When cancer spreads or metastasizes to the spine, fracture can occur. The vertebral bone collapses. Pain and neurologic problems often develop. The best treatment for these problems is still being studied.
The fractured vertebra can be repaired with cement injected into the center. But how much cement should be used? Should the tumor be removed first? How much tumor should be taken out?
In this study, researchers used a 3-D computer model of the lumbar spine to try different amounts of tumor removal and cement. Results of an earlier study using cadaver models provided some baseline information for the computer model.
Twelve different methods of tumor ablation (removal with laser) were used. In some cases, 30 per cent of the tumor was removed. In other models, up to 60 per cent was taken out. Three measures of cement volume were tested with each of the tumor volumes. The model tested the sensitivity of fracture risk for each tumor and cement volume.
The results of this study made it possible to develop guidelines for cement fill in patients with spinal metastases. The goals are to control pain and restore vertebral stability. Tumor removal is done first. The amount of cement injected depends on how much tumor is still left — not the size of the hole where the tumor was.
The authors warn against over filling the vertebra. The metastatic disease can affect adjacent bones. If the fractured vertebra is too stiff from the cement, the next bone may be at increased risk of fracture. When properly applied, full restoration of spine stability is possible with this treatment.