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Updated: Aug 15, 2026
Fracture Apparatus Design and Protocol Optimization for Closed-stabilized Fractures in Rodents
Published on: August 14, 2018
Cyclooxygenase-2 inhibitor delays fracture healing in rats
Kenji Endo1, Koichi Sairyo, Shinji Komatsubara
1Department of Orthopedics, The University of Tokushima, Japan. endoken@clin.tokushima-u.ac.jp
Background:
Cyclooxigenase-2 (COX-2) inhibitors have been reported to delay fracture healing. To investigate the major inhibitory period of COX-2 inhibitors in fracture healing, we administrated etodolac, a COX-2-specific inhibitor, to a rat fracture model by altering the period of administration from early to late.
Method:
After closed fractures had been created at the middle of the femoral shafts in 12-week-old Wister rats, a standardized dose of etodolac was administrated in three ways: group I received it for 3 weeks, group II for just the first week after operation, and group III for just the third (final) week. Group IV was the vehicle control group. Bone maturation was estimated by radiographic scoring system, and mechanically by a three-point bending test.
Results And Interpretation:
In both the radiographic and mechanical studies, groups I and II showed lower scores than group IV, indicating that even a short period of administration of a COX-2-specific inhibitor in the early phase of fracture healing creates a risk of delayed healing. blacksquare, square, filled.
