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 .
Early migration characteristics of a hydroxyapatite-coated femoral stem: an RSA study
Measurement of early stem subsidence can be used to predict the likelihood of long-term femoral component loosening and clinical failure . Data that examines the early migration pattern of clinical ly proven stems will provide clinicians with useful baseline data with which to compare new stem design s. This study was performed to evaluate the early migration pattern of a hydroxyapatite-coated press-fit femoral component that has been in use for over ten years . We enrolled 30 patients who underwent THA for osteoarthritis . The median age was 70 years ( range , 55–80 years ) . Patients were clinical ly assessed using the Harris hip score .  Radiostereometric analysis was used to evaluate stem migration at three to four days , six months , one year and two years . We observed a mean subsidence of 0.73 mm at six months , 0.62 mm at one year and 0.58 mm at two years and a mean retroversion of 1.82 ° at six months , 1.90 ° at one year and 1.59 ° at two years . This data suggests that subsidence is confined to the first six months after which there was no further subsidence . The results from this study can be compared with those from novel cementless stem design s to help predict the long-term outcome one may expect from new cementless stem design
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 .