Despite thorough preparation, the risks involved in revision hip replacement surgery are increased several fold from the level of risk of a primary hip replacement. The surgery is more difficult and time consuming, the soft tissues, nerves and blood vessels more difficult to mobilize and protect and the prostheses are more complex to implant properly into the supporting bone. The soft tissues become more difficult to stretch and the pain of revision hip replacement surgery can be an obstacle to full mobilization of the joint. Notably, it is important that patients realize that the revised hip frequently never reaches the same level of function as did the first hip replacement. Complications and chronic pain are far more common with revision hip replacement surgery than it is with primary hip replacement.
When replacing a diseased hip joint, an orthopaedic surgeon inserts an artificial joint called a prosthesis. In New Zealand thousands of total hip joint replacements are performed each year by orthopaedic surgeons.
The ORI - How to Recognize a Failing Hip Replacement
In contrast, when the reason for the revision hip replacement is infection or instability, the implanted components are usually very well attached to the supporting bone and the removal of the prosthesis can be quite laborious and time consuming. Great care is taken so that while removing the prosthetic implant, as little supporting bone is removed as is possible. The bone of the more senior patient is often quite osteoporotic and the process of removing the implant can result in fractures of the supporting bone, thereby greatly complicating the situation and leading to the need for a more complex implant than was originally intended. One trick that the experienced surgeon uses to extract the femoral component is to split the bone in a controlled fashion to allow access to the well-fixed stem. With the use of sophisticated burrs and other surgical instruments, the stem can be freed and the femur put back together to hold the new prosthesis.
Classification of hip joint infections
For a hip replacement to function well, the ball must be retained within the socket at all times. Several factors must work in concert to keep this mechanical relationship intact, including proper alignment of the acetabular prosthesis (the socket) and the femoral prosthesis (articulating ball part). In addition, the muscles that attach to both the pelvis and the femur must be strong and able to withstand pressure. Sometimes the muscles of the elderly patient are quite weakened with age or health related issues and are unable to hold the ball in the socket.
Int J Med Sci 2009; 6(5):227-233
The most common situations that lead to the need for a revision hip replacement are instability / dislocation, mechanical loosening and infection. According to one national review study, instability issues account for 22% of all revision hip replacements, aseptic loosening for 20% and infection the cause of 15% of yearly revision hip replacement surgeries . Periprosthetic fracture, component failure and osteolysis-related wear are the causes for the remaining revision hip replacements done each year. Of great concern looking forward is that infection by the year 2030 will account for 48% of all revision hip replacements that will be done . This has grave economic implications as infection is one of the most expensive complicating events related to joint replacement surgery.