Revision Total Knee Replacement

A Revision or Redo surgery is a surgery done when a knee or hip replacement loosens and needs to be performed again.

Artificial joints cannot last forever. Current knee and hip replacements on an average can be expected to last around 15 to 20 years or so, depending on several factors. When a knee or hip replacement gets loose or wears out, patients experience pain, limp, stiffness, difficulty walking, swelling or instability. Hence the joint needs to be taken out and a new knee or hip replacement needs to be performed (Revision).

Loosening may be natural loosening that occurs due to wearing out of the artificial joint over a period of time (called Aseptic Loosening) or may be due to infection (Septic loosening).

Infection is a devastating complication of any surgical procedure. In total knee replacement, the large foreign metal and plastic implants can serve as a surface for the bacteria to latch onto, inaccessible to antibiotics. Even if the implants remain well fixed, the pain, swelling, and drainage from the infection make the revision surgery necessary. With current surgical techniques and antibiotic regimens, the risk of infection from total knee replacement is less than 1%.

Friction caused by the joint surfaces rubbing against each other wears away the surfaces of the implant, creating tiny particles that accumulate around the joint. In a process called aseptic (non-infected) loosening, the bond of the implant to the bone is destroyed by the body's attempt to digest the wear particles. During this process, normal bone is also digested (a condition called osteolysis), which can weaken or even fracture the bone.

When the decision for revision replacement is made, standard assessments are performed, including x-rays, laboratory tests, and possibly other imaging modalities like bone scans, CT scans, or Magnetic Resonance Imaging (MRI) studies. X-rays may demonstrate a change in the position or condition of the components. MRI or CT scan helps to determine the cause, location, and the amount of bone loss before surgery. Aspiration of the knee or hip (joint fluid removed with a needle) may be required if infection is suspected. This aspirated fluid will then be sent to a laboratory for analysis to identify the specific type of infection.

Revision surgery is complex and challenging and needs considerable surgeon training and expertise. Loose joints have bone loss around them and it may be difficult to fit in a new joint into such bones. Joints that are revised may not last as long as the first replacement lasted. This surgery needs extensive planning, specialized equipment and specialized parts (implants). The surgery takes considerably longer to perform compared to a standard hip or knee replacement and often needs x rays to be performed during the surgery to check on the implant positioning. If there has been considerable bone loss in the patient and a new implant cannot be fitted, we use allograft bone (bone taken from another person via a bone bank) or specialized material called Trabecular Metal to fill the voids in bone; we also used specialized implants made of trabecular metal into which bone grows rapidly, thus enabling the new revision parts to obtain a secure grip.

For aseptic loosening, the old artificial joint is removed, the bone is cleaned, and a new knee or hip replacement surgery is performed into available bone.

For septic loosening (infection), the old joint is removed, material is sent from the bone and tissues to the laboratory for evaluation to identify the bacteria causing the infection, the tissues near the bone and the bone itself is thoroughly cleaned and washed, and an antibiotic temporary joint (called ‘Spacer’) is placed over the bone. The patient is given antibiotics for atleast 6 to 8 weeks, and once the infection is under control, a new knee or hip replacement is performed.

The aim of a revision surgery is to relieve pain and improve function. Greater than 90% of patients who undergo revision procedures can expect to have good to excellent results. Although expected outcomes include pain relief with increased stability and function, complete pain relief and restoration of function is not always possible. Up to 20% of patients may still experience some pain, stiffness or a limp following revision surgery.

We have state-of-the-art equipment to remove prosthesis and re-insert new prosthesis. Operation theatres available here have very low infection rates comparable with the best centers in USA and UK. Our Anesthesiologists can successfully manage patients who need long revision surgeries and who also have other problems such as diabetes, high blood pressure and kidney problems. Postoperatively, nurses here are familiar with patient care and look after the patient comprehensively. Intensive care As a result, we receive patients from across India, Africa, the Middle East and even UK and Canada due to high quality health care.
Dr Ameet Pispati has been trained to perform complex revision surgeries in the UK, USA and Germany.