Presentation
Moderate right tibial pain in a patient with a history of invasive papillary urothelial carcinoma of the left renal pelvis.
Patient Data
Radiographs of the right tibia/fibula demonstrate lytic lesions in the proximal to mid tibia, occupying greater than 50% of the medullary cavity in diameter. There is cortical thinning, periosteal reaction, and soft tissue mass/edema at the anterior aspect of the proximal tibia. A soft tissue mass, or fluid collection/bursitis is seen in the infrapatellar soft tissues. Lytic lesions are also visible in the distal tibia. There is no acute fracture.
Nuclear medicine Tc-99m MDP bone scan demonstrates multiple areas of abnormal radiotracer uptake in the right distal femur and right tibia, consistent with malignancy. The patient's status is post-left shoulder arthroplasty and left nephroureterectomy. A small focus of radiotracer uptake in the right mid-humerus is indeterminate.
Postoperative radiographs of the right tibia/fibula demonstrate prophylactic intramedullary nailing of the right tibia. The underlying lytic lesion is visible in the proximal to mid-tibia with cortical thinning and periosteal reaction.
Case Discussion
An impending pathologic fracture involves an area of the bone with weakened biomechanical architecture, resulting in a tendency to fracture with less force than normal bone ². Several classification systems can be used to predict the risk of an impending fracture. Mirels classification is a simple, validated tool that can be used for this purpose. However, it is only applicable to metastatic lesions in long bones.
The tibial lesion in this patient was determined to have a high Mirels score of 9-10 and was therefore prophylactically nailed.
Case co-contributor: Christine Lee (Loyola University).
Unable to process the form. Check for errors and try again.