[An experimental study of ischemic damage and repair on the femoral head epiphysis in growing rabbits].
The vascular changes and repair processes in the femoral head epiphysis and growth plate in growing rabbits influenced by an interruption in the blood supply were investigated angiographically and histologically. Forty-one rabbits (six-week-old female Japanese White rabbit) were sacrificed for this study. The Interruption in the blood supply to the femoral head epiphysis was achieved by severing the nutrient arteries by electrocauterization in surgery. The revascularization process was examined by microangiography and histopathology of the epiphysis and growth plate at two-week intervals from 2 to 16 weeks after the surgery. The penetration of newly formed vessels into the bony epiphysis began at 4 to 6 weeks after the surgery. At 16 weeks, the vessels had penetrated into the growth plate. Granulation tissue without woven bone formation was seen on the loaded portion of the bony epiphysis, although woven bone was seen on the non-loaded portion. The articular cartilage diminished in thickness and cellular counts declined during the 16 weeks after the surgery. The degenerated columnar structure was replaced with mesenchymal tissue which intruded into the growth plate and connected epiphysis to the metaphysis at 8 weeks. The columnar structure of the growth plate was progressively disorganized with time, after 8 weeks. From these results, we concluded that the deformation of the femoral head epiphysis and premature closure of the growth plate were influenced by the vascular interruption of the nutrient arteries.
Department of Orthopaedic Surgery, Fujigaoka Hospital Showa University School of Medicine, Kanagawa, Japan.
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Yoshiwara
D000792:Angiography; D000818:Animals; D004838:Epiphyses / Q000098:blood supply / Q000502:physiology; D005260:Female; D005270:Femur Head / Q000098:blood supply* / Q000502:physiology; D006132:Growth Plate / Q000098:blood supply* / Q000502:physiology; D007511:Ischemia / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D011817:Rabbits; D013997:Time Factors