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 .
Periapatite May Not Improve Micromotion of Knee Prostheses in Rheumatoid Arthritis
Prosthesis migration in bone inevitably occurs in cemented and uncemented total knee arthroplasty tibial components . Cemented design s as the gold st and ard give immediate fixation whereas cementless design s need a period of bone ingrowth onto the surface irregularities of the implants . The addition of bioactive coatings may enhance this process of ingrowth . A controlled r and omized prospect i ve RSA study was carried out on 26 Duracon implants in a rheumatoid arthritis patient group to evaluate the effect of a periapatite coating on the fixation of the tibial tray . The coated and the noncoated groups were matched for sex , age , body mass index , and HSS Knee Score . Stage of preoperative joint destruction and preoperative and postoperative mechanical leg axis showed no differences . We saw no differences in migration between the two groups , but a trend for lesser translations along and rotations about all three axes in the periapatite group . The periapatite-coated components showed a lower variance in subsidence than did the uncoated components . Both groups also showed a high variance in anterior tilting of the components . The cementless PA-coated Duracon prosthesis used in patients with RA may provide improved fixation of tibial components although we could not demonstrate improvement in this small controlled series . Level of Evidence : Therapeutic Level II . See the Guidelines for Authors for a complete description of levels of evidence
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 .