Implant Movement Analysis (IMA), A New CT Based Technique for Diagnosis of Aseptic Loosening of Total Knee Arthroplasty
Per Wretenberg
Abstract
Background and purpose: Aseptic loosening is the most common indication for revision surgery after Total Knee Arthroplasty (TKA). However, the diagnosis is often difficult from planar radiography as well as other methods, making decision regarding revision surgery problematic. Implant Movement Analysis (IMA) is a newly introduced method of analysing uncertain aseptic loosening of orthopaedic implants. This is the first study where this technique is applied for analysis of potentially loose knee prosthesis. The IMA technique is based on Computer Tomography (CT) with rotational as well as varus and valgus provocation to expose any movement of the implant relatively to the surrounding bone. Our aim was to evaluate the role of IMA as a complementary method to planar radiography and clinical examination in diagnosing aseptic loosening of (TKA).