{"references": ["U. Holzwarth and G. Cotogno., Total hip arthroplasty: State of the art,\nchallenges and prospects. 2012: Joint Research Centre of the European\nCommission.", "A. O. Association., National Bone and Joint Registry Annual Report.\n2011.", "S. Kurtz et al., Projections of primary and revision hip and knee\narthroplasty in the United States from 2005 to 2030. The Journal of\nBone & Joint Surgery, 2007. 89(4): p. 780-785.", "L. Blunt et al., The role of tribology and metrology in the latest\ndevelopment of bio-materials. Wear, 2009. 266(3): p. 424-431.", "B. Orthopedics, Precautionary Statement. 2006.", "B. Orthopedics, BIOLOX\u00aedelta Option Ceramic Femoral Head System\nProduct Features and Instructions for Use. 2010.", "R. Bruhn, C. Schaerer, N. Gronau and U. Wyss, 2010.", "J. P. Heiney, S. Battula, G. A. Vrabec, A. Parikh, R. Blice, A. J.\nSchoenfeld et al., Impact magnitudes applied by surgeons and their\nimportance when applying the femoral head onto the Morse taper for\ntotal hip arthroplasty. Arch. Orthop. Trauma Surg, 2009. 129: p. 793-\n796.", "M. L. Mroczkowski, J. S. Hertzler, S. M. Humphrey, T. Johnson, C. R.\nBlanchard, Effect of impact assembly on the fretting corrosion of\nmodular hip tapers. Journal of Orthopaedic Research, 2006. 24: p. 271-\n279.\n[10] Annelie Rehmer, N. E. Bishop, Michael M. Morlock, Influence of\nassembly procedure and material combination on the strength of the\ntaper connection at the head\u2013neck junction of modular hip\nendoprostheses. Clinical Biomechanics, 2012. 27: p. 77-83.\n[11] A.T. Pennock, A.H.S., C.A. Bourgeault, Morse-type tapers\u2014factors that\nmay influence taper strength during total hip arthroplasty. Journal of\nArthroplast, 2002. 17: p. 773-778."]}

Excessive fretting wear at the taper-trunnion junction (trunnionosis) apparently contributes to the high failure rates of hip implants. Implant wear and corrosion lead to the release of metal particulate debris and subsequent release of metal ions at the tapertrunnion surface. This results in a type of metal poisoning referred to as metallosis. The consequences of metal poisoning include; osteolysis (bone loss), osteoarthritis (pain), aseptic loosening of the prosthesis and revision surgery. Follow up after revision surgery, metal debris particles are commonly found in numerous locations. Background: A stable connection between the femoral ball head (taper) and stem (trunnion) is necessary to prevent relative motions and corrosion at the taper junction. Hence, the importance of component assembly cannot be over-emphasized. Therefore, the aim of this study is to determine the influence of head-stem junction assembly by press fitting and the subsequent disengagement/disassembly on the connection strength between the taper ball head and stem. Methods: CoCr femoral heads were assembled with High stainless hydrogen steel stem (trunnion) by Push-in i.e. press fit; and disengaged by pull-out test. The strength and stability of the two connections were evaluated by measuring the head pull-out forces according to ISO 7206-10 standards. Findings: The head-stem junction strength linearly increases with assembly forces.