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In the interesting linked article,1 authors Dr Raine Sihvonen and colleagues suggest that arthroscopic partial meniscectomy (APM) may lead to long-term harms (by increasing the risk of knee osteoarthritis (OA)) with no clear benefits in patient-reported outcomes. This study was a carefully executed multicentre, randomised, participant-blinded and outcome assessor-blinded, placebo-surgery controlled efficacy trial in participants aged 35 to 65 years who had had knee symptoms for more than 3 months, consistent with the diagnosis of a degenerative medial meniscus tear.1 Participants had not responded to conventional conservative treatment and were free of advanced knee osteoarthritis. A degenerative meniscus tear was verified on both MRI and knee arthroscopy. Patients with an obvious traumatic onset of symptoms or a recent history of a locked knee were excluded. Participants were followed up by questionnaires at 2, 6, 12, 24, 36, 48 and 60 months. At the 24-month and 60-month follow-up, standardised clinical examinations were carried out to all participants by an independent orthopaedic surgeon unaware of the treatment allocation. In the partial meniscectomy group, radiographic signs of knee OA signs were more common than in the placebo group.
The clinical challenge—managing degenerative meniscal tears
APM is the most common orthopaedic surgical procedure with well over half a million procedures performed annually in the USA and over one million in the UK between 1997 and 2017. APM for degenerative meniscus tears in early OA was thought to improve knee pain caused by the meniscus pathology and intended to increase function as well as quality of life. However, a series of rigorous trials, summarised in a recent clinical practice guideline2 linked with two systematic reviews,3 4 provide compelling evidence that APM leads to little short-term to medium-term benefit over sham surgery or non-surgical management for most patients suffering from degenerative knee disease. There are currently no data to suggest that a degenerative meniscus tear left untreated increases the risk of knee OA.
The evidence for change
To evaluate whether APM (resection of degenerative meniscus tears) per se accelerates or delays the development of knee osteoarthritis in patients with an arthroscopically-verified degenerative tear of the medial meniscus, Dr Sihvonen and his Finnish colleagues carried out a pre-registered long-term (5-year) follow-up of their 2013 placebo-surgery controlled FIDELITY trial.5 6 The second primary objective of FIDELITY was to assess the long-term efficacy of APM on knee symptoms and function.
In this BJSM paper,1 the authors suggest that APM is associated with increased risk of progression of knee OA by the Kellgren-Lawrence and Osteoarthritis Research Society International (OARSI) scales. The between-group difference was very small for both Kellgren-Lawrence (-2% to 28%) and OARSI (0.1 to 1.3) and not clinically significant. This is supported by the findings of no difference in clinical OA according to American College of Rheumatology criteria and subsequent need for ‘corrective’ surgery (high tibial osteotomy or total knee replacement) between groups. Also, there were no between-group differences in patient-reported outcomes. Therefore, we contend that Dr Sihvonen’s conclusion that arthroscopic partial meniscectomy is associated with a greater risk of osteoarthritis is too strong for the data presented. Radiographs to diagnose OA are notoriously difficult. Radiographic tibiofemoral OA has been almost twice as common using OARSI atlas criteria compared with the Kellgren-Lawrence system.7 This discrepancy is likely to contribute to the large variability of OA prevalence observed in the literature and is important for clinicians to consider when diagnosing radiographic OA.
Should orthopaedic surgeons change their practice of arthroscopic meniscectomy in this patient group?
High quality randomised controlled trials in patients with early OA patients (Kellgren-Lawrence 1 to 2) with degenerative meniscal tears show that exercise training, weight reduction and general physical activity are effective treatments. Knee surgeons agree with this too. This new 5-year follow-up by Sihvonen et al showing that APM does not provide long-term benefits and may be associated with an increase in Kellgren-Lawrence and OARSI scale values as well as in subsequent corrective surgery, adds valuable data to the field. Importantly, it should influence shared decision-making between doctors and patients—and this should lead to practice change.
The BJSM reader should keep in mind that this study relates to degenerative menisci in mild degenerative knees, not to arthroscopic partial meniscectomy or repair in young patients (aged <35 years) with traumatic meniscal tears. The conclusions reported here are specific to the study population. There are different types of meniscal tears; therefore, proper diagnosis and individualised treatment is important. Younger patients with traumatic onset of knee pain and clicking represent a different population.
Contributors Both have written and revised the editorial.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; internally peer reviewed.
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