Total knee arthroplasty (TKA) designs evolve continuously to improve
patient outcomes. However, incidences of radiolucent lines (RLL) in
the latest TKA system have recently been reported, raising concerns.
The purpose of the current study was to compare radiographic
outcomes of this new TKA implant to its predecessor design.
A group of 100 patients undergoing TKA using the newer design
(Attune) was matched by age and gender to 191 patients with the
classic design (LCS). All patients underwent computer-navigated
primary TKA by the same surgeon using the same technique.
Radiographs were taken before discharge, and 2 and 12 months
postoperatively. Radiographic analysis was performed independently
by three assessors, using the Modern Knee Society Radiographic
Evaluation System and Methodology (MKSRES).
At 12 months postoperatively, the incidence of RLL did not
statistically differ between the two implants (14%,
n = 14 Attune vs. 8% n = 17 LCS, n.s.).
The posterior femoral flange was most commonly affected (12%;
n = 12 Attune vs. 7.9%; n = 15 LCS,
n.s.) followed by the anterior flange (1%; n = 1
Attune vs. 3.1%; n = 6 LCS, n.s.). The tibial
baseplate was only affected in 1% (n = 1) of the
Attune and 2.6% (n = 5) of the LCS (n.s.).
LEVEL OF EVIDENCE
At 12 months follow-up we found no significant difference in
RLL between the two implants. Both Attune and LCS TKA systems showed
RLL predominantly at the posterior femoral flange. The reasons for
the RLL remain a matter of speculation; however, shortcomings in
surgical and cementing techniques seem to be more important than