Aneurysmal bone cyst of the patella- A case report

Abstract

Primary tumours of the patella account for less than 0.06% of bone tumours and metastatic lesions are even rarer. Aneurysmal bone cyst (ABC) accounts for 1% among primary bone lesions, and its occurrence in the patella is very rare. Twenty one year old male presented to orthopaedic OPD with complaints of swelling and pain in left knee since one year with increased pain and episodic fever since 3months. There was a history of minor trauma of left knee a year back which healed without any complications there was no other revelant past history. On radiological examination which included x-ray, CT and MRI revealed a osteolytic cystic lesion of patella and provisional diagnosis of aneurismal bone cyst of Patella made and bone curettage was done. On clinic-radiological and histopathological correlation diagnosis of primary ABC of patella was made. The mainstay of treatment of ABCs is intralesional curettage with locally applied adjuvants such as liquid nitrogen or phenol. Other options include enbloc dissection or selective arterial embolization. Young age and open physes are associated with an increased risk of local recurrence. Hence close follow up of patient has to be made.