INTERPRETATION There was a clinical ly relevant association between early migration of acetabular cups  and late revision due to loosening .
BACKGROUND AND PURPOSE The association between excessive early migration of acetabular cups  and late aseptic revision has been scantily reported .
We therefore performed 2 parallel systematic review s and meta-analyses to determine the association between early migration of acetabular cups  and late aseptic revision .
Introducing new technology: a stepwise algorithm.
In this issue of Spine , a novel method for managing chronic discogenic low back pain with a thermal intradiscal catheter is reported . This study raises some general questions regarding the introduction of new treatment techniques and devices . Decisions about medical treatment should be based on a careful appraisal of the best evidence available . A step-wise introduction is necessary to increase the use of evidence -based decision making in the implementation of new surgical techniques and implants while exposing as few patients as possible to the potential risk of failure . The development of the total hip arthroplasty procedure , for example , could have been different if the introduction of new devices and techniques had been done more carefully and performed in a step-wise manner . Inferior properties could have been revealed earlier , thus reducing the number of failures and allowing for necessary improvements . It is also desirable , therefore , that members of this profession agree on a st and ardized way to introduce new surgical techniques and implants in the field of spinal disorders . Based on the results of Swedish reports and practice , the following schedule for step-wise clinical introduction of new implants is suggested ( Figure 1 ) : The initial step is a pre clinical testing and is beyond the scope of this discussion . The first clinical step is the open prospect i ve and preferably r and omized trial that includes a minimum of patients but yields a relevant evaluation . The strict rules of prospect i ve , r and omized trials should be adhered to . In this first clinical phase , methods associated with high accuracy , such as radiostereometric analysis ( RSA ) , are required . Within 6 to 24 months , this method has the potential to identify implants/ methods that provide inferior fixation and increased polyethylene wear . Results from this first step determine whether further clinical evaluation is worthwhile . It should be noted and stressed that all types of complications can not be predicted and that further follow-up study is necessary . If favorable results are obtained in the first step , the second step , a multicenter trial exposing the new procedure to a broader aspect in the orthopedic community , can be initiated . In the first step , there is a risk for susceptibility and performance bias because the inventors themselves often perform this introductory investigation . The protocol in the multicenter trial must be prepared carefully and agreed on by all participating inventors . A sufficient number of patients should be included to allow adequate statistical analysis . The ultimate goal for step two is to make even the multicenter trial r and omized by using well-documented methods /implants as the gold st and ard . The final step in the evaluation , step three , is to include a continuous control group by using register studies based on large cohorts to reveal early or unusual and potential clinical catastrophic complications . In a rather small and closed community such as Sweden , the register should be nationwide and include all units in a specific field . When applying the principles for step-wise introduction to the investigation of chronic discogenic low back pain with a  thermal intradiscalcatheterbySaal  and Saal , oneobserves that the current study falls between the pre clinical step and step one . The lack of r and omization toward either conservative or surgical intervention is a definite limitation of the study , and before this method is introduced to a larger study group , a r and omized trial must be considered . A multicenter trial exposing the new procedure to a broader aspect of the orthopedic community is recommended before using it in general orthopedic practice . The length of the follow-up period was very short in this study , and no long-term clinical conclusions can be drawn based on the results
INTERPRETATION There was a clinical ly relevant association between early migration of acetabular cups  and late revision due to loosening .
BACKGROUND AND PURPOSE The association between excessive early migration of acetabular cups  and late aseptic revision has been scantily reported .
We therefore performed 2 parallel systematic review s and meta-analyses to determine the association between early migration of acetabular cups  and late aseptic revision .