Objective    To observe whether osteoprotegerin (OPG) is effective in reducing bone destruction and treating aseptic loosening in a mouse air pouch model.     Methods    Air was injected into the mouse back to form an air pouch

and the skull from another homologous mouse was implanted into the air pouch to obtain an air pouch model. Mice were divided into a blank group

a particle group

and an OPG group. Normal saline was injected into the air pouches of mice in the blank group. Polyethylene particles and physiological saline were injected into the air pouches of mice in the particle group. Polyethylene particles and OPG were injected into the air pouches of mice in the OPG group. Three weeks later

pouch walls and implanted skull tissues were collected

and the inflammatory reaction and the quantity of exuded inflammatory cells were detected through HE staining. The concentrations of inflammatory cytokines IL-1 and TNF-α in tissue homogenate were measured with ELISA. The differentiation and maturation of osteoclast were observed through tartrate-resistant acidic phosphatase staining. The resorption of bone slices was detected with scanning electron microscopy.     Results    The quantities of exuded inflammatory cells in the particle group[(3 812±628)/eyeshot] and the OPG group[(3 665±297)/eyeshot] were significantly higher than that in the blank group[(1 820±598)/eyeshot

P0.05]．The IL-1 and TNF-α concentrations in the particle group[ (210.57±4.26)

（188.36±7.33）pg/ml] and the OPG group [(198.59±6.90)

(179.28±2.11)pg/ml] were significantly higher than those in the blank group [(138.34±2.32)

(156.14±4.17)pg/ml

P0.05]．The percentage of tartrate-resistant acidic phosphatase staining positive area to visual field area in the particle group (4.34±1.53)% was significantly higher than that in the blank group [(0.89±0.12)%

P0.05] and that in the OPG group [(0.96±0.55)%

P0.05]. The percentage of bone slice resorption area to visual field area in the particle group (14.58±2.68)% was significantly higher than that in the blank group[(3.09±0.62)%

P0.05]and that in the OPG group [(3.25±0.78)%

P0.05].     Conclusion    Mouse air pouch model is established. OPG has no significant inhibitory effect on the inflammatory reaction induced by polyethylene wear particles

but can inhibit the differentiation and maturation of osteoclast and reduce the bone resorption induced by polyethylene wear particles．