INTERPRETATION The guidelines have improved method ological reporting in RSA studies , but adherence to these guidelines is still relatively low .
BACKGROUND AND PURPOSE Guidelines for st and ardization of  radiostereometry ( RSA )  of implants were published in 2005 to facilitate comparison of outcomes between various research groups .
In this systematic review , we determined how well studies have adhered to these guidelines .
Factors associated with excessive migration in bone impaction hip revision surgery: a radiostereometric analysis study.
A prospect i ve radiostereometric analysis ( RSA ) study of 18 patients with cemented revision hip surgery and impaction grafting with an Exeter stem  was done with a follow-up of 2 years for all patients . All factors that could influence migration ( ie , micromotion ) of the stem were analyzed with a repeated measurements analysis of variance . Two groups could be identified : a stable group and a continuous migrating group . Two factors significantly influenced micromotion during the follow-up measurements . The first factor was the Paprosky classification ( the bigger the defect , the higher the micromotion ) . The second factor was cement mantle defects in > or = 1 Gruen zones . The migrating hip stems had more Gruen zones with cement mantle defects ( 45 % ) compared with the stable prostheses ( 21 % ) . The effect of the first factor on micromotion was limited and probably clinical ly less relevant . Because the cement mantle defects found in this study were caused by poor instrumentation , the second factor stresses the importance of good instrumentation , which is essential to make this technically dem and ing technique effective in creating a stable stem-allograft construct in the defective femoral canal
INTERPRETATION The guidelines have improved method ological reporting in RSA studies , but adherence to these guidelines is still relatively low .
BACKGROUND AND PURPOSE Guidelines for st and ardization of  radiostereometry ( RSA )  of implants were published in 2005 to facilitate comparison of outcomes between various research groups .
In this systematic review , we determined how well studies have adhered to these guidelines .