Total hip replacement surgery has been one of the most successful surgical procedures over the last 50 years, allowing patients to live more productive and active lives free of chronic pain. While most commonly used to treat osteoarthritis, hip replacement is also used to treat malfunctioning hip joints due to trauma, infection, bone death (avascular necrosis), mal-formed hips from birth, and tumors. Modern hip replacements are lasting longer and longer and often can last 20 – 30 years and beyond. However, occasionally hips put in years ago or even more recent hip replacements can have pain or implant failure. Some of the potential reasons for painful or failed hip replacement includes implant deterioration/wear, hip dislocation/instability, implant loosening from the bone, infection, fracture/injury, poorly positioned implants, and metal ion disease. An evaluation by a fellowship trained Orthopaedic surgeon trained in revision surgery is recommended to determine if revision of part or all of the hip replacement may benefit the patient and alleviate symptoms.
Why do Implants fail?
Gradually, the friction put on the joint replacement causes tiny particles to break off of the replacement. This causes loosening of the bond between the bone and the implant. Occasionally, tiny particles that break off the plastic spacer collect around the hip joint and then are attacked by the body’s immune system. Unfortunately this immune response also attacks the healthy bone around the implant, producing a condition called osteolysis. Osteolysis causes the bone around the implant to deteriorate, making the implant loose or unstable. When this occurs, the hip can become swollen and painful to move, making it challenging to do everyday activities.
Other times, the hip implants which are “press-fit” snuggly into the patients bone do not adhere to the bone from the beginning and can have persistent pain ever since surgery. Most common modern hip replacements are designed for the patients bone to grow into and secure to the implant over the first few months. For many different reasons, occasionally this process does not successfully occur which can leave the patient in pain.
Infection is a possible complication in any surgical procedure, including total hip replacement. An infection may occur at any time from shortly after surgery to years later. Infection can spread from recent colds or urinary infection to involve joint replacement.
If an artificial hip joint becomes infected, it often will become swollen, painful and stiff. The infection may cause the implant to lose its attachment to the bone. Infection around a hip replacement requires one or more revision surgeries to treat the infection.
Hip replacements rely on appropriate positioning of implants and appropriate leg length and tension of the surrounding tissue to maintain stability. Occasionally hip replacements can dislocate. This typically requires being brought to the emergency department to put the hip back in socket. Once this happens the patient is likely to experience recurring dislocation that may require revision of one or all of the implants to resolve.
A periprosthetic fracture is a broken bone around the components of a total hip replacement. A fall most often causes this type of fracture, and usually requires revision surgery.
In establishing the extent of the revision required, the Orthopaedic specialist will take into account a number of factors, including the location and the type and of fracture, the quality of the remaining bone, and if the implant is loose. Revision surgery may require fixing the fracture alone, fixing the fracture and revising the implant, or completely removing the implant and fracture pieces and replacing with a larger more complex total hip replacement.
Over time the plastic component of the hip replacement can wear thin. This can often be identified with a simple X-ray. It is recommended to have routine follow-up of all hip replacements every few years to monitor for this. If left for too long, this can lead to the implants coming loose from the bone or the hip dislocating.
Metal ion disease
When two metals meet, they can wear and lead to small metal particles being spread around the hip. This can occur with “metal on metal” hips which were commonly used in the past. More recently it has been shown that this can also happen in patients that do not have metal on metal hips but has other areas of the hip replacement in which 2 metals meet such as modular hip replacements and hips utilizing cobalt chrome heads with plastic liners. If your hip replacement may have this condition, it is recommend to get a simple blood test that looks for metal ions in the blood stream. If this is elevated your surgeon may get an MRI of your hip. Metal ion disease can be either painful or painless to the patient. Your surgeon will evaluate your situation on a case-by-case basis to determine if revision surgery may be recommended.
How we can help
If you are experiencing pain or problems with your hip replacement, an evaluation with our fellowship trained Orthopaedic surgeon Dr. Paul Roettges is recommended. He will evaluate the entirety of your case to determine if revision surgery may be right for you. This evaluation will include a review of your prior surgical documents and images, a detailed physical exam, and often an array of specialized tests looking for potential reasons for your symptoms. With this, the potential benefits of revision surgery will be explained in detail to the patient.
Although with the same goal to reduce pain and increase function, revision surgery is different from first time total hip replacement. Revision surgery is often longer and more complex requiring specialized planning, tools, and implants to achieve a better result.
There are different types of hip revision surgery. In some cases, only one piece of the prosthesis has to be replaced. In other cases, multiple or all of the components need to be replaced. More complex revisions often require specialized implants and augments to replace damaged bone and muscle.
If our Orthopaedic Specialist is able to determine a failure of the implant or reason for symptoms, revision surgery patients commonly experience satisfactory long-term outcomes, including pain relief and increased stability and function. However, complete pain relief and restoration of function are not always achievable.
If you are having problems with your hip replacement, it’s important to talk to our fellowship-trained Orthopaedic Specialist, Dr. Paul Roettges.