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F H Sim

Publications and source records attributed to F H Sim.

At least 37 records · Page 2Linked to original sources
PubMed1990

Chondrosarcoma of bone in children.

Chondrosarcoma of bone rarely occurs in children. This report analyzes the clinicopathologic features in a series of 47 patients with conventional chondrosarcoma who were less than 17 years of age. Of the 47 cases, 14 were from the Mayo Clinic files, and 33 were from our consultation files. Most of the lesions occurred in the trunk and upper ends of the long bones, with the humerus being the most frequent skeletal site. Twelve of the 47 tumors were secondary. The radiographic findings were the same as those seen in adult chondrosarcoma. Pathologically, the tumors were low grade. En bloc resection is the treatment of choice because of the high incidence of local recurrence with lesser surgical margins. Prognosis in childhood chondrosarcoma is no different from that in adult chondrosarcoma. None of the patients with follow-up data had metastasis.

Adolescent↗
PubMed1990

Soft tissue sarcoma. Integration of brachytherapy, resection, and external irradiation.

Between December 1981 and August 1988, 63 patients with clinically localized nonretroperitoneal soft tissue sarcomas underwent 65 brachytherapy procedures in conjunction with conservative resection with (61 tumors) or without (four tumors) external beam irradiation. Implant doses of 1500 to 2000 cGy were combined with 4500 to 5000 cGy of external irradiation. External irradiation was given preoperatively for larger lesions near bone or neurovascular structures, whereas it was used postoperatively for smaller, more resectable lesions or those that had previously been inadequately excised. There were 47 high-grade tumors, 34 tumors greater than 5 cm, and nine patients with recurrent lesions (five with previous irradiation). With mean follow-up of 20 months, conclusions on local control are tentative, but only two of 56 tumors (4%) with brachytherapy as part of initial management had recurred locally and three of nine recurrent tumors had re-recurred locally. Only one of five local recurrences was within the implanted volume. Only two of 40 implantations (5%) performed at initial resection followed by postoperative external irradiation led to wound complications, whereas four of 16 implantations (25%) performed at resection after preoperative external irradiation were associated with wound problems. This technique does not increase local morbidity and may enhance local tumor control in comparison with either external radiation or brachytherapy alone as an adjuvant to conservative resection.

Brachytherapy↗
PubMed1990

Case report 628: Low-grade central osteosarcoma.

In summary, low-grade central osteosarcoma is a clinically recognizable rare subtype of osteosarcoma, representing 1.9% of all osteosarcomas found at the Mayo Clinic. The lesion is locally aggressive but also has the potential for metastasis, particularly after local recurrence. The tumor may be difficult to distinguish radiographically and histologically from benign conditions, particularly fibrous dysplasia. This difficulty has led to inadequate treatment. In most cases, a wide surgical margin achieved by either local resection or amputation should result in a cure. Because of the low metastatic potential of the initial lesion, there seems to be no need for adjuvant chemotherapy.

Adult↗
PubMed1990

Rehabilitative techniques for athletes after reconstruction of the anterior cruciate ligament.

A wide spectrum of protocols is available for rehabilitation after anterior cruciate ligament reconstruction, and little agreement exists on the specifics of strengthening exercises or the sequence of activities. In this article, we discuss the current rehabilitative techniques used at the Mayo Clinic for athletes who have undergone anterior cruciate ligament reconstruction. These techniques are based on established principles of rehabilitation, clinical experience, and new information about the related biomechanics of the knee. An illustrative case reflects the benefits of this rehabilitation program, which lasts up to 1 year and is divided into five stages. The early stages focus on protected mobilization and a strengthening program that emphasizes closed rather than open kinetic chain exercises. Later, neuromuscular-proprioceptive training and sport-specific agility training redevelop the reaction time and the "coordination engrams" necessary for athletic competition. High-quality surgical care and a closely supervised rehabilitation program, based on kinesiologic and biomechanical factors as they pertain to the anterior cruciate ligament, are necessary for a successful outcome.

Adolescent↗
PubMed1990

Ice hockey injuries. A review.

Ice hockey is a fast-paced game involving both finesse and controlled aggression. Injuries are related to direct trauma (80%) and overuse (20%), with high puck velocities, aggressive stick use, and body checking (collisions) accounting for most of these. A participant can anticipate an injury after playing 7 to 100 hours of hockey, depending on his age, and most injuries are caused during the actual game rather than during practice. Although facial injuries are common, they are decreasing because of adequate use of helmets and masks. Conversely, cervical spine injuries are being reported more frequently. Injuries to the upper extremity include acromioclavicular joint dislocations, scaphoid fractures, and 'gamekeeper's thumb.' Injuries to the lower extremity predominantly involve soft tissue, with strains of the hip adductor, tears of the medial collateral ligament of the knee, and contusions of the thigh are common. Scientific studies have reduced injury by providing improved protective equipment, stricter rules and their enforcement, and effective training and conditioning.

Arm Injuries↗
PubMed1990

Metastatic bone disease. A study of the surgical treatment of 166 pathologic humeral and femoral fractures.

A retrospective study of the surgical treatment of 166 metastatic lesions of the humerus and femur in 147 patients was performed. There were 106 women and 41 men whose average age was 62 years. Two-thirds of the patients were treated for complete fractures, while one-third were treated for impending fractures. Breast, lung, and kidney carcinoma accounted for the majority of the primary lesions. One-half of the patients died within nine months of surgery, while one-quarter were alive 19.1 months after surgery. The patients with breast cancer had the best prognosis, while the patients with lung cancer had the worst. The probability of implant failure increased linearly with time to 33% at 60 months. The probability of failure for the femoral lesions was greater, with 44% at 60 months. The average survival in the patients with failed fixation in the femoral lesions was 34.5 months with a mean interval to failure at 17.7 months. The failure rate was high (23%) in proximal femoral lesions treated with a compression screw or nail plate. Common reasons for failure included poor initial fixation, improper implant selection, and progression of disease within the operative field. Bone cement augmentation should be used with the fixation device when possible. Complications due to hip-screw cut-out from the head may also be reduced by applying bone cement around the screw threads.

Adolescent↗
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↗