The stability of three different cementless tibial components. A randomized radiostereometric study in 45 knee arthroplasty patients.
We conducted a prospective, randomized study of 45 patients to evaluate 3 different uncemented tibial component designs in total knee arthroplasty. The stability of the components was assessed by radiostereometry (RSA), both as migration during 2 years and as inducible displacement at 2 years. The PCA resurfacing, the Tricon stem and the Tricon-M prosthesis groups showed a similar level of migration at 2 years, about 1.4 mm. In response to externally applied rotatory forces, the Tricon groups rotated more than the PCA group, interpreted as a consequence of the more conforming articular surface in the Tricon design. The series was divided into one group of continuously migrating prostheses with a poor prognosis (unstable, one third) and another group of prostheses in which migration stopped after 1 year (stable, two thirds). With this classification, no differences between the prostheses design groups were revealed. However, the unstable group showed a larger inducible displacement by provocation, an association hitherto not established.
Hilding
M B
MB
Department of Orthopedics, Central Hospital, Västerås, Sweden.
Yuan
X
X
Ryd
L
L
D000368:Aged; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000502:physiology*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D009068:Movement; D011446:Prospective Studies; D011474:Prosthesis Design; D011859:Radiography; D013997:Time Factors