Meniscal Tears

By admin On Oct 16, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Meniscal Tears

Michael Schettino

Jeffrey W. R. Dassel

Basics

Description

Menisci are the cartilaginous structures that serve in transmitting tibiofemoral load, shock absorption, lubrication, and passive stabilization of the knee.
The peripheral 1/3 zone has a vascular supply, while the central 2/3 zone is avascular.
Tears are classified as longitudinal, radial, oblique, horizontal, degenerative, complex, flap, or bucket-handle.
Meniscal tears can disrupt knee biomechanics, causing varying degrees of symptoms and predisposing the knee to other short- and long-term sequelae, including quadriceps or hamstring inhibition, patellofemoral pain syndrome, altered gait, and osteoarthritis.
Synonym(s): Cartilage tear (common usage by patients for a meniscal tear)

Epidemiology

One of the most common knee problems; annual incidence is 60–70 per 100,000 persons (1).
Traumatic tears typically occur in 13–40-yr-old individuals with sports-related injuries.
Degenerative tears typically develop in patients over 40.
Posterior horn of medial meniscus is most commonly affected location.
More common in males than females, with ratio between 2.5:1 and 4:1 (1)

Risk Factors

Abnormal mechanical axis
Ligament deficiency
Degenerative joint disease
Discoid meniscus
Poor quadriceps control

Etiology

A meniscal tear may occur following twisting, shearing, or compressive forces from contact or noncontact mechanisms.

Commonly Associated Conditions

∼1/3 of traumatic meniscal tears associated with anterior cruciate ligament (ACL) injury
Tibial plateau and femoral shaft fractures

Diagnosis

History

With a skilled practitioner, diagnosis can be correctly made in 75% by history alone (2)[B].
Traumatic tears in the younger, athletic population are most frequently associated with a significant cutting/twisting injury, whereas degenerative tears in older patients usually lack identifiable trauma.
Pain in area of medial or lateral joint line
Pain with weight-bearing and twisting/turning of knee or squatting
Degree of pain usually such that individual is able to ambulate after acute injury and may be able to continue sports participation
May be associated with slow onset of effusion over several hours
Catching, locking, or clicking sensation
Episodes of giving way
Symptoms may wane, but typically recur with resumption of activities.
Subsequent intermittent effusions not uncommon

Physical Exam

With a skilled history and physical, clinical examination can reach 88–92% accuracy (3)[C].
Exam findings suggestive of meniscal tear:
- Effusion/hemarthrosis may be a sign of meniscal, ligament, or osteochondral injury.
- Locked knee is suggestive of bucket-handle meniscal tear, ligament tear, or loose body.
- Valgus/varus instability suggestive of medial collateral ligament (MCL)/lateral collateral ligament sprain, which may have associated meniscal injury.
- Positive anterior/posterior drawer or Lachman test indicates cruciate ligament injury, which may have associated meniscal injury.
- Tenderness to palpation isolated over the medial or lateral joint line is the most common finding on physical exam (sensitivity 71–85%, specificity 86–93%) (2)[B].
- Positive McMurray's test: Palpable click and pain over joint line produced when meniscal fragment catches during test (sensitivity 48–80%, specificity 86–94%) (2)[B]
- Positive Apley test: Pain over the respective joint line with the patient prone and the knee flexed to 90 degrees, while the leg is internally and externally rotated under an axial load (sensitivity 41%, specificity ranges 80–93%) (2)[B]
- Positive Thessaly test: Pain over the respective joint line with the patient standing on the affected leg at 5 and 20 degrees of knee flexion, followed by internal and external rotation of the leg and torso (sensitivity 66–92%, specificity 91–97%) (2)[C]
- Atrophic quadriceps suggestive of chronic inhibition by pain or effusion
- May have decreased range of motion secondary to pain or effusion

Diagnostic Tests & Interpretation

Imaging

Standard weight-bearing anteroposterior/lateral/tunnel/patellar (sunrise, merchant) views to rule out other conditions such as loose body, arthritis, osteochondritis dissecans, or fracture
MRI useful to evaluate for concomitant structural damage when the diagnosis is in question or for operative planning
Should be performed quickly for locking symptoms or suspicion for substantial injury. Otherwise, is typically reserved for symptoms persisting >4–8 wks in the otherwise healthy knee
MRI findings of meniscal tear include meniscal cleavage signal, which extends to the meniscal surface.

Differential Diagnosis

Synovitis
Intra-articular loose body
Articular cartilage defect
Ligamentous injury, particularly ACL and/or MCL
Patellar subluxation/dislocation
Degenerative joint disease
Chondromalacia patellae
Tibial plateau fracture

Treatment

Initial treatment is RICE—rest, ice (20 min several times per day), compression, elevation—and NSAIDs.
Immobilization is not recommended unless evaluating for fracture or major ligamentous injury; however, a hinged knee brace may offer support, protection, and symptom relief.
While infrequently required, crutches with partial weight-bearing may provide relief.
Sports activity should be restricted until symptoms resolve or (if indicated) MRI is performed.
Further management decisions are based upon patient's age, symptomatology, type of tear, and co-existing knee conditions.
Younger patients with traumatic tears should be thoroughly evaluated and more aggressively treated.

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Additional Treatment

Referral

Expedited surgical referrals should be made for:
- Traumatic longitudinal or radial peripheral tears measuring ≥1 cm (4)[B]
- Locking symptoms, flap tears, and bucket-handle tears
- Associated cruciate ligament injury, osteochondral defect, loose bodies, or fracture
Nonurgent referrals include tears treated nonoperatively but that continue to cause pain or disability.
Individuals with degenerative joint disease will likely have meniscal tears, and the presence of one is not necessarily a cause for a surgical referral.

Additional Therapies

Small (<1 cm) peripheral meniscal tears often spontaneously heal. Even if they persist, they will likely become asymptomatic. Pain typically improves over 6–12 wks (4)[B].
For discomfort persisting several weeks, intra-articular corticosteroid injections often provide significant relief.
Stationary bicycle riding or a home exercise program/physical therapy addressing balance, quadriceps and hamstring strength can reduce pain, increase range of motion, and help protect the knee from further injuries.
While surgery is not contraindicated, nonoperative interventions (including NSAIDs and corticosteroid injections) are appropriate initial treatment for:
- Smaller central tears
- Complex/degenerative tears
- Tears in setting of degenerative joint disease

Surgery/Other Procedures

Both partial meniscectomy and meniscal repair are outpatient-based procedures.
Partial meniscectomy is frequently performed for flap and bucket-handle tears or for tears failing nonoperative treatment.
Horizontal tears are typically degenerative tears and have a minimal chance of healng. As they may progress to flap tears, they may be excised.
Meniscal repair is attempted most commonly for traumatic longitudinal or radial tears in the periphery (4)[C].
Occasionally bucket-handle tears are amenable to repair.

Ongoing Care

Prognosis

∼20% of meniscal tears may heal without surgical intervention. These are typically small (<1 cm), traumatic longitudinal or radial tears along the meniscal periphery (4)[B].
Younger patients are more likely to spontaneously heal than older patients, and have better outcome with meniscal repair (5)[C].
In the carefully chosen patient, meniscal repair is successful in up to 80% (6)[B].
Successful repair compared to resection has a lower incidence of degenerative change after 5 yrs (6)[B].
Regardless of healing, many meniscal tears become asymptomatic (4)[B].
Greatest factor affecting long-term outcome after meniscectomy is presence of articular cartilage damage. 80–90% of patients without articular cartilage damage have good to excellent results with partial meniscectomy within 1st 5 yrs (6)[B].
Total meniscectomy in previously normal knees results in significant arthrosis in 2/3 of patients by 15 yrs from surgery.

Complications

Injury to peroneal nerve possible with lateral meniscus repair
Injury to infrapatellar branch of saphenous nerve possible with medial meniscus repair
Repair could fail, resulting in repeat arthroscopy
Infection

References

1. Arendt EA, ed. Orthopaedic knowledge update: sports medicine 2. Rosemont, Ill: American Academy of Orthopaedic Surgeons; 1999.

2. Karachalios T, Hantes M, Zibis AH, et al. Diagnostic accuracy of a new clinical test (the Thessaly test) for early detection of meniscal tears. J Bone Joint Surg Am. 2005;87:955–962.

3. Mohan BR, Gosal HS. Reliability of clinical diagnosis in meniscal tears. Int Orthop. 2006.

4. DeHaven KE. Meniscus repair. Am J Sports Med. 1999;27:242–250.

5. Stärke C, Kopf S, Petersen W, et al. Meniscal Repair. Arthroscopy. 2009;25:1033–1044.

6. Greis PE, Holmstrom MC, Bardana DD, et al. Meniscal injury: II. Management. J Am Acad Orthop Surg. 2002;10:177–187.

7. Ryzewicz M, Peterson B, Siparsky PN, et al. The diagnosis of meniscus tears: the role of MRI and clinical examination. Clin Orthop Relat Res. 2007;455:123–133.

Additional Reading

Andersson-Molina H, Karlsson H, Rockborn P. Arthroscopic partial and total meniscectomy: A long-term follow-up study with matched controls. Arthroscopy. 2002;18:183–189.

Greis PE, Bardana DD, Holmstrom MC, et al. Meniscal injury: I. Basic science and evaluation. J Am Acad Orthop Surg. 2002;10:168–176.

Klimkiewicz JJ, Shaffer B. Meniscal surgery 2002 update: indications and techniques for resection, repair, regeneration, and replacement. Arthroscopy. 2002;18:14–25.

Codes

ICD9

836.0 Tear of medial cartilage or meniscus of knee, current
836.1 Tear of lateral cartilage or meniscus of knee, current
836.2 Other tear of cartilage or meniscus of knee, current