What is limb-salvage surgery?
Limb-salvage surgery is a surgical option for children with a malignant tumor in a long bone of their leg or arm.
Limb-salvage surgery helps preserve the limb by removing the part of the bone involved with the tumor and some of the tissues that surround it. The bone is replaced with an implant, which can be either a bone graft or a metal prosthesis.
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Limb-salvage surgery is part of the treatment for osteosarcoma or Ewing sarcoma. The goal of limb-salvage surgery is to preserve as much of the limb as possible. However, the arm or leg will never be as strong as it was before surgery. Children who have this surgery will not be able to participate in high-impact sports using the affected limb.
What types of implants can be used to replace bone during limb-salvage surgery?
There are three main categories of implants used as part of limb-salvage surgery:
- Endoprosthesis, a metal implant that replaces the bone. A traditional “adult” endoprosthesis can't be lengthened and is most often used on full-grown or almost fully grown teens and young adults. If a patient has a small amount of growth remaining, the surgeon may implant a slightly longer endoprosthesis so the two limbs will be close in length when the other has finished growing.
- Expandable prosthesis, a relatively new option for children at a middle stage of growth. As the child grows, they will have periodic limb lengthenings. A strong magnet is used to extend a tube inside another tube in the metal implant. The prosthesis is expanded in small increments so that both limbs remain about the same length.
- Allograft bone replacement, bone from an organ donor replaces the bone around the tumor. An allograft implant does not grow. The surgeon may therefore implant a slightly longer length of bone to compensate for future growth of the other limb.
Expandable prosthesis overview
Who is a good candidate for an expandable prosthesis?
An expandable prosthesis may be a good choice for children most likely to develop a difference of two centimeters or more in the length of their limbs as one grows and the other does not. Generally, this includes girls between the ages of 8 and 12 and boys between 8 and 14.
If a child is too young, the implant may not set properly in their developing bones. The prosthesis can also only be extended a certain amount, based on how much bone it is replacing. Therefore, an expandable prosthesis may not have enough growth potential for a very young child. In some cases, it is possible to use a bone graft from the child’s body, such as the small bone in the calf (fibula) to replace a bone that has to be removed.
If a child is already close to fully grown, a traditional, non-expanding rod may be a better option. If they develop a small difference in leg length, they can wear shoe inserts to compensate.
How are expandable prostheses lengthened?
Lengthening an expandable prosthesis is a non-surgical procedure. The child lays on an exam table and places their limb inside a magnetized device that extends the prosthesis.
Limbs are typically lengthened up to 5 millimeters at a time, about the width of a pencil’s eraser. Lengthening the limb in small amounts gives the muscles and tissues around the rod a chance to adapt. The limb may feel stiff for a day or two after the procedure, but this usually goes away quickly. How often the child will have their limb lengthened depends on their rate of growth. During growth spurts, they may have to have their limb lengthened more often.
How are limb-salvage surgery and chemotherapy used together?
Most children have chemotherapy for 11 to 14 weeks before they have surgery. Chemotherapy uses medications to stop the growth of cancer cells and typically begins soon after a child is diagnosed with bone cancer. Because it is important for children with malignant tumors of the bone to get the full doses of the medications, chemotherapy treatments continue after the surgery.
Do chemotherapy and limb-salvage surgery affect a child’s growth?
Chemotherapy can temporarily slow a child’s growth. However, most children start growing again after their treatment is completed.
Limb-salvage surgery may permanently stop further growth in the affected limb. This depends on the size of the tumor and how close it is to growth plates, the ends of the bones where new bone grows. The surgeon will make every attempt not to disturb the growth plates on either end of the bone, but this is not always possible.
Is limb-salvage surgery a good option for my child?
Whether or not limb-salvage surgery is a good option for a child depends on several factors, including their age and stage of development. Surgeons also consider the size and location of the tumor. If the tumor is large or has spread into the knee, amputation may be the safest choice.
On a personal level, families need to consider the child’s interests, personality, and types of activities they enjoy now and may want to do in the future. Limb-salvage surgery may not be the best option for highly active kids who love high-impact sports. After limb-salvage surgery, they will be limited to activities that don’t put the bone or prostheses at risk of damage.
What are the pros and cons of limb-salvage surgery?
Pros: Limb-salvage surgery allows a child with a malignant bone tumor to keep their full limb. They will have a scar from the surgery and usually smaller muscles but otherwise, the limb will look much like their other, healthy limb. After recovering from surgery, the child will be able to use their arm or leg for low-impact activities like walking, swimming, or riding a bike.
Cons: The salvaged limb can wear out over time. Someone who chooses limb-salvage surgery will need to be monitored by an orthopedic specialist throughout their lives. They may need more surgery if the prosthesis wears out, becomes infected, or breaks.
What are the other surgical options for a child with bone cancer?
Rotationplasty preserves the lower leg and rotates it so the ankle will function as a knee. The child will use a prosthetic lower leg to walk, run, and play.
- Pros: Compared to limb-salvage surgery, rotationplasty allows kids to be more active. Compared to amputation, the residual limb is longer and children find it easier to re-learn high-level activities. The prosthetic limb can be adjusted in size as the child grows.
- Cons: The leg looks very different.
Amputation removes the limb from above the tumor site.
- Pros: If the tumor is very large, the surgeon may recommend amputation as the safest way to guard against a recurrence after treatment. The prosthetic limb can be adjusted in size as the child grows.
- Cons: The residual limb is short. If the affected limb is the child’s leg, they will have to re-learn how to walk and run with a full-leg prosthesis.
How long does it take to recover from limb-salvage surgery?
Limb-salvage surgery is a major operation with a long recovery period. The continuation of chemotherapy after surgery also prolongs the recovery period. Most kids start good physical therapy about 4 to 6 months after the surgery. It generally takes about a year for a child to walk well without crutches after the procedure.
How we approach limb-salvage surgery
Dana-Farber/Boston Children's Cancer and Blood Disorders Center pioneered limb-salvage surgery in 1977. We continue to be a center of excellence in surgeries for children with malignant tumors of the bone. Ours is one of the few centers in the United States with surgeons who specialize in limb-salvage surgery and rotationplasty. The expertise we’ve gained through hundreds of these complex surgeries translates into better outcomes for our patients.
We collaborate with hospitals around the region and the world to care for children and young adults with osteosarcoma and Ewing sarcoma. Many of our patients from out of state have chemotherapy at a participating hospital near their home and travel to Boston for the surgery. If they have an expandable prosthesis, they then return to Boston approximately twice a year to have their prosthesis lengthened.