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Prospective evaluation of the scandinavian total ankel replacement (star)




 J. Louwerens SMK  Orthopedic Surgeon 
 J. Schimmel SMK  Health Scientist 
 P. Anderson SMK  Experimental Psychologist 


Sint Maartenskliniek


Purpose of this study is to get insight in the mid- and long-term clinical and radiological results of the STAR total ankle prosthesis, for different indications. Specific interest will be evaluation of the learning curve, if present.


All patients who are indicated for an ankle arthroplasty will be included in the study. X-ray's, Kofoed and FFI score will be taken preoperatively and at 1, 2, 3, 5, 7½, 10, 12½ and 15 years postoperatively. Extra X-ray's will be taken at 3 and 6 months postoperatively. After 5 and 10 years Kofoed score and FFI score will be analyzed. A Kaplan Meier survival curve will be made. Also clinical and radiological findings of the failed prosthesis will be reviewed.


Results of the first 49 patients will be compared to the last 50, in order to determine if a learning curve exists. For statistical analysis Student's t-test, Chi²-toets and Kaplan-Meier survival curve were used.


Results regarding the first group were already published (2008). A significant improvement of the FFI score was observed and the mean postoperative Kofoed ankel score was good. First analyses of the second group reveal comparable clinical results. Radiological the prosthesis was somewhat better aligned and less complications were observed. A learning curve was observed for alignment and occurrence of complications but was not observed for clinical scores. Results regadering the second group will be published in the first half of 2011. The first results about the mid-term clinical and r