Abstract
Kinematically aligned total knee arthroplasty (KATKA) was developed to more anatomically
align the knee prosthesis to restore the native alignment of the knee and promote
physiological kinematics. Even though there are concerns with implant survival, and
follow-up at 10 years or more after KATKA has not been reported, there is a negligible
incidence of failure of a tibial component at 2 to 9 years. Early clinical results
with this technique are encouraging and demonstrate better functional outcomes compared
with mechanically aligned TKA (MATKA). The purpose of this study is to perform a systematic
review and meta-analysis of the literature to determine whether there are any clinical
differences between KATKA and MATKA. The authors conducted a systematic review of
the English literature. Five randomized controlled trials (RCTs) which compared clinical
outcomes of KATKA and MATKA were finally included. Four RCTs used patient-specific
instrument, and one RCT used navigation. Data were extracted and meta-analysis was
conducted. KATKA patients had better outcomes: Mean difference between KATKA and MATKA
and p-value are presented in brackets after each variable: the Western Ontario and McMaster
Universities Osteoarthritis Index (WOMAC) (–12.5; p < 0.0001), Oxford Knee Score (OKS) (2.3; p = 0.030), combined Knee Society Score (C-KSS) (13.1; p < 0.0001), Knee Function Score (KFS) (6.4; p = 0.0070), and postoperative range of motion (ROM) (4.1°; p = 0.0010). There was no significant difference concerning the complication rates
which needed reoperations or revision surgery (odds ratio, 1.01; p = 0.99). KATKA components had a more femoral valgus (–1.8°; p < 0.0001), more tibial varus (1.2°; p = 0.0001), and more tibial slope (1.2°; p = 0.0001), all being statistically significantly different. Better clinical outcomes
were obtained in KATKA and component placement in KATKA is significantly different
from that in MATKA. There was no increase of patients with poor clinical results due
to implant position especially for varus placement of tibial component. This systematic
review of five RCTs suggests that KATKA is of potential alternative method to MATKA
since the risk of revision for tibial loosening is negligible compared with MATKA
for the same follow-up period.
Keywords
knee osteoarthritis - total knee arthroplasty - kinematic alignment - mechanical alignment
- outcomes
