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

INTRODUCTION: 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.
MATERIALS AND METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.