The rat model that is commonly used to study femoral head osteonecrosis involves the induction of osteonecrosis by surgery employing a lateral approach to the hip joint. However, this approach induces hip joint luxation, which means it is difficult to determine whether the osteonecrosis arises because of the vascular deprivation or because of the hip joint luxation. Whether or not femoral head osteonecrosis can be induced by the medial approach to the hip joint, which does not generate hip joint luxation, was assessed.
Materials and methods: twelve 6-month-old F344 rats were subjected to the lateral or medial approach.
Results: four weeks after surgery, the lateral approach group showed luxation upon radiography, but the medial approach group did not. Histopathology revealed both groups exhibited osteonecrosis of the femoral head.
Conclusion: a surgically induced model of femoral head osteonecrosis that employs the medial approach is a more effective model than that using the lateral approach.