Scanning electron microscopic examinations on retarded bone defect healing in spontaneously diabetic BB/O(ttawa)K(arlsburg) rats
N. Follak1, I. Klöting2, D. Ganzer1 and H. Merk1
1Orthopedic Research Laboratories, Department of Orthopedic Surgery, Ernst Moritz Arndt University, Greifswald, Germany and 2Institute for Pathophysiology, Division of Laboratory Animal Science, Karlsburg, Ernst Moritz Arndt University, Greifswald, Germany
Offprint requests to: N. Follak, MD, Orthopedic Research Laboratories, Department of Orthopedic Surgery, Ernst Moritz Arndt University, F. Sauerbruch Str., 17487 Greifswald, Germany. Fax: +49-3834-867052. e-mail: follak@mail.uni-greifswald.de
Summary. To date, no detailed knowledge from animal
experiments is available on the kind and extent of osseous and
mineral metabolic disorders in genetically determined, insulin-dependent
Type I diabetes. The purpose of this study was to examine the
influence of the diabetic metabolic state in spontaneously diabetic
BB/O(ttawa)K(arlsburg) rats on bone defect healing.
Eighty spontaneously-diabetic BB/OK rats with a blood-glucose
value of 391±106 mg% (mean ± SD) at the time of
manifestation were used in the study. Based on blood-glucose values
at the time of surgery (mg%), postoperative blood-glucose course
(mg%) and postoperative insulin requirements (IU/kg), the animals
were divided into groups with well-compensated (n=40, 170±101
mg%; 221±120 mg%; 2.1±1 IU/kg) or poorly compensated
(n=40; 371±158 mg%; 357±83 mg%; 5.2±1.4 IU/kg)
metabolic state. Forty LEW.1A rats served as the normoglycemic
controls (95±18 mg%). Using a 1-mm-diameter Kirschner wire,
a hole of femoral bone ca. 1 cm proximal to the knee joint space
was centrally drilled. Ten animals from each group were killed
on postoperative days 7, 14, 24, and 42, and specimens were taken
for analysis. Using SEM to measure regions of new bone semiautomatically
and quantitatively, also determining the number, area, and circumference
of regions not yet filled with new bone.
Up to postoperative day 14, very significant differences (p<0.0001)
for all investigated characteristics were found between the spontaneously-diabetic
BB/OK rats and the control animals in favor of the controls
and up to postoperative day 24 within the group of spontaneously-diabetic
BB/OK rats, where the well-compensated animals had significantly
better results in terms of number and area of regions of bone
not yet filled with new bone formations. Forty-two days postoperatively,
SEM observations showed no differences between examination groups.
The process of bone defect healing in spontaneously-diabetic rats
was disturbed only in the early phase and exhibited retardation
in its progression. After 42 days, bone defect healing was complete,
regardless of the diabetic metabolic state; no differences were
detected with the SEM between examination groups at this time
point. Histol. Histopathol. 18, 111-120 (2003)
Key words: Spontaneously-diabetic rats, New bone formation,
Scanning electron microscopy, Remodelling, Bone defect healing
DOI: 10.14670/HH-18.111