It means the limitation of a joint’s directional movement whether it is congenital or happen after a while.Congenital types usually affect more than one joint.Eburnations which happen after some time usually have many reasons.

Serious skin lacerations and burns, rheumatismal Diseases, arthritis, infectious diseases in joint and neighbouring joint  regions, hits against joints, breaking, dislocation or other reasons, following plasters after a joint surgery and joint staying still for a long time may cause eburnation.Eburnation can also happen in paralysed arms and legs after paralysis caused by various reasons.