Long term clinical outcome of total knee arthroplasty. The effect of limp alignment, implant placement and stability as controlled by surgical technique

Abstract

The numbers of total knee arthroplasties (TKAs) performed per year is increasing rapidly. In the year 2005, 533,000 procedures were performed in the US and it is estimated that by the year 2030, the numbers of procedures will reach the level of three million per year [1]. Outcomes of TKA are satisfactory with a reported survival of 95.9 % at 15 years with revision for any reason, of 97 % with revision for mechanical failure and of 98.8 % with revision for aseptic loosening as an end point [2]. Other studies have also reported excellent results with a survival rate ranging from 90 to 98 % at the level of 10-15 years follow up [3-7]. Ritter et al. [8] and Lachiewicz et al. [9] have also reported survival rates of 95 % and 96.8 %, with revision for aseptic loosening as an end point at a minimum 15 years follow up. Common reasons for TKA failure have been identified (e.g., polyethylene wear, aseptic loosening, instability, infection, arthrofibrosis, malalignment or malposition, deficient extensor mechanism, avascular necrosis of the patella, periprosthetic fracture and isolated patellar implant failures) [10], while the most common reasons for reoperation are extensor mechanism problems, infection and instability [11, 12]. Sharkey et al. [10] have shown that the most prevalent cause of early failure in their series was infection (17.5 %), and for late failure polyethylene wear (25 %). Moreover, infection and surgical technique errors were the main reasons for early reoperations (within 5 years of the primary procedure) in an evaluation of 440 revision TKAs [13]. © Springer-Verlag London 2015.