Development of a novel rat model of lumbar facet joint osteoarthritis induced by persistent compressive injury

The aim of the present study was to develop a novel animal model of lumbar facet joint osteoarthritis induced by persistent compressive injury. An intraspinal compression spring was randomly implanted into either the L4/5 or the L5/6 spinal segments of 40 Sprague Dawley (SD) rats to induce compression. Sham-operations were used in the other segment of the same rats as the control levels. The animals were sacrificed at 7, 14, 28, 42 and 56 days after surgery, prior to the radiological confirmation of the spring location. Degeneration of the lumbar facet joints was evaluated by macroscopic observation in addition to histological and immunohistological analyses. The results of this present study revealed the absence of spring dislocation during the entire observation period. Macroscopic and Osteoarthritis Research Society International scores of the compression levels were found to be higher in the compression levels compared with those noted in the control levels (P<0.05). In addition, interleukin-1β and tumor necrosis factor-α expression in the compression levels were increased over time compared with those recorded in the control levels. In conclusion, persistent compressive injury may induce degeneration of the lumbar facet joint. This novel animal model could serve as a useful tool for further studies into the mechanisms of action and potential treatment of lumbar facet joint osteoarthritis.