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Biomedical subjects

F H Sim

Publications and source records attributed to F H Sim.

At least 55 records · Page 3Linked to original sources
PubMed1998

Psychologic, situational, and physiologic variables and on-ice performance of youth hockey goalkeepers.

OBJECTIVE: To determine the relationship between psychologic, situational, and physiologic variables and on-ice performance of youth hockey goalkeepers. DESIGN: This study was structured to identify relationships and predictors of goalie performance. MATERIAL AND METHODS: Because athletes playing solo positions in team sports have not been analyzed in depth in terms of precompetition anxiety and because goalkeeper performance is critical to game outcome, we undertook a study of 43 goalies at a hockey camp. These goalies completed psychometric inventories to assess trait and state anxiety, confidence, life stress, and social support. Holter monitors measured heart rate while the goalies rotated through on-ice stations. Goalies were videotaped at the puck-shooting machine station, and performance (percent saves) was calculated. RESULTS: Trait (somatic) anxiety and positive mood state (ability to share) had different but significant relationships with on-ice performance. Heart rates ranged from 88 to 208 beats/min at the on-ice stations. Mean heart rate for older goalies (14 to 18 years of age) was 164 beats/min at the puck-shooting machine and 176 beats/min at other stations such as the slap-shot station. CONCLUSION: Older goalies performed well at a high level of arousal. Better performing goalies were more experienced, had faster heart rates "in the net," and had lower scores on all measures of anxiety.

Adolescent↗
PubMed1998

Total hip arthroplasty for the treatment of an acute fracture of the femoral neck: long-term results.

We reviewed the long-term results of 126 consecutive total hip arthroplasties performed with cement in eighteen men and 108 women who had an acute fracture of the femoral neck. The patients had a mean age of seventy-five years (range, thirty-nine to eighty-nine years) at the time of the operation and were followed for a minimum of 10.1 years (or until the patient died or had a revision operation) and a maximum of 20.4 years. The median duration of follow-up was 8.8 years for all patients and 15.7 years for the twenty-two patients who were alive at the end of the study period. Six hips (5 per cent) were revised because of aseptic loosening. Survivorship analysis revealed that the probability of survival of the prosthesis without revision (with 95 per cent confidence intervals) was 95 per cent (91 to 99 per cent) at five years, 94 per cent (88 to 98 per cent) at ten years, 89 per cent (79 to 97 per cent) at fifteen years, and 84 per cent (66 to 97 per cent) at twenty years. Of the 118 patients who were alive at the one-year postoperative examination, 117 (99 per cent) had no pain or mild pain and eighty-one (69 per cent) had regained or had an improvement in the preoperative level of function. At the latest follow-up examination, eighty-seven (86 per cent) of the 102 patients who were available still had no pain or only mild pain. Twenty-six patients (21 per cent) had had perioperative medical complications, and twenty-one patients (17 per cent) had had operative complications, including thirteen patients (10 per cent) who had had a dislocation of the hip. Total hip arthroplasty performed in elderly patients for the treatment of an acute fracture of the femoral neck was associated with a higher rate of complications than usually is reported for hemiarthroplasty in such patients. However, the total hip arthroplasty provided good clinical results and was associated with long-term survival of the prosthesis.

Adult↗
PubMed1998

Functional laboratory assessment after oncologic shoulder joint resections.

A laboratory evaluation was undertaken to assess the shoulder range of motion and distal strength after oncologic resection and reconstruction involving the shoulder joint and to compare these functional parameters based on potentially important variables. Inclusion in the study was limited to 32 patients with bone tumors of the proximal humerus or scapula treated surgically by resection of the shoulder joint including the proximal humerus from 1976 through 1992. Active shoulder range of motion and isometric elbow extension and forearm supination strength are significantly less after surgery in patients with greater amounts of bony resection and with resection of the deltoid. Patients who had a modified Tikhoff-Linberg resection were able to achieve 10 degrees to 15 degrees greater shoulder motion in each direction than were patients who had the classic procedure including complete scapulectomy. However, elbow flexion and extension strength and forearm pronation strength were greater for the patients with the classic resection. Osteoarticular allografts as a reconstructive alternative provide as a group the best shoulder motion and overall distal upper extremity strength, but these reconstructions were performed only when the rotator cuff muscles and deltoid were able to be reconstructed. Diminishing elbow strength was seen with longer followup in the patients with osteoarticular reconstructions, corresponding temporally to subchondral collapse observed on radiographs. Range of shoulder motion except rotation was just as good for allograft vascularized fibular arthrodeses as for the osteoarticular allografts, but strength was significantly less with the arthrodeses.

Adolescent↗
PubMed1997

Chondrosarcoma of small bones of the hands and feet.

BACKGROUND: Cartilaginous tumors of the hands and feet are not uncommon. Most are enchondromas, but they tend to show high cellularity, enlargement of nuclei, and many double-nucleated cells. Hence, differentiation between a benign lesion and chondrosarcoma may be difficult. METHODS: The files of patients treated at the Mayo Clinic and the consultation files were reviewed for examples of chondrosarcoma of small bones of the hands and feet. Histologic features and clinical charts were reviewed in all cases, and radiographs were reviewed in 111 cases. RESULTS: Seventy-five lesions involved the feet and 88 involved the hands. Bones of the fifth finger and the calcaneus were the most common sites of involvement. Nineteen tumors were secondary. Of the 104 intramedullary lesions studied radiologically, 96 showed cortical destruction, 83 a soft tissue mass, and 52 a permeative lytic pattern. Histologically, soft tissue extension and permeation of preexisting bone indicated malignant disease. One hundred sixteen tumors were Grade 1, 44 were Grade 2, and 3 were Grade 3. Of the 12 patients with distant metastasis from chondrosarcoma, 7 died of disease. Chondrosarcomas of the calcaneus and the talus were more likely to metastasize. CONCLUSIONS: Chondrosarcoma of small bones of the hands and feet has the potential to be fatal.

Adolescent↗
PubMed1997

Small cell osteosarcoma of bone. Review of 72 cases.

BACKGROUND: Small cell osteosarcoma of bone is a rare form of osteosarcoma, with an incidence rate of 1.3%. This tumor must be differentiated from other small cell malignancies because of treatment considerations, particularly patient response to chemotherapy. METHODS: Clinicopathologic findings in 72 cases (22 from Mayo Clinic files and 50 from consultation files) of small cell osteosarcoma of bone were studied. RESULTS: The femur was the most common bone involved, although the tumor was found in all portions of the skeleton. Radiographic features (available in 35 cases) suggested a diagnosis of osteosarcoma in 20 cases, Ewing's sarcoma or lymphoma in 14 cases, and giant cell tumor in 1 case. Histologically, there were four types according to the predominant cell size and cytologic features. Osteoid production was identified in all tumors. Complete treatment and follow-up data were available for 45 cases. Generally, in those cases without surgical treatment, greater than 60% of patients died of disease within 2 years. If the surgical procedure was associated with a marginal tumor margin, the prognosis was poor. In the 30 patients with wide or radical surgical margins, at last follow-up 13 were alive with no evidence of disease, 2 were alive with disease, and 15 died of disease at 5 months to 13.1 years after diagnosis. In 16 of 22 Mayo Clinic patients, excluding those who presented with metastasis, the cumulative 5-year survival rate was 28.9%. Median survival time in patients who had surgery with additional chemotherapy was 13.4 years, compared with 1.4 years in patients who underwent surgery alone (P = 0.17). CONCLUSIONS: Small cell osteosarcoma is a definite reproducible histologic entity. Treatment should be based on a protocol for osteosarcoma.

Adolescent↗
PubMed1997

Malignant fibrous histiocytoma of bone. A clinicopathologic study of 81 patients.

BACKGROUND: Malignant fibrous histiocytoma of bone, a relatively rare primary malignant neoplasm occurring in bone, is a distinct clinicopathologic entity formerly included in the category of osteosarcoma or fibrosarcoma. A series of patients treated at the Mayo Clinic for malignant fibrous histiocytoma of bone was studied to determine whether the prognosis for this disease is different from that of osteosarcoma and whether treatment should be different. METHODS: The bone tumor files of the Mayo Clinic were reviewed for examples of malignant fibrous histiocytoma of bone. Clinical records and histologic slides were reviewed for 81 patients. Roentgenograms of 13 patients were available for review. RESULTS: Patients with malignant fibrous histiocytoma of bone ranged in age from 6 to 81 years. The region most commonly affected was the knee. Seventy-eight percent of the lesions arose de novo and 22% in preexisting conditions. Histologically, most of the tumors were classified as the storiform pleomorphic type, although other histologic subtypes were identified. The prognosis depended on the types of surgical margins involved. Patients with wide or radical margins had a better prognosis than patients in whom the margins were contaminated. Some patients who received radiation therapy alone became long term survivors. CONCLUSIONS: The overall prognosis for patients with malignant fibrous histiocytoma was not found to be significantly different from that described for patients with osteosarcoma in recent series. However, at least in this small series, some patients with malignant fibrous histiocytoma had a good response to radiation therapy. Osteosarcoma is generally considered radioresistant.

Adolescent↗
PubMed1997

Malignant giant cell tumor of the tendon sheaths and joints (malignant pigmented villonodular synovitis).

Malignant pigmented villonodular synovitis (PVNS) is a rare lesion whose existence may be debatable. We studied eight cases that we consider to be examples of malignant PVNS. The three male and five female patients were aged 12 to 79 years. The knee was involved in three cases; the ankle in two; and the cheek, dorsum of the foot, and thigh in one each. Four patients had swelling for 6 months to 17 years before presentation. Three cases of malignant PVNS were secondary, arising in patients in whom PVNS had been documented previously, and five cases were primary, with histologic features similar to those of the secondary ones. Important histologic features of malignancy were (a) a nodular, solid infiltrative pattern of the lesion; (b) large, plump, round or oval cells with deep eosino philic cytoplasm and indistinct borders; (c) large nuclei with prominent nucleoli; and (d) necrotic areas. Atypical mitoses were occasionally seen. Four patients died with pulmonary metastasis (two also had metastasis to inguinal lymph nodes). Four patients are alive from 3 1/2 to 5 years after the last surgical treatment. The malignant nature of this lesion, the histologic architecture similar to that of PVNS, and the fibrohistiocytic appearance of the cells suggest that malignant PVNS is an entity.

Adult↗
PubMed1997

Free vascularised fibular grafting for reconstruction after tumour resection.

We have reviewed 30 patients at a mean of 36 months after free vascularised fibular transfer to reconstruct massive skeletal defects after resection of primary bone tumours. There were 23 malignant and 7 benign neoplasms, half in the lower limb and half in the upper. Arthrodesis was performed in 15 and intercalary bone replacement in 15. The mean fibular graft length was 189 mm. Union was achieved in 27 (90%) at an average of 7.6 months, and the 3-year survival was 89%. There was a high complication rate (50%), but most resolved without greatly influencing the final outcome. There was local recurrence in two (6.7%), but 16 of the 24 assessed patients (67%) had satisfactory functional results. This is a reasonably effective means of reconstruction for limb salvage after resection of tumours.

Adolescent↗
PubMed1997

En bloc resection of tumors of the distal end of the ulna.

The operative treatment of malignant tumors and aggressive benign tumors involving the distal end of the ulna often necessitates en bloc resection. The oncological and functional results for eight patients in whom a neoplasm involving the distal end of the ulna had been treated with en bloc resection without reconstruction of the osseous defect were reviewed retrospectively at a mean of seventy-nine months (range, twenty-three to 271 months). Four patients had a giant-cell tumor; two, a low-grade osteogenic sarcoma; one, a hemangioendothelioma; and one, a soft-tissue epithelioid sarcoma with osseous involvement. The amount of bone that was removed from the distal end of the ulna ranged from 3.1 to 9.0 centimeters. In the four patients who had a malignant tumor, a minimum of 7.5 centimeters was removed in order to achieve an adequate wide margin proximally. In the patients who had a benign tumor, a maximum of 6.6 centimeters was resected. Extraperiosteal resection was performed in three of the patients who had a malignant tumor and in one of the patients who had an aggressive giant-cell tumor. Subperiosteal resection was performed in the three patients who had a benign tumor and in one patient who had a parosteal osteogenic sarcoma. None of the patients had local or systemic evidence of recurrence of the tumor. The functional result was excellent for six patients and good for two. Grip strength was reduced by a mean of 15 per cent compared with the strength on the contralateral side, and this reduction did not appear to be related directly to the amount of bone that had been resected. The findings of this study support the concept that routine reconstruction of the osseous defect is not necessary after en bloc resection of a neoplasm of the distal end of the ulna.

Adult↗
PubMed1997

Malignant melanoma: Mayo Clinic experience.

To present the Mayo Clinic experience with treatment of melanoma of the trunk and extremities, we reviewed previous Mayo Clinic studies on the management of malignant melanoma and summarized the survival data and treatment-related outcome. A prospective trial involving elective lymph node dissection in 171 patients with malignant melanoma showed no advantage in overall survival and disease-free survival in the group whose nodes were removed. In an assessment of the treatment variables, a Cox stepwise multiple regression analysis showed a strong correlation of lesion thickness and level of invasion with survival. Another study of 535 patients with melanomas that involved the trunk and extremities, who were treated at the Mayo Clinic between 1971 and 1980, showed an overall survival of 83%. Patients with thin lesions (less than 0.76 mm thick) had a 98% 5-year survival, whereas patients with lesions 4 mm thick or thicker had only a 45% 5-year survival. Because the Mayo Clinic prospective randomized study showed no benefit for patients with melanoma who undergo immediate or delayed lymphadenectomy in the trunk and extremities, we do not perform elective lymph node dissection; however, close follow-up of patients is instituted, and lymph node dissection is performed when nodal involvement is first suspected.

Humans↗
PubMed1997

Prosthetic hip replacement for pathologic or impending pathologic fractures in myeloma.

The authors retrospectively reviewed 53 hip replacements performed in 50 patients (mean age, 65 years) for plasmacytoma (four lesions) or multiple myeloma (49 lesions) of the hip region. Perioperatively, 49 patients received chemotherapy. Twenty-four hip lesions had radiation therapy. Within a mean followup period of 32.6 months, 15 (28%) complications occurred. Late deep infection, dislocation, and aseptic loosening with medial migration of the acetabular component occurred in one patient each. Three patients died during the first postoperatively month. All of the remaining patients postoperatively regained their previous ambulatory status; hip pain relief was achieved in 98% of patients. At the time of the latest followup evaluation, 84% of the patients had died (median survival time, 18 months) and 16% were still alive (median survival time, 76 months). Patients with plasmacytoma had longer survival than did patients with multiple myeloma (median survival, 6.3 years versus 18 months, respectively). No significant association was found between patient survival and the stage of disease at diagnosis, age, gender, type or location of the myeloma lesion, or the type of implant used. Because of the relatively long survival time, prosthetic replacement is indicated for extensive hip lesions in patients with plasmacytoma or multiple myeloma.

Adult↗
PubMed1996

The clinicopathologic spectrum of myxoid and round cell liposarcoma. A study of 95 cases.

BACKGROUND: The prognosis of patients with myxoid liposarcoma (ML) or round cell liposarcoma (RCL) has never been adequately defined. METHODS: We evaluated the clinical and pathologic features of 95 patients with biopsy proven ML or RCL examined at the Mayo Clinic between 1971 and 1992. Routine hematoxylin and eosin stained slides of all cases were reviewed. Morphologic variable evaluated included percent of round cell differentiation, percent of lipoblastic differentiation, and presence of tumor necrosis. Clinical follow-up was available for 86 patients (range: 6 months-23.4 years; mean: 7.2 years; median: 5.9 years). Flow cytometry for determination of DNA ploidy was performed on paraffin embedded tissue available from 46 cases. Survival analyses for the 86 patients with adequate clinical follow-up were performed by the Kaplan-Meier test using the approximate chi-square statistic for the log rank test. RESULTS: Age at diagnosis ranged from 16 to 81 years (median: 44 years). The extremities were involved in 91 cases, the retroperitoneum in 3 cases, and the perineum in 1 case. The single most common location was the thigh (61 cases). Histologically, round cell differentiation was present in 41 cases (43%) ranging from 5% to 100% of the tumor volume. Only one case of "pure" RCL was used in the study. Spontaneous tumor necrosis was noted in 4 cases. By flow cytometry, 38 tumors were diploid, 6 were aneuploid, and 1 was tetraploid. The data from 1 case was uninterpretable. Thirty patients (35%) developed metastasis; 27 (31%) died from the disease. CONCLUSIONS: With multivariate analysis, age ( > 45 years), percent of round cell differentiation ( > or = 25%), and the presence of spontaneous tumor necrosis are significantly associated with a poor prognosis. No correlation was observed between DNA ploidy (i.e., diploid vs. aneuploid) and percent of round cell differentiation or clinical outcome.

Adipocytes↗
PubMed1996

Sacropelvic resection and intraoperative electron irradiation in the management of recurrent anorectal cancer.

PURPOSE: To provide local control and palliation of pain, a multimodal ity approach, including external beam radiation therapy, surgical resection, and intraoperative electron irradiation (IOERT), has been used for patients with locally advanced anal or recurrent rectal cancers involving the sacrum. METHODS: Sixteen consecutive patients (11 males; 5 females; ages, 44-76) underwent surgical exploration, sacrectomy, and IOERT, between 1990 and 1994. RESULTS: Proximal extent of resection was S2-3 in four patients, S3-4 in five, and S4-5 in five. Two patients had resection of the anterior table of the sacrum. Margins were clear in 11, close in 3, and microscopically involved in 2 patients. Operative times ranged from 6 to 17 (median, 12.5) hours, and blood loss ranged from 300 to 12,600 (median, 3,350) ml. No operative deaths resulted. Major postoperative complications occurred in eight patients (50 percent): posterior wound infections and dehiscence, urinary leak, and ileal fistula. Five (31 percent) and 3 (19 percent) patients developed no or minor complications, respectively. Intensive Care Unit stay was one night for all patients, and overall hospital stay ranged from 11 to 30 (median, 16.5) days. Follow-up was available on all 16 patients. Kaplan-Meier survival was 68 percent at one year and 48 percent at two years. At the time of analysis, 9 of 16 patients were alive. Of the nine alive patients who responded to a questionnaire, eight reported a reduction in pain and improved quality of life postoperatively. CONCLUSIONS: Sacropelvic resection, in conjunction with IOERT, provides palliation and offers potential for cure in patients with locally advanced or recurrent anorectal cancer.

Adult↗
PubMed1996

Low grade central osteogenic sarcoma. A long-term followup of 20 patients.

Osteogenic sarcoma is a heterogeneous family of tumors that has a variable biologic behavior. Low grade central osteogenic sarcoma is an uncommon form that is characterized by a long premorbid history and is compatible with prolonged survival after treatment. Twenty cases of low grade central osteosarcoma with long-term followup (16 [2.5-48] years) were studied retrospectively. The age distribution was broad (range, 15-83 years). All tumors arose in the lower limb. The primary symptom was pain; mean duration was 44 months (range, 1-180 months). A diagnosis of low grade central osteosarcoma was made primarily for 11 patients. For 9 others, fibrous dysplasia (3), nonossifying fibroma (2), fibroma (1), chondromyxoid fibroma (1), chondrosarcoma (1), and simple bone cyst (1) were diagnosed initially. Intralesional surgery was associated with recurrence in every case. Radical margins were not associated with local recurrence. Four recurrences were higher grade and 1 was dedifferentiated. Three of 4 patients with metastases died of their disease. Five- and 10-year survival was 90% and 85%, respectively. Histology and radiology are complementary for confirming the diagnosis. Low grade central osteosarcoma seems to be controllable by surgery alone if at least wide margins are used.

Adolescent↗
PubMed1996

Intercalary spacers in the treatment of segmentally destructive diaphyseal humeral lesions in disseminated malignancies.

During a 10-year period, 17 patients with segmentally destructive bone lesions of the humeral diaphysis in disseminated malignancies resulting in impending fracture (8 patients), pathologic fracture (6 patients), or failure of attempted internal fixation techniques (3 patients) were treated with resection of the involved diaphyseal segment and reconstruction with a cemented modular intercalary humeral spacer. Fourteen patients had metastatic cancer, 2 had multiple myeloma, and 1 had lymphoma. Breast and renal carcinoma were the most common pathologic diagnoses. The involved site was within the middle 1/3 in 8 patients, in the proximal-middle junction in 5, in the middle-distal junction in 2, and within the proximal and distal 1/3 in 1 patient each. Early pain relief was successful in 88% of patients. Early in the postoperative hospital course, patients generally were able to use the ipsilateral hand to assist feeding. Radiographic analysis revealed that the limited selection of stem lengths led to 76% of the distal stems and 47% of the proximal stems being shorter than the ideal length. The complication rate independent of disease progression was 29%. The most common complication was temporary radial nerve injury (3 patients). There were 3 implant failures, most commonly due to disengagement of the male-female junction. Two periprosthetic fractures occurred, 1 proximally (due to tumor progression) and 1 distally. Suggestions are given for modification of the implants to improve the major problems of limited versatility in intramedullary stem length and inadequate mating at the junction.

Adult↗