The role of surgical treatment in osteoarthritis of the knee continues to evolve. The indications for arthroscopy have narrowed. Orthopedic surgeons continue to explore options less invasive than total knee replacement for isolated unicompartmental arthritis of the knee joint. In addition to arthroscopy, this article discusses the merits and drawbacks of and indications for osteotomy, interpositional arthroscopy, patellofemoral replacements, and emerging technologies for total knee replacements.