ABSTRACT
BACKGROUND: More than 650,000 arthroscopic procedures are performed each year when medical therapy fails in the treatment of osteoarthritis (OA) of the knee. Uncontrolled studies have shown that up to half of patients receive pain relief from this procedure; however, the exact reason is unclear. There is no evidence that arthroscopic surgery contributes to the cure or arrest in the natural course of OA.
POPULATION STUDIED: The investigators enrolled patients (mean age 52.3 ± 11.3 years) recruited from the Houston Veterans Administration Medical Center who had OA of the knee, as defined by the American College of Rheumatology. The patients reported at least moderate knee pain on average (at least a 4 on a 10-point visual analogue scale) despite at least 6 months of medical treatment. These patients had not undergone arthroscopy in the past 2 years. Patients were excluded for severe pain, severe deformity, and serious medical problems.
STUDY DESIGN AND VALIDITY: This double-blind, randomized controlled trial evaluated 3 treatments: arthroscopic lavage alone, arthroscopic debridement along with lavage, or placebo (“sham”) procedure. Allocation to these groups was appropriately concealed. One orthopedist performed all the operations. The lavage-only group had the joint lavaged with 10 L of fluid and no general debridement was performed. “Bucket-handle” tears to a meniscus or mechanically important deficits were repaired as in the debridement group. The debridement group underwent arthroscopy and joint lavage with 10 L of fluid, shaving of any rough articular surface, removal of debris, and repair of any torn menisci to form a smooth, firm, and fixed rim. Patients in these 2 groups received general anesthesia and were intubated. The placebo procedure simulated debridement by placing three 1-cm incisions in the skin and the surgeon asking for all of the instruments and manipulating the knee as if arthroscopy was being performed. These patients received a short-acting intravenous tranquilizer and an opioid and spontaneously breathed oxygen-enriched air but were not fully anesthetized.
OUTCOMES MEASURED: The primary end point was pain in the study knee 2 years after the intervention, as assessed by a 12-item self-reported Knee-Specific Pain Scale created for this study. The scale ranged from 0 to 100 with higher scores indicating more pain. Five secondary end points were assessed using 2 measures of pain and 3 measures of function.
RESULTS: Mean pain scores for all groups did not differ at any of the recorded time intervals (mean Knee-Specific Pain Scale scores in all 3 groups were 51–54 out of 100). The improvement in pain occurred within the first 2 weeks for all groups (6-to 12-point improvement) and then increased slightly for the remaining 2 years.
Arthroscopy does not provide any benefit over “sham surgery” in reducing pain symptoms or physical functioning. Both, probably, had a placebo effect, although the combination of surgery and anesthesia is an expensive and potentially dangerous placebo.