Hip and Knee Replacements

Management of joint arthritis before hip and knee replacements

Hip and knee replacements have dramatically improved the mobility and function of patients with severe arthritis. Although these are very successful procedures, our philosophy at Abraham Orthopaedics is that these surgical procedures should be a last resort after all other forms of conservative management have been exhausted. Every surgical procedure carries some level of risk, and knowing that all other non-surgical methods of management have been exhausted gives confidence that the right decision is being made when it comes time to deciding on surgery. Dr. Mathew Abraham is an expert in the non-surgical management of arthritis, both of the joints and of the spine, and patients referred to Abraham Orthopaedics for arthritis management will generally begin with an evaluation for conservative measures to improve pain and function without surgery. These measures may include physical therapy, activity modifications, exercise programs, weight loss programs, and injections. There are several types of injections that can be performed both in the joints and in the spine that are very useful in alleviating pain from arthritis in these locations. Once an injection is performed, an operation should not be done on that same joint until about three months have elapsed. This is because the wound healing response requires initiation of the body’s inflammatory cascade, which is shut off by the steroids typically used in joint injections. Once the three month period has passed, the effect of the steroid on the incision is gone and the operation can be safely undertaken. It is important to know that in many cases, these conservative measures may give a long period of relief and may push any potential surgery back significantly. Even if that is not the case, these measures will help improve the outcome of any potential surgery. The phase of exhausting conservative management is a critical part of the overall management and should not be avoided to get the best possible outcome.

Hip Replacement

Total hip replacement is considered one of the most successful surgical procedures currently offered in any field of medicine. It is no surprise that nearly half a million hip replacements are performed in the United States in a year. Hip replacements can restore significant function and mobility to the patient suffering from severe arthritis. During the surgical procedure, the hip is opened by using one of several approaches, and the ball is removed from the socket, called a dislocation. The neck and head of the top of the femur are cut and removed, giving access to the socket. A spherical tool with cheese-grater-like cutting bumps, called a reamer, is used to remove the cartilage and dense cortical bone from the socket and expose healthy bleeding cancellous bone. A metal hemisphere-shaped socket is fixed into the acetabulum (the body’s natural bony socket), and sometimes held in place with screws. Then a plastic liner is placed into this component. On the femur side, the shaft of the bone is prepared to accept a metal wedge shaped piece called a stem, which is then malleted into place. A variety of ball sizes can be trialed until the best fit is identified, and then the permanent ball is fixed to the stem. The ball is placed back into the socket and the hip is sewn closed. The patient can bear full weight on the leg immediately, and in many cases can go home the same day. The initial period after the surgery is the period with the highest risk for complications, including dislocation. For this reason, it is generally recommended that the patient be somewhat cautious during the first 6-8 weeks after surgery to prevent complications. Follow up protocol is visits with the doctor at 2 weeks, 8-12 weeks, then 6 months and then annual or bi-annual screening check up visits with X-ray.

Knee Replacement

Total knee replacement is an extremely successful procedure for patients with end-stage arthritis of the knee. This is an approximately one-hour procedure in most cases, and involves opening the knee and trimming the cartilage and small amount of bone off the end of the femur, tibia, and patella. These cut surfaces are then prepared to accept the metal components of the replacement. The metal components are fixed into place, usually with bone cement, and a plastic insert is placed between the metal components. The patella, or kneecap, is usually resurfaced with a plastic “button”. The range of motion of the knee is tested and then the joint is sewn closed. For many patients, knee replacement can be done as an outpatient operation, allowing the patient to return home on the same day as surgery, after a physical therapy evaluation is completed. The knee generally remains swollen and somewhat stiff for the first several weeks, but range-of-motion exercises and routine walking and elevation help rehabilitate the knee to its final improved condition. Once the knee replacement is completed, follow up visits usually take place at the 2 and 8-12 week timepoints after surgery, and then at 6 months, followed by annual or bi-annual check-up visits with X-rays. Patients can expect to have improved overall leg alignment and range of motion once they are healed from surgery, and the knee should be completely or nearly pain free once the rehabilitation period is completed.

Revision Hip and Knee Replacements

Hip and knee replacements, as successful as they are, can fail over time. This can be for a variety of reasons. Early failures may be due to mechanical problems such as dislocations, or technical problems such as imperfect alignment, or biologic problems such as infection. Late problems with joint replacements are often due to wear of the plastic components, or sometimes just loosening of the implant over time. In many of these cases, the joint replacement may need to be revised, or redone. Approximately 10% of joint replacements will need to be revised within 15 years. In particular, when the polyethylene (plastic) liners wear out, they generate tiny particles of plastic which become embedded in the bone and soft tissue around the joint. The body has mechanisms to try to get rid of these particles, but those mechanisms also remove small portions of bone as well. This process is called osteolysis, and over time, can generate large bone defects around a failing joint replacement. These bone defects contribute to the complexity of the joint revision procedures, since it is usually not simply a matter of “changing out parts”. There are often significant challenges due to the large bone defects, thinned out bone which promotes fracture, particle disease and resulting synovitis with increased blood flow and bleeding, and a number of other complicating factors. For this reason, revision joint replacement is best left to surgeons who are experienced in performing these procedures, and have a track record of success.

Complex Revision Hip and Knee Replacements

As many of the techniques used in orthopaedic oncology surgery are translatable to joint revision surgery, it is not uncommon that orthopaedic oncologists also perform a significant number of joint revision procedures as well. Large scale joint replacement procedures are often part and parcel of an extremity cancer operation. In particular, revision surgery of the socket side, or acetabulum, of a hip replacement can be particularly challenging. This is due to the complex anatomy of the pelvis, which is the major bone that makes up the acetabulum, and also the high density of critical structures like nerves and blood vessels around the area. In some cases, the osteolysis here can be so severe that no implants are available off the shelf that can address them. In these cases, implants may need to be custom-made for a particular patient based on a CT scan image of the pelvis. This is a type of revision surgery that is of particular interest to Dr. Abraham, who is one of the leading surgeons for custom made joint replacement in the country. Revision joint replacement has been a staple of the orthopaedic practice of Dr. John Abraham. He not only performs a large volume of these operations, and is one of the leaders in revision joint replacement in the region, but also teaches these procedures to residents, fellows, and junior surgeons. He has been on multiple nationwide panels for the joint replacement industry, and is also involved in the design of new implants for the future that have improved characteristics over the current models. Dr. Mathew Abraham is heavily involved in creating rehabilitation plans for these types of patients, and helping address the pre- and post- operative issues that can limit recovery. Abraham Orthopaedics is dedicated to getting the best possible outcomes for patients from these difficult situations, and utilizes all of these areas of expertise to get our patients the highest level of function possible.