Arthroscopic surgery for degenerative knee arthritis and meniscal tears: a clinical practice guideline



## Population

## The evidence
The panel requested two systematic reviews to inform the recommendation. The systematic review on the net benefit of knee arthroscopy compared with non-operative care pools data from 13 randomised trials for benefit outcomes (1668 patients) and an additional 12 observational studies for complications (>1.8 million patients). [bib_ref] Knee arthroscopy versus conservative management in patients with degenerative knee disease: a..., Brignardello-Peterson [/bib_ref] gives an overview of the patients included, the study funding, and patient involvement in the design of the studies.
Panel members identified three outcomes-pain, function, and quality of life-as the most important for patients with degenerative knee disease who are considering surgery. Although the included studies reported these patient-important outcomes, it is difficult to know whether changes recorded on an instrument measuring subjective symptoms are important to those with symptoms-for example, a change of three points might have completely different meanings in two different pain scales.
Therefore, a second team performed a linked systematic review addressing what level of individual change on a given scale is important to patients, 20 a characteristic called the minimally important difference (MID). [bib_ref] Interpreting treatment effects in randomised trials, Guyatt [/bib_ref] The study identified a range of credible MIDs for each key outcome; this range of MID estimates informed sensitivity analyses for the review on net benefit, informed discussions on the patient values and preferences, and was key to interpreting the magnitude of effect sizes as well as the strength of the recommendation. 20

## Understanding the recommendations
The infographic provides an overview of the benefits and harms of arthroscopy in standard GRADE format.
Arthroscopic knee surgery for degenerative knee disease is the most common orthopaedic procedure in countries with available data [bib_ref] Ambulatory surgery in the United States, Cullen [/bib_ref] and on a global scale is performed more than two million times each year [fig_ref] Fig 1 |: Population adjusted trends in frequency of knee arthroscopy [/fig_ref]. [bib_ref] Arthroscopy for knee osteoarthritis has not decreased after a clinical trial, Adelani [/bib_ref] [bib_ref] Trends in elective knee arthroscopies in a population-based cohort, Bohensky [/bib_ref] [bib_ref] Knee arthroscopy: influence of systems for delivering healthcare on procedure rates, Hamilton [/bib_ref] [bib_ref] Large increase in arthroscopic meniscus surgery in the middle-aged and older population..., Thorlund [/bib_ref] Arthroscopic procedures for degenerative knee disease cost more than $3bn per year in the US alone. [bib_ref] Arthroscopic surgery for knee pain, Jarvinen [/bib_ref] A high prevalence of features advocated to respond positively to arthroscopic surgery (such as meniscal tears, mechanical symptoms, and sudden symptom onset) as well as financial incentives may explain why arthroscopic knee surgery continues to be so common despite recom- - Degenerative knee disease is an inclusive term, which many consider synonymous with osteoarthritis. We use the term degenerative knee disease to explicitly include patients with knee pain, particularly if they are >35 years old, with or without: -Imaging evidence of osteoarthritis -Meniscus tears -Locking, clicking, or other mechanical symptoms except persistent objective locked knee -Acute or subacute onset of symptoms - Most people with degenerative arthritis have at least one of these characteristics. The term degenerative knee disease does not include patients having recent debut of their symptoms after a major knee trauma with acute onset of joint swelling (such as haemarthrosis) The panel is confident that the randomised controlled trials included adequate representation from groups commonly cited to derive benefit from arthroscopic knee surgery for degenerative knee disease-notably those with meniscal tears, no or minimal radiographic evidence of osteoarthritis, and those with sudden but non-traumatic symptom onset. Thus the recommendation applies to all or almost all patients with degenerative knee disease. Further, the evidence applies to patients with any severity of mechanical symptoms, with the only possible exception being those who are objectively unable to fully extend their knee (that is, a true locked knee). We did not consider young patients with sports related injuries or patients with major trauma in any age.
Trials that enrolled a majority of patients without radiographic osteoarthritis showed similar effect sizes to trials enrolling patients with radiographic evidence of osteoarthritis. Most of these trials exclusively included patients E stimates of baseline risk for effects comes from the control arms of the trials; for complications, comparator risk was assumed to be nil.
The panel is confident that arthroscopic knee surgery does not, on average, result in an improvement in long term pain or function. Most patients will experience an important improvement in pain and function without arthroscopy. However, in <15% of participants, arthroscopic surgery resulted in a small or very small improvement in pain or function at three months after surgery-this benefit was not sustained at one year. In addition to the burden of undergoing knee arthroscopy (see practical issues below), there are rare but important harms, although the precision in these estimates is uncertain (low quality of evidence).
It is unlikely that new information will change interpretation of the key outcomes of pain, knee function, and

## How the recommendation was created
A randomised controlled trial published in The BMJ in June 2016 found that, among patients with a degenerative medial meniscus tear, knee arthroscopy was no better than exercise therapy. [bib_ref] Exercise therapy versus arthroscopic partial meniscectomy for degenerative meniscal tear in middle..., Kise [/bib_ref] This study adds to the body of evidence suggesting that the benefits of arthroscopy may not outweigh the burden and risks. The RapidRecs executive felt that the study, when considered in context of the full body of evidence, might change practice. [bib_ref] Introduction to BMJ Rapid Recommendations, Siemieniuk [/bib_ref] Our international panel including orthopaedic surgeons, a rheumatologist, physiotherapists, a general practitioner, general internists, epidemiologists, methodologists, and people with lived experience of degenerative knee disease (including those who had undergone and those who had not undergone arthroscopy) met to discuss the evidence. No person had financial conflicts of interest; intellectual and professional conflicts were minimised and managed (see appendix 1 on bmj.com).
The panel followed the BMJ Rapid Recommendations procedures for creating a trustworthy recommendation and used the GRADE approach to critically appraise the evidence and create recommendations (appendix 2). [bib_ref] GRADE: an emerging consensus on rating quality of evidence and strength of..., Guyatt [/bib_ref] The panel considered the balance of benefits, harms, and burdens of the procedure, the quality of evidence for each outcome, typical and expected variations in patient values and preferences, and acceptability. Recommendations can be strong or weak, for or against a course of action.

## How patients were involved in the creation of this article
Three people with lived experience of osteoarthritis, one of whom had arthroscopic knee surgery, were full panel members. These panel members identified important outcomes and led the discussion on values and preferences. Pain was weighed as higher importance for most patients: for example, the patient panel members felt that a possible small benefit to function without a reduction in pain would be unimportant to almost all patients. Those with lived experience identified key practical issues including concerns with cost and accessibility for both arthroscopy and interventions provided by physiotherapists. The members participated in the teleconferences and email discussions and met all authorship criteria. - To what extent might you use information in this article to alter the conversations you have with patients with degenerative knee disease, or those considering arthroscopic surgery?
ing or physical activity is limited during the recovery period. 27 outlines the key practical issues for those considering arthroscopic knee surgery versus nonsurgical management for degenerative knee disease.
Degenerative knee disease is a chronic condition in which symptoms fluctuate. On average, pain tends to improve over time after seeing a physician for pain, and delaying knee replacement is encouraged when possible. [bib_ref] The American Academy of Orthopaedic Surgeons evidencebased clinical practice guideline on surgical..., Mcgrory [/bib_ref] Values and preferences Our strong recommendation against arthroscopy reflects a low value on a modest probability (<15%) of small or very small improvement in short term pain and function that does not persist to one year, and a higher value on avoiding the burden, postoperative limitations, and rare serious adverse effects associated with knee arthroscopy. The panel, including the patient participants, felt that with meniscus tears. Meniscus tears are common, usually incidental findings, and unlikely to be the cause of knee pain, aching, or stiffness. 1 Mechanical symptoms were also a prominent feature for most trial participants, and many had sudden or subacute onset of symptoms. [bib_ref] Knee arthroscopic surgery is beneficial to middle-aged patients with meniscal symptoms: a..., Gauffin [/bib_ref] [bib_ref] A randomized trial of arthroscopic surgery for osteoarthritis of the knee, Kirkley [/bib_ref] [bib_ref] Finnish Degenerative Meniscal Lesion Study Group. Mechanical symptoms and arthroscopic partial meniscectomy..., Sihvonen [/bib_ref] [bib_ref] Finnish Degenerative Meniscal Lesion Study (FIDELITY) Group. Arthroscopic partial meniscectomy versus sham..., Sihvonen [/bib_ref] Given that there is evidence of harm and no evidence of important lasting benefit in any subgroup, the panel believes that the burden of proof rests with those who suggest benefit for any other particular subgroup before arthroscopic surgery is routinely performed in any subgroup of patients.

## Practical issues
It takes between two and six weeks to recover from arthroscopy, during which time patients may experience pain, swelling, and limited function. almost all patients would share these values. The recommendation is not applicable to patients who do not share these values (that is, those who place a high value on a small, uncertain, and transient reduction in pain and function, and a low value on avoiding the burden and postoperative limitation associated with arthroscopy).

## Costs and resources
The panel focused on the patient perspective rather than that of society when formulating the recommendation. However, implementation of this recommendation will almost certainly result in considerable cost savings for health funders. A rigorous economic analysis found that knee arthroscopy for degenerative knee disease is not close to cost effective by traditional standards, even in extreme scenarios that assume a benefit with arthroscopy. [bib_ref] Cost-effectiveness analysis of arthroscopic surgery compared with non-operative management for osteoarthritis of..., Marsh [/bib_ref] The panel made a strong recommendation against arthroscopy, which applies to almost all patients with degenerative knee disease, implying that non-use of knee arthroscopy can be used as a performance measure or tied to health funding. 31

# Future research
Key research questions to inform decision makers and future guidelines are:
- Randomised trials-Does arthroscopic knee surgery benefit patients who are objectively unable to fully extend their knee or who have persistent, severe, and frequent mechanical symptoms?
- Implementation studies-What are the most effective ways to reduce the overuse of arthroscopic surgery for degenerative knee disease? [fig_ref] Table 2 |: New evidence which has emerged after initial publication There are currently no... [/fig_ref] shows evidence which has emerged since the publication of this article. As new evidence is published, a group will assess the new evidence and make a judgment on to what extent it is expected to alter the recommendation.

## Updates to this article
We thank Alison Hoens for critical review of the recommendation and manuscript. We also thank Tahira Devji for expertly leading the systematic review of minimally important differences.
Funding: This guideline was not funded.
Competing interests: All authors have completed the BMJ Rapid Recommendations interests disclosure form, and a detailed, contextualised description of all disclosures is reported in appendix 1. As with all BMJ Rapid Recommendations, the executive team and The BMJ judged that no panel member had any financial conflict of interest. Professional and academic interests are minimised as much as possible, while maintaining necessary expertise on the panel to make fully informed decisions.
Transparency: R Siemieniuk affirms that the manuscript is an honest, accurate, and transparent account of the recommendation being reported; that no important aspects of the recommendation have been omitted; and that any discrepancies from the recommendation as planned (and, if relevant, registered) have been explained.
[fig] Fig 1 |: Population adjusted trends in frequency of knee arthroscopy; percent. Arthroscopic knee surgery remains common despite accumulating evidence suggesting little benefit [/fig]
[fig] : Project: how many arthroscopic procedures are scheduled in your organisation for degenerative knee disease? Based on the information you have read in this article or in this package of Rapid Recommendation articles, is there anything which you might alter your practice? [/fig]
[fig] Fig 2 |Fig 3 |: Characteristics of patients and trials included in systematic review of arthroscopic knee surgery No commercial reuse: See rights and reprints http://www.bmj.Practical issues about use of arthroscopic knee surgery versus non-surgical management for degenerative knee disease [/fig]
[table] Table 1 |: Support from current guidance for arthroscopic surgery in patients with subgroups of degenerative knee disease [/table]
[table] 28: Most patients cannot bear full weight on the leg (that is, they may need crutches) in the first week after surgery, and driv-Use this information to gauge how similar your patients' conditions are to those of people studied in the trialsMEAN SYMPTOM DURATION monthsNo trials involved patients in design or conduct 12 of 13 trials were free of industry funding [/table]
[table] Table 2 |: New evidence which has emerged after initial publication There are currently no updates to the article [/table]