How successul is a hip arthroscopy for treatment of a labral tear of the hip?

Hard to Say. You may want to consider stem cell therapy for your labral tear. So far the only practice that has significant research and patient base regarding stem cell therapy are the Regenexx Physicians Network. They have over 6500 patients in their registry with pretty good results. Check out Regenexx.Com.
Very. The success of healing a labral tear is high. People who struggle after surgery typically have significant cartilage wear. The extent ofthis cartilage wear dictates how well people reapond to surgery.
Excellent. Hip arthroscopy is typically very successful if all of the pathology is treated. Labral tears can often be repaired, but if the tear is a result of hip impingement, the impingement must also be addressed.
Usually very. Usually it is very successful with improvement in symptoms in over 90% of patients. About 85% of professional athletes can return to the same high level of play afterwards. This surgery requires a lot of physical therapy postop, and if a patient does not do his/her part afterwards, the results are less successful (scar tissue and tendonitis can occur which cause lingering pain).