technetium-tc-99m-medronate and Epiphyses--Slipped

Premature closure of the physis of the greater trochanter has been reported to be a predictive sign of chondrolysis in hips with slipped capital femoral epiphysis (SCFE). In the present series, the physis of the greater trochanter showed decreased activity on bone scintigraphy in 16 patients with SCFE and concurrent or developing chondrolysis. In five of these patients, the scintigraphic pattern (decreased activity of the physis of the greater trochanter) preceded radiographic changes of chondrolysis. In 13 patients with SCFE without chondrolysis, the physis of the greater trochanter appeared normal on scintigrams and open on radiographs. Use of scintigraphy in patients with SCFE permitted earlier recognition of chondrolysis, increasing the potential of altering the course of the disease.

Topics: Adolescent; Cartilage Diseases; Child; Epiphyses, Slipped; Female; Hip Joint; Humans; Male; Pelvic Bones; Radiography; Radionuclide Imaging; Technetium Tc 99m Medronate

The effect of pulsed electromagnetic stimulation on bone formation was tested in a lower-limb-lengthening model in the rabbit. Limb lengthening was performed by distraction epiphysiolysis. A specially designed external distraction device allowed 10 mm of lengthening of the tibia. Coils to generate a pulsed electromagnetic field were clipped onto the distractor. Stimulation started after a distraction period of three weeks and was continuous for 18 weeks. A control group received the same treatment without stimulation. Bone formation in the elongated zone was evaluated by computed tomography, scintigraphy, and histology. Bone healing involved accretion of callus followed by a process of remodeling, resulting in the formation of a solid cortex. The formation of a diaphysislike structure at the original site of the metaphysis progressed from the distal end of the elongated zone upward. Electromagnetic stimulation had no effect on the rate or extent of bone formation and remodeling.

Topics: Animals; Bone Development; Bone Lengthening; Bony Callus; Electromagnetic Fields; Epiphyses, Slipped; Female; Rabbits; Radionuclide Imaging; Technetium Tc 99m Medronate; Tibia