Joint cracking is a popping sound that occurs as a result of tissues rubbing together abnormally. The sound results from an abnormal interaction between air, fluid, or bone. A common example of joint crepitus is when rough surfaces in a joint rub together and result in a popping and crackling sound or an irregular feeling in your joint. Another example is when air escapes from the sinuses and can be felt in the skin overlying a facial bone fracture.
Joint cracking or Knee crepitus is often the result of arthritis or a previous joint injury. However, a crackling or popping sound and irregular feeling in your joint may also result from the presence of air in the tissues. Knee Crepitus can be due to a wide variety of conditions, and associated symptoms can also vary widely. Soft tissue crepitus, due to air inside body tissues, is a serious type of crepitus. Crepitus due to arthritis or joint problems can be a sign of chronic disease or joint damage.