Final answer:
A dislocation is the proper term for the displacement and deformity of a joint. It is distinct from other joint-related conditions such as sprains, ankylosis, bursitis, and arthritis which have different characteristics and causes.
Step-by-step explanation:
The displacement and deformity of a joint is called a dislocation. A dislocation occurs when the ends of bones are forced from their normal positions. This often results in displacement of the joint, with the two bone surfaces that usually form the joint being no longer in proper contact with each other. This condition is different from a sprain, which involves an injury to the ligaments around a joint. Ankylosis refers to stiffness or immobility of a joint due to fusion of the bones, typically related to arthritis. Bursitis is the inflammation of a bursa, which is a small fluid-filled sac that provides a cushion between bones and tendons or muscles around a joint. Arthritis is a group of conditions involving damage to the joints of the body, often characterized by pain and stiffness.