A pathologic fracture may be defined as a break in a bone caused by an underlying disease. An otherwise healthy bone typically fractures as a result of trauma. A diseased bone may do so either without trauma or due to minimal trauma. Diseases of the bone that predispose bones to fracture easily include osteoporosis, osteomyelitis, osteomalacia, Paget’s disease and malignancy (primary or secondary).
Pathologic fractures can affect any bone that is diseased, and the symptoms depend on the type and location of the bone involved. Many diseases affect the spinal vertebrae, which are prone to pathologic fractures, which can cause a range of symptoms from pain in back, legs, and arms to neurological impairment, such as numbness and/or weakness in the arms or legs.
Pathologic fractures are detected on imaging, which is initiated either by a suggestive history and physical exam or staging, restaging or surveillance workup for cancers.
- X-ray – plain film radiographs provide an overall assessment of bone integrity and the presence and the extent of the fracture. It can also detect spinal dislocation or slippage, kyphosis, scoliosis, etc. In addition to these, it can detect specific bony abnormalities such as bone spurs, disc space narrowing, vertebral body fracture, collapse or erosion, etc. Dynamic or flexion/extension X-rays may help in detecting any abnormal or excessive movement or instability in the spine at the affected levels.
- Computed tomography scan (CT scan) – shows more detailed images of the bones and the soft tissue, and is best suited for evaluating the extent of the fracture.
- Magnetic resonance imaging (MRI) – is more suitable for evaluating soft tissue damage occurring as a result of the fracture. It is especially useful for the detection of neural damage. MR (or CT) angiography is considered when vascular compromise is suspected.
- Nuclear bone scan – this scan can be helpful when surveilling for distant bone metastases, in addition to detecting bone infections, especially when MRI is not possible.
The goals of treatment are pain relief, reversal or stabilization of neurological deficits and stabilization. For less severe pathologic fractures, nonoperative/conservative management is considered. Severe pathologic fractures require surgical treatment, and the choice of procedure is based on the location of the bone and the extent of the injury. Spinal pathologic fractures can lead to collapsed vertebrae and vertebroplasty or kyphoplasty is required, during which a cement mixture is injected into the fractured bone to stabilize the fracture, treat pain, and prevent further spinal deformity from progressing. In cases where the collapsed vertebrae impinge on the nerve roots or the spinal cord itself, the surgeon may need to remove diseased bone to relieve pressure and possibly perform a spinal fusion to stabilize the spine until it heals. The underlying disease process needs to be adequately managed as well – whether it’s bisphosphonates for osteoporosis or suitable cancer treatment for metastatic disease.