Excision of bone sarcoma with implantation of prosthesisMedical editor Ole Jacob Norum MD
Oslo University Hospital
Raphael Pollock, MD, PhD
MD Anderson Cancer Center
Resection with extremity conserving surgery is an alternative for most patients with a primary tumor in the bone. In certain cases, metastases to the skeleton can be treated with resection and prosthesis. Prosthesis surgery is a complicated procedure requiring excellent planning.
Prostheses are made of metal; most commonly of titanium. The prosthesis can be anchored to the skeleton such that the patient's bone grows into a rough surface on the prosthesis or the prosthesis is fastened with bone cement. Getting ligaments and muscles to attach to the prosthesis is a great challenge. There are multiple methods for solving this.
When there is a lot of remaining growth of the patient's bone, a growth module must be connected to the prosthesis to allow the length of the extremity to be extended.
The prostheses are made modularly, that is, they are constructed by parts connected to each other and customized for the operation defect. Bone sarcomas are usually distal femur and proximal tibia. In the lower extremity, the entire or part of the femur, hip joint, knee joint, and the upper part of the leg bone may be replaced with by prosthesis. The function which is achieved depends on what muscles and which nerves are to be removed.
About 95% of patients with a tumor in the shoulder/upper arm can be treated with limb-saving surgery.
The proximal humerus is one of the most common locations for high-grade malignant bone tumor. It is the third most common location for osteosarcoma. A tumor in this location often has a large extra-osseous component.
Implantation of prosthesis in the shoulder seldom leads to normal function in the shoulder joint but if the nerves in the hand are spared, the elbow and hand function can be nearly normal.
- High-grade malignant bone sarcoma
- Some cases of low-grade malignant bone sarcoma
- Some cases of soft tissue sarcoma with infiltration to bone tissue
- Some cases of metastatic carcinoma
- Tumor affecting important structures such as arteries, nerves, and muscles leading to poor function in the extremity.
- The operation is performed in an operating room with laminar flow.
- Prosthesis components must be available.
- Surgery tray
- The surgery is planned precisely and the position of the patient on the operation table is determined.
- If possible, the specific exercises which will be relevant after the surgery should be practiced preoperatively.
- Antibiotic and thrombosis prophylaxes are given.
- Preoperative wash of the entire body with chlorhexidine soap to reduce the amount of bacteria on the skin should be done.
The procedure is separated into three stages:
- Tumor resection
- Implantation of prosthesis
- Reconstruction of soft tissue
- An incision is made to obtain good overview and access. Nerves and vessels must be dissected from the tumor.
- The resection of the involved bone and surrounding muscle should be done with a wide margin.
- All previous biopsy canals and potentially contaminated tissue must be removed within the surgical specimen.
- In bone marrow, a margin of 2-4 cm is necessary depending on the type of tumor.
- The prosthesis is positioned.
- Important muscles/ligaments (hip abductor, patellar ligament) are attached to the prosthesis to obtain good function. As a remedy for this, the prosthesis is covered with a textile stocking fixed with strong sutures. Ligaments and muscles can then be sutured onto this stocking and growth fixation will be adequate after a few weeks.
- The prosthesis should be covered with vital muscle tissue and skin. On the calf where the muscle coverage is poor, the prosthesis should be covered with a gastrocnemius muscle flap.
- A vacuum drain is applied and the skin is closed. In some cases, the skin is closed with a split-thickness skin graft covering the muscles.
- An X-ray is taken to check that the prosthesis is situated correctly.
- For surgery in the lower extremity, the limb is elevated for the first days after the surgery to avoid edema.
- The patient obtains daily physical therapy, often 2-3 times per day according to guidelines set by the orthopedist for mobilization, strain, and exercise.
- The patient should be observed for infection.
- Pain treatment.
- Joint movement
- Muscle power
- The attachment points of the prosthesis in the bone
Frequent checks are assessed individually by the orthopedist.
- Late infection in the prosthesis
- Mechanical failure/breakage of the prosthesis
- Wear in the plastic
- Reduced function
Complications may necessitate reoperation.