By Kay M Crossley (@KayMCrossley) , Joanne L Kemp (@JoanneLKemp), Charles Ratzlaff, and Ewa M Roos (@Ewa_Roos)
In 2002, a randomised controlled trial (RCT) in the New England Journal of Medicine  made us all sit up and take note. The trial was remarkable because participants were randomised to arthroscopic debridement (including chondroplasty, removal of debris and partial meniscectomy), arthroscopic lavage (sham surgery), or placebo surgery (skin incisions only).
Arthroscopic surgery is no better than sham
The intervention (arthroscopic treatment) group never reported less pain or better function than the placebo group at any follow-up time point. This contradicted contemporary practice, where arthroscopic debridement was commonplace for knee osteoarthritis, including in younger patients and in sports medicine settings. The sports medicine and orthopaedic community continued to promote knee arthroscopy, moving the focus from knee osteoarthritis to arthroscopic partial meniscectomy. Since degenerative meniscal tears are part of the knee osteoarthritis disease process , this re-branding (‘menisectomy’ instead of ‘debridement’) allowed surgeons to continue performing essentially the same operation, but under a different guise.
In the past 12 years, five more RCTs have evaluated knee arthroscopy; one examined debridement  and four specifically focussed on meniscectomy [4-7]. Of these, Sihvonen and colleagues  reported no benefits of partial meniscectomy over sham arthroscopy. Importantly, this study was done in those who we would have thought were most likely to benefit (ie. patients with a degenerative tear, but no radiographic osteoarthritis).
Thus, despite the difficulties inherent in conducting RCTs of surgical treatments, six high quality RCTs failed to provide any evidence that arthroscopic meniscectomy provides additional improvements in pain relief or physical function over placebo/sham surgery[1-6]or non-surgical treatments, such as physiotherapy [3,5,7]. These findings are consistent, regardless of whether concomitant debridement was performed or not.
This high quality evidence trumps the positive results from uncontrolled case series studies and dictates that meniscectomy is an ineffective treatment for symptomatic degenerative meniscal tears. In addition, while degenerative meniscal tears increase the risk for incident radiographic osteoarthritis , long-term follow-up studies following meniscectomy provide an equally bleak picture: people undergoing meniscectomy have an approximate ten-fold increase in osteoarthritis at 10-20 years compared to controls [9-10].
Arthroscopy for degenerative meniscal tears no longer supported
The increasing evidence against meniscectomy is reflected in the recent guidelines. The UK’s NICE guidelines  state: “Do not refer for arthroscopic lavage and debridement as part of treatment for osteoarthritis, unless the person has knee osteoarthritis with a clear history of mechanical locking (as opposed to morning joint stiffness, ‘giving way’ or X-ray evidence of loose bodies)”. However, the assimilation of meniscal tears within the osteoarthritis process makes the differential assessment of “clear history of mechanical locking” challenging  and subgroup analyses from aforementioned RCTs suggest no difference in treatment effect in those with mechanical problems. Even the leading body for surgeons, the American Academy of Orthopaedic Surgeons  state: “We are unable to recommend for or against arthroscopic partial meniscectomy in patients with osteoarthritis of the knee with a torn meniscus.”
So why are patients still subjected to this procedure?
Millions of people worldwide undergo meniscectomy for degenerative meniscal tears, despite no additional benefit to that from sham surgery, placebo surgery or nonsurgical treatments. Patients are subjected to unnecessary and substantial costs and risks. While fewer arthroscopies were performed for patients with knee osteoarthritis over the past decade [14-15], rising rates of meniscectomy are reported over the same period [14-16]. Notably, there was a 2-fold increase for patients aged 35-55, and a 2.7-fold increase for those older than 55 years .
Approximately half a million arthroscopic knee meniscal procedures are performed annually in the US alone [14-17]. This may reflect that arthroscopic meniscectomy is funded through Medicare in the United States, whereas debridement with or without meniscectomy for knee osteoarthritis is not. It may simply reflect that contemporary practice is not keeping pace with the evidence. Or it may reflect the opinions of a recent editorial in Arthroscopy, which states that “patients who may not be of entirely sound mind are selected as research subjects (in placebo controlled surgical studies), and research performed on such individuals would not be generalizable to mentally healthy patients”. The authors also argue that it is unethical to perform sham surgery (ie a surgery without a therapeutic intervention). However, arthroscopy (ie. meniscectomy  or debridement ) provides no benefit and, hence is not therapeutic. Their own reasoning suggests that both arthroscopic debridement and meniscectomy are unethical.
Sports medicine clinicians (physicians, surgeons, physiotherapists and other allied health professionals) have an important role to bring clinical practice into line with the evidence. Recent high-quality RCTs [1-3, 5-7,19], clinical guidelines [11-13] and editorials [20-21] inform us that meniscectomy for degenerative meniscal tears is no more beneficial than placebo/sham or physical therapy approaches. And armed with this information, we must make informed, evidence-based decisions regarding optimal patient care and challenge the continued practice of meniscectomy.
1. Moseley JB, O’Malley K, Petersen NJ, et al. A Controlled Trial of Arthroscopic Surgery for Osteoarthritis of the Knee. New England Journal of Medicine 2002;347(2):81-88 doi: doi:10.1056/NEJMoa013259[published Online First: Epub Date]|.
2. Englund M, Roemer FW, Hayashi D, et al. Meniscus pathology, osteoarthritis and the treatment controversy. Nature Reviews Rheumatology 2012;8(7):412-19
3. Kirkley A, Birmingham TB, Litchfield RB, et al. A randomized trial of arthroscopic surgery for osteoarthritis of the knee. The New England journal of medicine 2008;359(11):1097-107 doi: 10.1056/NEJMoa0708333[published Online First: Epub Date]|.
4. Herrlin S, Hallander M, Wange P, et al. Arthroscopic or conservative treatment of degenerative medial meniscal tears: a prospective randomised trial. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA 2007;15(4):393-401 doi: 10.1007/s00167-006-0243-2[published Online First: Epub Date]|.
5. Katz JN, Brophy RH, Chaisson CE, et al. Surgery versus Physical Therapy for a Meniscal Tear and Osteoarthritis. New England Journal of Medicine 2013;368(18):1675-84 doi: doi:10.1056/NEJMoa1301408[published Online First: Epub Date]|.
6. Sihvonen R, Paavola M, Malmivaara A, et al. Arthroscopic Partial Meniscectomy versus Sham Surgery for a Degenerative Meniscal Tear. New England Journal of Medicine 2013;369(26):2515-24
7. Yim JH, Seon JK, Song EK, et al. A comparative study of meniscectomy and nonoperative treatment for degenerative horizontal tears of the medial meniscus. American Journal of Sports Medicine 2013;41(7):1565-70
8. Englund M, Guermazi A, Roemer FW, et al. Meniscal tear in knees without surgery and the development of radiographic osteoarthritis among middle-aged and elderly persons: The multicenter osteoarthritis study. Arthritis and Rheumatism 2009;60(3):831-39
9. Roos H, Laurén M, Adalberth T, et al. Knee osteoarthritis after meniscectomy: Prevalence of radiographic changes after twenty-one years, compared with matched controls. Arthritis & Rheumatism 1998;41(4):687-93 doi: 10.1002/1529-0131(199804)41:4<687::aid-art16>3.0.co;2-2[published Online First: Epub Date]|.
10. Englund M, Lohmander LS. Risk factors for symptomatic knee osteoarthritis fifteen to twenty-two years after meniscectomy. Arthritis & Rheumatism 2004;50(9):2811-19 doi: 10.1002/art.20489[published Online First: Epub Date]|.
11. National Institute for Health and Care Excellence (NICE). Arthroscopic knee washout, with or without debridement, for the treatment of osteoarthritis. In: NHS, ed. UK, 2007.
12. Englund M, Roemer FW, Hayashi D, et al. Meniscus pathology, osteoarthritis and the treatment controversy. . Nat Rev Rheumatol 2012;8(7):412-9
13. American Academy of Orthopaedic Surgeons. Treatment of Osteoarthritis of the Knee – Evidence based guidelines 2nd Ed., 2013.
14. Kim S, Bosque J, Meehan JP, et al. Increase in outpatient knee arthroscopy in the United States: a comparison of National Surveys of Ambulatory Surgery, 1996 and 2006. . J Bone Joint Surg Am 2011;93(11):994-1000
15. Potts A, Harrast JJ, Harner CD, et al. Practice patterns for arthroscopy of osteoarthritis of the knee in the United States. Am J Sports Med 2012;40(6):1247-51 doi: 10.1177/0363546512443946[published Online First: Epub Date]|.
16. Thorlund JB, Hare1 KB, Lohmander LS. Large increase in arthroscopic meniscus surgery in the middle-aged and older population in Denmark from 2000 to 2011. Acta Orthop 2014;May 6. [Epub ahead of print]
17. Cullen K, Hall M, Golosinskiya A. Ambulatory surgery in the United States, 2006. National health statistics reports. In: Statistics NCfH, ed., 2009.
18. Lubowitz JH, Provencher MT, Rossi MJ. Could the New England Journal of Medicine Be Biased Against Arthroscopic Knee Surgery? Part 2. Arthroscopy 2014;30(6):654-55
19. Herrlin S, Hallander M, Wange P, et al. Arthroscopic or conservative treatment of degenerative medial meniscal tears: a prospective randomised trial. . Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA. 2007;15(4):393-401
20. Buchbinder R. Meniscectomy in Patients with Knee Osteoarthritis and a Meniscal Tear? New England Journal of Medicine 2013;368(18):1740-41
21. Jarvinen T, Sihoven R, Englund M. Arthroscopy for degenerative knee- a difficult habit to break? Acta Orthopaedica 2014;85(3):215-17
Charles Ratzlaff: Bone Radiology, Rheumatology, Brigham and Women’s Hospital / Harvard Medical School, Boston, Massachusetts, USA, firstname.lastname@example.org