Should we reconsider all-polyethylene tibial implants in total knee replacement?
The role of modular tibial implants in total knee replacement is not fully defined. We performed a prospective randomised controlled clinical trial using radiostereophotogrammetric analysis to compare the performance of an all-polyethylene tibia with a metal-backed cruciate-retaining condylar design, PFC-Sigma total knee replacement for up to 24 months. There were 51 patients who were randomised into two treatment groups. There were 10 subsequent withdrawals, leaving 21 all-polyethylene and 20 metal-backed tibial implants. No patient was lost to follow-up. There were no significant demographic differences between the groups. At two years one metal-backed implant showed migration > 1 mm, but no polyethylene implant reached this level. There was a significant increase in the SF-12 and Oxford knee scores after operation in both groups. In an uncomplicated primary total knee replacement the all-polyethylene PFC-Sigma tibial prosthesis showed no statistical difference in migration from that of the metal-backed counterpart. There was no difference in the clinical results as assessed by the SF-12, the Oxford knee score, alignment or range of movement at 24 months, although these assessment measures were not statistically powered in this study.
Muller
S D
SD
Department of Orthopaedics, Freeman Hospital, Freeman Road, High Heaton, Newcastle upon Tyne, UK. s.d.muller@ncl.ac.uk
Deehan
D J
DJ
Holland
J P
JP
Outterside
S E
SE
Kirk
L M G
LM
Gregg
P J
PJ
McCaskie
A W
AW
D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000601:surgery; D019645:Arthroplasty, Replacement, Knee / Q000379:methods; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D007720:Knee Prosthesis; D008297:Male; D020370:Osteoarthritis, Knee / Q000601:surgery; D010780:Photogrammetry / Q000379:methods; D020959:Polyethylene; D011446:Prospective Studies; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D013977:Tibia / Q000601:surgery*; D016896:Treatment Outcome
D020959:Polyethylene