After stratification on follow-up time and age , the revision rates were not substantially different , aside for younger patients in short term from studies with short-term follow-up .
Conclusion No essential differences between the two design s were observed .
MB and FB UKA design s have comparable revision rates .
Purpose Two design concepts are currently used for unicondylar knee arthroplasty ( UKA ) prostheses :  fixed bearing ( FB ) and mobile bearing ( MB ) .
While MB prostheses have theoretical advantages over their FB counterparts , it is not clear whether they are associated with better outcomes .
Does a high-flexion design affect early outcome of medial unicondylar knee arthroplasty? Clinical comparison at 2 years.
Recently , implant companies have sought to target a more active segment of the population with high-flex implants . Our aim was to compare a successful medial UKA implant with its newer high-flex version . Sixty-one patients ( nonflex , 33 ; high-flex [ HF ] , 28 ) were prospect ively followed after medial UKA  with a minimum of 2-year follow-up . Patients were evaluated using Short Form 12 , Western Ontario and McMaster Osteoarthritis ( WOMAC ) , Knee Society Scores , and range of motion ( ROM ) . The HF group exhibited significantly higher WOMAC Physical Function scores at 3-month follow-up and higher WOMAC Pain and SF-12 Mental Component scores at 2-year follow-up ; all other comparisons were not statistically different , including ROM . The HF cohort had significantly higher improvements in Knee Society Function and Knee score at 1- and 2-year follow-up , respectively ; all other comparisons yielded no significant differences in mean improvement from baseline , including ROM or survivorship
After stratification on follow-up time and age , the revision rates were not substantially different , aside for younger patients in short term from studies with short-term follow-up .
Conclusion No essential differences between the two design s were observed .
MB and FB UKA design s have comparable revision rates .
Purpose Two design concepts are currently used for unicondylar knee arthroplasty ( UKA ) prostheses :  fixed bearing ( FB ) and mobile bearing ( MB ) .
While MB prostheses have theoretical advantages over their FB counterparts , it is not clear whether they are associated with better outcomes .