An unusual localization of chondroblastoma: The triradiate cartilage; from a case report a reconstructive technique proposal with imaging evolution.

Abstract

Chondroblastoma (also known as Codman tumor) is a rare intermediate grade cartilaginous neoplasm, representing less than 1% of all primary bone tumors; it characteristically arises in the epiphysis or apophysis of a long bone in young patients, predominantly males. The most frequent location of chondroblastoma is the humerus (70% incidence rate) and more rarely it is located in the pelvis. When it affects the hip, the triradiate cartilage is the most common site. An unusual case of Chondroblastoma located in the triradiate cartilage is reported. The surgical technique and the imaging are emphasized: a homoplastic fascia latae was used to reconstruct the cartilage layer then a layer of engineered homoplastic bone was superiorly positioned to reconstruct the subchondral bone; the residual cavity was filled with a homoplastic hemi-femoral head concavity molded to best correspond to the acetabular roof and morcelized bone. At four years of follow-up the patient is pain free and able to walk without crutches; the imaging showed a rearrangement of the trabecula distribution following the lines of force. The suggested technique could be a valid option in reconstructing acetabular roof in benign lesions. A correct radiological assessment could be helpful for diagnosis and an early detection of local recurrence.