Patients and doctors alike tend to look for a treatment that will “fix” the problem, which may be why we have continued to use arthroscopic partial meniscectomy to attempt to relieve symptoms of meniscal tears despite a lack of evidence to support the practice.
Guidelines from the American Academy of Orthopaedic Surgeons state that the evidence for medial meniscectomy in patients with a torn meniscus and osteoarthritis (OA) is inconclusive; the organization offers no guidelines for patients with a torn meniscus who don’t have OA.2 The American College of Occupational and Environmental Medicine states that there is insufficient evidence to support arthroscopic partial meniscectomy for symptomatic, torn medial menisci for select patients and “the vast majority of patients [with medial meniscal tears] do not require surgery.”3 Previous studies have concluded that arthroscopic surgery for OA of the knee provides no additional benefit to optimized physical and medical therapy.4 Furthermore, research by Katz et al5 shows that meniscectomy provides no benefit over conservative treatment in functional status at six months in patients with OA and a medial meniscal tear.
That said, arthroscopic partial meniscectomy is still the most common orthopedic procedure in the United States.1 Although its use has decreased in the past 15 years, it is performed nearly 700,000 times annually at a cost of approximately $4 billion.1,6,7 Like any surgical procedure, meniscectomy carries a risk for complications. In the double-blind, randomized trial reported on here, Sihvonen et al1 compared meniscectomy to a sham procedure for patients with knee pain but not OA.
STUDY SUMMARY
Meniscectomy and shamsurgery are equally effective
Sihvonen et al1 conducted a randomized, double-blind, sham-controlled trial at five orthopedic clinics in Finland. Patients ages 35 to 65 were enrolled if they had clinical findings of a medial meniscus tear and knee pain for more than three months that wasn’t relieved by conservative treatment. The trial excluded patients who had an obvious traumatic onset of symptoms; clinical or radiologic evidence of knee OA; a locked knee that could not be straightened; knee instability or decreased range of motion; previous surgery on the affected knee; fracture within the past 12 months on the affected limb; or other notable pathology on MRI or during arthroscopy.
Before randomization, 160 patients underwent diagnostic arthroscopy. Fourteen patients were excluded: six because they did not actually have a medial meniscal tear, one because he also had a lateral meniscus tear, three due to a major chondral flap, two who had already undergone meniscal repair, and two due to an osteochondral microfracture.
At the end of the diagnostic arthroscopy, each patient was blindly randomized to arthroscopic partial meniscectomy or sham surgery. To simulate the meniscectomy procedure, the surgeon similarly manipulated the knee, made comparable noise and vibration using tools and suction, and ensured that the patient was kept in the operating room (OR) for a comparable time. Only the orthopedic surgeon and OR staff were aware of which surgery the patient underwent, and these staff members were not included in further treatment or follow-up. After the procedure, all patients received the same walking aids and instructions for a graduated exercise program.
The 70 patients in the meniscectomy group and the 76 in the sham surgery group were similar in age (mean: 52 years), sex, BMI, and duration of pain (mean: 10 months). Patients in both groups also had similar tears noted on arthroscopy.
Three primary outcomes were measured before surgery and at 12 months: knee pain, knee symptoms and function, and quality of life (QoL). Knee pain after exercise was evaluated on a scale of 0 to 10, with 0 indicating no pain. The validated Lysholm knee score was used to assess knee symptoms and function, and the Western Ontario Meniscal Evaluation Tool (WOMET) was utilized to evaluate QoL; both are 100-point scales in which lower scores indicate more severe symptoms.
Both groups had marked improvement in pain and function from baseline to 12 months, and there was no significant difference between the two groups. Knee pain scores improved by 3.1 points in the meniscectomy group and 3.3 points in the sham surgery group. Lysholm symptom and function scores improved 21.7 points in the meniscectomy group and 23.3 points in the sham surgery group (a change of 11.5 points would have been considered clinically significant). The mean between-group difference was –1.6 points.
WOMET QoL scores improved 24.6 points in the meniscectomy group and 27.1 points in the sham surgery group (a change of 15.5 points would have been considered clinically significant). The mean between-group difference was –2.5 points.
There were no significant between-group differences in serious adverse events or number of patients who required subsequent knee surgery. Similar proportions in each group thought they had sham surgery, which confirmed the effectiveness of the blinding. Ninety-six percent of patients in the sham procedure group and 93% in the meniscectomy group reported they would be willing to repeat the procedure.
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