Radiological features about pathological fracture of giant cell tumor around the knee joint

Abstract

Objective To compare the radiological differences of giant cell tumor (GCT) around the knee between those with pathological fracture and those without pathologic fracture and explore the radiological features of pathological fracture.Methods From March 2000 to December 2013,91 patients with GCT around the knee from domestic five bone tumor centers were involved,including 40 males and 51 females,with an average age of 36.81 years (range,17-78).All patients were divided into non pathological fracture group (53 cases) or pathological fracture group (38 cases).The radiological differences such as tumor volume,the distance between tumor and subchondral bone,Campanacci classification,soft tissue invasion and bone displacement were analyzed.Results GCT most frequently occurred in young adults between 20 and 40 years of age (58.2％,53/91),pathological fracture group with 78.9％.The proportion of tumors on the distal femur of pathological fracture group was higher than the non pathological fracture group,which showed statistical significance (x2=10.40,P=0.001).The tumor volume of pathological fracture group [(98.46±53.35) cm3] was greater than the no pathological fracture group [(63.19±34.92) cm3],there was statistical difference between the two groups (t=3.57,P=0.001).The distance between tumor and subchondral bone of pathological fracture group [median (M)=0.145 cm,range (R)=0.46 cm] was lower than that non pathological fracture group (M,0.170 cm; R,1.90 cm),and the difference was statistically significant (u=2.853,P=0.004).There were also significant differences in the incidence of pathologic fracture between the degree of soft tissue invasion (x2=l 1.08,P=0.004).Conclusion Tumor volume,distance between tumor and subchondral bone and the degree of soft tissue invasion are closely related to pathological fracture of GCT around the knee. Key words: Knee joint; Giant cell tumor of bone; Fractures, spontaneous; Radiography