Arthroscopic surgery has revolutionized operative treatment of the knee over the last 30 years. Owing to the magnification achieved with fiber optics used in modern arthroscopy, this technique allows the surgeon to visualize the inside of the knee through incisions as small as 1 cm in length. The surgeon can also view the inside of the knee on a television screen in far greater detail than is allowed to open surgery. Instruments can be inserted through a separate small portal to perform therapeutic procedures through arthroscopic surgery.
Arthroscopic knee surgery involves lavage (to remove particulate material, such as cartilage fragments) and debridement (to smooth the articular surfaces). A procedure of low invasiveness and morbidity, arthroscopy does not interfere with future surgery. These treatments have varying success rates and should be performed only by surgeons experienced in arthroscopic surgical techniques. In theory, arthroscopy for osteoarthritis (OA) should relieve symptoms by removing the debris and inflammatory cytokines that cause synovitis. Debridement can remove torn meniscal fragments and loose cartilage flaps. However, the role of arthroscopy in treating knee OA is controversial. A randomized, controlled trial in patients with moderate-to-severe OA found that arthroscopic surgery for OA of the knee provided no additional benefit beyond that afforded by optimized physical and medical therapy.
An evidence-based review of the literature on the arthroscopic treatment of knee OA by Siparsky et al in 2007 found limited support for its use. Dervin et al showed the importance of patient selection before knee arthroscopy. Patients with evident lesions of the meniscus or cartilage flaps may benefit from surgery. Another study demonstrated that in well-selected middle-aged patients with knee-arthritis, arthroscopic debridement may be valuable for providing transient relief of symptoms. Patients with less extensive arthritis, as seen by radiology, less severe involvement of articular cartilage and a younger age at the time of surgery have greater success. A short duration of pain and mechanical symptoms and mild-to-moderate radiographic stages of arthritis also correlate with a better result.
It can thus be concluded that arthroscopic debridement should not be used as routine treatment for knee OA, although patients with symptomatic meniscal tears and loose bodies with locking symptoms could benefit. It is an outpatient procedure with less serious potential complications than other surgical treatments for OA. The postoperative course is predictable and the risk of complications is acceptably small for most patients. It does not preclude later definitive surgery and so patient and surgeon may feel it is worth trying. Nevertheless, it cannot alter the progression of OA; it may only be a helpful instrument to reduce pain in well-selected patients. Patients who undergo arthroscopy usually require a period of crutch use or exercise therapy. This period typically last days but sometimes extends for weeks.