Overview
Arthroscopic surgery has revolutionized operative treatment of the knee over the past thirty years. This technique allows the surgeon to visualize the inside of the knee through incisions as small as one centimeter in length - a dramatic contrast to the large incisions required with open surgery.
Owing to the magnification achieved with fiber optics used in modern arthroscopy, and a television screen that is viewed in the operating room, the surgeon can also view the inside of the knee in far greater detail than is allowed in open surgery. He or she can then insert instruments through a separate small portal to perform therapeutic procedures through arthroscopic surgery.
Arthroscopic surgery has been documented to be extremely valuable for dealing with conditions such as meniscal tears or loose bodies in the joint, and for performing reconstructive procedures such as anterior cruciate ligament reconstruction. The value of arthroscopy in patients with osteoarthritis of the knee, however, has not been well-documented and is somewhat controversial.
A Study of the Technique
A study published by Mosley, et al, in the New England Journal of Medicine entitled "A Controlled Trial of Arthroscopic Surgery for Osteoarthritis of the Knee" attempted to determine whether arthroscopic surgery was a useful treatment for people with advanced arthritis. This study involved a comparison of arthroscopic surgery (debridement or removal of tissue or fragments that may cause pain or impede movement) for knee osteoarthritis to placebo treatment. In this case, the placebo treatment was either sham surgery where incisions were made in the usual locations and either nothing further was done (sham group) or only a saline lavage (a washing-out) of the knee was performed (lavage group).
The merit of this study is that it was a randomized trial in which patients were randomly allocated to one treatment group or another. This is the most valid form of scientific clinical research, as it allows the treatment groups to be as similar as possible, aside from the intervention (in this case surgery) they receive.
As with all studies, there were several potential weaknesses in this trial. The severity of participants' arthritis was not well-defined--a difficult task in any case. Moreover, the authors made no mention of the alignment of the lower extremities (the development of a "bow leg" or "knock knee"), which is an important prognostic factor for osteoarthritis. Also, patients with mechanical symptoms of "locking" or "giving-way" were not looked at separately.
Overall, the investigators found that there were no major differences between patients who underwent arthroscopic debridement, arthroscopic lavage or placebo surgery. All patients experienced some benefit over time, but there were no major differences between the groups in a wide variety of outcome measures including pain, function and walking ability.
Ultimately, despite the limitations mentioned, this study demonstrates that arthroscopic surgery for degenerative knee arthritis remains of questionable value, and, in itself does not offer significantly better results than placebo surgery. However, this study does not rule out the possibility that if other pathology is present in the knee, such as a meniscal tear, loose body, or large flap of cartilage which is causing mechanical symptoms, then arthroscopy may be worthwhile.
Nonsurgical Options
Nonsurgical treatments are also effective options for some patients with osteoarthritis of the knee. These include physical therapy, anti-inflammatory medication, chondroitin and glucosamine supplements, use of a cane and steroid injection. In cases where osteoarthritis of the knee cannot be controlled with these measures and the patient is experiencing severe pain and/or disability, surgery such as osteotomy or knee replacement may be recommended.
