**Abstract**

Primary total hip and knee arthroplasty (THA, TKA) are among the most common procedures performed in the United States. The volume of revision TKAs and THAs are also exponentially rising each year. Paramount to the success of total joint arthroplasty (TJA) is the correct choice of biomaterials which are used to reconstruct a particular joint. This chapter explores the history of common arthroplasty biomaterials, their biomechanical properties and current applications. This chapter also discusses modern strategies of improving biomaterial mechanical properties, survivability and sterilisation methods. The contents of this chapter will form an essential resource for practicing orthopaedic surgeons, orthopaedic trainees, researchers and engineers interested in tribology and biomechanics of biomaterials in adult reconstruction.

**Keywords:** primary hip arthroplasty, primary knee arthroplasty, biomaterials, alloy, polymer, ceramic, sterilisation
