The hip joint is a ball-and-socket joint, and a normal hip has a perfectly round ball (femoral head) and a socket (acetabulum) that matches it and is concentric.  Any bony abnormalities of the ball or socket can lead to bony impingement and injury to the cartilage and labrum.  Another form of hip impingement is pincer impingement, where the hip socket is too deep and covers too much of the ball.  This excess coverage causes impingement and damage to the cartilage and labrum.  If non-surgical treatments fail to alleviate pain and improve function, pincer impingement can be properly treated with surgery, including hip arthroscopy for the vast majority of cases, and occasionally a surgical dislocation of the hip.  Surgically, the pincer is resected using a motorized burr to remove bone.  A portable x-ray machine is used to ensure the proper amount of bone is removed and to help reestablish a socket with normal depth and coverage.  Once adequately resected, the hip no longer impinges during motion and activity. Frequently, the labrum is torn in the setting of pincer impingement, and when it is a labral repair is performed.  Rehabilitation from a pincer resection and labral repair typically follows the same outline in the hip arthroscopy section and is modified as needed.