Knee popping may also occur if the patella is slightly out
of alignment, and rubs on the adjacent tissues. Other
causes of joint noise is the snapping
of tendons or scar tissue over a prominence, or cavitation. Cavitation occurs in synovial joints when a small vacuum forms in the synovial fluid and a rapid release produces a sharp popping or cracking sound.If it persists or other symptoms are present, it is best that you have this checked by your doctor for proper evaluation.