Chapter 94 Is There a Role for Arthroscopy in the Treatment of Knee Osteoarthritis?
Arthroscopy was first described to treat osteoarthritis (OA) of the knee by Burman and coauthors1 in 1934. Over the past several decades, arthroscopic debridement of the degenerative knee has become a commonly performed orthopedic procedure. Despite its popularity, the exact role of arthroscopy in treating OA is controversial. Older, primarily uncontrolled cohort studies have suggested that arthroscopy has a variety of benefits in patients with early OA.2–6 However, a more recent study has suggested that the placebo effect may be responsible for the benefit related to arthroscopic treatment.7 The variety of arthroscopic procedures, the retrospective nature of the majority of published studies, and the lack of control subjects probably adds even more confusion as to which patients will benefit from arthroscopy.8
OPTIONS
Nonoperative management begins with activity modification, physical therapy, and a trial of anti-inflammatory medications. Many patients will often experience significant relief after intra-articular corticosteroid injections and hyaluronate injections. It is important to note that the degree of pain relief, as well as how long it lasts, can be varied.9
EVIDENCE
Several studies have been conducted in an effort to examine the effectiveness of arthroscopy in treating OA of the knee (Table 94-1). However, after conducting an evidence-based review of the current literature, we found only 1 study that contained Level I evidence. This study, by Moseley and colleagues,7 was a prospective, randomized, placebo-controlled trial of 180 patients with OA who were assigned to receive arthroscopic debridement, arthroscopic lavage, or placebo surgery. Their inclusion criteria included: (1) age < 75 years, (2) OA as defined by the American College of Rheumatology, (3) knee pain despite at least 6 months of conservative management, and (4) no arthroscopy performed on the knee in the previous 2 years. The severity of OA was assessed radiographically and graded from 1 to 4. The scores from all 3 compartments were added for a total of 0 to 12. Of note, patients were excluded for severe deformity, for a score of more than 9 on the scale, or if there was a medical contraindication. Patients and assessors of outcome were blinded to the treatment group assignment, and outcomes were assessed at multiple points over a 24-month period with the use of 5 self-reported scores. The authors conclude that the outcomes after arthroscopic lavage or arthroscopic debridement were no better than those after a placebo procedure.
Several details about this study require a more in-depth evaluation because they are certainly relevant to the authors’ conclusion that surgical intervention provided no benefit compared with placebo surgery. Forty-four percent of the eligible participants declined to participate in the study, which creates a selection bias; that is, it is possible that the patients who declined to participate had lower grades of OA and, therefore, might have experienced the best outcome.10 In addition, the presence or absence of joint effusion was not reported. This is significant because some of the indications for knee arthroscopy, such as loose bodies or meniscal tears, can be manifested clinically by a joint effusion. Finally, the method of grading OA may lead to conflicting results. For example, a patient with one severely arthritic compartment may receive the same score as a patient with mild arthritis in all three compartments. These patients are probably not comparable clinically and would most likely have different outcomes after surgical intervention. Despite these criticisms, this investigation is still the only Level I study that addresses the role of arthroscopy in OA; therefore, the authors’ conclusion should be acknowledged and taken into account when treating these patients.
Patients with symptomatic OA of the knee have a reported incidence rate of meniscal tears in up to 91% of magnetic resonance imaging (MRI) scans.11 Some surgeons have proposed that patients who have pain secondary to clinically significant meniscal tears will benefit from arthroscopic mensical debridement. Dervin and investigators,8