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Biomedical subjects

F H Sim

Publications and source records attributed to F H Sim.

At least 37 records · Page 2Linked to original sources
PubMed2000

Primary fibrosarcoma of bone. Outcome after primary surgical treatment.

To investigate outcome and evaluate prognostic factors in primary fibrosarcoma of bone, all patients at the authors' institution who had surgical treatment for primary fibrosarcoma of bone from 1910 to 1995 were studied. Medical records, surgical reports, radiographs, and histologic slides of 92 patients (51 males, 41 females; mean age, 38 years; range, 8-84 years) were reviewed. The most common tumor locations were the femur (28 patients), tibia (21 patients), and pelvis (14 patients). Sixty-one tumors (66%) were Enneking Stage IIB. Twenty-nine patients (31.5%) had adjuvant therapy: 16 had radiation, nine had chemotherapy alone, and four had radiation and chemotherapy. Amputation or disarticulation was performed in 61 patients (66%), wide excision was performed in 13 (14%), marginal excision was performed in 15 (16%), and intralesional excision was performed in three (3.3%). Local recurrence occurred in 14 patients (15%) at a median time of 7 months (range, 3-21 months). Metastases developed in 58 of the 85 patients (68%) with Stage I or II tumors at presentation, at a median of 9 months (range, 1-51 months). Survivorship analysis showed that the overall probability of survival was 33.4% at 5 years after surgery. Multivariate analysis showed that the main prognostic risk factors affecting overall survival included age older than 40 years, tumor location in the axial skeleton, and high-grade tumor (Grade 3 or 4). With the high incidence of systemic failure after surgical treatment, perioperative adjuvant treatment modalities should be considered.

Adolescent↗
PubMed2000

Surgical treatment for metastatic disease of the pelvis and the proximal end of the femur.

Advances in the treatment of invasive cancers continue to improve the longevity of patients who have these diseases; thus, the care of patients who have bone metastases is an issue of the utmost importance to the orthopaedic surgeon. In terms of maintaining the ability to walk, no site of potential metastatic involvement is more crucial than the proximal end of the femur and the acetabulum. Advances in femoral and acetabular implants, imaging modalities, and operative techniques now allow reconstruction of even the most complex acetabular and proximal femoral defects. However, the orthopaedic surgeon must recognize the need to approach management of these patients from a multidisciplinary perspective. The oncologist, radiotherapist, rehabilitation medicine specialist, radiologist, and pathologist each have a role to play. Only through cooperation among all members of the team will a patient who has metastatic disease or a myeloma be given the best possible care.

Arthroplasty, Replacement, Hip↗
PubMed1999

High grade surface osteosarcoma: a clinicopathologic study of 46 cases.

BACKGROUND: High grade surface osteosarcoma is a rare subtype of osteosarcoma arising on the surface of bone, accounting for only 8.9% of surface osteosarcomas at the study institution. METHODS: This study reviews 46 cases of high grade surface osteosarcoma, comprised of 13 cases from the Mayo Clinic files and 33 from the authors' files. Histologic features were reviewed in all cases, and radiographs were reviewed in 29 cases. RESULTS: There was a definite male predominance, and 70% of the patients were in the second and third decades of life. Forty-four of the 46 patients had lesions involving the long bones, the most common site being the midportion of the femur. Radiographically, the majority of lesions showed dense to moderate mineralization with a fluffy, immature appearance. Radiating spicules of bone perpendicular to the long axis of the bone, characteristic of periosteal osteosarcoma, were sparse. Histologic findings were identical to those of conventional osteosarcoma. Overall, survival at 5 years was 46.1%. Statistical analysis revealed that marginal excision was associated with an increased risk of local recurrence and that the patients with Broders Grade 3 tumors had a better prognosis than those with Grade 4 tumors. A good response to chemotherapy was associated with better clinical outcome. CONCLUSIONS: High grade surface osteosarcoma is a rare subtype of surface osteoscarcoma that has a prognosis similar to that of conventional osteosarcoma, in contrast to the more common type of osteosarcoma arising on the surface of bone. Wide excision and effective systemic chemotherapy are associated with better clinical results.

Adolescent↗
PubMed1999

Reoperation results after segmental prosthetic replacement of bone and joint for limb salvage.

Thirty-eight patients who had undergone reoperations because of complications or implant failure subsequent to a prosthetic replacement for limb salvage procedure for the treatment of musculoskeletal neoplasm were followed until death or a minimum of 2 years, then reviewed. The mean follow-up time before reoperation was 35 months, and the mean follow-up time after reoperation was 51 months. The major indication for reoperation was aseptic loosening (34%). The reoperative procedures included 19 major revisions of the prosthesis and 19 other reconstructions. There were 7 complications, including 1 local tumor recurrence. Twelve patients died of metastatic disease at a mean of 16 months after reoperation. The probability for patient survival was 74% beyond 3 years and 67% after 5 years. The surgical staging, site of tumor involvement, and type of reoperation all correlated with long-term patient survival. Overall, 72% of the patients achieved excellent or good functional results: a rate that was slightly inferior to that of the initial arthroplasty. Despite this, 84% of the implants demonstrated either excellent or good performance at 5 years. Therefore, reoperation because of a failed initial prosthesis or for other reasons after a limb salvage procedure using custom-designed or modular-segmental bone and joint implants seems feasible with no significant effect on subsequent functional performance or on patient survival.

Adolescent↗
PubMed1999

Primary alveolar soft part sarcoma of bone.

AIMS: Alveolar soft part sarcoma is a distinct, rare soft tissue tumour occurring primarily within the skeletal muscles or musculofascial planes in young adults. Primary involvement of bone is extremely rare. We report on six patients with alveolar soft part sarcoma occurring primarily in bone. METHODS AND RESULTS: Thorough clinical and radiographic examinations were done to rule out any other primary site. The patients were four women and two men aged 17-35 years (mean, 24.5 years). The primary site of the tumour was the femur in three patients, the ilium in one and the fibula in two. In one of the patients with fibular involvement, the tibia was also involved by direct extension. Of the long bone lesions, three were centred in the metaphysis and one in the diaphysis. Radiographically, all of the lesions demonstrated an osteolytic pattern of bone destruction with ill-defined margins and a wide zone of transition between the lesion and adjacent normal bone. Microscopically, all tumours showed the typical histological pattern of alveolar soft part sarcoma. Diastase-resistant, periodic acid-Schiff-positive crystalline structures were identified within the cytoplasm and confirmed ultrastructurally. Immunohistochemically, a keratin stain was negative in all cases; there was positive staining for MyoD1 in the cytoplasm but not the nuclei. Distant metastasis developed in four patients; one died. CONCLUSION: Alveolar soft part sarcoma arising in bone is extraordinarily rare but should be considered in the differential diagnosis of metastatic hypernephroma in a young patient.

Adolescent↗
PubMed1999

Osteosarcoma of the foot: a review of 52 patients at the Mayo Clinic.

This is a review of 52 osteosarcomas of the foot. The incidence of osteosarcoma of the foot is very low. It appears to affect older patients and the calcaneus is a common site. The incidence of chondroblastic tumors is high and most tumors are high grade. In many cases, amputation is required for local control of disease.

Adolescent↗
PubMed1999

Head and neck replacement prostheses in revision hip arthroplasty: experience with a single modern design.

This study reviewed 52 revision hip arthroplasties in which calcar cortical deficiencies were addressed by implantation of a cemented, modern-design head and neck replacement femoral prosthesis. Mean clinical follow-up was 38 months. Radiographic follow-up beyond 22 months was available for 34 patients (mean: 35.8 months). Mean Mayo clinical hip score (maximum: 80) improved from 28.2 preoperatively to 55.2 at last follow-up. No femoral component was revised for aseptic loosening. However, radiographic analysis demonstrated one prosthesis was probably loose and two were possibly loose. A 92.7% Kaplan-Meier 5-year implant survival rate free from radiographic loosening was projected. This type of prosthesis has yielded good clinical results and excellent early survival.

Adult↗
PubMed1999

Vertebra plana of the lumbar spine caused by an aneurysmal bone cyst: a case report.

The patient was a 15-year-old girl who had a lesion of the fourth lumbar vertebra. Plain radiographs suggested vertebra plana, with complete collapse of the body of the fourth lumbar vertebra and no involvement of the intervertebral disk spaces. The presumptive diagnosis was eosinophilic granuloma. Progressive neurologic symptoms required surgical excision of the lesion, decompression, and fusion. Histopathologic examination of the operative specimen confirmed the diagnosis of an aneurysmal bone cyst.

Adolescent↗
PubMed1999

Reoperation for failed prosthetic replacement used for limb salvage.

Patients with segmental bone and joint replacement prostheses because of tumors increasingly need revision surgery because of their long term survival. Between 1970 and 1990, 208 custom prosthetic replacements were performed for limb salvage in patients with tumors. Reoperations were required in 52 patients. The mean time to reoperation was 37 months. The reoperation procedures included 35 prosthetic revisions, 11 amputations, four arthrodeses, one vascularized fibular graft, and one open reduction and internal fixation of a fracture with supplemental bone graft. Functional assessment using the new Musculoskeletal Tumor Society scoring system was available for the 36 living patients, and their mean rating was 63% (18.9) at 12 years' mean followup. Of the 35 patients who received a new prosthesis, 12 (33%) patients needed a third operation at mean followup of 68 months. The probability of prosthetic survival in the group of 35 patients needing revision to the same or another prosthesis was 79% at 5 years and 65% at 10 years. The chance and frequency of needing reoperation increased as patients survived longer. Reoperations for tumor recurrence or infection usually resulted in amputation. Reoperation for failed initial segmental bone and joint prosthetic replacement is feasible and effective and can be done without jeopardizing subsequent patient and implant survival or without significantly affecting functional results compared with the values before reoperation.

Adolescent↗
PubMed1999

Biologic attachment of an allograft bone and tendon transplant to a titanium prosthesis.

An Achilles tendon allograft with its bony insertion was used to bridge a Titanium implant, containing an endoprosthetic tendon anchor, and the sheep biceps muscle. Twelve sheep were operated on unilaterally and followed up clinically and histologically for 2, 4 (n = 2), 8, and 12 months (n = 4). Full function of the front limb was regained after 8 to 12 weeks. There were no signs of mechanical loosening at all times. The morphologic changes at the bone block and implant fixation site were an initial revascularization of the allograft bone, which was observed at 2 months and enhanced at 4 months but occurred without any evidence of bone remodeling. This was changed in all specimens taken at 8 and 12 months where intensive new bone development, remodeling, and bone ingrowth in the titanium implant was found. Bone mass was shifted significantly to the tendon insertion half of the bone block because of a creeping substitution of the cancellous allograft bone and bone ingrowth to the implant. Overall bone mass slightly decreased with time but resorption of allograft bone outweighed new bone development only at lesser loaded areas. Transplantation of a bone and tendon allograft to an implant resulted in a revitalized, mechanically stable, and biologically anchored compound.

Achilles Tendon↗
PubMed1999

Bone tumors of the coracoid process of the scapula.

Bone tumors of the coracoid process of the scapula are rare, and diagnosis and treatment often are delayed. The records of 18 patients with bone tumors of the coracoid process were reviewed. Histologic types included eight cases of ordinary chondrosarcoma, three cases of dedifferentiated chondrosarcoma, two cases of osteoid osteoma, and one case each of osteosarcoma, plasmacytoma, lymphoma, giant cell tumor, and aneurysmal bone cyst. All 18 patients had shoulder pain, and eight of them had been treated with steroid injections for nonneoplastic conditions. Radiologically, chondrosarcoma did not always show clear cortical destruction, and one giant cell tumor had features mimicking those of chondrosarcoma. Five patients (three with dedifferentiated chondrosarcoma, one with chondrosarcoma, one with plasmacytoma) died of disease. The coracoid process was the site with a markedly high proportion of chondrosarcomas. Bone tumors of the coracoid process may be difficult to detect on plain radiographs. In the patient with persistent shoulder pain unresponsive to the selected treatment, additional imaging studies should be considered to eliminate the possibility of a bone lesion.

Adolescent↗
PubMed1998

Aneurysmal bone cyst of the spine. Management and outcome.

STUDY DESIGN: The clinical records, radiographs, histologic sections, and operative reports of 52 consecutive patients with an aneurysmal bone cyst of the spine were reviewed to evaluate diagnostic and therapeutic options and to correlate treatment and outcome. OBJECTIVES: To define the incidence, clinical presentation, diagnostic and therapeutic options, and prognosis of patients with aneurysmal bone cyst of the spine. SUMMARY OF BACKGROUND DATA: There are special considerations in the management of spinal lesions: relative inaccessibility of the lesions, associated intraoperative bleeding, necessity of removing the entire lesion to avoid the possibility of recurrence, proximity of the lesion to the spinal cord and nerve roots, and potential postoperative bony spinal instability. METHODS: Fifty-two consecutive patients with an aneurysmal bone cyst of the spine were treated from 1910 to 1993. Forty patients initially treated for a primary lesion had operative treatment (19 intralesional excision and bone grafting and 21 intralesional excision); four also had adjuvant radiation therapy. Preoperative arterial embolization was performed in two. RESULTS: There was a recurrence rate of 10% within 10 years. All recurrences were noted less than 6 months after surgery. Of 12 patients treated for a recurrent lesion, two had a subsequent recurrence (16.7%) within 9 years. At last follow-up examination, 50 patients (96%) were free of the disease. One patient died of postradiation osteosarcoma, and one died of intraoperative bleeding. CONCLUSION: Current treatment recommendations involve preoperative selective arterial embolization, intralesional excision curettage, bone grafting, and fusion of the affected area if instability is present.

Adolescent↗
PubMed1998

Excision curettage and allografting of giant cell tumor.

Between 1987 and 1994 we followed 22 patients with giant cell tumors involving the long bones. Their average age was 31 years (range 17-50 years). Five patients had grade II tumors and the other 17 grade III lesions. The average volume of lesions after curettage was 231 ml (range 56-450 ml). All of the patients underwent a modified excisional curettage, and the cavity was filled with deep-frozen allogenic corticocancellous bone graft with supplementary fixation. Two patients developed postoperative complications including a superficial wound infection in one case and a traumatic tibial plateau fracture in one case. The overall outcome was good or excellent in 91% of the patients (i.e., 20/22 cases). There was no degenerative joint arthritis and, surprisingly, no instance of tumor recurrence. Allograft infection and fracture were not present. An allogeneic cortical strut with cancellous bone graft can be used safely and is effective for grafting cavitary lesions created after complete removal of the tumor.

Adolescent↗