Comparison of Fixed Bearing and Mobile Bearing Total Knee Arthroplasty Using Identical Femoral Component
Sakarin Wonglertsiri MD*, Charoenwat Uthaicharatratsame MD*
Affiliation : * Department of Orthopaedic Surgery, Nopparat Rajatanee Hospital, Bangkok, Thailand
Background : The theoretical advantages of Mobile bearing (MB) prosthesis does not appear to be documented in terms of
functional outcomes compared to Fixed bearing (FB) designs. Rarely that two identically designed knee prostheses were
compared in the literature.
Objective : Compare clinical and functional results of MB and FB prostheses using identical femoral components at
intermediate term follow-up.
Material and Method: Total knee arthroplasties (TKA) performed between January 2004 and December 2006 at Nopparat
Rajatanee hospital were retrospectively reviewed. The American Knee Society scoring system and functional score were
used for outcome measurement.
Results : There were 102 and 103 patients in FB and MB group respectively. At the average follow-up of 75 months for FB
and 73 months for MB group, the knee scores and functional scores of both groups had obviously improved from the
preoperative period. However, no statistically significant differences were noted between the two groups. One patient in the
MB group developed infected loosening 5.1 years after the operation and had two stages revision successfully done.
Conclusion : MB prosthesis has no clinical advantage over FB at intermediate term follow-up despite using identical femoral
component.
Keywords : Mobile bearing total knee arthroplasty, Fixed bearing, Identical femoral component
