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Biomedical subjects

F H Sim

Publications and source records attributed to F H Sim.

At least 199 records · Page 11Linked to original sources
PubMed1984

Magnetic resonance imaging of aneurysmal bone cyst.

A case of aneurysmal bone cyst is presented, and the radiographic, computed tomographic, and magnetic resonance imaging findings are discussed. The potential advantages of magnetic resonance imaging compared with those of computed tomography are explained. The case is presented to illustrate the potential value of magnetic resonance imaging in the evaluation of bone and soft tissue tumors.

Adult↗
PubMed1984

Clear cell chondrosarcoma of bone. Observations in 47 cases.

Clear cell chondrosarcoma of bone, a low-grade malignant tumor, frequently presents diagnostic difficulties. Its clinical, roentgenographic, and pathologic characteristics separate it from conventional chondrosarcoma and, more importantly, from several benign bone tumors with which it is often confused. This report analyzes 47 cases seen at the Mayo Clinic and in consultation. The lesion is more common in males than females (2.6:1) and has a predilection for the end of long bones, particularly the proximal femur. The age range is wide; most patients are in the third and fourth decades of life. Roentgenographically, the lesion most often is purely lytic and slightly expansile, with a sharp margin between the tumor and the adjacent normal bone. Pathologically, clear cells arranged in an indistinct lobular pattern characterize the tumor. Frequently, areas mimicking other primary bone tumors, benign and malignant, are present, often to such an extent as to obscure the true identity of the process. The overall mortality in the present series was 15%. En bloc resection, including a margin of normal bone and soft tissue, appears to be the treatment of choice.

Adolescent↗
PubMed1984

Randomized study of systemic chemotherapy following complete excision of nonosseous sarcomas.

Between June 1975 and April 1981, 61 of the 177 eligible patients whose nonosseous sarcomas of extremity or trunk origin had been completely excised primarily or after local recurrences agreed to participate in a randomized study of adjuvant chemotherapy. Dermatofibrosarcoma, lymphomas, myeloma, Kaposi's sarcoma, and embryonal rhabdomyosarcoma were excluded as were patients with significant second primary cancers and those who received either preoperative or postoperative radiation therapy. After stratification by anatomic status of disease, site of origin, and histologic grade, a random one half of the 61 participants began alternating courses of vincristine/cyclophosphamide/dactinomycin, and vincristine/doxorubicin/dacarbazine at six-week intervals for one year. The control group was evaluated at six-week intervals without adjuvant chemotherapy, but these patients were offered this chemotherapy later if they had progressive disease excised. Although 30% of the 61 patients experienced local recurrence of disease within the first five years after randomization, and only 54% were continuously disease free for five or more years, 82% were surviving at five years (Kaplan-Meier calculations) with a median follow-up of 64.3 months. Partial suppression of distant metastasis by adjuvant chemotherapy was apparent in the overall study, in the extremity tumor category, and in the subgroup of patients who had received limb-sparing surgery; however, no survival advantage for chemotherapy-treated patients was demonstrated. The 30 adjuvant chemotherapy-treated patients received a total of three thoracotomies as compared with 17 salvage thoracotomies for the 31 control patients; however, salvage surgery for local recurrences has been similar in the two groups. Recent improvement in the survival of patients with soft-tissue sarcomas is not necessarily a result of adjuvant chemotherapy or radiation therapy.

Adolescent↗
PubMed1984

Dedifferentiated parosteal osteosarcoma.

Parosteal osteosarcoma is an uncommon malignant tumor of bone, and in a review of Mayo Clinic records we identified eleven cases of so-called dedifferentiated parosteal osteosarcoma. Ten of the eleven patients had had a long history of treatment for multiple recurrences of the tumor as a low-grade parosteal osteosarcoma and then for a definite recurrence as a high-grade undifferentiated osteosarcoma. The prognosis in this group of patients was similar to that in patients with conventional osteosarcoma.

Adolescent↗
PubMed1983

Segmental replacement of long bones using titanium fiber metal composite following tumor resection.

A series of 17 long bone defects following tumor resections were reconstructed using titanium fiber metal implants with adequate bone grafts. There were nine diaphyseal segmental arthroplasties and eight arthrodeses of the knee. The results were excellent in 11 and satisfactory in five, and there was one failure. Sixteen patients became fully weight-bearing. Adequate bone grafts, especially from both posterior iliac crests, and good skin coverage are essential to adequate bony reconstruction.

Adult↗
PubMed1982

Hemangiopericytoma of bone.

Hemangiopericytoma primary in bone is a rare tumor. A review of 15 cases (five from the Mayo Clinic files and 10 from the consultation files) revealed that all tumors were unifocal and that the most common location was the pelvis (three lesions in the sacrum and two in the ischium). The series involved seven male and eight female patients whose ages ranged from 14 to 74 years. Histologically, all of the tumors were composed of cells with round to oval nuclei arranged around vascular spaces. On the basis of cellularity, nuclear atypia, and mitotic activity, four tumors were benign, two intermediate, and nine malignant. Surgery was the primary treatment for the 15 patients. Of the 14 patients with adequate follow-up, eight died of disease, three were alive with recurrent disease, and three were alive and disease-free.

Adolescent↗
PubMed1982

Computed tomographic evaluation of primary osseous malignant neoplasms.

A total of 128 patients with pathologically confirmed primary osseous malignant lesions was examined by computed tomography (CT). In each case, the CT findings were compared with those from the standard radiographs, tomograms, and isotope bone scans as well as with the clinical findings, in regard to tumor detection, diagnosis, and extent. Even though CT demonstrated all lesions, 96% were seen on radiographs, with only 4% of tumors identified solely by CT. In 7% of cases, CT provided unique diagnostic information not obtainable by other means. In 77% of cases, CT gave a better indication of tumor location, extent, and relationships than did any of the other methods. After treatment, CT was efficacious in the detection or ruling out of recurrences and in patient follow-up after chemotherapy or radiation therapy.

Bone Neoplasms↗
PubMed1982

Synovial sarcoma.

One hundred and eighty-five patients, whose ages ranged from two to seventy years (mean, thirty years), have been treated at the Mayo Clinic for synovial sarcoma. Sixty-nine per cent of the tumors occurred in the lower extremity: 25 per cent, in the upper extremity; and 6 per cent, in the trunk. Histological characteristics included a predominant bimorphic pattern in 33 per cent of the tumors, a monomorphic pattern in 31 per cent, and a mixed pattern in 36 per cent. For all patients, the five-year survival rate was 38 per cent and the ten-year rate was 23 per cent, with a median survival time of thiry-nine months. However, for those patients treated since 1960, the five-year survival rate was 55 per cent and the ten-year rate was 38 per cent. Female patients had a significantly better survival time than did male patients. Younger patients had a better survival rate, and the prognosis was better for those patients whose tumor were either less than five centimeters in diameter or located in the lower extremity. Survival rates were best for those patients who had wide local excision, but this type of surgery was performed for the lesions that had a more favorable prognosis. A regression study indicated that the size of the tumor was the single most important prognostic variable for survival. Second in importance was the extent of disease on initial presentation, followed by the chronological time of treatment, the age of the patient, and the anatomical site of the tumor.

Adolescent↗
PubMed1982

Treatment of pathologic fractures or impending fractures of the humerus with Rush rods and methylmethacrylate. Experience with 55 cases in 54 patients, 1968-1977.

A retrospective study of 54 patients with established or impending pathologic humeral fractures was done to evaluate the technique of intramedullary fixation with a Rush rod, during the period from 1968 to 1977. Breast carcinoma, multiple myeloma, and hypernephroma were the most common metastatic tumors. Primary tumors included Ewing's sarcoma and a low-grade chondrosarcoma, in which case the patient refused any other form of treatment. An anterolateral incision was used to expose the fracture site and a deltoid-splitting incision to introduce the Rush rod. Thirty-eight of the 55 procedures utilized methylmethacrylate to help stabilize the fracture. All patients had relief of their preoperative pain after the procedure. Seven patients subsequently experienced pain: four had proximal migration of the Rush rod with impingement, three of which required removal of the Rush rod; three other patients had discomfort two years postoperatively. All patients except one had good functional motion. Six patients had complications: three with proximal migration of the Rush rod, two with transient subluxation of the humeral head, and one with limited glenohumeral motion secondary to a technical error. This procedure provides significant pain relief and maintains function.

Adolescent↗
PubMed1981

Aggressive thoracotomy for pulmonary metastatic osteogenic sarcoma in children and young adolescents.

During a 6-yr period, 57 children and young adults less than 21 yr of age underwent 111 thoracotomies for pulmonary metastatic osteogenic sarcoma. Follow-up after the initial thoracotomy averaged 36.8 no and ranged from 1 to 78 mo. Twenty-eight patients (49%) underwent more than one thoracotomy--the number of multiple thoracotomies averaged 2.9 and ranged from two to eight. Twenty-six of the 57 patients are currently alive, and 25 of these are free of disease. Median survival was 36 mo. Actuarial survival curves demonstrated a 5-yr survival of approximately 40%. Seventy-one percent of patients who had a tumor-free interval of greater than 1 yr are currently alive, compared with 39% of patients who had a tumor-free interval of less than 1 yr. Patients with disease confined to one lobe at the initial thoracotomy had a better survival (64%) than patients with diffuse or bilateral disease (41%). An aggressive surgical approach toward osteogenic sarcoma with pulmonary metastasis thus appears to be justified.

Actuarial Analysis↗
PubMed1981

Hip salvage by proximal femoral replacement.

Total hip arthroplasty with a special segmental replacement of the proximal end of the femur which varied in length from eighty to 150 millimeters was performed in twenty-one patients who had severe non-neoplastic conditions of the proximal part of the femur that necessitated salvage. Ten patients had previously failed arthroplasties associated with loss of bone structure; seven had non-union of a proximal femoral fracture or osteotomy associated with severe hip disease; there had a failed resection arthroplasty; and one had an arthrodesis and incapacitating low-back pain. Clinical and roentgenographic data during follow-up of twenty-five to ninety-two months showed that only one patient had loosening of the acetabular component. In twenty of the twenty-one patients, total hip arthroplasty with proximal femoral replacement was effective in restoring the integrity of the bone and restoring function of the hip.

Adult↗
PubMed1980

Management of hip fractures by total hip arthroplasty.

One hundred and twelve patients ranging in age from 40 to 89 with acute intracapsular fractures of the hip were treated between the years 1970 to 1978 by total hip arthroplasty; 63% were subcapital, 27.6% were midcervical, and 8.9% were basilar; 53.5% were classified as Garden's Stage IV, 34.8% as Stage III and 11.6% as Stage II. A significant number of patients had associated medical conditions that made them poor risks for a possible second-stage operation. Moreover, 16 patients were considered for total hip arthroplasty because of associated hip disease. Of 85 patients evaluated after one year, 81.2% had no pain. Most patients maintained their previous levels of activity, but 13 were more active than before injury; 33 were worse. The decrease in activity was generally due to deterioration in associated medical conditions. Our experience indicates that total hip arthroplasty is best reserved for the previously active elderly patient with a displaced subcapital fracture who meets the criteria for prosthetic replacement.

Adult↗