| Images of Musculoskeletal Oncology |
| Chondroblastoma - Upper Tibia |
| 15 year old boy was seen with one year of right knee pain and swelling. Physical exam reveals mild tenderness over his upper tibia. |
| The routine AP radiograph demonstrates a subtle mild increase in bone density of his right proximal tibia epiphysis. (This radiograph could have easily been diagnosed as normal). |
| The MRI reveals a discrete lesion in the proximal tibia epiphysis heterogenous in nature, but with a defined border and extending from the articular cartilage to the epiphyseal plate. |
| |
| |
| The diagnosis was considered to be an epiphyseal chondroblastoma on the basis of location, age of patient and MRI findings. Open biopsy reveals tissue made of chondroblasts, multinucleated giant cells and chondrocytes and blue matrix all confirming the diagnosis. At this point a thorough curettage was performed and the resultant cavity packed with allograft cortical and cancellous bone grafts without violating the articular surface or the epiphyseal plate. |
| |
| The chondroblastoma has disappeared, and the bone appears normal. |
| |
|
| The patient did well after surgery and had normal knee function without recurrence 18 months after surgery. Radiographs at 13 months after surgery demonstrate incorporation of the bone grafts and healing of the lesion. |
| Learning Issues: 1. A lytic lesion confined to an epiphyseal region in a teenager is often a chondroblastoma. 2. Aggressive curettage with allograft cortical and cancellous bone of the bony defect usually leads to excellent results. 3. Chondroblasts with multinucleated giant cells, usually with calcification are the typical findings histologically. 4. Routine radiographs do not always reveal the true nature of the lesion. MRI clearly demonstrates the lesion. CT would also have been satisfactory. |
| Images of Musculoskeletal Oncology |
| University at Buffalo Department of Orthopaedics |