Meniscal injuries ; symptoms, Diagnosis and Management

Meniscal injuries may be the most common knee injury. Meniscus tears (see the image below) are sometimes related to trauma, but significant trauma is not necessary. A sudden twist or repeated squatting can tear the meniscus.
Magnetic resonance imaging scan showing a torn medial meniscus.

Signs and symptoms

Most meniscal injuries can be diagnosed by obtaining a detailed history. Important points to address include the following:

• Mechanism of injury (eg, twisting, squatting, changes in position)
• Pain (commonly intermittent and usually localized to the joint line)
• Mechanical complaints (eg, clicking, catching, locking, pinching, or a sensation of giving way)
• Swelling (usually delayed, sometimes absent; degenerative tears often manifest with recurrent effusions)

Physical findings that are significant in the examination of a patient with a possible meniscus injury include the following:

• Joint line tenderness (77-86% of patients with a meniscal tear)
• Effusion (~50% of patients presenting with a meniscal tear)
• Impaired range of motion – A mechanical block to motion or frank locking can occur with displaced tears; restricted motion commonly results from pain or swelling

Provocative maneuvers that may elicit characteristic results in the presence of a meniscal tear include the following:

• McMurray test – Pain or a reproducible click
• Steinmann test – Asymmetric pain with external (medial meniscus) or internal (lateral meniscus) rotation
• Apley test – Pain at the medial or lateral joint
• Thessaly test – Pain or a locking or catching sensation at the medial or lateral joint line
• Similar tests, including those that elicit the Bragard, Böhler, Payr, Merke, Childress, and Finochietto signs

Diagnosis

Imaging studies that may be considered include the following:

• Plain radiography – Anteroposterior weight-bearing view, posteroanterior 45° flexed view, lateral view, and Merchant patellar view
• Arthrography – Once the standard imaging study for meniscal tears but now largely supplanted by magnetic resonance imaging (MRI)
• MRI – Criterion standard for imaging meniscus pathology and all intra-articular disorders

Abnormal meniscal signals on MRI are classified into the following groups:

• Grade I – Small area of increased signal within the meniscus
• Grade II – Linear area of increased signal that does not extend to an articulating surface
• Grade III – Abnormal increased signal that reaches the surface or edge of the meniscus (indicative of meniscal tearing)
• Root tears – Meniscal extrusion of at least 3 mm in the mid-coronal plane^[1]

In competent hands, arthroscopy is the best tool for meniscal tear diagnosis, with sensitivity, specificity, and accuracy approaching 100%. Being both therapeutic and diagnostic, it offers the option of immediate treatment of most disorders.

Management

Conservative treatment should be attempted in all but the most severe cases. In the acute phase, such treatment may include the following:

• Home physical therapy program
• Simple rest with activity modification
• Ice
• Nonsteroidal anti-inflammatory drugs (NSAIDs)

If conservative treatment does not lead to resolution, surgical treatment is considered. Surgical options (arthroscopic or open) include the following:

• Partial meniscectomy – The treatment of choice for tears in the avascular portion of the meniscus or complex tears that are not amenable to repair
• Meniscus repair – Recommended for tears that occur in the vascular region (red zone or red-white zone), are longer than 1 cm, root tears, involve greater than 50% of the meniscal thickness, and are unstable to arthroscopic probing
• In cases of previous total or subtotal meniscectomy, meniscus transplantation – A relatively new procedure for which specific indications and long-term results have not yet been clearly established

In the recovery phase, physical therapy may involve the following:

• Partial meniscectomy – Low-impact or nonimpact workouts on postoperative day 1, advancing rapidly to preoperative activities; this can usually be accomplished without formal physical therapy, but such therapy should be initiated if deficits persist
• Meniscus repair – More intensive rehabilitation; one option is avoidance of weight bearing for 4-6 weeks, with full motion encouraged; the authors prefer to allow full weight bearing with the knee braced and locked in full extension for 6 weeks, while encouraging full motion when the knee is not bearing weight

Medical therapy can be used during trials of nonoperative management with associated rest, ice, and a rehabilitation program. If surgical treatment is indicated, medical therapy is valuable in postoperative management.

Source
http://emedicine.medscape.com/article/90661-overview