Abstract
We studied the relationship between effective treatment with range of motion exercises and the preventive effect of joint contracture development. For this experiment, the removal of immobilization and then re-immobilization was needed during the load on immobilization of the knee joint. We therefore devised an external joint fixation method for immobilization of the knee joint in rats. The parts included 0.7-mm Kirschner wires (K-wires) and interconnected fixation devices (4.0 mm vertical × 3.0 mm horizontal × 2.0 mm depth). Each device was perforated with 1.0 mm perpendicular two holes for the K-wires, which were secured with captive screws. K-wires were inserted into the middle portion of the femur and the tibia in the left extremity of the rats in the vertical sagittal plane. Each K-wire was fixed to another perpendicular K-wire using the interconnecting device. This immobilized the knee joint, which made it easy to remove the immobilization and then re-immobilize the knee joint by loosening and tightening a screw. We conducted effectiveness testing of this external joint fixation method in experimental rat knee joint contracture models. Characteristic changes in joint contracture, such as decrease in joint range of motion and adhesion, vascular proliferation, and intra-articular hemorrhage were identified after five weeks of immobilization loading. Moreover, harmful effects, such as edema, inflammation and congestion, were not found. These results suggest that this external joint fixation method is useful for establishing experimental joint contracture models.
