A 16 year old male presented with a history of knee pain that was getting worse over an 8 week period of time.  He related the pain, which was on the front of his knee at the joint line, to an injury when he stopped suddenly when playing football slightly hyperextending his knee. 

On exam he had mild swelling around his knee and he did indicate that he had night pain for the 2 weeks before the appointment with the Denver Clinic physicians.  His symptoms and xrays were suspicious for some type of cancerous process so he underwent an MRI.

MRI of thigh bone, dark area is the bone tumor.

The MRI confirmed the suspicion for an osteosarcoma and CT biopsy confirmed the diagnosis.  He underwent 4 cycles of intra-arterial chemotherapy with good response.

It was determined the best reconstructive option for him was a distal femoral modular prosthesis with a tibial base. He was taken to surgery and the tumor was resected.

Resected bone tumor lying next to the replacement prosthesis.

The prosthesis was placed in the area of resection and he did well post-operatively. He was able to return to sports activities after his rehabilitation.