What are some safety considerations when working with patients with bone metastases?
There are some cancers that are more prone to metastasize to bone. Those are breast, lung and prostate cancers. Lesions in the long bones (femurs, humerus, as well as the spine) present the greatest risk of pathologic fracture. We generally don't perform formal manual muscle testing or progressive resistive exercises in an affected limb with a bony metastasis. The reason being is the torque and the stress that we put through a bone. If the integrity of that bone is compromised because of a bony metastasis, there's potential to cause a pathologic fracture.
Now I think that you could fairly put a little asterisk next to these next two points because I think that more times than not, there is room for a discussion with the referring MD. For example. I've worked with a young mother with bony metastatic disease who had a young child and she said that her child is 20 pounds and like it or not she needed to pick up the child to care for him. So was it better for us to say no strengthening exercises or was it better to have a conversation with the referring doctor to talk about certain limits of strengthening and emphasize the importance of body mechanics and safe lifting techniques to minimize that patient's risk of injury.
These are general precautions to keep in the back of your mind, but I think if you're encountering a patient with bony disease almost always there should be a discussion with the referring MD if strengthening is indicated in your plan of treatment. We may need to consider offloading weight-bearing through an affected limb with an assistive device. Fro example, a patient with a bony met in the femoral neck and with the stress and torque that goes through the femoral neck as a patient that goes through the gate cycle could increase the risk of fracture. As therapists, we may need to offload the extremity with either a cane, crutches, or a walker.
Typically if there are bony mets to the spinal column, we do observe spinal precautions. Those include no bending, lifting, and twisting.
The last safety consideration is to monitor for increasing functional pain. I find this one the most important. Increasing functional pain has actually been found to be the single greatest predictor of a pathologic fracture and so when I'm working with a patient with known or even suspected bony disease, I'm asking them every step of the way how's this feel, any pain with this, tell me how you're feeling. I don't necessarily tell them why I'm being so persistent with my questioning but that is why. Now overwhelmingly so, there have been several studies that show rehab interventions are generally safe and effective and do not increase the risk for fractures.