Revision Knee Replacement
Restoring Comfort and Function After Previous Knee Surgeries.
Occasionally, a primary knee preplacement may require replacement for reasons like persistent pain or indications of wear. This surgical procedure involves the adept removal and replacement of one or more components of your initial knee implant and,depending on your specific condition, it may also involve the reconstruction of damaged bone and soft tissues using bone grafts, augments, or specific types of constrained prostheses.
This intricate process demands the expertise of an experienced orthopaedic surgeon like Dr Keeley with specialised training and a dedicated focus on revision knee replacement procedures.
WHY IMPLANTS CAN FAIL
Common reasons for implant failure include:
- Wear and Tear: Over time, the materials used in knee implants can wear down, especially with active use. The polyethylene components, in particular, may degrade, leading to small particles being released into the joint. This wear can cause the implant to loosen, resulting in pain and reduced function.
- Loosening of the Implant: Loosening is one of the most common causes of implant failure. It can occur when the bond between the bone and the implant weakens, either due to wear, inadequate initial fixation, or changes in bone quality over time. This loosening often leads to discomfort and instability in the knee.
- Infection: Infections around the knee implant can occur either shortly after surgery or years later. An infection can damage the surrounding bone and tissue, leading to implant failure. It is one of the most serious complications and often necessitates a revision surgery to remove the infected implant, treat the infection, and replace the implant.
- Implant Misalignment: If the implant components are not properly aligned during the initial surgery, it can lead to uneven wear and increased stress on certain parts of the knee. This misalignment can cause pain, limited range of motion, and eventually implant failure.
- Fractures: Bone fractures around the implant, known as periprosthetic fractures, can compromise the stability of the knee replacement. These fractures may occur due to trauma, such as a fall, or weakened bone around the implant. Depending on the severity, this may require a revision procedure to repair or replace the implant.
- Scar Tissue Formation: Excessive scar tissue, or arthrofibrosis, can develop around the knee joint after surgery, leading to stiffness and limited movement. In severe cases, this can affect the function of the implant and necessitate a revision surgery to remove the scar tissue and restore mobility.
- Allergic Reactions: Some patients may develop an allergic reaction to the materials used in the implant, such as metal components. This can cause pain, swelling, and inflammation, potentially leading to implant failure.
- Patient Factors: Individual factors such as weight, activity level, and overall health can impact the longevity of a knee implant. High-impact activities, obesity, or underlying conditions like osteoporosis can increase the risk of implant failure.
PROSTHETIC IMPLANTS & REVISION KNEE REPLACEMENT
Modern implant technology has significantly improved the outcomes of revision knee replacement surgeries, offering enhanced durability, stability, and range of motion.Dr Keeley selects specialised implants based on your unique anatomy and the specific challenges of your revision procedure. For example, modular implants can offer flexibility for anatomical variations and future adjustments, while constrained implants provide added stability when knee ligaments are compromised.
Implant components in revision knee replacement procedures may include:
Preserves bone while ensuring stability and durability, often made from materials like titanium or cobalt-chromium.
Enhances contact between the patella and femur, improving stability and longevity.
Offers a stable foundation with cemented or mechanical attachment for immediate and long-term support.
Acts as a cushion between the metal femoral and tibial components, providing a smooth surface for movement. It can be customised in thickness to help with alignment and stability.
Provides flexibility, available in fixed and mobile versions with varying constraints.
Ensure a snug fit, minimising implant overhang and complications.
Provide crucial support for secure fixation, enhancing overall implant stability.
Extensions of the femoral or tibial components that fit into the bone’s canal, providing additional stability, particularly in cases where the bone quality is compromised.
Distal and Posterior Femoral Augments: Address bone defects and restore biomechanical balance.
Such as tibial wedges or blocks, used to fill bone defects and help achieve proper alignment and fit of the implant.
Specialised components used when there is significant instability in the knee, offering a higher level of constraint to control joint movement.
A highly constrained implant used in cases of severe instability, where the knee joint requires significant supportand controlled motion.
REVISION KNEE REPLACEMENT SURGICAL TECHNIQUES
Depending on your specific needs and your overall health, revision knee surgery may be performed as either a one stage or, two stage procedure:
One-Stage Revision: This approach involves removing the faulty implant(s) and replacing them with new ones in a single surgery. It is typically chosen when no infection is present or when the infection can be effectively managed during the procedure.
Two-Stage Revision: If an infection is present, a two-stage revision is often required. In the first stage, the infected implant is removed, and a temporary spacer is inserted to allow for antibiotic treatment. Once the infection is cleared, a second surgery is performed to place the new implant components.
Most revision total knee replacements take longer to perform than primary procedures, about two to three hours per surgery.
SURGICAL REVISION KNEE SURGERY TO IMPROVE YOUR COMFORT AND FUNCTION
It’s important to understand that the complexity of revision knee surgery can vary widely. Some patients may require relatively straightforward procedures, while others involve more extensive operations. During your consultation, Dr Keeley will take a comprehensive clinical history, conduct a thorough examination, and carefully review your scan results to determine theright revision knee replacement plan specifically for you.