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Biomedical subjects

F H Sim

Publications and source records attributed to F H Sim.

At least 145 records · Page 8Linked to original sources
PubMed1989

Chondroblastoma of bone.

Chondroblastomas are unusual benign lesions of bone. They classically occur at the ends of long bones in young persons. The roentgenographic and histologic features are typical. We had an opportunity to study a large number of chondroblastomas. Most of the cases came from the consultation file started by Dr D. C. Dahlin at the Mayo Clinic. This method of ascertainment may tend to load our series with unusual and atypical examples. We found some unusual locations, such as the skull and facial bones and the small tubular bones of the hands and feet. We also found some unusual histologic features, such as mitotic activity, necrosis, and cellular atypia. However, despite the unusual features, the biological behavior of these tumors was that of a benign process with only limited local aggressiveness.

Adolescent↗
PubMed1989

Solitary plasmacytoma of bone: Mayo Clinic experience.

A review of 46 cases of solitary plasmacytoma of bone was undertaken in an attempt to better define the clinical features and prognostic indicators associated with this disease. Criteria for inclusion in the study included the following: (a) solitary lytic bone lesion on skeletal survey; (b) histologic confirmation of the lesion; and (c) bone marrow plasmacytosis of less than 10 percent. Patients with extramedullary plasmacytomas and osteosclerotic lesions were excluded. All patients were evaluated with serum and urine protein studies at the time of diagnosis. The median follow-up was 90 months with a minimum of 30 months. Fifty-four percent of the lesions involved the vertebral column. The thoracic spine was the single most commonly involved site (13/46 patients). The initial lesion was treated with radiotherapy in all but three patients in whom complete surgical resection was achieved. Total doses ranged from less than 20 Gy to 70 Gy with a median of 39.75 Gy. Overall, 54% developed multiple myeloma, 2% failed with new bone lesions without multiple myeloma, and 11% developed local recurrences. No patient receiving 45 Gy or more to the solitary lesion had a local failure. While the median time to progression was 18 months, 23% of the failures occurred after 60 months. The five local failures occurred at 7, 12, 18, 40, and 114 months. The overall survival was 74% at 5 years and 45% at 10 years. The 5- and 10-year disease-free survivals, however, were 43 and 25%, respectively. Evidence of abnormal serum and/or urine protein was found in 25 of 46 patients. Neither survival nor disease-free survival was significantly influenced by the presence of abnormal proteins even if they persisted after irradiation.

Adolescent↗
PubMed1989

Surgical management of malignant melanoma of the trunk and extremities.

The surgical management of newly diagnosed melanoma should be tailored to the characteristics of the individual lesion. The actual thickness of the lesion is the main consideration in planning surgical treatment. Prophylactic lymphadenectomy is no longer routinely recommended. For early detection of clinically suspicious nodes, however, close follow-up of the patient is necessary so that therapeutic lymphadenectomy can be accomplished. Surgical intervention plays a limited role in the management of disseminated melanoma.

Arm↗
PubMed1989

Dedifferentiated chondrosarcoma of bone.

Dedifferentiated chondrosarcoma is a highly malignant variant of chondrosarcoma. Approximately 11% of chondrosarcomas can be expected to dedifferentiate into more anaplastic lesions. Radiographic evidence of a benign-appearing cartilage lesion adjacent to a lytic, highly aggressive lesion suggests dedifferentiation. Despite radical surgical treatment, the prognosis is unfavorable, with a 5 year survival rate of 10%.

Aged↗
PubMed1989

Salvage of the limb in the treatment of malignant pelvic tumors.

From 1970 through 1985, at the Mayo Clinic, sixty patients had operative treatment, with salvage of the limb, for a primary malignant tumor of the pelvis. Chondrosarcoma, osteosarcoma, and fibrosarcoma were common diagnoses. There were twenty-three iliosacral, twenty-five acetabular, and twelve ischiopubic lesions. Most of the resections were done with a wide margin and disruption of femorosacral continuity. Reconstruction included ten iliosacral, fourteen iliofemoral, and three ischiofemoral arthrodeses, and approximately 50 per cent of the procedures resulted in fusion. The average length of follow-up exceeded five years. Seventeen per cent of the patients, primarily those in whom an iliosacral lesion extended into the sacrum or along the spinal column, had a local recurrence. Twenty-one patients (37 per cent) had metastasis. The best functional results were seen after resections in which femorosacral continuity was maintained or reconstructed. If satisfactory margins can be achieved by the excision of a pelvic tumor, salvage of the limb is justified from both an oncological and a functional standpoint.

Adolescent↗
PubMed1989

Metastatic diaphyseal fractures of the shaft of the humerus. The structural strength evaluation of a new method of treatment with a segmental defect prosthesis.

The surgical treatment of extensive metastatic diaphyseal lesions of the humerus with pathologic fractures is difficult. Patients with failed internal fixation often have large segments of bone loss. Rigid fixation often is not possible in these cases. Four patients were treated with a titanium segmental defect (SD) prosthesis with good clinical results. A comparative in vitro analysis of fixation with the SD prosthesis, a Rush rod, and a dynamic compression plate (DCP) augmented with methylmethacrylate was performed. The SD prosthesis performed better than the Rush rod and DCP in both the nondestructive four-point bending test and the destructive torsional test. The reconstructed humeri using the SD prosthesis had a torsional strength approaching that of an intact specimen. Hence, the SD prosthesis is a useful adjunct device in treating patients with extensive destructive lesions of the humerus secondary to metastatic disease and hematologic malignancies and in patients with malignant diseases who have had failed attempts at internal fixation.

Adult↗
PubMed1989

Wedge resection of the symphysis pubis for the treatment of osteitis pubis.

Ten patients had a wedge resection of the symphysis pubis for the treatment of symptoms of osteitis pubis that had been recalcitrant to non-operative treatment for at least six months. Preoperatively, the average duration of symptoms was thirty-two months. The symptoms included a waddling gait and crepitus, pain, and tenderness over the symphysis pubis. The early radiographic signs of the disease were rarefaction of the adjacent pubic bones and widening of the symphysis pubis. Later signs included sclerosis and narrowing of the symphyseal joint space. Pathological examination of the resected joint revealed chronic inflammatory reaction in all patients. At an average of fourteen months postoperatively, all of the patients had marked improvement and were fully active. However, at an average of ninety-two months postoperatively, three of the ten patients were not satisfied with the result. One patient needed bilateral sacro-iliac arthrodesis for pain that was caused by instability.

Adult↗
PubMed1988

Soft-tissue sarcoma: Mayo Clinic experience.

Soft-tissue tumors encompass a wide variety of lesions and continue to pose a difficult treatment problem. The outlook, however, is improving, and there have been recent advances in pretreatment assessment, clinicopathologic correlation, and adjuvant treatment programs. We retrospectively reviewed our experience in a large series of soft-tissue tumors treated at the Mayo Clinic as well as recent experience using chemotherapy and radiation treatment.

Adult↗
PubMed1988

Anterior knee pain.

Anterior knee pain is a common symptom, especially in adolescence, and often no specific cause is sought or identified. Physicians who treat patients with knee pain should understand the normal anatomic features and the biomechanics of the patellofemoral joint. We review this information and discuss important aspects of the physical examination and roentgenographic evaluation in patients with anterior knee pain. Once the clinical cause of anterior knee pain has been established, directed nonoperative treatment including physical therapy should be initiated. Surgical intervention is generally reserved for patients in whom nonoperative management is unsuccessful and identifiable abnormalities exist.

Adolescent↗
PubMed1988

Xanthoma of bone.

The authors report on 21 cases of "primary" xanthoma of bone. Twenty of the patients were older than 20 years old. The male-female ratio was 2:1. The presenting symptom was pain in 13 patients and neurologic symptoms in 2; in 6 patients, the lesion was an incidental finding. All but one of the lesions in this series were solitary, and the flat bones (pelvis, rib, skull) were the most frequently involved sites. Radiographically, a well-defined, sometimes expansile lytic lesion, with either a small area of surrounding reactive bone or a distinct sclerotic margin, was seen. Microscopically, foam cells, giant cells, cholesterol clefts, and fibrosis were present in varying degrees. In none of these cases was there an identifiable underlying lesion. The differential diagnosis includes Erdheim-Chester disease (a multisystemic granulomatosis) and bone involvement in sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease). More important is the differential diagnosis with metastatic clear cell carcinoma. Xanthoma of bone is a benign lesion, and complete or even partial removal is effective. Xanthomas may represent a "burnt-out" benign condition such as fibrous dysplasia or histiocytosis X.

Adolescent↗
PubMed1988

Ice hockey injuries.

Ice hockey is a team sport that has recently grown in popularity not only in the United States but also in Canada and Europe. With this increase in popularity has come a growing concern about the number and severity of injuries. The world literature on the biomechanics and physiology of ice hockey was reviewed in an attempt to evaluate the forces and mechanisms involved in the game. The influence of rule and equipment changes on injury patterns was particularly studied. Several studies on the epidemiology of injuries, providing data on the types of injuries and the mechanisms of those injuries, were analyzed to determine the conclusions that could be supported and those that require further study. Possible changes in the patterns and types of injury are outlined.

Adolescent↗
PubMed1988

Metastatic tumors of the foot and ankle.

In a review of the Mayo Clinic files, 17 biopsy-proven cases of metastatic tumors of the foot and ankle were found; 4 additional cases were considered to have metastatic disease on the basis of clinical and radiographic evidence but no histological confirmation was available. Lung, kidney, and colon were the most common sites of the primary tumors. The patients survived as long as 28 months after discovery of the metastasis. Treatment consisted of individualized combinations of orthotics, surgery, and radiotherapy to maintain mobility. In 9 of these 17 cases, no primary lesion was identified at the time the metastasis was diagnosed. Metastatic tumors of the foot present special problems in diagnosis and management.

Adult↗
PubMed1988

Primary leiomyosarcoma of bone.

Adequate treatment of primary leiomyosarcoma of bone requires surgical ablation with the goals being those for any malignant tumor of bone--eradication of the lesion and preservation of as much function as possible. Careful preoperative staging will determine whether amputation is necessary or whether successful limb-saving resection is possible.

Aged↗