Knee replacement revision

Modern knee prostheses have good survivorship, but over the years they can loosen, wear, become unstable or get infected; polyethylene wear or a ligament imbalance can appear before loosening does. When that causes pain, instability or stiffness that limits function, a revision may be indicated.

Before operating it is essential to know why the prosthesis is failing. Radiographs, blood tests and, whenever there is any doubt, a joint aspiration are used to rule out infection, because a painful prosthetic knee is infected until proven otherwise and the treatment changes completely (see two-stage revision).

A prosthesis that is painful but well-fixed and not infected calls for looking for other causes before indicating a revision, so as not to reoperate without a clear reason.

The failed components are removed, the bone and ligaments are assessed, and reconstruction uses revision implants: stems that distribute load toward healthy bone, augments that replace lost bone and, when the ligaments are insufficient, prostheses with a greater degree of constraint that provide the stability the ligaments can no longer give.

Recovery of range of motion and strength is usually slower than after a primary replacement, so consistency in physiotherapy is even more important. Weight-bearing is progressed according to the reconstruction performed.

The decision to operate is made together: we discuss your symptoms, their impact on daily life, the expected benefits, the risks and the alternatives. Surgery does not guarantee an outcome; it aims to improve pain and function in selected patients.