intraosseous ganglion of the medial condyle of the tibia: a case series of 7 patients

background: intraosseous ganglia (ig) are solitary, osteolytic lesion juxtaarticular in the epiphyses of long bones. the origin of articular cysts is controversial and is not recognized well.methods: from 2006 to 2011 in shafa orthopedic hospital we identified 7 cases with final diagnosis of intraosseous ganglion cyst in medial condyle of tibia. we surveyed their medical documents and images and after final visit described the pattern of presentation, radiologic feature, treatment and their outcome after treatment.results: of 7 patients, 6 were female and 1 was male. all had chief complaint of posteromedial knee palpable identified to be sub pes anserine bursa. there were two evidence of moderate degenerative joint disease (djd) in the knee joint. we found conduit between the cysts beneath or near the pes anserine and the ganglion cysts in the medial condyle of the tibia in all of the cases. after surgery, patients became symptoms free, and there was no evidence of recurrence in 25 months mean follow up.conclusion: igs of medial condyle of tibia are usually associated with soft tissue component. considering the strength of cortex and resistance of bone trabeculation of medial condyle of tibia, it is more likely that the primary lesion originates in the bone and then will spread to the adjacent softtissue.