Revision Knee Surgery

Why Revision Surgery May Be Required

Modern knee replacements are highly durable, but they are not permanent. Over time, mechanical and biological factors can lead to a previously successful replacement becoming painful, unstable, or dysfunctional. Identifying the precise cause of failure is the critical first step in planning an effective revision.

• Aseptic loosening — loss of the bond between implant and bone, usually due to osteolysis from polyethylene wear particles over many years
• Periprosthetic joint infection (PJI) — deep infection presents a significant management challenge, often requiring staged surgery with antibiotic spacer placement
• Instability — ligamentous insufficiency leading to pain, giving way, and loss of function
• Stiffness — severe arthrofibrosis (excessive scar tissue) limiting flexion may require surgical release or implant exchange
• Periprosthetic fracture — fracture around the implant, frequently after a fall, requiring fixation or component revision
• Polyethylene wear — thinning of the bearing insert, causing pain and increasing risk of loosening

Pre-operative Assessment

Thorough evaluation before revision surgery is even more important than before a primary replacement. Establishing the cause of failure guides every aspect of surgical planning.

• Detailed history including symptom timeline, any prior wound complications, and systemic symptoms
• Weight-bearing radiographs to assess alignment, component position, bone loss, and implant integrity
• CT scanning to characterise bone defects and plan augmentation requirements
• Blood inflammatory markers (ESR, CRP, D-dimer) and joint aspiration for culture and cell count to exclude or confirm infection
• Nuclear medicine or PET-CT when the aetiology remains uncertain after initial investigations

The Procedure & Recovery

Revision knee surgery is significantly more demanding than primary replacement. Existing well-fixed components must be carefully extracted, bone defects must be managed using augments, wedges, sleeves, or structural allograft, and longer-stem implants are commonly required to achieve stable fixation in compromised bone.

Operating time is longer and hospital stay is generally extended compared to primary replacement. Recovery is also slower and more variable, reflecting the complexity of the reconstruction, the quality of remaining bone and soft tissue, and the underlying reason for revision. Dedicated physiotherapy remains essential throughout recovery.

Despite its complexity, revision knee replacement performed by an experienced joint revision surgeon reliably reduces pain and improves function in the majority of appropriately selected patients.