Cedera Meniskus Lutut
Published on September 10, 2026
Risk Factors
Young athletes in pivoting/contact sports (soccer, basketball, football), middle-aged and older adults with degenerative joint changes, occupations requiring prolonged squatting or kneeling, concurrent ACL injury, obesity
Etiology
Acute traumatic tear from twisting or pivoting on a planted foot with the knee in flexion; degenerative tear from chronic wear in older patients
Presentation
Knee pain along the joint line (medial or lateral), swelling developing over hours, mechanical symptoms such as locking, clicking, or catching during movement
Classic Exam
Positive McMurray test (audible click or pop with pain during knee extension with rotation), joint line tenderness, positive Apley compression test, inability to fully extend the knee in bucket-handle tears
Diagnostics
MRI showing increased signal within the meniscus on T2-weighted images; X-ray is normal but used to exclude fracture or osteoarthritis
Management
Conservative therapy (rest, ice, NSAIDs, physical therapy) for small stable tears in the vascular zone; arthroscopic meniscal repair for peripheral tears in young patients; arthroscopic partial meniscectomy for tears in the avascular zone
01Pathophysiology
The menisci are paired, C-shaped fibrocartilaginous structures located between the femoral condyles and the tibial plateau. The medial meniscus and the lateral meniscus serve as shock absorbers, load distributors, and secondary stabilizers of the knee joint. They also contribute to joint lubrication and proprioception. Without intact menisci, focal contact pressures across the articular cartilage increase dramatically, accelerating degenerative changes.
The medial meniscus is injured far more frequently than the lateral meniscus. This is because it is firmly anchored to the deep fibers of the medial collateral ligament (MCL) and the joint capsule, which makes it relatively immobile. During a twisting force on a flexed, weight-bearing knee, the medial meniscus cannot escape the shearing force between the femur and tibia, and it tears. In contrast, the lateral meniscus has looser capsular attachments and greater mobility, which allows it to accommodate rotational stress more effectively.
Understanding the vascular anatomy of the meniscus is essential because it determines both the healing potential and the management strategy. The meniscus receives its blood supply from the perimeniscal capillary plexus, which branches from the medial and lateral genicular arteries. This blood supply penetrates only the outer 10 to 30 percent of the meniscal width. Based on vascularity, the meniscus is divided into three zones:
Red-red zone (outer third): Fully vascularized. Tears here have the best healing potential and are candidates for surgical repair.
Red-white zone (middle third): Partially vascularized. Healing is variable and depends on tear pattern and patient factors.
White-white zone (inner two-thirds): Avascular. Tears here do not heal on their own and typically require partial meniscectomy rather than repair.
The mechanism of acute meniscal injury involves a rotational force applied to the knee while it is in flexion and bearing weight. During sudden pivoting, the femur rotates on the fixed tibia, trapping and shearing the meniscus. This is why athletes in cutting and pivoting sports are disproportionately affected. In older adults, the collagen within the meniscus undergoes myxoid degeneration, making it prone to tearing from trivial or minimal trauma such as rising from a squatting position.
A displaced meniscal fragment, particularly a bucket-handle tear (a longitudinal tear in which the central fragment flips into the intercondylar notch), can physically block full knee extension. This is the pathophysiologic basis for the classic complaint of the knee "locking" in a flexed position.
02Classification and Clinical Manifestation
TEAR TYPE | PATTERN DESCRIPTION | TYPICAL PATIENT | CLINICAL FEATURES |
|---|---|---|---|
Longitudinal (Vertical) | Tear runs parallel to the circumferential fibers of the meniscus | Young athletes with acute trauma | Joint line pain, may progress to bucket-handle if it extends |
Bucket-Handle | A displaced longitudinal tear where the central fragment flips into the intercondylar notch | Young, active patients | Mechanical locking of the knee in flexion, inability to fully extend, significant functional impairment |
Radial | Tear runs perpendicular to the circumferential fibers, disrupting the hoop stress mechanism | Variable | Pain with weight-bearing, loss of meniscal load distribution, predisposes to early arthritis |
Horizontal (Cleavage) | Tear splits the meniscus into upper and lower leaves along the horizontal plane | Older adults with degenerative changes | Gradual onset of pain, intermittent swelling, may form a meniscal cyst (especially lateral meniscus) |
Flap (Oblique) | A combination of vertical and radial components creating a mobile flap | Variable | Intermittent catching or clicking, episodic sharp pain when the flap displaces |
Complex (Degenerative) | Irregular, multi-directional tear involving more than one pattern | Middle-aged and elderly with osteoarthritis | Chronic joint line pain, stiffness, effusion, often coexists with chondral damage |
03Diagnostic Workup
TEST | ROLE | KEY FINDINGS |
|---|---|---|
Clinical Examination (McMurray, Apley, Joint Line Tenderness) | Best initial assessment | McMurray: click/pop with pain during extension and rotation. Apley: pain with axial compression and rotation in prone position. Joint line tenderness: high sensitivity but lower specificity |
Plain Radiograph (X-ray) of the Knee | Excludes fracture and assesses for osteoarthritis | Normal in isolated meniscal tears. Used to rule out tibial plateau fracture, loose bodies, or advanced degenerative changes |
MRI of the Knee | Best non-invasive confirmatory test (gold standard imaging) | Increased intrameniscal signal that contacts the articular surface on T2-weighted or proton density sequences. Sensitivity and accuracy both exceed 90% |
Arthroscopy | Most accurate overall (gold standard for both diagnosis and treatment) | Direct visualization of the tear. Reserved for cases where MRI is inconclusive or when surgical intervention is already planned |
The workup begins with a thorough history and physical examination. A patient who describes a twisting injury on a planted foot followed by knee pain, swelling that developed over several hours, and mechanical symptoms such as locking or catching should immediately raise suspicion for a meniscal tear. The delayed onset of effusion (developing 6 to 24 hours after injury) is a distinguishing feature, as opposed to the rapid hemarthrosis (within 1 to 2 hours) seen with ACL rupture.
On examination, joint line tenderness is the most sensitive finding but is not very discriminating on its own. The McMurray test is the most commonly tested maneuver and is performed with the patient supine. To test the medial meniscus, the examiner flexes the hip and knee maximally, applies a valgus stress with external rotation of the tibia, and then slowly extends the knee. A palpable click or pop along the medial joint line with pain constitutes a positive test. To test the lateral meniscus, the maneuver is repeated with internal rotation and varus stress. A common exam trap is confusing which rotation tests which meniscus: remember that external rotation tests the medial meniscus.
The Apley compression (grinding) test is performed with the patient prone and the knee flexed to 90 degrees. The examiner applies a downward axial load through the tibia while rotating the leg. Pain with compression favors meniscal pathology, whereas pain with distraction (Apley distraction test) suggests ligamentous injury.
Plain radiographs should be obtained as the initial imaging study, not because they will reveal the meniscal tear, but because they are essential for excluding fractures, loose bodies, and underlying osteoarthritis. The menisci are soft tissue structures and are not visible on X-ray.
MRI is the best non-invasive confirmatory test and is the imaging modality of choice when clinical suspicion is high. On MRI, a meniscal tear is identified by abnormal signal intensity within the meniscus that extends to at least one articular surface. MRI also provides valuable information about concomitant injuries (ACL, chondral lesions, bone bruises) and the tear pattern, which guides the surgical approach.
Arthroscopy remains the definitive diagnostic and therapeutic tool but is invasive. It is not ordered as a standalone diagnostic test. Arthroscopy is pursued when the clinical picture strongly supports a surgically significant tear, when MRI findings are equivocal, or when the patient has failed conservative management.
04Management and Treatment
CLINICAL SCENARIO | MANAGEMENT | DETAILS |
|---|---|---|
Small, stable tear in the red-red zone | Conservative therapy | Rest, ice, compression, elevation; NSAIDs (e.g., ibuprofen 400 to 600 mg every 6 to 8 hours, or naproxen 500 mg twice daily for 7 to 14 days); quadriceps strengthening physical therapy for 4 to 6 weeks |
Peripheral tear in a young patient (red-red or red-white zone) | Arthroscopic meniscal repair | Suture repair preserving meniscal tissue. Post-operative rehabilitation with protected weight-bearing and restricted range of motion for 4 to 6 weeks, full recovery over 3 to 6 months |
Tear in the white-white zone or complex degenerative tear | Arthroscopic partial meniscectomy | Resection of only the unstable fragment while preserving as much functional meniscal tissue as possible. Faster recovery (2 to 4 weeks) than repair |
Bucket-handle tear with mechanical locking | Urgent arthroscopic surgery (repair or meniscectomy) | Locked knee is a relative surgical urgency. Goal is to reduce the displaced fragment and restore extension. Repair is preferred in young patients if the tear is in a vascular zone |
Degenerative tear with concurrent osteoarthritis | Conservative management preferred | Physical therapy, weight management, activity modification, intra-articular corticosteroid injection for refractory symptoms. Arthroscopic surgery has not been shown to improve outcomes over physical therapy in this population |
Acute phase management follows the standard approach for soft tissue injuries. The patient should be instructed to rest the knee, apply ice for 15 to 20 minutes several times per day, use a compressive wrap, and elevate the limb. NSAIDs are the first-line pharmacologic agents for pain and inflammation control. If the patient has a contraindication to NSAIDs (renal insufficiency, active peptic ulcer disease, pregnancy in the third trimester), acetaminophen up to 3 grams per day can be used as an alternative analgesic, though it lacks anti-inflammatory properties.
The decision between conservative versus surgical management hinges on the tear location (vascular zone), tear pattern, patient age and activity level, and the presence of mechanical symptoms. Tears in the outer vascular zone in young patients are the best candidates for arthroscopic repair because the blood supply supports biological healing. In contrast, tears in the inner avascular zone will not heal and are managed with arthroscopic partial meniscectomy, where only the torn, unstable tissue is removed.
A bucket-handle tear causing a locked knee is treated as a relative surgical urgency. The displaced fragment blocks the normal gliding mechanics of the joint and prevents full extension. Surgical reduction of the fragment (with repair or meniscectomy) is the next best step.
Long-term management focuses on physical therapy emphasizing quadriceps and hamstring strengthening, proprioceptive training, and a gradual return to activity. After partial meniscectomy, patients can typically return to full activity in 4 to 6 weeks. After meniscal repair, return to sport is delayed to 3 to 6 months to protect the healing tissue.
An important point for exam purposes: in older patients with degenerative meniscal tears and coexisting osteoarthritis, arthroscopic surgery provides no additional benefit over structured physical therapy. This has been consistently demonstrated in randomized trials and is a commonly tested concept. The best management in this population is conservative.
05Differential Diagnosis and Distractors
DIFFERENTIAL | WHY IT IS SIMILAR | KEY DISCRIMINATOR |
|---|---|---|
ACL Tear | Also caused by a twisting/pivoting mechanism, also presents with knee pain and swelling after sports injury | ACL tear causes immediate hemarthrosis (swelling within 1 to 2 hours), positive Lachman test and anterior drawer test, and a sensation of the knee "giving way" rather than locking. Meniscal tears produce delayed effusion and mechanical locking |
MCL Sprain | Also follows a valgus stress injury, medial knee pain, associated with the "unhappy triad" | MCL sprain produces tenderness over the MCL (not the joint line), positive valgus stress test at 30 degrees of flexion, no mechanical symptoms |
Patellofemoral Pain Syndrome | Anterior knee pain, common in young active patients, may also cause clicking | Pain is anterior and peripatellar (not along the joint line), worsened by prolonged sitting ("theater sign"), stair climbing, and squatting. Positive patellar grind (Clarke) test |
Tibial Plateau Fracture | Acute knee pain and swelling after trauma, may have valgus mechanism | Fracture is visible on X-ray (depression or split of the tibial plateau). Hemarthrosis with lipohemarthrosis (fat-fluid level) on lateral X-ray is pathognomonic. CT for surgical planning |
Osteoarthritis of the Knee | Chronic joint line pain, stiffness, effusion, common in older adults | Gradual onset over months to years, morning stiffness lasting less than 30 minutes, joint space narrowing and osteophytes on X-ray. No acute traumatic event. Bony enlargement on exam |
Osteochondritis Dissecans | Knee pain, catching, locking, effusion in a young patient | Wilson test positive (pain with internal rotation during extension, relieved by external rotation). Involves the articular cartilage and subchondral bone of the femoral condyle. MRI or X-ray shows a focal subchondral lesion |
06Traps and High-Yield Pearls
The most common way students miss meniscal injury questions is by confusing the clinical presentation with an ACL tear. Both injuries share a similar mechanism (twisting on a planted foot during sports), but the timing of the effusion is the key separator. ACL tears produce immediate hemarthrosis that develops within the first 1 to 2 hours because of bleeding from the ruptured ligament. Meniscal tears produce a reactive, non-hemorrhagic effusion that develops gradually over 6 to 24 hours because the inner meniscus is avascular and does not bleed. If the vignette describes a swollen knee the morning after a game rather than immediately on the field, think meniscus.
Another frequent trap involves the McMurray test rotation. Students often reverse which direction tests which meniscus. The rule is: external rotation of the tibia with valgus stress tests the medial meniscus; internal rotation with varus stress tests the lateral meniscus.
The "unhappy triad" (also called the O'Donoghue triad) is a classic board concept involving simultaneous injury to the ACL, MCL, and medial meniscus. This occurs with a valgus force combined with external rotation, commonly seen in contact sports (e.g., a lateral blow to the knee). When a vignette describes all three structures injured together, the student must recognize that the meniscal component requires separate evaluation and management beyond the ligament injuries.
Be cautious with degenerative meniscal tears in elderly patients. A vignette presenting an older patient with chronic knee pain, a degenerative meniscal tear on MRI, and underlying osteoarthritis is testing whether you know that the correct answer is physical therapy, not arthroscopic surgery. Selecting surgery in this scenario is the intended wrong answer.
Finally, any vignette describing a patient who cannot fully extend the knee after a twisting injury ("the knee is locked") should immediately trigger consideration of a bucket-handle tear. This is a displaced longitudinal tear and is a relative surgical urgency. The next best step is arthroscopic intervention, not conservative management with physical therapy.