Better outcomes are associated with cementless fixation in primary total knee arthroplasty in young patients: A systematic review and meta-analysis of randomized controlled trials.

Background: The use of cemented and cementless fixations in primary total knee arthroplasty (TKA) in young patients is controversial. Previous reviews predominantly relied on data from retrospective studies. This systematic review and meta-analysis of randomized controlled trials (RCTs) evaluated the optimal fixation mode in TKA for young patients.
Methods: The PubMed, Embase, Medline, Web of Science, and full Cochrane Library electronic databases were searched from inception to July 2018. The outcome measurements consisted of functional outcomes (Knee Society Score [KSS], range of motion [ROM]), radiolucent lines, aseptic loosening, total complications, and reoperation rate. Study data were pooled using a random-effects model.
Results: Six RCTs were included in the systematic review and meta-analysis. The mean follow-up period was 12 years (range, 2-16.6 years). Cementless TKA was associated with higher KSS-function (P < .0001), higher KSS-pain (P = .005), better ROM recovery (P = .01), and fewer radiolucent lines (<1 mm) (P = .04) compared with cemented TKA. No significant intergroup differences were observed for KSS-knee, total complications, aseptic loosening, or reoperation rate. These results based on a random-effects model were unchanged by sensitivity analysis assumptions.
Conclusion: Cementless TKA was substantially superior to cemented TKA in young patients. Although the complication and survival rates were similar between groups, better clinical outcomes were obtained with cementless fixation. Further well-designed studies with long follow-up durations are necessary to confirm our findings.