Orthopedics is a branch of medicine that deals with deformities in bone structure, injuries, and disorders of the skeleton and associated structures such as the ligaments and tendons. Orthopedic devices and implants treat injuries and deformities using spinal surgery, joint replacement or reconstruction, and trauma fixation. Joint replacement surgeries are commonly performed in the hip, elbow, knee, wrist, ankle, shoulder, and fingers. Orthopedic implants are usually made from titanium and stainless steel alloy. They are often coated with plastic due to its properties such as resistance to corrosion, rigidity, fracture toughness, stiffness, long fatigue life, and biocompatibility.