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 .
Migration Pattern of a Short Femoral Neck Preserving Stem
The CFP stem represents a short collared neck-retaining stem with very proximal metaphyseal anchoring along the calcar combined with up-to- date metallurgy . Despite theoretical advantages , the stability and clinical outcome are unknown . We prospect ively measured the migration pattern of this new stem and cup . Twenty-six patients ( 26 hips ) with a mean age of 54 years ( range , 40 - 66 years ) underwent THA  and were followed for 2 years with  radiostereometry , radiographs , and clinical scores . The stem showed some early retroversion ( mean , SEM 0.6 ° , 0.3 ) , but stabilized before 1 year . Subsidence ( 0.05 mm , 0.06 ) and varus-valgus tilting ( 0.03 ° , 0.01 ) were low . We observed no bone loss in the calcar region . Factors related to patients , implant design , and implantation did not predict migration patterns . The two-dimensional wear of the ceramic/conventional articulation was 0.09 mm at 2 - 24 months . The low migration of this short neck preserving stem suggests a favorable long-term outcome but longer followup is needed to substantiate this prediction . This design might become an alternative to st and ard stems and hip resurfacing . Level of Evidence : Therapeutic Level IV . 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 .