Total knee arthroplasty 2010

Abstract

The Bone and Joint Decade from 2000 to 2010 has almostreached his end. The decade was invited by the UnitedNation and the World Health Organisation in order toincrease the awareness to people with musculoskeletaldiseases. The rapid increase in the prevalence of osteoar-thritis will have a growing impact on the health care andpublic health care system.It has been estimated that the number of patients diag-nosed with osteoarthritis will increase by 40% in the next25 years. The number of patients with symptomaticosteoarthritis has grown from 21 to 27 Million in the USAbetween 1995 and 2005 [4]. There are several reasons forthis development. First, the world population is currentlyincreasing from 6 Billion in 2000 to almost 7 Billion in2010 [8]. Thus, there will be more patients in the futuresuffering on osteoarthritis. The second major reason seemsto be the aging of our world population. It has been esti-mated, that the number of people over an age of 60 will risefrom one-fifth in 1995 to one-fourth in 2020, which meansan increase of about 40% in this group of age.Murphy et al. [6] estimated the lifetime risk of symp-tomatic knee osteoarthritis of about 45%. Many of thesepatients will be potential candidates for joint replacement.Disability and pain are the major indications for total kneearthroplasty. Nowadays people getting more demandingand want to be mobile and maintain their level of activityas long as possible. According to the Swedish kneearthroplasty register the average age of the patients hasdropped for total knee arthroplasty (TKA) from 72 to 69and for unicompartmental knee arthroplasty (UKA) evendown to 64 between 1995 until 2005. Based on these factsit is not surprising that the cost for total joint replacement ispermanently rising and exceeds in the United Statesalready 1% of the gross domestic product in 2007.The number of both primary and revision arthroplastywill increase about 300% in the next 15 years. Especiallydue to hip and knee arthroplasty the quality of life can besignificantly improved and many of the patients return to alevel of activities which makes them physically active andhappy in their older days [1].Nevertheless, not all of the patients will do perfectlywell. The success rate after TKA has been reportedbetween 80 and 90%. Going into more detail the satisfac-tion rate in pain relief varies between 72 and 86% and forspecific activities like getting in and out a car or bus (70%)or ascending stairs (73%) [5]. In order to find the cause forpersistent knee pain after TKA may sometimes be verydifficult. A new diagnostic algorithm to evaluate painfulknees after TKA has been introduced by Hirschmann andco-authors [3], in the current issue. They report about acombination of both single photon emission tomographyand conventional computerized tomography. This tech-nique allows the analysis of the component position byusing the reconstructed 3D-scan. In addition it will provideinformation about the bone metabolic status around theknee too. However, further studies are required in order tofind out whether this tool will be useful and specific enoughin patients with unexplained pain following TKA on aregular basis.Despite the improvement of diagnostic tools we have toimprove our understanding of the complexity of the kneeby further anatomical and kinematic studies as well. Itincludes the understanding for the natural knee kinematics