Deckard, Evan R.Azzam, Khalid A.Meneghini, R. Michael2018-04-192018-04-192018Deckard, E. R., Azzam, K. A., & Meneghini, R. M. (2018). Contemporary Dual Mobility Head Penetration at Five Years: Concern for the Additional Convex Bearing Surface? The Journal of Arthroplasty. https://doi.org/10.1016/j.arth.2018.02.061https://hdl.handle.net/1805/15867Background Dual mobility (DM) bearings are increasingly popular and second-generation designs contain highly cross-linked polyethylene. The purpose of this study is to report head penetration rates in modern DM bearings. Methods A review of 63 consecutive DM bearings was performed. Radiographs were analyzed for head penetration using Martell methodology at regular postoperative intervals. Results Thirty-four DM bearings were analyzed. Mean linear head penetration was 1.59 mm/y at 1 year, 1.07 mm/y at 2 years, and 0.27 mm/y at 5 years following an exponential regression model (R2 = 0.999). Mean volumetric wear was 783 mm3/y at 1 year, 555 mm3/y at 2 years, and 104 mm3/y at 5 years following an exponential regression model (R2 = 0.986). Conclusion Initial head penetration of DM bearings is larger than contemporary cross-linked polyethylene bearings; however, rates approach steady state after 2 years, analogous to traditional bearings. The larger “bedding-in” head penetration may be due to the additional convex bearing surface, creating 2 surfaces for deformation/wear.enPublisher Policydual mobilitytotal hip arthroplastybearing wearArticle