Biomedical subjects

F H Sim

Publications and source records attributed to F H Sim.

At least 127 records · Page 7Linked to original sources

PubMed1991

Survival and management considerations in postirradiation osteosarcoma and Paget's osteosarcoma.

Postirradiation and Paget's osteosarcomas are high-grade malignancies. The five-year survival was only 10% in recent experience at the author's institution. Progressive pain is an important clinical feature in both conditions. Careful roentgenographic studies demonstrate cortical destruction and a soft-tissue mass in virtually all patients. Metastasis was present in 25% of both groups of patients at presentation. In contrast to previous series, more than 80% of the patients with postirradiation osteosarcoma had had irradiation for malignant entities and more than 70% had been treated with modern radiotherapy regimens (cobalt-60 or linear accelerator). Twice as many patients with postirradiation osteosarcoma were evaluated and treated in the 1980s than in the previous decade. The initial indication for irradiation often was carcinoma of the breast, uterus, or cervix, or lymphoma. Two-thirds of the patients had progressive disease that was not controllable within six months after diagnosis. Early detection may be the only effective means of improving survival with postirradiation or Paget's osteosarcoma. These patients require lifelong follow-up evaluations.

Bone Neoplasms↗

PubMed1991

Dislocation of the knee.

The results of treatment for vascular and ligamentous injuries in 17 patients who suffered complete dislocation of the knee were reviewed. Eight patients had 23 associated injuries. All nine patients who had injuries of the popliteal artery had arterial reconstruction with saphenous vein bypass grafts, which were successful in eight (89%). Intraoperative arteriography after vascular repair showed a narrowed anastomosis requiring revision in two (22%) of the nine patients and distal thrombi requiring removal in five (55%) patients. Delay in arterial repair was responsible for the one failure. Eleven patients had satisfactory results after early open ligament repair. The results were less favorable in the patients not treated with early ligament repair.

Adolescent↗

PubMed1991

Resection of malignant bone tumors about the shoulder. A preliminary report of reconstruction with a new modular spacer.

Reconstruction after resection of malignant bone tumors about the shoulder is difficult. Twelve patients had reconstruction using a new titanium modular spacer. This modular system allows the surgeon to reconstruct variable lengths of the proximal humerus. Although the patient has no active shoulder motion, excellent hand and elbow function is preserved. The spacer serves as a temporary device in the young active patient. A more definitive reconstructive procedure can be performed after the completion of chemotherapy and a sufficient disease-free interval.

Adolescent↗

PubMed1991

Total knee arthroplasty for osteoarthrosis in patients who have Paget disease of bone at the knee.

Thirteen patients who had had sixteen total knee arthroplasties for pagetic gonarthrosis were followed for a mean of seven years (range, two to fifteen years). Involvement of the femur or tibia with Paget disease was associated with multiple technical difficulties at operation and with a final position in suboptimum varus or valgus alignment (ten limbs) or suboptimum alignment of the mechanical axis (nine limbs). The presence of bone with Paget disease did not affect the amount of blood lost during the operation, the postoperative course, or the rate of loosening of the prostheses. At the most recent evaluation, nine patients had no pain, three had mild pain, and one had moderate pain. The mean Knee Society pain score improved from 42 points preoperatively to 88 points and the mean functional score, from 33 to 86 points.

Aged↗

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