Cementless fixation in medial unicompartmental knee arthroplasty: a systematic review

The aim of this study was to evaluate clinical outcome, failures, implant survival, and complications encountered with cementless fixation in unicompartmental knee arthroplasty (UKA). A systematic review of the literature on cementless fixation in UKA was performed according to the PRISMA guidelines. The following database was comprehensively searched: PubMed, Cochrane, Medline, CINAHL, Embase, and Google Scholar. The keywords "unicompartmental", "unicondylar", "partial knee arthroplasty", and "UKA" were combined with each of the keyword "uncemented", "cementless" and "survival", "complications", and "outcome". The following data were extracted: demographics, clinical outcome, details of failures and revisions, cumulative survival, and complications encountered. The risk of bias of each study was estimated with the MINORS score and a further scoring system based on the presence of the primary outcomes. From a cohort of 63 studies identified using the above methodology, 10 papers (1199 knees) were included in the final review. The mean follow-up ranged from 2 to 11 years (median 5 years). The 5-year survival ranged from 90 to 99 % and the 10-year survival from 92 to 97 %. There were 48 revisions with an overall revision rate of 0.8 per 100 observed component-years. The most common cause of failure was progression of osteoarthritis in the retained compartment (0.9 %). The cumulative incidence of complications and revisions was comparable to that reported in similar studies on cemented UKAs. The advantages of cementless fixation include faster surgical time, avoidance of cementation errors, and lower incidence of radiolucent lines. Cementless fixation is a safe and effective alternative to cementation in medial UKA. Clinical outcome, failures, reoperation rate, and survival are similar to those reported for cemented implants with lower incidence of radiolucent lines. IV.