Surgical ReconstructionMost of Wirganowicz’s cases involve unidentified masses in soft tissues or bone, often uncovered by x–rays. Although the origin of most tumors of the extremities can be uncertain, it is rarely trauma. An injury, Wirganowicz stressed, merely draws attention to the tumor. “An unusual pain or mass may be treated as a muscle pull or sports injury, mistakenly attributed to a traumatic event. Patients will say to a family practitioner, ‘I’ve had a bump on my leg for six months. I noticed it after I hit it on a table’, or ‘I was playing baseball and somebody ran into me’”, said Wirganowicz. “But if these seemingly trauma–related injuries persist for an abnormally long time, practitioners need to look for another reason, such as a malignancy”.
“The overall survival from sarcoma is about 75% thanks to sophisticated forms of treatment”. Patients may also complain that there is an asymptomatic appearance of one arm or leg compared to the other side. “If a patient has been working out at a gym and can’t build his left arm up to his right, he may wonder what is wrong with his left arm. It may turn out that the left arm is entirely normal but there is a tumor in the right one”.
Endoprosthesis vs. Allograft
Once a malignant tumor is removed, the Orthopedic oncologist is faced with a choice of two methods for replacing the damaged joint or bone. Both the limb–sparing surgery and reconstruction are performed in a single operation.
One possibility is an endoprosthesis, a metal and plastic joint replacement similar to a traditional hip or knee replacement, but often incorporating areas of bone beyond the joint. The other major method of reconstruction is a transplant, using cadaver bone. A combination of a limited endoprosthesis with some bone replacement may be used in an allograft prosthetic composite.
Wirganowicz said, two schools of thought had evolved regarding orthopedic replacement following sarcoma removal. One heavily favors endoprosthesis, the other leans strongly toward allograft. “Most people are trained in only one technique and may have some prejudice against the other form”, noted Wirganowicz, who sees advantages to each procedure. In children, he prefers allograft in order to save the joint. In adults, or in cases where the location of the tumor makes saving the joint impossible, he uses an endoprosthesis.
After removing Femur from the knee“There are enough pros and cons with each approach that there is no general consensus on which is the better way to go”, he explained. “For example, full weight bearing is possible immediately following endoprosthetic replacement whereas, after allograft reconstruction, weight bearing is restricted until signs of bone healing at the host and allograft bone interface is evident, generally after six months”. Picture shows after removing femur from about the knee of a 32–year–old woman with a large, low–grade osteosarcoma of the femur, intra–operative photo shows limb salvage using an endoprosthesis that includes knee joint replacement.
Wirganowicz is trained in both procedures. He took a fellowship at UCLA which emphasized the endoprosthetic side of sarcoma surgery, followed by a second year of training in the allograft approach at the University of Washington. Though occasional unexplained rejection is encountered with bone transplants, they stand a smaller chance of rejection than do live organs, since they are taken from cadavers and processed to remove the antigens involved in rejection.
Alavi, who deals primarily with tumors that show signs of metastasizing to other parts of the body, said that, among bone tumors, chemotherapy is generally effective only against osteogenic sarcoma, Ewings sarcoma, and a particularly rare bone lymphoma. Chemotherapy is still important, but may be less effective in cases of soft tissue sarcomas or other bone sarcomas in adults.
A Return to Normal Function
Several months of rehabilitation are usually required following tumor removal, to aid in strengthening the bone and re–establishing the range of motion. Wirganowicz said that, following limb reconstruction surgery in the leg, patients are able to participate in most normal activities, including walking, biking and swimming. Function is usually not as good after limb salvage in the upper extremity because the arm has a much greater range of motion than the leg. However, it does allow patients to return to daily self–care activities, such as combing their hair and eating by themselves.