Meniscal damage

Definition

Loss of tissue or various types of tearing in part of a meniscus; this most often affects the posterior medial meniscus, usually in the thin, avascular white zone. Near the joint capsule, the peripheral meniscus is relatively thick and well vascularized (red zone). Farther inward, toward the articulating cartilage surfaces, there is a less vascular red-white zone; the innermost region close to the articular cartilage is quite thin and no longer vascularized.

The middle region of the meniscus (red-white zone), which still has some vascular supply, is affected much less often; the peripheral meniscus (red zone) is affected more frequently, although it is still significantly vascularized. This is because, in addition to rolling friction and especially sliding friction during knee flexion and extension, axial loads combined with these movements and rotation place stress on the meniscus.

An acute meniscal lesion often presents with the triad of immediate pain, joint locking and swelling. Chronic meniscal lesions lead to recurrent joint effusions; snapping or jumping may sometimes be palpable and audible. Atrophy of vastus medialis is not uncommon, and a feeling of instability may occur. The most important meniscal tests provoke pain, with joint line tenderness being the most important. As only the outermost edge of the meniscal base contains nerve fibers, the pain elicited is likely to be largely related to accompanying local synovitis. Clicking, snapping and jumping at joint-line level usually suggest a meniscal tear. Individual meniscal tests have different diagnostic characteristics depending on the study and patient group. Combining them with the history and other clinical findings is more informative than an isolated test result. MRI may be useful for assessment and treatment planning; its indication depends on the clinical question, not solely on a positive provocation test.

The aims of meniscal repair are pain relief and the fullest possible preservation of meniscal function for a favorable prognosis. Whether suturing or refixation is feasible and appropriate depends on tear pattern, location, tissue quality, stability, associated injuries and functional demands. Peripheral longitudinal tears are often suitable candidates, but the indication is not limited to this situation. Length alone is neither a sufficient indication for surgery nor a general reason to exclude repair. There is no age limit for refixation; the indication depends more on tear pattern and the absence of substantial tissue degeneration. In children, repair should always be attempted. Rehabilitation after meniscal suturing is generally longer than after partial resection. Return to sport depends on the type of tear and repair, biological healing time, range of motion, absence of effusion, strength and neuromuscular control. The EU-US consensus gives a minimum rehabilitation period of approximately four months for repaired vertical tears; complex, radial, horizontal and root tears may require six to nine months. These are guides, not automatic clearance for unrestricted sport. Insufficient or torn cruciate ligaments should be treated beforehand or at the same time. During refixation, the tear edges are freshened to remove necrotic tissue and improve healing potential. Needling may also be performed, piercing the meniscus from outside inward to encourage vascularization and healing. A fibrin clot may additionally be placed in the tear.

The possible complications of meniscal suturing, which occur infrequently, include persistent or recurrent symptoms, failure of the repair to heal or a new tear, restricted movement and, rarely, infection or neurovascular injury. Risk depends on tear pattern, location, surgical technique and associated injuries. During medial procedures, branches of the saphenous nerve are particularly at risk, which can cause infrapatellar branch syndrome; during lateral procedures, the common fibular nerve may be at risk. Cysts may also occur. A universally applicable overall complication rate cannot be given without specifying the procedure, outcome and follow-up period. The structural healing of a meniscal repair depends on factors including tear pattern, location, associated injuries and surgical technique. A meta-analysis of 41 studies involving 1908 people reported a pooled complete healing rate of 74% (95% confidence interval 67–80%) on second-look arthroscopy. Results varied markedly between studies and do not provide an individual prognosis. Structural healing, clinical freedom from symptoms and later revision surgery are different outcomes. In selected cases, replacement procedures may be considered for persistent symptoms after substantial meniscal loss. These include donor grafts, partial scaffolds and synthetic replacement implants, with different requirements and limitations. Young age or an unfavorable repair prognosis alone does not justify meniscal replacement. Cartilage condition, leg alignment, ligament stability and remaining meniscal tissue are important selection factors. A functionally important meniscal root tear can substantially impair conversion of axial loading into circumferential tension. This can reduce the tibiofemoral contact area and increase local contact pressure. The magnitude depends on the affected root, tear pattern, knee flexion and remaining ligament connections. Loading increases measured after meniscal resection cannot simply be presented as measurements of a root tear. Experimental measurements also do not directly predict an individual risk of osteoarthritis. Precise positioning is particularly important for synthetic meniscal replacement. Incorrect positioning can severely impair its biomechanical protection of the articular cartilage and can also expose the implant to excessive wear.

A discoid meniscus is a shape variant that is broader and disc-like rather than normally crescent-shaped; it predominantly affects the lateral meniscus. The Watanabe classification distinguishes complete, incomplete and Wrisberg variants. In the Wrisberg variant, normal posterior meniscotibial or capsular attachments are absent, which can make the meniscus hypermobile. Morphology, tearing and peripheral stability must be assessed separately. A discoid meniscus may be unilateral or bilateral and may be asymptomatic. Possible symptoms include painful snapping, swelling, locking or an extension deficit. Normal radiographs do not exclude it. MRI is an important noninvasive investigation of shape, tears and associated changes; instability and pediatric variants in particular may require additional experience. An asymptomatic incidental finding is generally not operated on prophylactically. In clinically significant cases, treatment depends on the tear, stability and functional impairment. If surgery is required, meniscus -preserving reshaping and, when appropriate, suturing or stabilization of the peripheral rim are preferred. Complete removal should be avoided whenever possible because of the consequences of meniscal loss.

Meniscal cysts, often termed parameniscal cysts or meniscal ganglia, are fluid-filled changes (soft-tissue cysts) at the meniscal margin. They are frequently associated with a meniscal tear, particularly a horizontal component, and are only rarely situated far within the joint. Symptoms may include painful swelling and tenderness at the joint line; some cysts are asymptomatic imaging findings. Adjacent structures such as the fibular nerve may rarely be affected, or bony erosions may occur. Incidental meniscal ganglia are found in up to 4% of asymptomatic knees. Meniscal ganglia can cause erosions in the tibia. MRI can show the cyst and associated meniscal tear; superficially located cysts can also be assessed with ultrasound. Treatment depends on symptoms and associated lesions. Selected cases may be observed, treated by image-guided aspiration or managed by surgical decompression or removal. Recurrence is possible, particularly if communication with the tear persists. During surgery, meniscal tissue should be preserved as far as possible. A 2021 systematic review reported freedom from symptoms or only minimal residual symptoms in 85.7% after arthroscopic treatment and an overall cyst recurrence rate of 7.1%. These are different outcomes in selected surgical populations, largely from case series; they establish neither a general 85% chance of success nor the superiority of surgery over every conservative treatment.

Arthroscopy

If a meniscus is damaged, part of it may need to be resected when it is liable to become trapped and cause substantial pain. After meniscal removal, knee loading is distributed over a smaller area. This can increase pressure on the articular cartilage and promote wear. Important factors include not only the amount of tissue removed but also the location of the resection, knee flexion, leg alignment, ligament stability and pre-existing cartilage damage. In 1983, Ahmed and Burke demonstrated marked changes in pressure distribution after complete medial meniscal removal in knee specimens. A 2012 study by Seitz and colleagues showed that even limited partial removal can have consequences: removing 50% of the local meniscal depth in a 10-mm-wide segment of the posterior medial meniscus increased the highest measured contact pressure at 60° of knee flexion and reduced the load-bearing contact area. This change was not detected at 0° or 30°. The effect of partial removal therefore also depends on joint position. Roos and colleagues investigated long-term consequences in 107 people 21 years after open meniscal removal. Clear radiographic signs of osteoarthritis were present in 48 out of 100, compared with 7 out of 100 in the control group. Comparing operated patients with controls of similar age and the same sex in matched pairs, the authors calculated an approximately 14-fold increase in the risk of such radiographic changes. The precise magnitude of this increase could, however, be estimated only imprecisely. The study mainly shows that osteoarthritic changes were substantially more common in the long term after the meniscal removal performed at that time. It does not mean that every modern, limited partial resection has the same consequences. Radiographic changes also do not cause equally severe symptoms in everyone. Comparative studies suggest that advanced osteoarthritis develops less frequently after meniscal repair than after partial removal. For a suitable repairable tear, as much functional meniscal tissue as possible should therefore be preserved. Individual prognosis also depends on the original injury and the other conditions in the knee. For symptomatic degenerative meniscal lesions, nonoperative treatment with targeted rehabilitation is generally the first approach. The placebo-controlled FIDELITY trial studied 146 adults with a degenerative medial meniscal tear and without advanced osteoarthritis. After five years, arthroscopic partial resection provided no additional clinically relevant benefit for pain or function compared with sham surgery. The ten-year analysis in 2026 likewise provided no evidence of benefit; some outcomes were even less favorable. The lack of superiority of partial resection must not be generalized to meniscus -preserving suturing, acute traumatic tears or persistent true mechanical locking. People with clearly traumatic onset or a recently locked knee were excluded from FIDELITY. Meniscal suturing and resective arthroscopy are different procedures with different indications. For suitable repairable tears, comparative data suggest better long-term joint outcomes after preservation or suturing than after resection; this does not guarantee success for an individual. Combined surgery and physiotherapy has likewise not proved superior to conservative treatment alone, which generally argues against arthroscopy in view of its risks. The available studies concern patients aged 40 and older. Below that age, tears are mainly traumatic. Tears at older ages may also be traumatic, but degenerative damage commonly present later in life is thought to allow smaller traumatic events to cause a tear. Rotation of the lower leg in a loaded knee is an important trigger in most tears.

Arthroscopic suturing of a torn meniscus, by contrast, can substantially improve the condition in many cases.

This applies to older patients and older tears

and to less vascularized areas to a scarcely lesser extent,

so that meniscus -preserving arthroscopy is often worthwhile. Degenerated tissue may need to be removed in older tears. Biological adjuncts such as rasping, needling or platelet-rich preparations are being investigated to support meniscal healing. A reliable additional benefit has not been established for every tear pattern and procedure. The chance of success therefore cannot be expressed as a universal fixed percentage. Favorable results of arthroscopic suturing are apparent radiologically and even more so clinically. Flap tears with loss of connection to the meniscal base and attritional damage have a somewhat less favorable prognosis than other patterns. In these cases, a limited partial resection may be justified if there is a tendency to become trapped.

Meniscal degeneration generally increases with age. Degenerative meniscal lesions can be detected in 50% of people over 70.

Joint line tenderness and pain during combined flexion and rotation are diagnostically suggestive. Meniscal damage is sometimes accompanied by joint effusion or painful joint locking; Baker cysts also occur. MRI confirms the clinical suspicion.

Types of meniscal tears

Radial tear

A tear from the inner edge outward along the meniscal radius without reaching the outer margin, often asymptomatic for some time, usually traumatic and often affecting active young patients. If untreated, it may extend into a parrot-beak tear, with the tear continuing parallel to the margin. The unstable area then often causes recurrent joint effusions, a catching sensation and giving way.

Flap tear

When the tear curves to run parallel to the inner margin; usually more degenerative in origin and occurring from middle age onward.

Bucket-handle tear

A longitudinal tear through the meniscus, parallel to the principal fiber direction and not communicating with the inner margin. The anterior and posterior ends of the fragments remain connected to the rest of the meniscus. The free portion containing the inner margin can displace into the intercondylar notch and cause an extension block; this can often be reduced manually, producing a loud pop or click. Together with pain relief, this indicates successful reduction. Bucket-handle tears can also heal after appropriate reduction and repair. Repairability and prognosis depend on tissue quality, location, chronicity, reducibility and associated instability; a predominantly avascular location or universally worst healing should not be assumed.

Horizontal tear

A horizontally oriented tear, usually degenerative and occurring from middle age onward. One layer of the meniscus separates from the underlying layer and may become an unstable flap over time, causing mechanical symptoms. The flap can fold over and become interposed between the articular cartilage surfaces.

Vertical tear

A vertical tear parallel to the margin, with the separated portion remaining connected to the anterior and posterior horns. Further separation may turn a vertical tear into a bucket-handle tear.

The classic Stoller/Crues MRI signal classification distinguishes, in simplified form:

Grade 1: focal or localized intrameniscal increased signal without definite contact with an articular surface.
Grade 2: predominantly linear intrameniscal increased signal without definite surface contact.
Grade 3: increased signal definitely communicating with at least one meniscal surface, an important MRI sign of a tear.

Detailed assessment takes account of the imaging sequence, multiple slices, meniscal shape and possible artifacts. Fragment displacement and deformity are additional morphological findings, not prerequisites for every grade 3 tear. An MRI grade alone determines neither the cause of pain nor the need for surgery.

Meniscal root tears

Meniscal root tears affect the tibial attachment of a meniscal horn or a radial tear close to the root. Each knee has an anterior and a posterior root for both the medial and lateral meniscus, making four roots in total. Although the pronounced pain at the time of injury subsequently subsides, the affected medial or lateral meniscus is excessively mobile with only one remaining anchor, increasing the risk of osteoarthritis and greatly favoring entrapment. A root tear is therefore a serious knee disorder because of its associated complications. Entrapment toward the center of the joint causes sharp, shooting pain; more commonly, loss of hoop tension allows the meniscus to be displaced outward against the capsule, causing more persistent, diffuse pain. Even partial tears can cause abnormally increased meniscal mobility.

In all cases, the pressure-bearing area may be substantially reduced, promoting wear of the cartilage covering the bone (osteoarthritis). In posterolateral root tears, intact meniscofemoral ligaments may preserve part of the stabilizing or load-transmitting function. This does not justify a general conclusion that there is no functional impairment or increased osteoarthritis risk, although that risk appears lower. Tear configuration and associated injuries are decisive. The meniscofemoral ligaments are anatomically variable. The anterior meniscofemoral ligament (Humphrey) passes in front of the posterior cruciate ligament, while the posterior meniscofemoral ligament (Wrisberg) passes behind it. Detection depends on the examination method and population; one source reports their presence in 50% and 70%, respectively. Failure to visualize a ligament on imaging does not automatically mean that it is torn.

Root tears include partial and complete avulsions of the meniscotibial attachment and radial tears close to the tibial insertion, because the latter also cause excessive mobility of nearly the entire meniscus. A root tear also disrupts hoop tension in the ring-shaped meniscal structure: with normal meniscal anchors and an intact meniscus, axial loading is converted into tensile loading of its circumferential fibers, which are highly resistant to tension. Without hoop tension, the meniscus yields under pressure and may become completely ineffective, with an osteoarthritis risk comparable to partial resection or complete resection of the affected area. Root tears most often involve the two posterior horns, medial or lateral: acute tears are frequently associated with ligament injuries, occurring in 7–12% of cruciate ligament tears; chronic tears are degenerative, often affect overweight people and are usually located in the posterior medial meniscus. Degenerative posterior medial meniscal root tears are more common in middle and later life. Excess body weight and varus leg alignment may contribute. Medial and lateral root tears differ in their typical causes and associated injuries. Squatting, cross-legged sitting and kneeling positions common in Asian cultures contribute to a higher incidence than in Western countries. Lateral meniscal root tears are more often traumatic. Medial and lateral tears must therefore not simply be equated with avascular and vascularized tissue. Grades are distinguished as follows:

Root avulsion with intact meniscofemoral ligament or ligaments
Radial tear with intact meniscofemoral ligament or ligaments
Root avulsion or radial tear with rupture or absence of the meniscofemoral ligament or ligaments

MRI is generally the noninvasive diagnostic method of choice, but detecting avulsions requires considerable experience. Meniscal extrusion is a strong indication of a possible root tear or another important impairment of meniscal function. It must prompt targeted assessment of the roots and the rest of the meniscus, but does not prove a root tear on its own. Treatment of a degenerative meniscal root tear is not determined by such a grade alone. Cartilage condition, extent of osteoarthritis, leg alignment, tissue quality, symptoms, loading demands and associated injuries must be assessed together. Meniscus -preserving root refixation should be considered where suitable; partial resection is not automatically the standard consequence of a higher grade. Vascular supply, an important prerequisite for healing, depends on the location within the meniscus and other individual factors. The frequently affected medial meniscus also has a vascularized peripheral region. Medial and lateral tears must therefore not simply be equated with avascular and vascularized tissue. A corrective osteotomy should consequently be considered, particularly when varus knee alignment (bow legs) places increased load on the medial meniscus.

Meniscal root suturing should be performed by surgeons experienced in the procedure. After root refixation, loading and range of motion must initially be limited according to the operative findings and the prescribed rehabilitation protocol. As a guide for root tears, the EU-US consensus specifies six weeks without weight bearing and an initial range of motion of 0–90° for four weeks. The duration of forearm-crutch use, for example six to eight weeks, depends on the individually prescribed rehabilitation protocol. Associated procedures, repair stability and individual progress may require adjustments. This does not imply a universal restriction to a maximum of 90° until the end of the third month. If the tear occurred with other knee injuries, the protocol must be adapted accordingly. Leg malalignment such as bow legs may also require treatment adjustments.

Entrapment

A newly developed persistent extension block, for example from a displaced bucket-handle tear, should be assessed promptly by an orthopedic specialist. Such mechanical locking must be distinguished from pain-limited movement or transient snapping. Any necessary reduction and further treatment belong in experienced hands; repeated forceful self-manipulation is not recommended. Even if the block releases spontaneously, the underlying lesion should be investigated.

Treatment of degenerative meniscal lesions

For a wear-related meniscal tear, symptoms, mobility, stability and the condition of the entire knee are assessed together. MRI can show the tear and associated changes. Not every visible tear causes symptoms or requires surgery. Treatment is chosen together with the affected person. The 2015 DGOU guideline on meniscal disorders describes success with conservative treatment in approximately 70% of patients with pronounced to severe radiographic osteoarthritis (Kellgren-Lawrence grade 3–4) and no joint locking. This figure refers to the patient groups evaluated at the time and is not a universal success rate for all meniscal tears. The benefit of partial removal is also limited for degenerative medial meniscal tears without advanced osteoarthritis: in the FIDELITY trial, it provided no additional clinically relevant improvement in pain or function compared with sham surgery after five years. No additional benefit was demonstrated after ten years either. These results concern partial removal for degenerative tears, not suturing a suitable repairable tear or treating an acutely locked knee. Degenerative meniscal lesions are therefore usually treated first with a structured nonoperative approach including exercise therapy, muscle strengthening and adapted loading. Persistent substantial symptoms warrant reassessment. If surgery is indicated, as much functional meniscal tissue as possible should be preserved. Persistent true joint locking is a separate situation requiring prompt specialist assessment. In advanced knee osteoarthritis, treatment is guided primarily by symptoms, function and the condition of the entire joint. An abnormal radiograph alone does not mean that a joint replacement is required.

Meniscal replacement and biological adjuncts must be assessed separately according to the evidence for each procedure; they do not replace individualized decisions about suturing or resection. Root tears and displaced bucket-handle tears can substantially impair meniscal function, but they are not universally equivalent to one another or to every form of complete meniscal loss. Meniscus -preserving treatment should be considered for a suitable root tear or a reducible, repairable bucket-handle tear. Persistent true joint locking requires prompt assessment. Advanced osteoarthritis, substantial tissue degeneration, relevant malalignment or other associated findings may change treatment. Leg alignment is assessed as well; corrective osteotomy is an additional finding-dependent decision, not an automatic consequence of a single threshold.

Causes

Degenerative changes, beginning from around age 40: does everyone use up a little of the meniscal tissue reserve each day?
Traumatic: the magnitude of the triggering event required depends on the degree of pre-existing damage and therefore, statistically and approximately, on age and use.
Activities and sports that damage or wear down the meniscus

Predisposing factors

Alignment and postural abnormalities

Subluxations
Genu varum (bow legs)
Genu valgum (knock knees)
Hindfoot valgus / pronated foot
A tendency toward pronation or supination while walking or running, that is, hyperpronation or hypersupination
Ligament damage
Deviation from the leg axis during movement, including internal rotation of the thigh while bending the knee

Muscular factors

Weakness of the hip external rotators
Weakness of the abductors (smaller gluteal muscles)
Insufficient stability and muscular stabilization of the ankle joint

Behavior

Activities and sports involving knee rotation. The damaging effect is increased when the knee is flexed or extended during rotation.

Symptoms

When separated meniscal fragments become trapped: sharp pain on movement
Pain on loading
Rest pain may also occur with lower-leg rotation
Joint locking may occur; the degree of extension deficit is not proportional to tear size

Diagnosis

MRI
Tests and signs. These tests are based on joint line tenderness or provocation of meniscal subluxation: Steinmann I: the lower leg is rotated with the knee flexed. Pain during internal rotation suggests lateral meniscal injury; pain during external rotation suggests medial meniscal injury. Good sensitivity, only moderate specificity. Steinmann II sign: with knee flexion, the tender point moves from anterior to posterior, as the menisci move backward during flexion. Apley grinding test: rotation with the knee flexed, with the patient prone. Pain is interpreted as in Steinmann I. Good sensitivity, only moderate specificity. Böhler sign: pain with abduction or adduction (valgus and varus stress) at the knee. Good sensitivity, only moderate specificity. Payr sign: pressure on the inner side of the knee while sitting cross-legged provokes pain. Good sensitivity, only moderate specificity. Joint line tenderness on palpation. McMurray test: good sensitivity, only moderate specificity. Thessaly test. Pain during hyperflexion and hyperextension. Krömer test (positive only with larger lesions). Bragard test (positive only with larger lesions). Merke sign (positive only with larger lesions). Childress test (duck-walk test). Fouché sign (positive only with larger lesions). If associated posterior cruciate ligament insufficiency is suspected, the quadriceps active test or active drawer test may be used additionally; it is not a specific meniscal provocation test. Ege test. Chabot sign. Turner sign. Tschaklin sign. Finochietto sign (positive only with larger lesions). Pässler rotation-compression test.

Complications

Baker cyst
Entrapment with joint locking
Knee osteoarthritis
Meniscal tear with sudden pain
Increased osteoarthritis risk, particularly affecting the proximal tibial cartilage

Treatment

Physiotherapy
Persistent true joint locking should be assessed promptly by a specialist. Any necessary reduction and decisions about further treatment belong in experienced hands; repeated forceful self-manipulation is not recommended.
If surgery is indicated, preservation of functional meniscal tissue is the aim. Tear pattern, location, tissue quality, associated injuries, activity level and the ability to follow rehabilitation must be assessed together; chronological age alone does not decide the issue. Partial resection is a different procedure from suturing. Biological adjuncts such as rasping, needling or platelet-rich preparations are being investigated to support meniscal healing. A reliable additional benefit has not been established for every tear pattern and procedure. The chance of success therefore cannot be expressed as a universal fixed percentage.
For persistent symptoms after meniscal loss, meniscal allograft transplantation may be considered at a specialist center; it is not suitable for every cartilage or osteoarthritis condition.
Partial scaffolds and synthetic meniscal replacement implants such as NUsurface are different approaches. Improvements in pain and function have been reported in selected groups; long-term durability and proven protection against osteoarthritis have not been established for all procedures.
Cell-based meniscal regeneration and complex tissue-engineering procedures remain predominantly under clinical or preclinical investigation and are not generally established routine treatment for meniscal damage.
Improve alignment in knock knees or bow legs; if necessary, corrective osteotomy, including combined tibial and femoral procedures.
No well-established recommendation can be made for routine pharmacological prevention of osteoarthritis after meniscal damage using autologous conditioned serum (ACS, for example Orthokin) or interleukin-1 receptor antagonists. Studies of relief of pain and functional impairment in established osteoarthritis do not automatically demonstrate prevention of later osteoarthritis. Autologous conditioned serum is not a pure, standardized interleukin-1 receptor antagonist.

Asana practice and movement therapy

In meniscal damage, possible predisposing conditions must be investigated. These include leg malalignment such as knock knees or bow legs and abnormal foot structure or posture. Knock knees regularly cause symptoms around the lateral meniscus with a tendency toward osteoarthritis of the lateral condyles, while bow legs affect the medial meniscus with a tendency toward predominantly medial osteoarthritis. Possible effects on patellofemoral tracking should also be investigated. Foot deformities with calcaneal varus tend to overload the lateral side of the leg and thus the lateral meniscus, while calcaneal valgus positions such as a pronated foot put the medial meniscus at risk. Largely independently of structural foot deformities, abnormal foot posture or movement such as hypersupination or hyperpronation is also possible, overloading the lateral and medial meniscus, respectively. Development of demonstrable meniscal damage frequently depends on the type and extent of loading. These shape and alignment abnormalities therefore become apparent much earlier in people who spend considerable time on their feet, particularly during impact activities such as jogging or running, or sports in which these movements occur regularly, as in many team sports. Because meniscal vascularity decreases inward from the joint capsule, this cartilage has limited to almost absent regenerative potential. This supports reducing impact loading to a degree determined by the type and extent of meniscal damage. The innermost meniscal zone nevertheless requires a regulated amount of non-impact movement for its nutrition; cyclical sports such as cycling are particularly suitable.

Regarding body positions, it should be checked whether the affected person frequently sits cross-legged or in lotus-like positions. Few people have sufficient hip external rotation for these positions, so excessive compression of the inner knee can result from gravity-induced relative internal rotation of the thigh against the lower leg. Supporting the thighs close to the knees in these positions has two advantages: it markedly reduces the gravitational effect of the thigh that causes medial knee compression, and it also reduces the external-rotation requirement and thus the discrepancy between required and available external rotation.

Prolonged knee flexion is also unfavorable for the menisci, both under substantial load and under only moderate load, as when the feet are placed under a chair in a pointed-foot position. It is important to guide the knee in proper alignment rather than rotating the lower leg at the knee under load, especially while simultaneously flexing or extending the knee. The two neighboring joints, the hip and particularly the subtalar joint, are important for good knee guidance. Identifying and correcting muscle imbalances or insufficient muscle capacity is important, for example in the muscular sling system of the subtalar joint or the hip adductors, abductors, external rotators and internal rotators. Movement errors such as external rotation of the lower leg at the knee while walking or running must likewise be addressed. Their harmful effects extend beyond the tibiofemoral joint to patellofemoral tracking, which should also be assessed.

Often underestimated activities that put meniscal health at risk include breaststroke, because of its unphysiological leg action, and various dance styles in which the body accelerates into rotation while the foot remains on the floor. Without immediate rigid coupling, and because of inertia, unphysiological loaded rotation occurs at the knee. Various forms of sitting with crossed legs are also considered potentially harmful to the knee. During the breaststroke kick, the lower leg rotates at the knee as the leg extends to generate propulsion through an explosive leg movement; speed-dependent water resistance also creates appreciable valgus stress at the knee.

yogabook

pathology: meniscus damage