Incidence and Volume of Pelvic Osteolysis at Early Follow-up with Highly Cross-linked and Noncross-linked Polyethylene

Highly cross-linked polyethylene has shown decreased wear rates as compared to conventional polyethylene. However, the impact of this decrease on the occurrence of osteolysis remains uncertain. Forty hips implanted with noncross-linked Enduron and 36 implanted with 5-Mrad cross-linked Marathon polyethylene had a computed tomography at a minimum of 5 years after arthroplasty. Polyethylene wear, osteolysis incidence, location, and volume were compared. The incidence of osteolysis was statistically greater for patients with noncross-linked Enduron (11/40, 28%) compared to patients with the moderately cross-linked Marathon (3/36, 8%; P = .04). The average lesion volume for hips with Enduron liners (7.5 ± 6.7 cm3) was significantly greater than the average lesion volume for hips implanted with Marathon liners (1.2 ± 0.1 cm3, P = .01). Marathon cross-linked polyethylene has shown to have a decreased incidence and volume of pelvic osteolysis. Longer follow-up is necessary to determine if Marathon cross-linked polyethylene will continue to demonstrate the encouraging improved wear and osteolysis characteristics.