What is revision knees?
Revision knee replacement surgery is a procedure performed to replace or repair a previous knee replacement that has failed, worn out, or is no longer functioning effectively. Although most knee replacements provide excellent long-term outcomes, some patients may develop complications over time that require further surgery. Revision knee replacement is generally more complex than primary knee replacement surgery due to factors such as scar tissue formation, bone loss, ligament instability, or infection. The aim of revision surgery is to relieve pain, restore stability and function, improve mobility, and provide a durable knee joint that allows patients to return to daily activities.
Causes
There are several reasons why a knee replacement may require revision surgery. Common causes include loosening or wear of the implant components over time, infection around the joint, instability of the knee, stiffness, or fractures occurring around the prosthesis. In some patients, the plastic liner between the metal components can wear down, leading to inflammation and bone loss. Persistent pain, malalignment of the components, or recurrent swelling may also indicate failure of the original knee replacement. Younger or more active patients may place increased demands on their knee replacement, which can contribute to earlier wear or mechanical failure.
Symptoms
Patients requiring revision knee surgery often experience :
- Pain : worsening over time.
- Stiffness: in the knee.
- Walking: difficulty walking.
- Mobility: reduced mobility and difficulty climbing stairs, standing from a seated position and walking long distances.
- Limping
- Instability: feeling that the knee is unstable or “giving way” or sensation that the knee is loose.
- Mechanical symptoms: such as clicking, grinding or locking.
- Swelling, Redness, Warmth : around the joint, if infection is present.
- Fever: in cases of infection.
- Wound drainage: in cases of infection.
- Onset: Sudden onset of symptoms following trauma or implant failure.
- Progression: Gradual worsening of symptoms over time.
Can be gradual development over many years or a sudden onset of symptoms after trauma or implant failure.
Diagnosis
Begins with a thorough clinical assessment, including review of symptoms, medical history, and previous surgical procedures.
Physical examination allows assessment of knee movement, swelling, ligament stability, alignment, gait, and signs of infection. Blood tests are commonly performed to investigate for infection or inflammation.
In some cases, fluid may be aspirated from the knee joint for laboratory analysis to identify infection. Determining the underlying cause of failure is essential in planning the most appropriate treatment and surgical approach.
Imaging
Imaging studies are an important part of evaluating a painful or failed knee replacement. Standard X-rays are used to assess implant position, loosening, wear, alignment, and bone quality. CT scans may be required to provide more detailed assessment of component rotation, fixation, and bone loss, particularly in complex revision cases. In selected patients, MRI scans or nuclear medicine imaging may also be used to investigate soft tissue problems, infection, or inflammation around the knee replacement. These imaging studies assist in surgical planning and help determine the extent of reconstruction required.
Treatment
Conservative (non-operative)
In some cases conservative treatment may help manage symptoms associated with a knee replacement. Options can include physiotherapy to improve strength and mobility, activity modification, weight management, walking aids, anti-inflammatory medications, and pain relief strategies. Occasionally, braces or injections may be considered depending on the underlying problem. However, when there is significant implant loosening, instability, infection, severe stiffness, or ongoing pain that limits function, revision knee replacement surgery may be necessary to restore mobility and improve quality of life.
Surgical Treatment
Revision knee replacement surgery involves removing part or all of the existing knee replacement and replacing it with new prosthetic components. The complexity of the procedure depends on the reason for failure, the amount of bone loss, and the condition of the surrounding ligaments and soft tissues. Some patients may only require replacement of one component, while others require a complete reconstruction using specialised revision implants, stems, augments, or bone grafts. In cases of infection, surgery may be performed in one or two stages depending on the severity and type of infection.
Recovery
Recovery following revision knee surgery is often longer than after a primary knee replacement, but the aim is to reduce pain, improve stability and movement, and allow patients to return to daily activities with a more functional knee joint.