Primary bone cancer is rare, but can occur. The more commonly, bone cancer has metastasized from another tissue of the body. The most likely bone, involved in the structure of the knee, to experience cancer is the femur because of its exceptional vascular supply (Goodman).
Risk factors: (Palmer)
Bone pain described by a patient is deep and diffuse. They may use words like burning, aching, or stabbing. This pain may start out as episodic, but eventually becomes constant as the condition progresses. Any activity of the lower extremity will likely cause these patients pain, especially any activity in weight bearing (Goodman). These patients will experience their worst pains during the night and will often be awakened due to pain. Nothing will ease the patient’s pain, whether it be a change in position or resting. If the patient expresses that the only way they can gain relief from the pain is by taking Aspirin, this is a red flag, as it is a red flag for a specific kind of bone cancer. Neither heat or ice will make the pain feel better (Goodman). These patients may also be experiencing the other cardinal symptoms of cancer, but only if the cancer is a metastasis from another systemic tissue (Palmer).
Initial recognition of a cancerous mass in the bone, would be observed on a x-ray. A biopsy would be completed to confirm the malignancy of the tumor (Goodman). Swelling of the soft tissues around the lesion would occur if the mass if big enough to protrude beyond the normal boundaries of the bone. The swelling caused by a cancerous bone tumor would be more diffuse and tender to the touch than that of a benign tumor. The skin over the tumor will be warm to the touch (Goodman). If the tumor is close enough to the hip or knee to affect the joint, range of motion can be expected to be restricted and painful (Goodman).
Special tests: (Goodman)
Heel strike/bump: will reproduce the patient’s pain, especially when the tumor is accompanied by a fracture
If you suspect your patient with knee pain may have bone cancer, refer them immediately!! A positive diagnosis will be treated through surgical removal of the tumor and/or chemotherapy, depending on the stage and malignancy of the tumor (Palmer). Regardless of which plan of care is selected, physical therapy will be a vital part of this patient’s recovery. If the surgery is selected, they be treated like any other postoperative orthopedic patient, focusing on return of function and wound healing. If the more aggressive approach of chemotherapy is needed, they will need physical therapy for general conditioning (Palmer).
5 year survival rate for a localized (non-metastasized) osteosarcoma is about 70%. The survival rate is significantly less if the tumor is of metastatic origin (Palmer).
Predictors of a good prognosis: (Palmer)
- Goodman, C.C., and T.E.K. Snyder. Differential Diagnosis for Physical Therapists Screening for Referral. 4. St. Louis: Saunders Elsevier, 2007. Print.
- Palmer, E. "Osteosarcoma." CINAHL Rehabilitation Reference Center. EBSCO Publishing, 2012. Web. 3 Jul 2012. <http://web.ebscohost.com.p.atsu.edu/rrc/detail?sid=fa65cac9-9d65-456d-a4f5-ba5db29acdd0@sessionmgr12&vid=6&hid=9&bdata=JnNpdGU9cnJjLWxpdmU=
- Image Found at: http://danisfoundation.org/2012/05/22/overview-of-benign-bone-tumors/ (accessed on 06-30-12)