No abstract

We studied the bone mineral density (BMD) of 48 long-term survivors of highly malignant osteosarcoma who had been treated according to the chemotherapy protocols of the German- Swiss-Austrian Co-operative Osteosarcoma Study Group which include high-dose methotrexate. The mean age of the patients was 31 +/- 4.2 years and the mean follow-up 16 +/- 2.2 years. The BMD of the lumbar spine and of the proximal femur of the non-operated side was measured by dual-energy x-ray absorptiometry. A questionnaire was given to determine life-style factors, medical history and medication. Ten patients were osteoporotic, 21 osteopenic and 17 normal according to the WHO definition. Eighteen patients suffered fractures after receiving chemotherapy and all had significantly lower levels of BMD for all the sites measured.

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We investigated prospectively the bone mineral density (BMD) of the proximal femur after implantation of a tapered rectangular cementless stem in 100 patients with a mean age of 60 years (16 to 87). It was determined using dual energy x-ray absorptiometry, performed one week after surgery and then every six months until the end-point of five years. The BMD increased significantly in Gruen zones 2, 4 and 5 by 11%, 3% and 11% respectively, and decreased significantly in Gruen zones 1, 6 and 7 by 3%, 6% and 14% respectively, over the five-year period. The net mean BMD did not change over this time period. The changes in the BMD were not confined to the first 12 months after surgery. This investigation revealed no change in the overall periprosthetic BMD, but demonstrated a regional redistribution of bone mass from the proximal to distal zones.

Aneurysmal and solitary bone cysts develop most commonly during skeletal growth. The objective of our epidemiologic study was to evaluate the prevalence, recurrence rate, and probability of recurrence-free survival for aneurysmal and solitary bone cysts in young patients. We did a population-based analysis of 141 histologically confirmed cases. Seventy-three patients with aneurysmal bone cysts and 68 patients with solitary bone cysts were registered. The annual prevalence was 0.32 per 100,000 individuals (range, 0-1.238) for aneurysmal cysts, with a 1.8:1 male to female ratio and a median age of the patients of 11.1 years (range, 1-19.7 years). For solitary bone cysts, the calculated annual prevalence was 0.30 (range, 0-0.963) with a median age of the patients of 1.1 years (range, 0.5-19.9) and a 1.96:1 male to female ratio. Recurrent lesions occurred frequently in young males. Secondary aneurysmal bone cysts were observed only in females. During skeletal growth, aneurysmal and juvenile bone cysts more often occur in males with a peak prevalence at approximately 11 years of age. A greater prevalence of aneurysmal bone cysts in young individuals is associated with skeletal growth and immaturity. Young age and male gender are associated with an increased risk of local recurrence.