Hip revision surgery, which is also known as revision total hip arthroplasty, is a procedure in which the surgeon removes a previously implanted artificial hip joint, or prosthesis, and replaces it with a new prosthesis. Hip revision surgery may also involve the use of bone grafts. The bone graft may be an autograft, which means that the bone is taken from another site in the patient's own body; or an allograft, which means that the bone tissue comes from another donor.
Purpose
Hip revision surgery has three major purposes: relieving pain in the affected hip; restoring the patient's mobility; and removing a loose or damaged prosthesis before irreversible harm is done to the joint. Hip prostheses that contain parts made of polyethylene typically become loose because wear and tear on the prosthesis gradually produces tiny particles from the plastic that irritate the soft tissue around the prosthesis. The inflamed tissue begins to dissolve the underlying bone in a process known as osteolysis. Eventually, the soft tissue expands around the prosthesis to the point at which the prosthesis loses contact with the bone.
In general, a surgeon will consider revision surgery for pain relief only when more conservative measures, such as medication and changes in the patient's lifestyle, have not helped. In some cases, revision surgery is performed when x-ray studies show loosening of the prosthesis, wearing of the surfaces of the hip joint, or loss of bone tissue even though the patient may not have experienced any discomfort. In most cases, however, increasing pain in the affected hip is one of the first indications that revision surgery is necessary.
Other less common reasons for hip revision surgery include fracture of the hip, the presence of infection, or dislocation of the prosthesis. In these cases the prosthesis must be removed in order to prevent long-term damage to the hip itself.
Demographics
The demographics of hip revision surgery are likely to change significantly over the next few decades as the proportion of people over 65 in the world's population continues to increase. As of 2003, however, demographic information about this procedure is difficult to evaluate. This difficulty is due in part to the fact that total hip replacement (THR) itself is a relatively new procedure dating back only to the early 1960s. Since the design of hip prostheses and the materials used in their manufacture have changed over the last forty years, it is difficult to predict whether prostheses implanted in 2003 will last longer than those used in the past, and if so, whether improved durability will affect the need for revision surgery. On the other hand, more THRs are being performed in younger patients who are more likely to wear out their hip prostheses relatively quickly because they are more active and living longer than the previous generation of THR recipients. In addition, recent improvements in surgical technique as well as in prosthesis design have made hip revision surgery a less risky procedure than it was even a decade ago. One Scottish surgeon has reported performing as many as four hip revisions on selected patients, with highly successful outcomes. According to one estimate, 32,000 revision total hip arthroplasties were performed in the United States in 2000.
While information on the epidemiology of both THR and hip revision surgery is limited, one study of Medicare patients in the United States who had had either THR or revision hip surgery between 1995 and 1996 was published in January 2003. The authors found that three to six times as many THRs were performed as revision surgeries. Women had higher rates of both procedures than men, and Caucasians had higher rates than African Americans. Other researchers have reported that one reason for the lower rate of hip replacement and revision procedures among African Americans is the difference in social networks. African Americans are less likely than Caucasians to know someone who has had hip surgery, and they are therefore less likely to consider it as a treatment option.
Description
Hip revision surgery is hard to describe in general terms because the procedure depends on a set of factors unique to each patient. These factors include the condition of the patient's hip and leg bones; the type of prosthesis originally used; whether the original prosthesis was cemented or held in place without cement; and the patient's age and overall health. Unlike standard THR, however, hip revision surgery is a much longer and more complicated procedure. It is not unusual for a hip revision operation to take five to eight hours.
The most critical factor affecting the length of the operation and some of the specific steps in hip revision surgery is the condition of the bone tissue in the femur. As of 2003, defects in the bone are classified in four stages as follows:
Type I. Minimal bone defects.
Type II. Most of the damage lies at the metaphysis (the flared end of the femur), with minimal damage to the shaft of the bone.
Type III. All of the damage lies at the metaphysis.
Type IV. There is extensive bone loss in the femoral shaft as well as at the metaphysis.
The first stage in all hip revision surgery is the removal of the old prosthesis. The part attached to the acetabulum is removed first. The hip socket is cleaned and filled with morselized bone, which is bone in particle form. The new shell and liner are then pressed into the acetabulum.
Revision of the femoral component is the most complicated part of hip revision surgery. If the first prosthesis was held in place by pressure rather than cement, the surgeon usually cuts the top of the femur into several pieces to remove the implant. This cutting apart of the bone is known as osteotomy. The segments of bone are cleaned and the new femoral implant is pressed or cemented in place. If the patient's bone has been classified as Type IV, bone grafts may be added to strengthen the femur. These grafts consist of morselized bone from a donor (allograft bone) that is packed into the empty canal inside the femur. This technique is called impaction grafting. The segments of the femur are then reassembled around the new implant and bone grafts, and held in place with surgical wire.
A newer technique that was originally designed to help surgeons remove old cement from prostheses that were cemented in place can sometimes be used instead of osteotomy. This method involves the use of a ballistic chisel powered by controlled bursts of pressurized nitrogen. The ballistic chisel is used most often to break up pieces of cement from a cemented prosthesis, but it can also be used to loosen a prosthesis that was held in place only by tightness of fit. In addition to avoiding the need for an osteotomy, the ballistic chisel takes much less time. The surgeon uses an arthroscope in order to view the progress of the chisel while he or she is working inside the femur itself.
After all the cement has been removed from the inner canal of the femur, the surgeon washes out the canal with saline solution, inserts morselized bone if necessary, and implants the new femoral component of the prosthesis. After both parts of the prosthesis have been checked for correct positioning, the head of the femoral component is fitted into the new acetabular component and the incision is closed.
Diagnosis
In most cases, increasing pain, greater difficulty in placing weight on the hip, and loss of mobility in the hip joint are early indications that revision surgery is necessary. The location of the pain may point to the part of the prosthesis that has been affected by osteolysis. The pain is felt in both the hip area and the thigh when both parts of the prosthesis have become loose; if only the femoral component has been affected, the patient usually feels pain only in the thigh. As was mentioned earlier, however, some patients do not experience any discomfort even though their prosthesis is loosening or wearing against surrounding structures. In addition, a minority of patients who have had THR have always had pain from their artificial joints, and these patients may not consider their discomfort new or significant.
In general, diagnostic imaging that shows bone loss, loosening of the prosthesis, or wearing away of the joint tissues is an essential aspect of hip revision surgery—many orthopedic surgeons will not consider the procedure unless the x-ray studies reveal one or more of these signs. X-ray studies are also used to diagnose fractures of the hip or dislocatedprostheses. In some cases, the doctor may order a computed tomography (CT) scan to confirm the extent and location of suspected osteolysis; recent research indicates that CT scans can detect bone loss around a hip prosthesis at earlier stages than radiography.
Infections related to a hip prosthesis are a potentially serious matter. Estimated rates of infection following THR range between one in 300 operations and one in 100. Infections can develop at any time following THR, ranging from the immediate postoperative period to 10 or more years later. The symptoms of superficial infections include swelling, pain, and redness in the skin around the incision, but are usually treatable with antibiotics. With deep infections, antibiotics may not work and the new joint is likely to require revision surgery. One American specialist has said that the chances of salvaging an infected prosthesis are only 50/50.
Preoperative preparation
Certain health conditions or disorders are considered contraindications for hip revision surgery. These include:
Patients who are considered appropriate candidates for hip revision surgery are asked to come to the hospital about a week before the operation. X rays and other diagnostic images of the hip are reviewed in order to select the new prosthesis. This review is called templating because the diagnostic images serve as a template for the new implant. The surgeon will also decide whether special procedures or instruments will be needed to remove the old prosthesis.
Aftercare
Aftercare for hip revision surgery is essentially the same as for hip replacement surgery. The major difference is that some patients with very weak bones are asked to use canes or walkers all the time following revision surgery rather than trying to walk without assistive devices.
Risk factors
Factors that lower a patient's chances for a good outcome from hip revision surgery include the following:
Sex. Men are more likely to have poor outcomes from revision surgery than women, other factors being equal.
Age. Older patients, particularly those over 75, are more likely to have complications following revision surgery.
Race. African Americans have a higher rate of complications than Caucasian or Asian Americans.
Socioeconomic status (SES). Patients with lower incomes do not do as well as patients in higher income brackets.
Obesity. Many surgeons will not perform hip revision surgery on patients weighing 300 pounds or more.
Genetic factors. Recent British research indicates that patients who carry an inflammation control gene known as TNF-238A are twice as likely to require replacement of a hip prosthesis as those who lack this gene.
Specific risks of hip revision surgery
Risks following hip revision surgery are similar to those following hip replacement surgery, including deep venous thrombosis and infection. The length of the patient's leg, however, is more likely to be affected following revision surgery. Dislocation is considerably more common because the tissues surrounding the bone are weaker as well as the bone itself usually being more fragile. One group of researchers found that the long-term rate of dislocation following revision surgery may be as high as 7.4%.
Normal results
In general, hip revision surgery has less favorable outcomes than first-time replacement surgery. The greater length and complexity of the procedure often require a longer hospital stay as well as a longer period of recovery at home. The range of motion in the new joint is usually smaller than in the first prosthesis, and the patient may experience greater long-term discomfort. In addition, the new prosthesis is not expected to last as long. The life expectancy of implants used in first-time hip replacement surgery is usually given as 10–15 years, whereas revision implants may need to be removed after eight to 10 years.
Morbidity and mortality rates
There are relatively few analyses of mortality and morbidity following hip revision surgery in comparison to studies of complications following THR. One study published in 2003 reported the following figures for complications following hip revision surgeries (after 90 days) performed in the United States:
In some cases medications can be used to control the patient's pain, or the patient may prefer to use assistive devices rather than undergo revision surgery. If infection is present, however, surgery is necessary in order to remove the old prosthesis and any areas of surrounding bone that may be infected.
Alternative and complementary treatments
Alternative and complementary approaches that have been shown to control discomfort after hip revision surgery include mindfulness meditation, biofeedback, acupuncture, and relaxation techniques. Music therapy, humor therapy, and aromatherapy are helpful to some patients in maintaining a positive mental attitude and relieving emotional stress before surgery or during recovery at home.
See also
Hip replacement surgery.
BOOKS
Pelletier, Kenneth R., MD. "CAM Therapies for Specific Conditions." In The Best Alternative Medicine, Part II. New York: Simon & Schuster, 2002.
Silber, Irwin. A Patient's Guide to Knee and Hip Replacement:Everything You Need to Know. New York: Simon & Schuster, 1999.
Trahair, Richard. All About Hip Replacement: A Patient'sGuide. Melbourne, Oxford, and New York: Oxford University Press, 1998.
PERIODICALS
Alberton, G. M., W. A. High, and B. F. Morrey. "Dislocation After Revision Total Hip Arthroplasty: An Analysis of Risk Factors and Treatment Options." Journal of Bone and Joint Surgery, American Volume 84-A (October 2002): 1788–1792.
Blake, V. A., J. P. Allegrante, L. Robbins, et al. "Racial Differences in Social Network Experience and Perceptions of Benefit of Arthritis Treatments Among New York City Medicare Beneficiaries with Self-Reported Hip and Knee Pain." Arthritis and Rheumatism 47 (August 15, 2002): 366–371.
Drake, C., M. Ace, and G. E. Maale. "Revision Total Hip Arthroplasty." AORN Journal 76 (September 2002): 414–417, 419–427.
Mahomed, N. N., J. A. Barrett, J. N. Katz, et al. "Rates and Outcomes of Primary and Revision Total Hip Replacement in the United States Medicare Population." Journal of Bone and Joint Surgery, American Volume 85-A (January 2003): 27–32.
Nelissen, R. G., E. R. Valstar, R. G. Poll, et al. "Factors Associated with Excessive Migration in Bone Impaction Hip Revision Surgery: A Radiostereometric Analysis Study." Journal of Arthroplasty 17 (October 2002): 826–833.
Puri, L., R. L. Wixson, S. H. Stern, et al. "Use of Helical Computed Tomography for the Assessment of Acetabular Osteolysis After Total Hip Arthroplasty." Journal of Bone and Joint Surgery, American Volume 84-A (April 2002): 609–614.
ORGANIZATIONS
American Academy of Orthopaedic Surgeons (AAOS). 6300 North River Road, Rosemont, IL 60018. (847) 823-7186 or (800) 346-AAOS. <http://www.aaos.org>.
American Physical Therapy Association (APTA). 1111 North Fairfax Street, Alexandria, VA 22314. (703)684-APTA or (800) 999-2782. <http://www.apta.org>.
National Center for Complementary and Alternative Medicine (NCCAM) Clearinghouse. P.O. Box 7923, Gaithersburg, MD 20898. (888) 644-6226. TTY: (866) 464-3615. Fax: (866) 464-3616. <http://www.nccam.nih.gov.>.
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) Information Clearinghouse. National Institutes of Health, 1 AMS Circle, Bethesda, MD 20892. (301) 495-4484. TTY: (301) 565-2966. <http://www.niams.nih.gov>.
Rush Arthritis and Orthopedics Institute. 1725 West Harrison Street, Suite 1055, Chicago, IL 60612. (312) 563-2420. <http://www.rush.edu>.
OTHER
Hip Universe. June 15, 2003 [cited July 1, 2003]. <http://www.hipuniverse.homestead.com>.
Questions and Answers About Hip Replacement. Bethesda, MD: National Institutes of Health, 2001. NIH Publication No. 01-4907.
Rebecca Frey, Ph.D.
WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?
Hip revision surgery is performed by an orthopedic surgeon, who is an MD and who has received advanced training in surgical treatment of disorders of the musculoskeletal system. As of 2002, qualification for this specialty in the United States requires a minimum of five years of training after medical school. Most orthopedic surgeons who perform joint replacements and revision surgery have had additional specialized training in these specific procedures. It is a good idea to find out how many hip revisions the surgeon performs each year; those who perform 200 or more have had more opportunities to refine their technique.
In many cases, hip revision surgery is done by the surgeon who performed the first replacement operation. Some surgeons, however, refer patients to colleagues who specialize in hip revision procedures.
Hip revision surgery can be performed in a general hospital with a department of orthopedic surgery, but is also performed in specialized clinics or institutes for joint disorders.
QUESTIONS TO ASK THE DOCTOR
How much improvement can I expect from hip revision surgery?
