Cross-linked polyethylene does not reduce wear in total knee arthroplasty

Abstract Aim To compare two different types of inserts: ultra-high molecular weight polyethylene (UHMWPE) and cross-linked polyethylene with a quantitative and qualitative study of polyethylene wear particles in synovial fluid 3 years after total knee arthroplasty. Material and methods A prospective, randomised, controlled cohort study with blinded evaluation was carried out on 25 patients undergoing staged bilateral total knee replacement, 6 months apart. Knee arthrocentesis was performed on 12 patients 3 years after surgery, and the polyethylene particles were analysed. Results No significant differences were found in the number of particles generated by the two different types of inserts at 3 years from total knee arthroplasty (3000×: x ¯ cross-linked = 849.7; x ¯ UHMWPE = 796.9; p  = .63; 20,000×: x ¯ cross-linked = 66.3; x ¯ UHMWPE = 73.1; p  = .76). Likewise, no differences in the probability of finding elongated ( χ 2  = .19; p  = .66) or rounded ( χ 2  = 1.44; p  = .23) particles in both types of inserts were observed. However, the probability of finding fibrillar particles is 3.08 times greater in UHMWPE. Conclusions Cross-linked polyethylene does not significantly reduce the generation of polyethylene particles in patients with total knee arthroplasty, 3 years after the surgical procedure.