Osteoarthritis and Cartilage 22 (2014) 1749e1751

Editorial

Arthroscopic partial meniscectomy for degenerative tears: where do we stand?

Keywords: Meniscus Osteoarthritis Arthroscopy

In this issue of Osteoarthritis and Cartilage, Gauffin and colleagues report the findings of a randomized controlled trial of arthroscopic partial meniscectomy (APM) vs a physical therapy regimen in subjects with degenerative meniscal tears. This carefully executed study is an important addition to an evolving body of research on the role of APM and other arthroscopic procedures in patients with osteoarthritis. Each of the prior trials failed to show that surgical therapy led to greater pain relief or functional improvement than the comparators (physical therapy regimens or sham surgery). Thus, the trial of Gauffin et al. is especially notable because it documents clinically and statistically significantly greater improvement in pain severity 12 months after enrollment in the surgically treated subjects than in those receiving an exercise program. We review these trials of arthroscopic surgery in patients with OA and meniscal tear in order to place this trial in context and offer suggestions for clinicians and their patients with this condition. The menisci are cartilaginous, semi-lunar shaped knee structures that confer important load-bearing and stabilizing functions. Like other cartilaginous intraarticular structures such as the labra of the shoulder and hip, the menisci are vulnerable to degenerative tears. The introduction of magnetic resonance imaging in the latter decades of the 20th century facilitated non-invasive recognition of meniscal tear, revealing that over one-third of individuals greater than 50 years old and over three-quarters of persons with knee osteoarthritis have degenerative meniscal tears1,2. The introduction of arthroscopic surgical techniques in the same era provided a minimally invasive means of performing surgery to resect meniscal tears. Indeed, by the turn of the century, APM for degenerative meniscal tear had become among the most commonly performed orthopedic procedures, with over 400,000 performed in the US alone in 20063. Over the last 12 years several observations have questioned the effectiveness of arthroscopic treatment for patients with osteoarthritis. First, a randomized controlled trial of arthroscopic lavage and debridement for osteoarthritis showed considerable benefit in both arms with no additional benefit in surgically treated patients compared to those receiving sham surgery4. Similarly, a randomized trial showed that patients with osteoarthritis randomized

to arthroscopy and those randomized to a physical therapy regimen both showed substantial improvement with no difference between the two treatment arms5. On the basis of these trials most treatment guidelines including those of the American Academy of Orthopedic Surgeons suggest that arthroscopic lavage and debridement is not indicated for knee OA . Most arthroscopies in patients with knee OA are performed to address symptoms clinicians attribute to meniscal tear, rather than osteoarthritis per se. Several epidemiologic studies reported in the last decade have further complicated clinical decisionmaking for patients with meniscal tear by showing that these tears are often asymptomatic. For example, adults in a large community based sample found to have meniscal tear on MRI were no more likely to have knee pain than subjects without meniscal tear1. Similarly, subjects with meniscal tear and osteoarthritis had no more severe pain than subjects with OA and no tear2. These observations have challenged the clinical rationale for APM and set the stage for more rigorous evaluation of APM. Herrlin and colleagues published the first trial to evaluate the efficacy of APM in patients with degenerative meniscal tear in 20076,7. These investigators enrolled 97 subjects and randomized half to a rigorous exercise program that emphasized lower extremity strengthening as well as stretching, conditioning and balance. The other half received the same exercise program as well as APM. 28% of subjects randomized to the exercise arm crossed over to the surgical arm in the first 14 months, generally because of persistent symptoms. In intention to treat analyses (in which patients are analyzed in the groups they were randomized to, irrespective of the treatment they received), the APM group had, on average, a nine point greater change in KOOS Pain score over 6 months than the exercise-alone group. This difference was not statistically significant, though nine points on the KOOS Pain Scale is generally considered clinically meaningful8. In the MeTeOR Trial (Meniscal Tear in Osteoarthritis Research)9, 351 subjects from seven US referral centers were randomized to APM with an exercise regimen or to the exercise regimen alone. The exercise regimen was similar to that used by Herrlin et al. By 6 months, 30% of subjects randomized to the PT arm had crossed over to receive APM. On average, subjects in both arms improved

http://dx.doi.org/10.1016/j.joca.2014.07.016 1063-4584/© 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

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markedly from baseline by 6 months. The intention to treat analysis showed that the group randomized to APM improved 2.7 points more on the 100-point WOMAC Function Scale than the group randomized to PT. This difference was neither clinically meaningfully nor statistically significant. Yim and colleagues published a similar trial to the MeTeOR and the Herrlin trials in 201310. This South Korean study also documented marked improvement from baseline to 1 year in both groups with no clinically meaningful or statistically significant differences between arms in Pain Visual Analog Scale and Lysholm Scale. In contrast to the Herrlin and MeTeOR trials, there were also no crossovers in the study of Yim and colleagues. Sihvonen and colleagues published a sham-controlled trial of APM in 201311. They included patients with medial meniscal degenerative tear and no radiographic evidence of OA. The sham group received arthroscopic lavage but no partial meniscal resection. The investigators documented marked improvements in both groups in pain and function scores, and greater than 80% satisfaction in both groups with the results of surgery. There were no clinically important or statistically significant differences between the meniscal resection and sham treatment arms in improvement from baseline in pain or function. Against this backdrop of high quality trials that failed to demonstrate superiority of APM over either a PT regimen or sham surgery, Gauffin and colleagues present in this issue of Osteoarthritis and Cartilage a randomized controlled trial of APM vs a standardized PT regimen. As occurred in the Herrlin and MeTeOR trials, a substantial fraction of subjects crossed over from the PT arm and underwent APM (21% by 12 months). As in each of the studies reviewed above, both arms improved markedly from baseline to follow up. However in the intention to treat analysis, the group randomized to APM improved by 10.6 more points on the KOOS Pain score than the group randomized to PT. This difference was statistically significant and clinically meaningful. Clinicians, investigators, policy makers and payers are challenged to interpret these five randomized controlled trials of the efficacy of APM, four of which did not find APM to be statistically significantly superior to the comparator and one which did find APM to be associated with a statistically significant, clinically important advantage. Why the discrepant findings? One possibility is that the prior trials missed an important effect because they were too small. Indeed, the Herrlin trial demonstrated a 9.6 point difference between APM and PT groups in improvement in KOOS Pain but the difference was not statistically significant. However the

other trials did not demonstrate clinically important differences between study arms (Table I). Another possibility is that substantial cross over from nonoperative to surgical therapy makes the intention to treat analyses in these trials difficult to interpret. Indeed, in the Herrlin, MeTeOR and Gauffin trials, 20e30% of subjects assigned to the PT arm crossed over to surgery, potentially obscuring differences in outcome between PT and surgery in the intention to treat analyses. In fact the MeTeOR Trial provided a secondary ITT analysis that defined ‘failure’ as either a crossover or failure to improve by 8 points on the WOMAC Function scale. Surgery had significantly fewer failures, defined in this fashion, than nonoperative therapy (33% vs 56%, p < 0.001)9. Thus, the similar outcomes of subjects randomized to APM and those randomized to the comparator in these trials may have arisen in part from crossover from nonoperative therapy to APM. That explanation does not explain the findings of the trial of Yim et al., which had no crossovers.10 Third, as noted in Table I, APM was associated with substantial improvement in pain and function in each trial, on the order to 20 to 30 points on the 100 point outcome scales (KOOS Pain in three instances). Thus, the trials should not be interpreted as showing that surgery was not beneficial, but rather that in general the trials showed similar, clinically important improvements in both the surgical arms and the comparator arms. The findings of the sham-controlled trial of Sihvonen and colleagues merit careful consideration11. The trial shows similar outcome following APM and sham, suggesting that the effect of APM may be largely attributable to a placebo, or sham effect. The potency of sham surgery may relate to the substantial investment patients make into preparing for surgery and recovery, and the attendant raising of expectations12,13. Does the similar outcome of APM and sham surgery vitiate the value of APM as a clinical intervention? We think not. Subjects in both the APM and sham arms improved by a clinically important amount on standardized measures of pain and function and over 80% of subjects in each arm were satisfied with the outcome of surgery while over 90% in each arm stated they would choose surgery again if given the opportunity11. We are loathe to suggest eliminating an option associated with such dramatic pain relief. This would be throwing out the baby with the bath water. Nor do we d argue that clinicians should prescribe placebo. Rather, we suggest that these data should spur further research on harnessing benefits of sham and placebo interventions. We also note while physical therapy was associated

Table I Summary of five randomized controlled trials of APM vs comparator in patients with degenerative meniscal tear Author, year, country

Sample age, tear, OA status

Herrlin, 2007, Sweden

96/180 45e64 yo, medial MT, KL0-2 45 þ yo. MT, KL 351/1330 0e3

Katz, 2013, US

Yim, 2013, South Korea

43e62 yo, Horizontal medial MT, KL0-1 Sihvonen, 2013, 35e65 yo, MT, Finland KL0-1 Gauffin, 2014, Sweden

45e64 yo, MT, KL 0-2 (93% KL0-1)

#Randomized/ Intervention Comparator Primary outcome # eligible

Difference in outcome between treatment arms (ITT analysis)

Improvement in APM arm

Crossover

28% from PT to APM by 14 mo

Exercise þ APM

Exercise

Change in KOOS Pain (6 mo)

9 point difference favoring APM (NS)

Exercise þ APM

Exercise

Change in WOMAC Function (6 mo)

2.4 point difference favoring APM (NS)

108/162

APM

Strength exercises

Change in VAS Pain, Lysholm Score (24 mo)

2.0 difference in VAS and 0.1 in Lysholm, favoring APM (NS)

33 pts on KOOS Pain, 23 points on Lysholm 20.9 on WOMAC Fxn, 24.2 on KOOS Pain 34 on 100 mm VAS Pain, 19.2 pts on Lysholm

146/205

APM

Sham APM

150/179

Exercise þ APM

Exercise

Change in pain VAS pain w exercise, Lysholm (12 mo) Change in KOOS Pain (12 mo)

1.0 pts on VAS, 1.6 on Lysholm, favoring APM (NS) 10.6 points favoring APM (p < 0.01)

21.7 pts on Lysholm, 31 on 100 mm VAS pain 29 pts on KOOS Pain

MT ¼ meniscal tear; KL ¼ KellgreneLawrence Grade; APM ¼ arthroscopic partial meniscectomy; ITT ¼ intention to treat. To facilitate comparison, VAS, Lysholm, KOOS scores have been transformed in this Table to 0e100, 100 ¼ best.

30% from PT to APM by 6 mo None

None

21% from PT to APM by 12 mo

Editorial / Osteoarthritis and Cartilage 22 (2014) 1749e1751

with substantial benefits in these trials, no subjects received neither physical therapy nor sham, raising the possibility that the substantial benefits associated with PT regimens in these trials may also be due to placebo effect. This too requires further research. An economic analysis of treatment options for meniscal tear and OA would be most welcome as well, to guide policy in this clinical area. Ultimately, patients and their physicians must make integrate the findings of these trials and proceed with sensible clinical decisions. For the middle age patient with knee pain and degenerative meniscal tear, the preponderance of evidence today suggests that an initial regimen of strengthening-based physical therapy is a reasonable initial step. Patients who fail to improve following nonoperative therapy can be referred for APM. We do not know whether the benefits of surgery (or PT for that matter) are primarily physiologic or due to placebo effects. This question is ripe for further research. But we must work with the evidence gathered from five rigorous RCTs and summarized in Table I, suggesting that APM is associated with important gains in pain and functional status and has a role in the management of this prevalent, disabling condition.

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10. Conflicts of interest Neither of the authors has a conflict of interest. Acknowledgment Supported by NIAMS R01 AR055557, K24 AR057827. The funding sources had no role in this work.

References 1. Englund M, Guermazi A, Gale D, Hunter DJ, Aliabadi P, Clancy M. Incidental meniscal findings on knee MRI in middle-aged and elderly persons. N Engl J Med 2008;359(11):1108e15. 2. Bhattacharyya T, Gale D, Dewire P, Totterman S, Einhorn TA, McLaughlin S. The clinical importance of meniscal tears demonstrated by magnetic resonance imaging in osteoarthritis of the knee. J Bone Joint Surg 2003;85(1):4e9. 3. Kim S, Bosque J, Meehan JP, Jamali A, Marder R. Increase in outpatient knee arthroscopy in the United States: a comparison of National surveys of ambulatory surgery, 1996 and 2006. J Bone Joint Surg 2011;93(11):994e1000. 4. Moseley JB, O'Malley K, Petersen NJ, Menke TJ, Brody BA, Kuykendall DH. A controlled trial of arthroscopic surgery

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for osteoarthritis of the knee. N Engl J Med 2002;347(2): 81e8. Kirkley A, Birmingham TB, Litchfield RB, Giffin JR, Willits KR, Wong CJ. A randomized trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med 2008;359(11):1097e107. Herrlin S, Hållander M, Wange P, Weidenhielm L, Werner S. Arthroscopic or conservative treatment of degenerative medial meniscal tears: a prospective randomised trial. Knee Surg Sports Traumatol Arthrosc 2007/04/01;15(4):393e401. Herrlin SV, Wange PO, Lapidus G, Hallander M, Werner S, Weidenhielm L. Is arthroscopic surgery beneficial in treating non-traumatic, degenerative medial meniscal tears? A five year follow-up. Knee Surg Sports Traumatol Arthrosc Feb 2013;21(2):358e64. Roos EM, Lohmander LS. The Knee injury and Osteoarthritis Outcome Score (KOOS): from joint injury to osteoarthritis. Health Qual Life Outcomes 2003;1:64. Katz JN, Brophy RH, Chaisson CE, Cole BJ, Dahm DL, de Chaves L. Surgery vs physical therapy for a meniscal tear and osteoarthritis. N Engl J Med 2013;368:1675e84. Yim J-H, Seon J-K, Song E-K, Choi JI, Kim MC, Lee KB. A Comparative study of meniscectomy and nonoperative treatment for degenerative Horizontal tears of the medial Meniscus. Am J Sports Med July 1, 2013;41(7):1565e70. Sihvonen R, Paavola M, Malmivaara A, Joukainen A, Nurmi H, Kalske J. Arthroscopic partial meniscectomy versus sham surgery for a degenerative meniscal tear. N Engl J Med 2013;369(26):2515e24. Oken BS. Placebo effects: clinical aspects and neurobiology. Brain: J Neurol Nov 2008;131(Pt 11):2812e23. Knox KB, Kelly ME. Placebo power. Tech Vasc Interv Radiol Jun 2012;15(2):150e2.

J.N. Katz*, E. Losina Orthopedic and Arthritis Center for Outcomes Research, Department of Orthopedic Surgery and Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA *

Address correspondence and reprint requests to: J.N. Katz, Orthopedic and Arthritis Center for Outcomes Research, Department of Orthopedic Surgery and Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. E-mail address: [email protected] (J.N. Katz).

Arthroscopic partial meniscectomy for degenerative tears: where do we stand?

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