[Interregional mobility for total knee arthroplasty].

45.049 primary total knee replacements were performed in Italy in 2005, with large distribution all over the country. However referral to centers of excellence far from the area of residency is still common with massive interregional mobility. Aim of this study is to define this issue both in quantitative and qualitative terms. For the timeframe 2001-2005 the SDO database was used to calculate the number of discharges of both residents and non residents for each Region and for each year and the ability of each region to attract patients from other regions or the tendency of the resident population to migrate. Only 8 Regions present an attraction index better than the escape index. Among those 4 are located in the North of Italy, 2 in the Center and 2 in the South. Migration from the North or Center to the South was never observed. Interregional mobility for knee replacement is noteworthy. Such phenomenon is comparable to migration for other major procedures, especially the steady tendency of a south to north mobility. An accurate analysis of potential causes of migration as well as the empowering of southern and central centers is needed.