Biomedical subjects
Publications and source records attributed to F H Sim.
A case report presents a liposarcoma of the extremities and an overall review of this disease entity. Past and present histologic classifications of liposarcoma are discussed, as are the clinical behavior and treatment options in relation to the surgical stage of the tumor. The importance of a well-planned biopsy site is stressed.
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The outlook for the patient with sarcoma of the musculoskeletal system has improved dramatically because of recent advances in diagnosis and treatment. These new developments, as discussed in this review, allow greater success in achieving the goals of treatment, which include 1) control of the primary lesions, 2) maintenance of function, and 3) long-term survival.
One of the most challenging problems of limb salvage is a large tumor involving the knee joint. Since 1970, 79 patients, ranging in age from 14 to 74 years (mean, 27 years), have had reconstruction of the knee after en bloc resection of a primary bone tumor. Sixty-one patients had lesions involving the distal femur, with a mean resection length of 13.5 cm, and 18 patients had lesions involving the proximal tibia, with a mean resection length of 10.5 cm. Thirty-nine patients had malignant lesions, of which osteosarcomas predominated, and 40 patients had benign tumors, of which giant cell tumors were the most prevalent. Reconstruction was done with a custom total knee arthroplasty in 41 patients, a resection arthrodesis in 27, and an allograft in 11. The functional results were graded according to the rating system devised by the Musculoskeletal Tumor Society. of the patients with resection arthroplasty, 70% had a good or excellent rating, although ten required revision. Of the patients with resection arthrodesis, 74% had a good or excellent rating, as did 55% of the patients with osteochondral allografts. When a limb salvage procedure is done, careful consideration must be given to the type of procedure chosen to reconstruct the knee. This decision is based on a number of factors related to the tumor and the patient. Although these various procedures promise functional restoration, the reconstructive procedure should be individualized and designed to meet the needs of the patient.
Limb ablation for tumors of the shoulder is a devastating procedure. Recent advances in preoperative investigative measures, adjuvant chemotherapy, and reconstructive techniques have resulted in an increased interest in limb-sparing resection. For limb-sparing procedures to present a viable alternative in these cases, recurrence rates must be comparable to those obtained with ablative surgery. In addition, the resection must result in an improvement over the status obtainable with prosthetic devices. Twenty-four patients underwent limb-salvage procedures of various forms for primary bone tumors of the shoulder girdle. At follow-up (average: 33 months), 19 patients were alive without disease, one was alive with disease, and four were dead. One patient had local recurrence. All surviving patients enjoyed nearly normal function of the distal extremity. Improvements in techniques of soft tissue reconstruction in an effort to gain function and stability after wide resection of these tumors are necessary. Results indicate that these limb-salvage attempts offer successful alternatives to mutilating and crippling proximal amputations of the upper extremity.
The management of giant cell tumors involving the distal radius has always been a difficult problem. After resection to eradicate a primary or recurrent lesion, transplantation of a nonvascularized fibular autograft was used in 12 patients. Of these patients, ten had good to excellent functional results. The procedure can restore a functionally useful wrist.
In eighty patients who were seen with Paget's disease of the hip between 1969 and 1982, symptomatic coxarthrosis led to total hip arthroplasty in ninety-one hips. The long-term clinical and radiographic results were analyzed by use of the Mayo Clinic hip-scoring system. The cases of the forty-six patients (fifty-two hips) who had been operated on before 1975 were analyzed ten years after the arthroplasty. In this group, the incidence of aseptic loosening that required revision was approximately 15 per cent; radiographic evidence of loosening was evident in approximately 30 per cent of the femoral components and approximately 14 per cent of the acetabular components. Actuarial analysis comparing these forty-six patients with our over-all experience of total hip arthroplasty during the same period of time in 7,222 hips of patients who did not have Paget's disease revealed an increase of slight statistical significance in the incidence of revision for aseptic loosening in the patients who had Paget's disease. However, the over-all result was good or excellent in 74 per cent of these patients, suggesting that replacement of the hip using cemented components remains an acceptable form of treatment for degenerative coxarthrosis secondary to Paget's disease.
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A prospective randomized study was initiated at our institution in 1972 to determine the efficacy of routine elective lymphadenectomy in localized (stage I) melanoma. Included in the study were 171 patients, 62 of whom had no lymphadenectomy, 55 of whom had delayed lymphadenectomy, and 54 of whom had immediate lymphadenectomy. No significant difference was found among the three treatment groups with respect to survival or metastasis-free survival. Multifactorial analysis indicated that the level of invasion and the thickness of the lesion were the most important prognostic factors, followed by age (60 years or older), site (legs), and tumor type (nodular). A prognostic index based on these variables was highly predictive of metastasis or death. Even when this score was considered, no significant variation was noted among the three treatment groups. More subsequent complications of melanoma, however, occurred in the group with no lymphadenectomy--36 in this group but only 19 in each of the other treatment groups. This finding was not statistically significant but does indicate that a few additional problems may be associated with leaving regional nodes intact. Further studies are needed, and indeed are being conducted, to determine whether elective lymphadenectomy improves survival sufficiently to offset the costs and the complications associated with this approach.
The criteria for the management of patients with femoral neck fractures by internal fixation, hemiarthroplasty, or total hip replacement are becoming better defined. Our experience in 111 cases indicates that total hip arthroplasty has a definite role if the cases are carefully selected. The main indication is a high-risk fracture in an elderly patient with associated pre-existing joint disease.
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Dedifferentiated chondrosarcoma is a highly malignant variant of chondrosarcoma. Approximately 11 per cent of chondrosarcomas can be expected to dedifferentiate into more anaplastic lesions. In this report, we analyze the clinicopathological features and treatment of seventy-eight lesions of this type. The ages of the patients ranged from nineteen to eighty-two years (average, 54.6 years). The cartilaginous precursor was central in most patients. Eleven of the lesions developed in the site of a previously resected low-grade chondrosarcoma. Dedifferentiation was from low-grade chondrosarcoma to osteosarcoma in forty-two patients, to fibrosarcoma in thirty-three, and to malignant (fibrous) histiocytoma in three. Perforation of the cortex and a soft-tissue mass were found in most of the patients. Widespread metastatic disease within two years after resection was a frequent finding. The over-all five-year-survival rate was 10.5 per cent. Any potential for a "cure" is related to early diagnosis and adequate surgical treatment by amputation or resection.
This study was done to describe the magnetic resonance imaging (MRI) characteristics of osteosarcomas and to determine the clinical usefulness of MRI in the evaluation of patients with these tumors. Ten patients with osteosarcomas were examined with a Picker MRI scanner (0.15 Tesla resistive magnet). All had computed tomograms available for comparison. For demonstrating tumor extent in marrow, MRI was superior to computed tomography (CT) in 60% and about equal to CT in 40%. For defining soft tissue mass, MRI was superior to CT in 40% and about equal to CT in 60%. Direct sagittal and coronal images on MRI and superior contrast differences between tumor and normal tissues with MRI were the reasons for the advantage of MRI in these instances. CT was superior in all cases for demonstrating calcifications. Overall, MRI is better than CT for defining local extent of osteosarcomas. It is of greatest value in the peripheral skeleton, in the medullary canal, and in soft tissues.
Primary osteosarcoma of bone has originated in the spine in only a few patients. This report concerns twenty-seven of thirty patients who had the original diagnosis made and surgical treatment, if any, performed at the Mayo Clinic. The patients' ages ranged from eleven to eighty years. Pain in the area of involvement was the first symptom in all patients. In addition, nineteen patients (70 per cent) had neurological symptoms and signs when they were first seen. All patients had a surgical biopsy of the lesion, often combined with decompressive laminectomy. Twenty-one of the twenty-seven patients received postoperative radiation therapy in various dosages. Only five patients received adjunctive chemotherapy. All but one patient died of the disease, with a median length of survival of ten months (range, one to thirty-eight months). Although rare, osteosarcoma of the spine can usually be suspected on roentgenograms, and then the most aggressive therapy is justified.
Our experience involving 221 consecutive patients with giant-cell tumor who were treated from 1960 to 1982 is reported. Of one group of 146 patients, twenty-seven who were initially treated by wide resection and 112 who had thorough curettage had a recurrence rate of 23 per cent after an average length of follow-up of seven years. All thirty-three recurrences were noted less than six years after operation, and twenty-seven were noted within the first three years postoperatively. Over-all, the type of surgical removal was the most significant factor in recurrence. The recurrence rate was 34 per cent in the patients who had curettage of the lesion and 7 per cent in those who had a wide resection. In a second group of seventy-five patients, initially treated by us for a recurrent tumor, there were fifteen subsequent recurrences, after an average length of follow-up of seven years. Curettage and bone-grafting, with preservation of function of the joint, is the preferred treatment for most patients.
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