Abstract
Many studies have compared mobile-bearing (MB) and fixed-bearing (FB) unicompartmental
knee arthroplasties (UKAs) in patients with unicompartmental knee osteoarthritis (OA).
The present systematic review and meta-analysis examined the differences in the clinical
and radiological outcomes of MB UKA and FB UKA. PubMed, EMBASE, and Cochrane databases,
as well as Google Scholar were searched for relevant studies. Randomized controlled
trials (RCTs) and cohort studies that compared MB UKA and FB UKA were included. The
weighted mean difference in the knee scores and range of motion (ROM) as well as the
summary odds ratio of postoperative mechanical axis alignment, radiolucency, revision
rate, and complications were calculated in the MB UKA and FB UKA groups. Finally,
2 RCTs and 11 cohort studies that involved 1,861 patients (1,996 knees) were included.
The FB UKA group showed better postoperative Knee Society score (KSS), Western Ontario
and McMaster Universities Osteoarthritis Index (WOMAC), and ROM than the MB UKA group.
However, the MB UKA group had more knees with a neutral limb alignment and a lower
incidence of polyethylene wear than the FB UKA group. No significant differences were
observed between the groups with respect to radiolucency, revision rate, and complications,
such as arthritis progression, aseptic loosening, and postoperative pain. This meta-analysis
has demonstrated that both prostheses provided excellent clinical outcomes and survivorship
in patients with unicompartmental knee OA. The MB UKA group achieved the expected
postoperative neutral limb alignment as compared with the FB UKA group, while the
FB UKA group showed higher knee scores and superior ROM than the MB UKA group. Limited
evidence is currently available; therefore, the results of our meta-analysis should
be interpreted with caution.
Keywords unicompartmental knee arthroplasty - osteoarthritis - mobile bearing - fixed bearing
