A crackling or snapping of the hip joint can be disconcerting. It feels uncomfortable and it makes a loud noise that sometimes other people in the room can hear. The medical term for crackling or snapping is crepitus. In simplest terms, crepitus occurs because bone is rubbing against bone. The joint cartilage has broken down and the joint surfaces become irregular. When this happens, the joint no longer moves smoothly. There is friction between the two bones.
The joint may catch or get stuck momentarily before it starts to move again. Crepitus is often painful when the hip joint gets stuck. It may make you stop in your tracks as you are trying to move forward. It may make it especially hard for you to go up and down stairs. Factors other than osteoarthritis can cause crepitus.
Sometimes, the presence of a loose body or fragment of bone or cartilage moving in the joint can cause momentary friction. You can also get a grinding sensation if there is disruption in the joint surface such as from an old fracture. The presence of crepitus in an arthritic joint is usually a sign that arthritis is advanced and will soon require hip replacement.