Abstract

Ankylosis or anchylosis (from Greek ἀγκύλος, bent, crooked) is a stiffness of a joint due to abnormal adhesion and rigidity of the bones of the joint, which may be the result of injury or disease. The rigidity may be complete or partial and may be due to inflammation of the tendinous or muscular structures outside the joint or of the tissues of the joint itself.

When the structures outside the joint are affected, the term "false ankylosis" has been used in contradistinction to "true ankylosis", in which the disease is within the joint. When inflammation has caused the joint-ends of the bones to be fused together, the ankylosis is termed "osseous" or complete and is an instance of synostosis. Excision of a completely ankylosed shoulder or elbow may restore free mobility and usefulness to the limb. "Ankylosis" is also used as an anatomical term, bones being said to ankylose (or anchylose) when, from being originally distinct, they coalesce, or become so joined together that no motion can take place between them.

In 2014, there was a rare case of Ankylosis, wherein a six-year old girl was able to open her mouth only a couple millimeters after one of her jaw joints got fused. Liliana Cernecca was the patient's name. She underwent a surgery at King's College Hospital in London, during which her jaw was operated on and unlocked.She was said to be one of the youngest patients to have undergone this surgery.

Fossil record

Evidence for ankylosis found in the fossil record is studied by paleopathologists, specialists in ancient disease and injury. Ankylosis has been reported in dinosaur fossils from several species, including "Allosaurus fragilis", "Becklespinax altispinax", "Poekilopleuron bucklandii", and "Tyrannosaurus rex" (including the Stan specimen).