Clinical synthesis based on the most recent meta-analyses, randomised trials and international consensus statements: FIDELITY, ESCAPE, METEOR, ESSKA-AOSSM-AASPT 2024.

Degenerative meniscal lesions (DML), sometimes called degenerative meniscopathies, refer to a progressive structural failure of the meniscal tissue linked to ageing and cumulative mechanical load, as opposed to the acute traumatic tears of young people.¹ It is less a "tear" in the classic sense than a "disease of the meniscal organ" as a whole, involving changes in biological composition (loss of proteoglycans), disorganisation of the collagen fibres and a reduction in the biomechanical shock-absorbing properties.¹,² 🩻

How is this condition defined, who does it affect and what are the risk factors?

The operational definition of DML rests on three features: insidious onset (no identifiable traumatic event), age ≥ 40 years, and a degenerative MRI appearance (horizontal tear, complex lesion, grade 3 intrameniscal signal according to Stoller, possible extrusion).² It stands in categorical contrast to the vertical longitudinal traumatic tears of young athletes.

The prevalence is massive and rises steeply with age. In the Framingham cohort (Englund 2008 NEJM, n = 991 subjects aged 50 to 90), the prevalence of a meniscal tear or meniscal destruction visible on MRI ranges from 19 % in women aged 50-59 to 56 % in men aged 70-90 (51 % in women aged 70-90), with a continuous gradient with age.³ The Guermazi 2012 meta-analysis (BMJ, Framingham OA Study, n = 710 adults aged 50+ with no radiographic sign of osteoarthritis) confirms that most middle-aged and older adults' knees show structural lesions on MRI, regardless of pain.⁴

The Snoeker 2013 systematic review (JOSPT, meta-analysis of 22 studies, n > 14,000) identifies the main risk factors for the occurrence of a meniscal tear:⁵

• Older age : the most powerful and consistent factor. The risk roughly doubles every 10 years between the ages of 40 and 70.⁵
• Male sex : OR ≈ 1.5-2 across all forms, linked to occupational mechanical exposure.⁵
• High body mass index : overweight and obesity significantly increase the risk (OR ≈ 1.3-1.8 per 5 kg/m² increment).⁵
• Occupational activities involving squatting, prolonged kneeling, carrying heavy loads: builders, miners, farmers, pavers.⁵
• Concomitant tibiofemoral osteoarthritis : DML and osteoarthritis share common mechanisms and coexist in most symptomatic cases after the age of 50.⁶
• History of old trauma (sprain, ACL rupture): significant acceleration of the degenerative process at 5-10 years.

What happens in the body, and how do DMLs evolve naturally?

The pathophysiology involves a progressive biomechanical and biological cascade. The meniscus, a fibrocartilaginous organ that is essentially avascular in its inner zone (white zone), depends on the quality of its extracellular matrix: a network of type I collagen, proteoglycans, water (75 %). With age, the loss of proteoglycans reduces hydration and elasticity, increasing vulnerability to shear stresses.¹,²

A key biomechanical event is meniscal extrusion, defined as displacement of the meniscal body beyond the tibial margin. Extrusion > 3 mm is considered pathological and is strongly associated with progression of knee osteoarthritis : loss of tibiofemoral cartilage, increased joint space narrowing, deterioration in the KOOS.⁷ Extrusion reflects a loss of shock-absorbing function and directly increases the stresses on the hyaline cartilage.

The natural history is, however, considerably more benign than clinical intuition would suggest. Several longitudinal studies converge:

• The Framingham cohort (Englund 2008) documented that 61 % of subjects with a meniscal tear on MRI had had no pain, stiffness or discomfort in the previous month, and only 32 % reported meniscal symptoms after adjustment for osteoarthritis.³
• The 2-year follow-up of the ESCAPE patients (van de Graaf 2018, JAMA) shows that most degenerative tears remain radiologically stable and that symptoms evolve independently of MRI changes.⁸
• Fluctuations are the rule: many periods of spontaneous remission, transient flare-ups linked to specific stresses, with no linear trend towards worsening for most middle-aged patients.

The clinical corollary is essential: in most cases, DML should be understood as one of the manifestations of the global osteoarthritic process of the knee, rather than as an isolated entity warranting a specific structural treatment.

The diagnosis of DML rests above all on a structured clinical approach, not on an isolated imaging investigation. Diagnostic certainty emerges from the convergence between the history, a targeted physical examination and a clear understanding of the differential diagnoses, particularly in the very common context of concomitant tibiofemoral osteoarthritis.¹,²

Which questions should you ask to understand the patient and their history?

History-taking is the cornerstone of the diagnostic process in a patient with suspected DML. Attentive listening and targeted questions make it possible to build a solid clinical hypothesis, often more discriminating than isolated special tests.¹ 🧐

• Description of the pain : precise location (medial or lateral joint line, typically posteromedial), type (dull / sharp / mechanical), intensity (numerical scale 0-10), pattern (onset after exertion, persistence at rest, at night). Pain at night or at rest points towards an inflammatory component (advanced osteoarthritis, synovitis).
• Aggravating factors : getting up from a low chair, pivoting under load, going up/down stairs, squatting, carrying loads. The absence of a clear initial trauma is the main distinguishing feature compared with a traumatic lesion.
• Mechanical symptoms : the presence of true locking (inability to fully extend the knee without a specific manoeuvre) is highly suggestive but rare in the degenerative context. Sensations of pseudo-locking, catching and giving way are more frequent and less specific.³
• Swelling (effusion) : typically intermittent, occurring 12-24 h after an activity, partly resolving with rest. A major or persistent effusion should prompt reconsideration of the diagnosis (inflammatory flare of osteoarthritis, infection, occult fracture).
• History and context : age ≥ 40-45 years, occupational profile (squatting, carrying loads), level of sporting activity, old traumatic history (ACL rupture, severe sprain), history of osteoarthritis, BMI, alignment (varus/valgus).⁴
• Yellow flags : fear of movement, catastrophising, belief in a "serious lesion that needs an operation", expectations regarding imaging.

Which clinical tests should be performed, and which other conditions must be ruled out?

The physical examination aims to reproduce the symptoms and to rule out other causes of pain. The diagnostic accuracy of special tests in the DML population is moderate to low ; no single test is enough to confirm or rule out the diagnosis.¹

• Palpation of the joint line : the most sensitive test (pooled sensitivity ≈ 76-83 % according to Hegedus 2007 SR). Reproducible pain on palpation of the medial or lateral joint line is found in the great majority of symptomatic patients. But its specificity is low (≈ 29-42 %), because the pain may come from osteoarthritis, pes anserinus tendinopathy or the iliotibial tract.
• McMurray test : sensitivity 24-71 %, specificity 60-95 %, highly variable depending on the examiner and the version of the test. The "felt" McMurray (palpation + flexion-rotation) performs better than the "audible" McMurray (click only). Pooled LR+ ≈ 1.3-3.0, insufficient to confirm the diagnosis on its own.
• Thessaly test (5° and 20° weight-bearing): initially described with sensitivity > 90 % by Karachalios 2005, but later replications in real DML populations found much more modest performance (sensitivity ≈ 64 %, specificity ≈ 53 %). Its value remains debatable in routine practice.
• Apley compression test : sensitivity ≈ 60 %, specificity ≈ 70 %, overall intermediate performance.
• Combination of tests : recommended practice is to combine a typical history + joint line palpation + one or two dynamic tests. The combination outperforms any single test and significantly increases the post-test probability if all agree.

Critical differential diagnoses to rule out: ⚠️

• Tibiofemoral osteoarthritis : differential diagnosis no. 1. More diffuse pain, morning stiffness absent or brief (≤ 30 min), reduced range of motion, crepitus; morning stiffness > 30 min, on the contrary, points towards inflammatory rheumatic disease and should lead to referral to a doctor (NICE NG226, 2022). Very often coexists with DML: both often contribute to the symptoms at the same time.⁵
• Meniscal root lesion (root tear) : a distinct entity with a strong prognostic impact. Acute posterior pain, a "popping" sensation, massive extrusion on MRI, accelerated osteoarthritis. Covered in chapter 5.
• Spontaneous osteonecrosis of the knee (SONK, Ahlback disease) : intense, acute night pain over the medial femoral condyle, often without trauma, peak incidence at 60+ years. MRI shows characteristic bone oedema.
• Tendinopathies : pes anserinus (pain on the medial tibial surface 5-7 cm below the joint line), iliotibial band (lateral aspect, cyclical pain), quadriceps or patellar tendon (anterior pain).
• Vascular conditions : popliteal artery entrapment syndrome in young adult athletes (exertional claudication, calf pain).
• Neurological conditions : L3-L4 radiculopathy can produce referred pain to the anterior or medial aspect of the knee, without major low back pain.
• Patellofemoral pain syndrome : anterior pain made worse by prolonged sitting and going down stairs, but it may radiate.
• Infrapatellar / prepatellar bursitis : localised pain, focal swelling, inflammatory signs.

Should patients with DML be classified, and with what benefits?

The clinical stratification of patients with DML is increasingly recommended, not to apply a rigid label but to guide shared treatment decision-making.⁶ The aim is to distinguish the patients who will benefit most from a conservative approach from those for whom a surgical discussion might be relevant (a minority subgroup).

1. Mechanical profile (narrow subgroup):
   • Marked mechanical symptoms: frequent pseudo-locking, reproducible giving way, precise painful clicks;
   • Pain well localised to the joint line;
   • Clear intermittent effusion after certain activities;
   • Examination reliably reproduces the symptom;
   • Few or no signs of advanced osteoarthritis;
   • => Possible response to well-conducted PT; if it fails at 3-6 months, a surgical discussion may be considered.
2. Osteoarthritic profile (the majority):
   • Diffuse pain, morning stiffness, widespread bone tenderness;
   • Crepitus, reduced range of motion;
   • Radiographic signs of osteoarthritis (Kellgren-Lawrence ≥ 2);
   • Metabolic comorbidities (obesity, diabetes);
   • => DML = epiphenomenon ; management targets the osteoarthritis as a whole (weight, strength, education) and not the isolated meniscal lesion.

Main benefit: avoiding unnecessary surgery. Multiple randomised trials and meta-analyses converge: arthroscopic partial meniscectomy (APM) provides no clinically meaningful benefit over physiotherapy for the great majority of patients with DML, particularly when osteoarthritis is present.⁷,⁸ Classification helps to identify this majority, who should be directed towards PT, and to reserve the surgical discussion for a small selected subgroup.⁹

Critique and controversy: the tyranny of MRI

The major controversy in the diagnosis of DML lies in the frequent discordance between imaging findings and clinical presentation. The advent of MRI has led to a "tyranny of the image": the presence of a meniscal tear is automatically equated with the source of pain, triggering a cascade of interventions.

Yet the epidemiological data are unequivocal: 61 % of subjects with a meniscal tear on MRI had had no pain in the previous month (Englund 2008 NEJM).³ The Guermazi 2012 study (BMJ, Framingham) shows that most knees of adults ≥ 50 years show abnormalities on MRI regardless of symptoms.⁴ The real diagnostic challenge is not "finding the tear" but determining whether it is clinically relevant.

The modern consensus therefore argues for a clinical diagnosis first and foremost, resorting to MRI only in very selected cases: failure of well-conducted PT at 3 months, suspicion of another condition (root tear, SONK, osteochondritis, ligament injury), preoperative planning in a patient selected for surgical discussion.

The management of DML has undergone a major paradigm shift over the last decade. High-level evidence now consistently supports physiotherapy, centred on supervised exercise and therapeutic patient education, as the first line of treatment for the great majority of patients.¹,²,³ 🩺

Where do you start? What is the recommended hierarchy of interventions?

The hierarchy is clear and is the subject of a growing international consensus. The first-line intervention is a structured conservative treatment programme lasting 3 to 6 months before any surgical discussion.⁴,⁵

In the TeMPO trial (879 patients aged 45 to 85 with knee osteoarthritis and a meniscal lesion), adding in-clinic physiotherapy sessions to a home exercise programme did not reduce pain any further at 3 months (KOOS pain: 2.5 points; 98.3 % CI −1.3 to 6.2), below the threshold of clinical relevance; a sham session gave the same result, and encouraging text messages made no difference. At 6 months, a secondary analysis found a small advantage for the sessions (4.1 points), which had disappeared by 12 months. This trial does not tell us what exercise brings in itself: all the groups were doing it.¹⁶

• FIDELITY 2013 (Sihvonen R et al. NEJM, n = 146, Finland): APM vs sham surgery. No significant difference at 12 months in pain or function (WOMAC).⁶
• FIDELITY 5 years (Sihvonen R et al. BJSM 2020): confirmed at 5 years: no benefit of APM over sham surgery. The world's first study to test APM against sham surgery over 5 years.⁷
• METEOR 2013 (Katz JN et al. NEJM, n = 351, USA): APM + PT vs PT alone in DML + osteoarthritis. WOMAC difference at 6 months = 2.4 points (not clinically significant). 30 % crossover from the PT group to surgery at 12 months.⁸
• Kise 2016 (BMJ, n = 140, Norway): Supervised exercise for 12 weeks vs APM. No KOOS difference at 2 years. The exercise group had significantly greater quadriceps strength at 3 and 12 months.⁹
• ESCAPE 2018 (van de Graaf VA et al. JAMA, n = 321, Netherlands): PT 16 sessions vs early APM. Difference in IKDC at 24 months = 3.6 points (below the clinically relevant threshold of 8). 29 % crossover from PT to surgery.¹
• ESCAPE 5 years (Noorduyn JCA et al. JAMA Netw Open 2022): confirmed at 5 years: non-inferiority of PT vs APM maintained, with no clinically significant difference.⁵

The Thorlund 2015 meta-analysis (BMJ, 9 RCTs, n = 1,870 patients) concludes that surgery has a very limited benefit on pain (small, transient effect, with no difference at 1 year and beyond), at the cost of real harms (venous thromboembolism, infection, death 0-0.07 %).³ The BMJ Rapid Recommendations 2017 guideline (Siemieniuk RAC et al., international panel) issues a strong recommendation against arthroscopy for almost all DMLs.⁶

Surgery should only be considered in the event of proven failure of well-conducted PT, characterised by the persistence of disabling mechanical symptoms (true, real and repeated locking) AND the absence of functional improvement after 3-6 months of satisfactory adherence to the programme.⁸,¹³

What is the place of exercise, and is there a superior approach?

Therapeutic exercise is the cornerstone of conservative treatment. Its aim is not to "heal" the meniscus (impossible) but to improve the overall functional capacity of the knee, reduce the load on sensitised structures, modulate pain and restore confidence.

Recommended components (ESSKA-AOSSM-AASPT 2024 consensus Part II, Prill 2025 KSSTA):⁷

• Progressive muscle strengthening : focus on the quadriceps (seated knee extension, leg press, partial squat), hamstrings (curl, modified deadlift), glutes (bridge, monster walk, hip thrust), calves. Progressive intensity following the principle of graded overload.
• Neuromuscular control : proprioceptive exercises (double-leg/single-leg stance on a stable then unstable surface), dynamic control (step-down, single-leg squat with valgus control), progressive agility.
• Range of motion : full extension as a priority (an extension deficit perpetuates pain), progressive flexion.
• Low-impact aerobic activity : cycling (patella, but often well tolerated), swimming, walking, elliptical trainer. Encourage the maintenance of general physical activity.
• Education + home exercises : essential for long-term adherence.

To date, no specific exercise modality has shown clear superiority over another.⁸ Success rests on individualisation, graded progression, respect for the principle of "acceptable pain" (≤ 3-4/10 during and after exercise), and adherence.

Standardised programmes :

• OMEX (Stensrud 2012) : 12 weeks, 2-3 sessions/week, the basis used in Kise 2016.
• GLA:D (Good Life with osteoArthritis in Denmark) : a structured 6-8 week programme, education + neuromuscular exercise, rolled out in dozens of countries. Skou & Roos 2017 BMC Musculoskelet Disord demonstrated robust results at 1 year in 9,825 patients with osteoarthritis/DML.
• ESCAPE-knee-pain programmes : a group approach combining exercise + education + self-management.

Manual therapies, technologies: how effective are they really?

Passive approaches can be used as short-term adjuncts to facilitate engagement in the active programme, but must never form the core of treatment.

• Manual therapy (patellofemoral/tibiofemoral joint mobilisations, soft tissue techniques, mobilisation with movement): short-term effect on pain and range of motion. Limited evidence as a stand-alone treatment (Pollard 2018 review and Pollard meta-analysis).⁸
• TENS, ultrasound, shockwave : no high-quality evidence specific to DML. Possible symptomatic relief for some patients, but they do not change the course.
• Intra-articular injections : corticosteroids, short effect (weeks); hyaluronic acid, limited benefit; PRP, data still heterogeneous and of low quality. Case-by-case discussion, without routine use.
• Thermal modalities (cryotherapy, heat): symptomatically useful, with no impact on the natural history.

The main place of these modalities is to modulate the initial pain enough to allow active exercise, the true driver of change, to get under way.

Beyond the physical: how to educate the patient and act on psychological factors?

Therapeutic patient education (TPE) is probably the most powerful and most under-used lever. The patient's beliefs and emotions have a considerable impact on outcomes, often greater than structural indicators.⁹ 🧠

1. Take the drama out of the imaging report : explain in simple terms that degenerative lesions are to the knees what grey hair is to hair, a sign of ageing, present in most people of the same age, and most often asymptomatic. Quote the figures: the prevalence of DML on MRI ranges from 19 % in women aged 50-59 to 56 % in men aged 70-90, and 61 % of these lesions are painless (Englund 2008).
2. Explain pain : pain = a multifactorial protective experience, not a direct signal of damage. Modern concepts (pain neuroscience education, Louw et al.): fear of movement (kinesiophobia) maintains and amplifies pain.
3. Promote self-efficacy : give the patient the tools and the confidence to manage their symptoms. Concrete, progressive functional goals (climbing a flight of stairs without holding on, walking 30 minutes without pain, resuming Nordic walking 2x/week).
4. Avoid nocebo language : ban "your meniscus is torn / worn / damaged"; prefer "you have age-related changes in your meniscus, which are common and generally well tolerated with a good exercise programme".

Psychological factors (catastrophising, anxiety, depression) are more powerful predictors of pain and disability than MRI images.⁹ Identifying them and, where appropriate, referring the patient for specialist support is an integral part of management.

Critique and controversy: persistent overuse of surgery

Despite the accumulating evidence, APM remains one of the most frequently performed orthopaedic procedures in the world. Several factors perpetuate this gap between science and practice:

• The tyranny of MRI : the presence of a "tear" on the report creates a strong incentive towards surgery, both for the patient (anxiety) and for the surgeon (reparative logic). Yet in most cases this abnormality is an incidental finding.¹⁰
• Patient expectations : belief in a surgical "quick fix" remains very widespread. A 12-week exercise programme will seem less "tangible" than an operation.
• Heterogeneity of physiotherapy : "physiotherapy" can mean a high-quality structured active programme or an outdated passive treatment. The APM vs PT trials test highly standardised and supervised programmes; transposing these results to unstructured PT is risky.
• Economic factors : in many systems, surgery is better paid than long rehabilitation, creating an incentive bias.
• Placebo effect of surgery : FIDELITY showed that sham surgery produces the same results as real APM, suggesting that the perceived benefit comes from the symbolic intervention, post-operative rest and the rehabilitation that follows, NOT from the technical procedure on the meniscus.⁶,⁷

The real clinical challenge is therefore to effectively translate the science into routine practice, by educating patients and professionals about the primacy of the active conservative approach.

The durability of results after DML depends less on "repairing" the meniscal tissue (impossible in the average adult) than on optimising the overall function of the knee and on the patient's ability to manage their condition over the long term.¹,²

How to make the patient an active participant in their recovery through self-management?

Patient empowerment is crucial for preventing symptomatic recurrences. It turns a passive recipient of care into an active manager of their own joint health. It rests on two inseparable pillars: education + a structured, evolving exercise programme. 🧠

• Explain that DML is an integral part of the normal ageing of the knee, that it is very common and very often asymptomatic (Englund 2008 NEJM: 61 % of subjects with DML on MRI had no pain).³
• Shift attention from anatomical structure to function and capacity : what the knee can do matters more than what the MRI shows.
• A simple understanding of pain mechanisms (pain is protective, modifiable, not synonymous with damage), reduction of kinesiophobia.⁴
• Non-nocebo communication: prefer "you have age-related changes, well tolerated with the right programme" rather than "your meniscus is torn".

High-quality randomised trials have shown that a 12-week programme combined with education produces improvements in pain and function that are at least equivalent, or even superior, to APM in the short, medium and long term (up to 5 years, ESCAPE/Noorduyn 2022; FIDELITY/Sihvonen 2020).¹,⁵,⁶

• Progressive neuromuscular strengthening : quadriceps, hamstrings, glutes, trunk, calves. Fundamental for improving shock absorption and dynamic control of the knee (Bartholdy 2017 review).⁷
• Load management : the concept of "acceptable pain" (≤ 3/10 on the VAS during and after exercise) as a progression tool that does not trigger a flare-up.⁸ It allows exercise in the presence of tolerable pain, demystifying the fear of "doing damage".
• Long-term adherence : continuing the exercises beyond the supervised phase. Patients who build in a routine of 2-3 strengthening sessions per week have the best results at 1-5 years.⁹
• Self-monitoring : exercise diary, VAS pain, walking distance, sensations during exercise. Helps to identify a flare-up quickly and to adjust the load.
• Return to valued activities : walking, hiking, cycling, gardening, moderate-impact sports. A sedentary lifestyle is the main enemy in the medium term.

When and how to plan a safe return to sport and activities?

Return to sport (RTS) or to meaningful activities after DML should not be dictated by a fixed calendar, but by the achievement of objective functional criteria. A criteria-based approach minimises the risk of symptomatic recurrence and ensures that the knee tolerates the specific demands.¹⁰ 🏃

Key criteria for clearing a safe return (transposed from the ACL literature/ESSKA-AOSSM-AASPT 2024 Consensus Part II):¹¹

1. Basic clinical criteria:
   • Pain almost nil or absent during activities of daily living (VAS ≤ 1-2/10);
   • No significant joint effusion ("zero rule" of the stroke test);
   • Full, symmetrical range of motion (passive extension in particular);
   • Subjective confidence in the knee.
2. Strength criteria (Limb Symmetry Index, LSI):
   • Isokinetic or isometric quadriceps strength ≥ 90 % of the healthy side ;
   • Hamstring strength ≥ 90 % of the healthy side;
   • H/Q ratio ≥ 0.6 (asymmetry avoided).
3. Functional performance criteria (hop tests):
   • Single leg hop for distance ≥ 90 % LSI;
   • Triple hop for distance ≥ 90 % LSI;
   • Crossover hop ≥ 90 % LSI;
   • Y-balance test ≥ 90 % LSI.
4. Psychological criteria:
   • Score on the TSK (Tampa Scale of Kinesiophobia) < 37;
   • Score on the ACL-RSI (Return to Sport after Injury) or equivalent ≥ 65;
   • No reported "residual kinesiophobia".
5. Successful sport-specific test:
   • Key movement reproducible (pivoting, squatting, technical descent) without apprehension;
   • Sufficient endurance for the duration of a training session.

General progression: the rule of thumb "+10 % per week maximum" for the volume or intensity of the load allows progressive tissue adaptation without sudden overload (Gabbett's training-injury prevention paradox concept).¹² Constant dialogue with the patient about sensations and monitoring of the knee's response (post-exercise pain, swelling) are imperative.

Special case: after APM (rare and selective): rehabilitation after partial meniscectomy does not usually require immobilisation. Gradual resumption of walking, early exercises (D1-D2), progression similar to the conservative framework from W2-W3. RTS guided by functional criteria (Pujol 2025 KSSTA Part I).¹¹

Critique and controversy: grey areas in RTS criteria

Although functional criteria are recommended, several limitations deserve reflection:

1. DML vs ACL transposition : almost all the detailed criteria come from the ACL literature. Their specific validity for DML is extrapolated and has been little validated by prospective studies.
2. Vague definition of PT failure : "failure of well-conducted PT" remains subjective (adherence, intensity, psychosocial management). This subjectivity can lead to premature surgical referrals.
3. Feasibility of the tests : hop tests and isokinetic testing require equipment and time. In routine practice, many physiotherapists do not have access to these tools, leading to sub-optimal RTS decisions.
4. Uncertain mechanism of action : the benefits of exercise are attributed to strength gains and neuromuscular control, but other mechanisms could be involved (central effects, local anti-inflammatory effects, self-efficacy).

DML does not exist in a vacuum. Two clinical situations call for a differentiated approach: coexistence with advanced knee osteoarthritis (the most common situation after the age of 60) and meniscal root lesions (root tears, a distinct entity with a high prognostic impact). Neglecting these specific features leads to sub-optimal treatment decisions. 🦵

DML + osteoarthritis: what overall management?

Epidemiological finding : DML coexists with radiographic knee osteoarthritis in most symptomatic middle-aged and older patients. The OAI (Osteoarthritis Initiative) and the Framingham cohort show that more than 80 % of patients with Kellgren-Lawrence (KL) ≥ 2 knee osteoarthritis have concomitant meniscal involvement on MRI, and that DML is a predictor of osteoarthritis progression.¹,²

Major clinical implication : in patients with moderate to severe osteoarthritis (KL ≥ 3, joint space narrowing, osteophytosis), treating the meniscal lesion in isolation with surgery provides no demonstrated benefit. The METEOR trial (Katz 2013), conducted in patients with mild to moderate osteoarthritis, finds no added benefit of APM over PT alone at 6 months or in the long term.⁴

That said, a harmful effect of meniscectomy on osteoarthritis has not been established: at 10 years, the OMEX trial (140 patients with no or minimal osteoarthritis) found no significant difference in radiographic progression (incident osteoarthritis 23 % versus 20 %, wide interval),¹² and the 5-year MRI follow-up of FIDELITY shows a significant difference only for osteophytes, which were more frequent after meniscectomy.¹³ These trials did not include advanced knee osteoarthritis and do not make it possible to rule out a risk.

Recommended management in the context of DML + osteoarthritis (consolidated data from the OARSI 2019 guideline + ESSKA-AOSSM-AASPT 2024 Part II):⁵

• Weight management : a weight loss of 5-10 % of initial body weight significantly reduces pain (Hall 2018 review, GLA:D programme). A 1 kg reduction = 4 kg less load per knee when walking.
• Structured therapeutic exercise : a programme combining strengthening (quadriceps first), low-impact aerobic exercise (cycling, swimming, pool walking) and functional exercises. An effect equivalent or even superior to NSAIDs for pain at 3-6 months.
• Osteoarthritis education : structured programmes such as GLA:D, Good Life with Arthritis, ESCAPE-knee-pain (combining exercise + education + self-management).⁶
• Activity modification : ergonomic advice (avoid prolonged squatting), assistive devices (contralateral cane, varus unloader brace, insoles), changes to sporting practice (Nordic walking instead of running).
• Targeted analgesia : paracetamol, limited but useful in the acute phase, topical NSAIDs (1^st line), oral NSAIDs in short courses if needed, selective corticosteroid injections (effect 4-12 weeks).
• Osteoarthritis-specific red flags : severe inflammatory flare (suspected crystal arthropathy, to be investigated), progressive fixed loss of extension, rapid deformity (suspected necrosis, subchondral fracture).

When should total knee replacement be discussed? After failure of several months of optimised conservative management, with disabling daily pain, KL ≥ 3-4, and a major impact on quality of life and independence. The discussion is shared with the orthopaedic surgeon and the patient, taking into account expectations, age, comorbidities and activity level.

Meniscal root lesion (root tear): a distinct, high-risk entity

A meniscal root lesion (meniscal root tear) is a clinical entity distinct from classic DML, with a major biomechanical and prognostic impact. The meniscal root is the posterosuperior bony attachment of the meniscus to the tibial plateau; a complete rupture is functionally equivalent to a total meniscectomy, with loss of shock-absorbing function, massive meniscal extrusion and accelerated osteoarthritis.⁷ ⚠️

• Population : mainly women aged 50-65 (medial root); varus, BMI > 30, an initial squat (minor event often reported: getting up from a low chair, squatting, the first step in the morning).
• Symptoms : acute posteromedial pain (medial root), a perceptible "pop", a sensation of the knee "giving way". Waking at night is possible.
• MRI : meniscal extrusion > 3 mm (often ≥ 5 mm), loss of the posteromedial radial signal, ipsilateral subchondral bone oedema, root tear seen as low T2 signal.
• Natural prognosis : accelerated osteoarthritic progression without specific treatment. KL progression of +1-2 grades within 2-5 years in several series.⁸

Morphological risk factors (Oeding 2025 systematic review, Arthroscopy):⁹

• Steeper medial tibial plateau slope;
• More marked varus alignment;
• Reduced intercondylar distance;
• Reduced intercondylar notch width.

The systematic review by Lee/Krych 2025 (Arthroscopy, PMID 38401664) compares the three options in selected patients (KL ≤ 2, confirmed root tear):¹⁰

• Root repair (transosseous refixation): better radiological outcomes (reduced extrusion), better clinical outcomes (KOOS, IKDC) and fewer conversions to arthroplasty in the medium term;
• APM (partial meniscectomy) : intermediate results, functionally acceptable in the short term but accelerated osteoarthritis in the long term;
• Non-operative treatment : pain initially controlled but significant conversion to arthroplasty at 5-10 years (up to 35-50 % depending on the series).

Selective indication for root repair :

• Active patient < 65-70 years;
• KL ≤ 2 (little or no advanced tibiofemoral osteoarthritis);
• Acceptable alignment (varus ≤ 5°) or simultaneous correction possible (high tibial osteotomy);
• Recent symptoms with a root tear identified on MRI;
• Patient willing to follow a demanding post-operative rehabilitation protocol (6-8 weeks of partial weight-bearing, 4-6 months to RTS).

For patients with KL ≥ 3, age > 65 years, or severe varus alignment, the benefit/risk balance is more complex and requires specialist discussion. Physiotherapy remains the first step to assess the symptomatic and functional course before a surgical decision.

The analysis of clinical cases from the scientific literature is essential to translate the data from randomised trials into daily practice. It makes it possible to understand typical presentations, diagnostic traps and the treatment strategies suited to specific profiles. 👨‍⚕️

Analysis of a classic case: from assessment to resolution

Typical profile (synthesis of the Kise 2016 and ESCAPE van de Graaf 2018 trials):

• Patient : a woman or man aged 50-60, BMI 26-30, office or semi-active job, moderate level of physical activity (regular walking, occasional cycling).
• Complaint : pain on the medial aspect of the right knee, which appeared 4-6 months ago without any identifiable traumatic event, initially triggered when going down stairs, then gradually troublesome during prolonged walking (> 30 min) and when squatting.
• Clinical examination : pain localised on palpation of the medial joint line, equivocal McMurray (painless click), medial Thessaly positive at 5°, range of motion preserved (full extension, flexion 130°), no notable effusion, quadriceps strength 75 % of the healthy side.
• No red flags ; no true mechanical locking.

Diagnostic decision : clinical suspicion of DML, without resorting to MRI as a first-line investigation (high probability of irrelevant incidental findings according to Englund 2008, Guermazi 2012).¹,²

Management (Kise 2016 model, OMEX programme):³

• Supervised programme of 12 weeks, 2 sessions of 60 min/week with the physiotherapist;
• Progressive strengthening: quadriceps, hamstrings, glutes, calves, trunk ;
• Neuromuscular control: proprioceptive exercises on two legs then on one, dynamic control of the knee in step-down/step-up;
• Functional exercises: partial squat, progressive lunge, stair climbing/descending technique;
• Education: understanding of the condition, taking the drama out, encouragement to stay active;
• Home programme: 3 sessions/week of 30 min between the supervised sessions.

Expected course :

• W2-W4: progressive reduction in pain (VAS 6/10 then 4/10);
• W6-W8: functional improvement (stairs easier, prolonged walking better tolerated);
• W10-W12: KOOS pain +20 points on average, function +15 points;
• 3-6 months: home exercises continued 2-3x/week, return to Nordic walking, moderate hikes;
• 2-5 years: benefits maintained if adherent (confirmed by ESCAPE 5y, Noorduyn 2022; FIDELITY 5y, Sihvonen 2020).⁴,⁵

This profile represents the great majority of DMLs seen in community practice. A favourable course is the rule, with no need for imaging or surgery.

The diagnostic challenge: when DML mimics another condition

The high prevalence of asymptomatic DML (61 % in subjects with a tear on MRI, Englund 2008)¹ creates a major risk of causal attribution bias : genuine pain of another origin is attributed to a DML visible on MRI, delaying the correct diagnosis.

• Spontaneous osteonecrosis of the knee (SONK) : woman > 60 years, intense acute pain of the medial femoral condyle, often at night, without trauma. MRI is crucial: characteristic bone oedema. The pain may mimic an acute posteromedial DML.
• L3-L4 radiculopathy : nerve compression at the level of the lumbar spine that can cause referred pain to the anterior or medial aspect of the knee, without major low back pain. A targeted neurological examination (patellar reflexes, L3-L4 sensation) should be systematic in the absence of a clear local sign.
• Anserine bursitis : pain on the medial tibial surface 4-6 cm below the joint line, local tenderness at the insertion of the pes anserinus tendons. Common in women > 50 years with osteoarthritis, often mistaken for a medial DML.
• Iliotibial tract tendinopathy at Gerdy's tubercle: lateral pain on repeated flexion, sometimes mistaken for a lateral DML.
• Acute meniscal root lesion (see chapter 5): woman aged 50-65, audible pop, acute posterior pain => a distinct high-risk entity, prompt MRI.
• Pigmented villonodular synovitis (PVNS): rare but to be considered in cases of unexplained recurrent effusion.

Study of a complex case: DML + osteoarthritis + comorbidities

Profile (case-based synthesis, OAI/Framingham cohort + OARSI 2019 recommendations):⁶

• Patient : a 64-year-old woman, BMI 32, treated hypertension, type 2 diabetes (HbA1c 7.2 %), history of right knee sprain at the age of 25;
• Complaint : right knee pain for 8 months, initially intermittent, now almost constant. Waking at night when changing position, morning stiffness 25 min;
• Examination : moderate varus of the right lower limb (8°), quadriceps circumference -2 cm vs the healthy side, diffuse pain on periarticular palpation, poorly reproducible McMurray, crepitus in flexion-extension, 10° loss of extension (fixed deficit), moderate effusion;
• Weight-bearing radiographs : medial tibiofemoral joint space narrowing ≥ 50 %, osteophytosis, KL grade 3;
• MRI : complex DML of the medial posterior horn + 4 mm extrusion + focal cartilage loss in the medial compartment + condylar osteophytes.

Decision and management :

• The main clinical diagnosis is KL 3 medial femorotibial knee osteoarthritis in varus, with an associated DML which is an epiphenomenon of the global osteoarthritic process;
• APM would not be recommended here (METEOR Katz 2013: no benefit; Roemer 2017, case-control study nested in a cohort: more incident osteoarthritis after partial meniscectomy, a signal that the OMEX and FIDELITY trials did not confirm in patients without advanced osteoarthritis).⁷
• Global treatment plan:
  • Education : explanation of the condition as a multifactorial process, MRI myths dispelled;
  • Weight management : target loss of 7-10 % of initial body weight over 6-12 months (nutritional advice, referral to a structured programme);
  • Supervised 12-week exercise programme (GLA:D-like) : quadriceps strengthening as a priority, neuromuscular control, low-impact aerobic exercise (cycling 3x/week);
  • Activity modification : avoid prolonged squatting, limit stairs in the acute phase, insoles with a lateral wedge to unload the medial compartment;
  • Analgesia : topical NSAIDs as first line, paracetamol, oral NSAIDs in a short course if needed; possibly a corticosteroid injection in the event of an inflammatory flare;
  • Follow-up : reassessment at 3 months (KOOS, VAS, quadriceps circumference), discussion of total knee replacement if there is failure at 6-12 months and a major impact on independence.

This profile represents a large share of a physiotherapist's practice. Focusing treatment on the DML would miss the main problem (the osteoarthritis) and would probably lead to failure.

The practical application of evidence-based recommendations is the bridge between science and clinical improvement. It requires knowing not only what to do, but also when to act, how to measure and why certain barriers persist. This chapter offers concrete strategies for integrating best practice into the management of DML in routine practice. 🧑‍⚕️

When, and to which other health professionals, should the patient be referred?

The physiotherapist is often on the front line for DML, but their practice is part of a coordinated care network. Appropriate referral is a guarantee of safety and effectiveness. 🧐

Identifying knee red flags = a non-negotiable step before starting any treatment.¹ These signs may indicate a serious condition requiring immediate medical management:

• Significant acute trauma (fall, accident) with inability to bear weight or to flex actively: apply the Ottawa Knee Rules to decide on an X-ray: suspected fracture if ≥ 1 criterion is positive.²
• Suspected vascular cause : intermittent claudication, asymmetrical pedal pulses, distal cyanotic discolouration: urgent vascular surgery referral (PAES, ischaemia).
• Suspected neurological cause : widespread motor weakness, sensory disturbance in a dermatome, sphincter disturbance: suspected compressive radiculopathy, cauda equina syndrome.
• Systemic inflammatory syndrome : fever, chills, unexplained weight loss, night sweats: suspected septic arthritis, rheumatoid arthritis, neoplasm.
• Severe non-mechanical night bone pain : suspected osteochondritis, stress or insufficiency fracture, neoplasm (primary, or metastatic in a patient with a history of cancer).
• True joint locking that persists in extension: suspected bucket-handle tear, osteochondral loose body, displaced root lesion; prompt MRI + surgical opinion.
• Major effusion appearing rapidly without trauma: suspected haemarthrosis (anticoagulant, clotting disorder), crystal arthritis (chondrocalcinosis, gout), infection.
• Progressive deformity of the knee (varus, valgus, recurvatum) over a few weeks to months: suspected joint collapse, extensive osteonecrosis, subchondral fracture.

🚩 If any of these features is present, prompt referral to the GP or to the emergency department depending on the perceived urgency.

Referral to an orthopaedic surgeon to be considered in specific situations:

• Failure of well-conducted conservative treatment : no clinically meaningful improvement after 3 to 6 months of structured conservative treatment (home or supervised exercise) with satisfactory adherence.³
• Persistent true mechanical locking that cannot be reduced (a specific but rare sign in degenerative cases).
• Suspected meniscal root lesion in a patient with KL ≤ 2, age < 65 years (window of intervention for root repair).
• Disabling advanced osteoarthritis with a major impact on independence and quality of life, after conservative optimisation: discussion of total knee replacement.⁴
• Associated ligament injury that is unstable (ACL, grade III MCL).

Biopsychosocial approach : possible referral to:

• Psychologist or pain specialist therapist when yellow flags predominate: marked catastrophising (PCS ≥ 30), severe kinesiophobia (TSK-11 ≥ 41), clinically significant depression or anxiety.⁵
• Occupational physician / ergonomist to analyse and adapt the workstation if occupational demands (squatting, carrying loads) are a perpetuating factor.
• Dietitian if BMI > 28-30: a weight loss of 5-10 % has a major impact on pain in DML with osteoarthritis (Hall 2018, Bannuru OARSI 2019).⁶,⁷
• Endocrinologist in cases of poorly controlled diabetes (impact on tissue healing, associated sarcopenia).
• Sports physician for very active patients wishing to optimise their return to specific sporting activities.

The general practitioner remains the central pivot of this coordination, centralising information and ensuring the patient's overall follow-up.

How to measure outcomes and overcome the barriers to implementation?

To validate the effectiveness of management and justify its continuation, it is essential to measure progress objectively. At the same time, the barriers that prevent the application of best practice must be identified and overcome. 📈

Self-administered questionnaires (Patient-Reported Outcome Measures, PROMs) are strongly recommended to assess the impact on function and quality of life.⁸ For the knee, and more specifically for DML, the most validated are:

• KOOS (Knee injury and Osteoarthritis Outcome Score) : 42 items, 5 subscales (pain, symptoms, ADL, sport/recreation, quality of life), score 0-100 (100 = best). International reference for DML and knee osteoarthritis. MCID ≈ 8-10 points for pain and function.⁹
• IKDC subjective knee form : 18 items, score 0-100, focused on symptoms and function in meniscal and ligament conditions. Often used as the primary outcome in trials (ESCAPE).
• Lysholm Knee Scoring Scale : 8 items, score 0-100, a classic in orthopaedics, useful for tracking progress.
• Tegner Activity Scale : a 0-10 scale of sporting/occupational activity level. Important for monitoring the return to activities.
• VAS pain (visual analogue scale 0-10) or NRS (numerical 0-10): quick, reproducible assessment at each session.
• WOMAC (Western Ontario McMaster Universities Osteoarthritis Index) : 24 items (pain, stiffness, function), specific to knee osteoarthritis, useful in the context of DML + osteoarthritis.

• Range of motion (extension, flexion);
• Isometric or isokinetic strength of the quadriceps and hamstrings (LSI %);
• Thigh circumference 10 cm above the upper pole of the patella (a proxy for atrophy);
• Functional tests: 30-second chair stand test, stair climb test, 6-minute walk test, hop tests for more advanced levels.

These tools should be used at the start of treatment to establish a baseline, then repeated at regular intervals (every 4-6 weeks) to track progress and adapt the treatment plan.¹⁰

Overcoming barriers to implementation: 🚧

Despite the availability of high-quality recommendations, applying them in clinical practice remains a documented challenge.¹¹ The main barriers identified in the literature:

1. Time pressure : time constraints per session, which are particularly difficult for long programmes (12 weeks) with high-quality education and supervised exercise.
2. Lack of knowledge / training : difficulty integrating recent literature, critically appraising the evidence and updating protocols.
3. Clinician beliefs and attitudes : entrenched habits, cognitive biases (preference for passive modalities), professional inertia in the face of data that call long-standing practices into question.
4. Patient expectations : recurrent requests for MRI "to see", for surgery "to repair", for passive treatments (mesotherapy, injections without a clear indication). Social pressure that "something must be done".
5. Organisational barriers : remuneration that rewards passive, fragmented care, limited technical facilities for hop tests and isokinetic testing, lack of coordination with the doctor and the surgeon.
6. Gap between trials and real life : trials (ESCAPE, Kise, FIDELITY) recruit motivated patients without major comorbidities, with access to structured PT. Transposing these results to a patient with multiple comorbidities from a deprived neighbourhood remains a challenge.

• Targeted continuing education : webinars on exercise therapy for DML, practical workshops on hop tests, annual update on the literature;
• Peer support and mentoring : discussion groups between physiotherapists, case presentations, regular clinical supervision;
• Decision aids : summary algorithms (ESSKA, BMJ Rapid Recs), red flag checklists, downloadable patient leaflets;
• Patient education from the first session : set the evidence-based framework, explain why there is no routine MRI, present the favourable prognosis. Aligning expectations from the outset reduces later conflict;
• Report templates incorporating PROMs: they facilitate communication with the doctor and the surgeon around objective criteria;
• Multidisciplinary network working : coordination meetings, a defined patient pathway with the general practitioner, the surgeon and the dietitian.

Critique and controversy: persistent tensions

While this framework appears structured, reality is more complex. Several tensions deserve reflection:

1. The PROMs paradox : their usefulness has been demonstrated but their systematic integration remains low (time pressure, perception as an "administrative task"). The challenge is to turn them into a tool for dialogue that enriches shared decision-making rather than a burden.
2. The grey zone of surgical referral : "failure of well-conducted PT" remains subjective. Adherence, exercise intensity, management of psychosocial factors: all influence the outcome. Considerable variability in referral decisions between practitioners.
3. Fetishisation of the "biopsychosocial" : this model has become a mantra but risks being an empty slogan if clinicians do not have the skills to apply it (training in therapeutic communication, access to psychologists, pain education).
4. Tension between guidelines and personalised medicine : recommendations are based on population averages. The true clinical art is knowing when to adapt the guidelines to the individual patient, justifying departures from them with sound clinical reasoning.
5. Equity of access : the benefits of the conservative approach assume access to a structured exercise programme over 3-6 months, at home or supervised; in TeMPO, clinic sessions added nothing at 3 months. This access remains very unequal across countries, regions and socio-economic situations.