconstructions. The average functional evaluation in 14 surviving patients with composites was 87% of normal. In 10 surviving patients with megaprostheses, the average function was 80% when complications were avoided. Survival analysis of the patients with reconstructions showed a 10 year survival of 76% for the patients with composites and 58% for those with megaprostheses. Both composite and megaprosthetic reconstruction of the proximal femur seem to function equally well from the perspective of function and survival because no statistically significant difference could be shown by this review.

Adolescent↗
PubMed1995

Adamantinoma.

This is an unusual case of an adamantinoma in an early phase of evolution. It was much smaller than adamantinomas typically seen at presentation, although it was located in the usual anterior tibial cortical region. Slow growth and a prolonged period of symptoms are common with adamantinoma and were also observed in this patient. The multifocal presentation within the same bone is unusual. This case illustrated the need to consider adamantinoma in the differential diagnosis of any pre-tibial cortical lesion despite the small size, benign presentation, or the longevity of symptoms.

Adolescent↗
PubMed1991

Juxta-articular osteoid osteoma.

Osteoid osteomas that arise at the end of a long bone, within the insertion of the joint capsule (juxta-articular, intra-articular), may cause misleading clinical, radiographic, and histologic findings, resulting in unnecessary diagnostic tests and a delay in definitive treatment. To clarify optimum diagnostic procedures, we reviewed 20 cases of juxta-articular osteoid osteomas and found a mean delay from presentation to correct diagnosis of 24 months. Plain radiographs were either negative or showed only secondary changes. A periosteal reaction and proliferative synovitis with chronic inflammation was common, which could be misinterpreted as rheumatoid arthritis. Optimum diagnostic procedures were a bone scan followed by plain tomograms and an excisional biopsy of the nidus.

Adolescent↗
PubMed1990

Ki-67 and grading of malignant fibrous histiocytomas.

Although generally considered to be of high grade, malignant fibrous histiocytomas (MFH) show a range of histologic appearances and a diverse biologic behavior. More precise grading of this type of sarcoma is desirable. The rate of cell proliferation may reflect clinical behavior. A more sensitive measure of cell proliferation is the expression of the Ki-67 antigen. Frozen sections were prepared from 29 cases of MFH. Sections were immunohistochemically stained for Ki-67, and the results were quantitated by image analysis (CAS 100). The Spearman rank correlation test was used to compare the extent of the Ki-67 staining with the conventional histologic grade, nuclear grade, number of mitoses, extent of necrosis, and overall cellularity. There was a significant correlation between the extent of Ki-67 staining and the nuclear grade (cc = 0.56; P = 0.002) and overall histologic grade (correlation coefficient = 0.58; P = 0.001), but there was no significant, independent correlation between Ki-67 and prognosis.

Adult↗