Periosteal insulin-like growth factor I and bone formation. Changes during tibial lengthening in rabbits.
We investigated changes in periosteal insulin-like growth factor I (IGF-I) during tibial lengthening. In 37 rabbits, an osteotomy of the right middle tibia was made and fixed by a unilateral external fixator. The rabbits were randomized into 6 groups: the tibiae were distracted at 0.5 mm/day up to 4 weeks and the animals killed after 2 weeks, 4 weeks or 6 weeks, for each period there was a control group with no distraction. Periosteal IGF-I was measured by radioimmunoassay and bone formation was quantified by CT scanning. During bone lengthening, CT showed moderate bone formation, while IGF-I was increased. When lengthening was stopped, IGF-I returned to a basal level, and CT scanning showed considerable bone formation. Our study suggests that IGF-I plays a role in an early stage of bone formation.
Schumacher
B
B
Department of Orthopaedic Surgery, University Hospital of Aarhus, Denmark.
Albrechtsen
J
J
Keller
J
J
Flyvbjerg
A
A
Hvid
I
I
D000818:Animals; D001842:Bone and Bones / Q000000981:diagnostic imaging; D002113:Calcification, Physiologic / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology*; D010521:Periosteum / Q000737:chemistry*; D011817:Rabbits; D014057:Tomography, X-Ray Computed
D007334:Insulin-Like Growth Factor I