Cross-linked versus conventional polyethylene for total knee arthroplasty: a meta-analysis

BACKGROUND: Highly cross-linked polyethylene (HXLPE) has been reported as an effective material for decreasing polyethylene wear and osteolysis in total knee arthroplasty (TKA). Because no single study to date has been large enough to definitively determine the benefit of HXLPE in TKA, we conducted a meta-analysis to pool the results from randomized controlled trials (RCTs) and non-RCTs to make such a determination. METHODS: Potential candidate articles were identified by searching the Cochrane Library, Medline (1966-2015.10), PubMed (1966-2015.10), Embase (1980-2015.10), ScienceDirect (1985-2015.10), and other databases. “Gray studies” were identified from the included articles’ reference lists. Pooled data were analyzed using RevMan 5.1. RESULTS: Three RCTs and three non-RCTs were included in the meta-analysis. There were no significant differences between the groups in the total number of reoperations (P = 0.11), reoperations for prosthesis loosening (P = 0.08), radiolucent line (P = 0.20), osteolysis (P = 0.38), prosthesis loosening (P = 0.10), and mechanical failures related to the tibial polyethylene (P = 1.00). Similarly, no significant differences between the two groups were found in postoperative total knee score (P = 0.18) or functional score (P = 0.23). CONCLUSIONS: The meta-analysis showed that compared with conventional polyethylene, HXLPE did not improve the clinical and radiographic outcomes in mid-term follow-up after TKA. Additional high-quality multicenter prospective RCTs with good design, large study populations and long-term follow-up will be necessary to further clarify the effect of HXLPE in TKA.