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 .
Unicompartmental knee replacement provides early clinical and functional improvement stabilizing over time
Purpose Unicompartmental knee replacement preserves uninvolved osteocartilaginous and soft tissue structures , thereby allowing a more physiological and early clinical and functional recovery . The aim of this study was to report the results of  ZUK unicompartmental fixed metal-back prosthesis and how these results change over time . Methods Between 2005 and 2007 , 80 ZUK prostheses were implanted in 80 patients for unicompartmental osteoarthritis or osteonecrosis . Patients were clinical ly assessed using the International Knee Society scores . Postoperative values of mechanical axis were calculated 12 months after surgery and compared to the preoperative ones . Results The mean International Knee Society knee and function scores improved , respectively , from 46 ± 9 and 54 ± 8 preoperatively to 82 ± 5 and 94 ± 3 at the last follow-up ( P < 0.001 ) . Average flexion increased from 110 ° ± 9 ° to 127 ° ± 8 ° ( P < 0.01 ) . Patients with unicompartmental knee reached good clinical outcome very early and remained at the same level . Age did not significantly influence clinical and functional scores . Conclusions High success rates of the modern unicompartmental knee implants depend on the material s and design evolution , improvement of the surgical technique , and the strong restriction of indications . Level of evidence Prospect i ve non-r and omized case-series study , Level IV
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 .