Surgeons planning a second or revision surgery after the first total hip replacement must consider many factors. The biggest and most important one is bone loss. There are several different reasons for this bone loss. It sounds like you may have bone loss from the radiation treatments. But there are other reasons for implant failure that require revision surgery. Loosening of the implant, hip instability (partial or complete dislocation), osteolysis (bone loss) around the implant, and periprosthetic (around the implant) infection.
As you can see from the list, bone loss is a big problem that must be addressed whenever a second surgery is planned. In fact, it’s not just bone loss but also bone quality or density (called bone stock) that must be considered. And there are different patterns of bone loss from patient to patient. So, it’s never a one-surgery-fits-all kind of problem.
Each patient must be carefully evaluated before surgery (pre-operatively). X-rays and CT scans provide the surgeon with details needed in the planning process. Is there infection that must be dealt with? What’s the patient’s general health? (Is the patient healthy enough to have another major surgery)? How much bone loss was caused by the first surgery? Is there already a leg-length difference that could get worse with a second (revision) procedure where more bone will have to be removed?
Other factors the surgeon must look at include the presence of cement and/or hardware (metal plates, screws, wires) that must be removed; location of blood vessels, nerves, and ureters (tube from the kidneys to the bladder) in relation to the acetabulum (hip socket); and scar tissue from previous surgeries. In your case, any damage from radiation for cancer in the pelvis must be assessed.
The surgeon will look for any differences in leg length from one leg to the other that may need correction. There are different ways to correct this problem such as an osteotomy (removing portions of bone) to alter the angle of the bone or to lengthen the femur (thigh bone). An osteotomy can help make up for significant leg length differences.
With bone loss, it may be necessary to use bone grafting in the reconstruction of the hip. That’s another layer of consideration. The surgeon will try to find ways to aid you in gaining the best results for the longest period of time. If there is severe bone loss, new hip implant may have to be custom made to fit you.
In severe cases, the surgeon has to find inventive and creative ways to attach the implant. When the bone quality is so poor or the defect so large that there’s no place to firmly anchor the component part, a special triflange component is used. This device is specially made to bridge large gaps in the bone.
And to add to the surgeon’s challenge, cost considerations, the ability of your body to create bone ingrowth around the implant to secure it, and the long-term effects of stiff metal interfacing with living bone must all be reviewed and evaluated.
Revision of an original (primary) hip joint replacement can be a complex and challenging procedure for the surgeon, especially when any of the factors affecting the bone discussed here are present. Every effort to manage patient pain is usually made using conservative means before considering revision surgery. And efforts to salvage the joint are thoughtfully considered before recommending revision surgery.
It sounds like your surgeon is reviewing all of these important points and will get back to you with his or her recommendations. Hopefully, this information will help you ask further questions and participate in the decision-making process.