Surgery

Older cement prostheses have a particularly high rate of bone loss and loosening due to cement deterioration. In general, studies report reoperation rates of over 30% after 10 years. Fortunately, advances in cement and prosthetic implants are improving the implant survival rates and reducing the need for revision procedures.

Uncemented arthroplasty using porous material has shown good results for the hip, although it may be less successful for knee replacement. In spite of short-term success, longer experience with this method suggests it may not be superior to cement prostheses. Failure of bone to grow into the porous material is a relatively common event, a problem that does not occur with cement prostheses. Some experts recommend cement implants over cementless ones for total knee arthroplasty.

Revision Arthroplasty

A repair procedure called arthroplasty revision may be used in cases where the original transplant fails. The specific procedure depends on whether the bone defects that occurred are contained or uncontained.

• Contained defects can be repaired with small bone grafts, the use of cement, or oversized cementless implants as required.
• Uncontained defects are more severe and may require a large bone graft or specially constructed implants to restore bone.

If a second arthroplasty is required, the potential for complications is magnified: more bone is cut, more blood is lost, and the operation takes longer. Patients are also generally older and more vulnerable to complications.

Other Joint Procedures

Resection Arthroplasty. In resection arthroplasty, a false joint of scar tissue is created. This procedure is used most often in treating arthritis of the foot.

Osteotomy. If only a certain section (the medial compartment) of the knee is damaged and deformed by osteoarthritis, the surgeon may choose to perform osteotomy:

• A surgeon opens the knee.
• The surgeon performs a  debridement (removal of damaged tissue) in the joint to eliminate the loose or torn fragments that are causing pain and inflammation.
• The bone is then reshaped to remove the deformity.
• The procedure may ease symptoms and slow disease progression. It is best used in heavier adults who are under 60 years old.

Hemicallotasis. Hemicallotasis is a procedure for the knee that may be a less invasive alternative to osteotomy. The surgeon attaches the knee with pins to an external frame-like device that lengthens the deformed part of the knee over several weeks. The patient is mobile during this period. Infections at the pin site are the most common complications.

Arthrodesis. If the affected joint cannot be replaced, surgeons can perform a procedure called arthrodesis that eliminates pain by fusing the bones together. The patient must understand, however, that fusing the bones makes movement of the joint impossible. Bone fusion is most often done in the spine and in the small joints of the hands and feet.

Unicompartmental Knee Arthroplasty. Unicompartmental knee arthroplasty (also called unicondylar knee arthroplasty) may be a useful procedure in cases of limited knee damage. It is recommended for relatively sedentary patients who are 60 years or older and not obese. It may relieve pain and delay the need for a total knee replacement. The procedure involves a small incision and insertion of small implants. It retains important knee ligaments, which preserve more movement than a total knee replacement.

Cartilage Transplants. An interesting technique called autologous chondrocyte implantation, also called chondroplasty or the Carticel approach, is used for knees damaged by injuries. In this procedure, arthroscopy is used to first remove cartilage in eroded areas. The results have been good to excellent, although long-term benefits are questionable. Whether it has any benefit for older patients with osteoarthritis is not yet known. Other cartilage transplant procedures are also under study.

Hip Resurfacing. An experimental surgical alternative to total hip replacement involves scraping the surfaces of the hip joint and femur and placing a metal cap over the bone. The procedure preserves much of the bone, so that a standard hip replacement can be done years later if needed. It may provide more stability, a faster recovery, and greater range of motion, making it a potentially good option for young, physically active patients.