The decision most patients face at the scan stage

A report lands in your inbox — or a radiologist's letter arrives via your GP — describing a meniscal tear. The next conversation, often brief, ends with a referral for an arthroscopy. For many patients, that sequence feels almost automatic. It shouldn't.

Arthroscopic partial meniscectomy (APM), in which the torn portion of the meniscus is trimmed away, remains one of the most frequently performed orthopaedic procedures in the UK. Yet over the past decade the clinical evidence has shifted markedly, and NICE guidance now actively discourages its routine use. The procedure may reduce pain in the short term, but it does so by removing tissue the joint depends on for load distribution — and the downstream consequences can unfold over years, not months.

For the majority of patients presenting after the age of 40 with a degenerative or incidental tear, the real choice is not between surgery and doing nothing. It is between surgery and a structured conservative programme that, in randomised trials, produces comparable functional outcomes. That distinction matters enormously, and it is rarely explained clearly at the scan stage.

This article addresses the decision where most patients actually encounter it: scan in hand, surgery on the table, and time to think it through properly.

What the MRI scan can — and can't — tell you

Scans are extraordinarily good at finding meniscal tears. Whether that finding explains a patient's pain is an entirely different question.

Studies using MRI in asymptomatic volunteers show that 35% of people over 50 have a tear — and roughly two-thirds of those individuals report no knee pain whatsoever. The tear is there; the symptom is not. At the other end of the spectrum, 75% of patients with symptomatic radiographic knee OA also show a meniscal tear on imaging. That near-universal co-occurrence creates a genuine diagnostic trap: when both OA and a meniscal tear are present, attributing the pain to the tear rather than to the underlying joint degeneration is often speculative. Framingham population data (Englund et al.) go further still, suggesting that meniscal damage may itself be a feature of OA progression — not a discrete, structurally correctable lesion sitting apart from the joint disease around it.

This matters because the question the scan answers ('is there a tear?') is not the question the clinician needs to answer ('is that tear causing this patient's pain?'). A report describing a tear is a finding; it is not a diagnosis.

Patients who experience clicking, catching, or a sense of the knee giving way often feel this settles the matter — that a mechanical symptom must point to a mechanical fix. The evidence does not support that inference. A 2021 systematic review of 38 studies found that these symptoms show only modest sensitivity (0.32–0.69) and specificity (0.45–0.74) for confirming the presence of a tear, and no consistent evidence that patients who have them achieve better outcomes after surgery than those who do not. The symptoms are real; they are simply not a reliable guide to whether removing meniscal tissue will resolve them.

Pain is real whether or not the tear is driving it. The clinical task — separating structural finding from symptom source — is what a thorough assessment is designed to do, and it cannot be replaced by the scan report alone.

How removing meniscal tissue affects the joint long-term

Removing meniscal tissue is not a neutral act. The meniscus distributes load across the knee and absorbs shock during movement; when a portion is resected, that protective function disappears and the articular cartilage — which is not designed to carry the redistributed load — begins to bear the difference.

The consequences have now been quantified at a population level. In the Osteoarthritis Initiative (OAI) imaging cohort, Roemer et al. (2016) tracked 355 knees and found that those which had undergone partial meniscectomy in the prior year had 2.51-fold odds of developing incident radiographic osteoarthritis within that follow-up period (95% CI 1.73–3.64). Among knees that did develop OA, the same surgery was associated with 4.51-fold odds of worsening cartilage damage (95% CI 1.53–13.33). Population-level data reinforce the pattern: around 17% of patients who undergo APM go on to develop symptomatic knee OA, compared with approximately 2.3% in the general population — roughly a sevenfold increase.

For younger patients and active athletes the stakes are higher still. Estimates suggest that 65–90% of those who undergo meniscectomy in earlier life will develop OA at some point, which is why tissue preservation — rather than resection — is now considered paramount in this group.

A common misconception is that if a tear 'won't heal on its own', it must be removed. The meniscus's anatomy makes this reasoning incomplete. Only the outer peripheral red zone — approximately one-fifth of the structure — has a blood supply; it is the only region where biological healing is realistic. The inner white zone is avascular and cannot regenerate regardless of treatment. But that does not mean it requires resection. For most white-zone tears, a structured rehabilitation programme can manage symptoms and restore function without sacrificing the cartilage protection the remaining tissue continues to provide.

What the trial evidence shows about surgery versus physiotherapy

Two randomised controlled trials published in the New England Journal of Medicine in 2013 changed the clinical calculus fundamentally.

The METEOR trial enrolled patients with symptomatic meniscal tears and mild-to-moderate knee osteoarthritis, comparing arthroscopic partial meniscectomy combined with physical therapy against physical therapy alone. At six months, both groups showed equivalent functional outcomes — APM offered no measurable advantage. A 30% crossover rate deserves a mention: roughly one in three patients initially assigned to the PT-only group eventually proceeded to surgery. This does not confirm that surgery was necessary for those individuals, but it is honest context — a meaningful minority will transition to surgical management even when conservative care is the appropriate starting point.

The FIDELITY trial went a step further. In 146 patients aged 35–65 with degenerative meniscal tears, APM was compared with sham surgery — a skin incision and saline irrigation under identical anaesthetic conditions, without any tissue removal. At 12 months, APM was not superior on any primary or secondary outcome measure. The sham group improved just as much. It is difficult to design a more rigorous test of whether the procedure itself is responsible for any benefit.

Together, these trials establish a clear evidence base: for the most common clinical presentation — a middle-aged or older patient with a degenerative or incidental tear and underlying OA — removing meniscal tissue offers no functional advantage over conservative management. NICE has drawn precisely this conclusion, recommending against routine arthroscopic procedures for degenerative meniscal pathology unless a true locked knee is documented.

When surgery remains the right call

None of this evidence argues against surgery in every case. A distinct, narrower group does benefit from prompt intervention — and failing to identify them carries consequences just as real as unnecessary resection.

The clearest indication is a true locked knee: a displaced meniscal fragment that physically prevents full extension or flexion. This is not pain-limited movement or morning stiffness. When a patient cannot straighten or fully bend the knee because something is mechanically caught inside the joint, conservative care cannot resolve the obstruction, and timely surgery is usually required.

Large bucket-handle tears producing verifiable mechanical locking — confirmed on examination and imaging rather than patient-reported clicking alone — may also warrant surgery when function cannot otherwise be restored. Objective loss of range of motion is the relevant threshold, not symptom pattern.

Peripheral red-zone tears in younger, active patients represent a third category, and here the question shifts from whether to operate to how. Repair, not resection, is strongly preferred wherever the vascularity of the outer zone makes biological healing feasible. Repair preserves the meniscal architecture and its protective, load-distributing function; resection removes it permanently. For a younger patient with a repairable peripheral tear, that distinction carries meaningful long-term consequences for joint health.

NICE captures this structural-versus-degenerative split in its guidance — and it is precisely why surgeons discussing 'surgery for a meniscal tear' may mean very different procedures depending on the clinical picture in front of them.

What a conservative pathway looks like in practice

Conservative management, properly applied, is not rest and analgesia while hoping the joint settles. The supervised physiotherapy programmes used in both the METEOR and FIDELITY trials involved structured neuromuscular rehabilitation — targeted loading of the quadriceps and hip stabilisers, movement-quality work, and progressive reintroduction of demand on the knee. The aim is not simply short-term pain relief but restoring the joint's load-sharing capacity in a way that protects the remaining meniscal tissue.

A guided programme typically involves regular supervised sessions alongside a home exercise component, with meaningful symptom improvement expected within six to twelve weeks. Progress is measured by function — walking distance, stair tolerance, response to graduated loading — rather than imaging. The tear visible on the MRI does not need to disappear for the joint to tolerate normal demand again.

Injection therapy can play a supporting role in some presentations. A corticosteroid injection is sometimes considered when acute inflammation is limiting engagement with rehabilitation — reducing symptoms enough to allow the exercise programme to begin. Biologic options such as PRP feature in broader joint-preservation planning for some patients, particularly where cartilage health is also a concern alongside the tear. Both are adjuncts to rehabilitation, not substitutes for it; the full discussion of when and whether they apply sits outside this article.

Reassessment by a specialist is appropriate if symptoms are not improving meaningfully after eight to twelve weeks of a genuine supervised programme, if range of motion is restricted or worsening, or if examination suggests a structural pattern — such as true mechanical locking — that was not apparent at the outset. A joint-preservation specialist can then review whether the clinical picture has shifted and, if surgery becomes appropriate, ensure the pathway chosen preserves as much tissue as possible. The team at London Cartilage Clinic on Harley Street offers exactly this kind of structured reassessment for patients who have followed a conservative pathway and remain uncertain about next steps.