 This study will enable patients undergoing each procedure to be followed closely with the hope that we can determine objective factors that will allow us to stratify patients into one of the three surgical options: arthrocentesis, arthroscopy or arthroplasty. Our current approach is empiric and typically proceeds from arthrocentesis to arthroscopy to arthroplasty. All patients in this study will be offered the opportunity to have arthrocentesis performed. It is anticipated that a minority will achieve long-term benefit in terms of pain and function. We hope to be able to identify those factors which will predict which patients will benefit so that future patients selected to have arthrocentesis will have much higher success rates. Patients who fail to improve with arthrocentesis or who initially decline that procedure will be offered the opportunity to undergo arthroscopy. It is anticipated that a majority of patients will achieve long-term benefit in terms of pain and function. Again it is hoped that we can identify those factors which will predict which patients will benefit so that future patients selected to have arthroscopy will have even higher success rates. Patients who fail to improve with arthroscopy or who initially decline both arthrocentesis and arthroscopy will be offered the opportunity to undergo arthroplasty provided that clinical and radiographic evidence exists to support the presence of either a diseased or displaced cartilage disc. 