Meniscal tears

Anatomy

There are two meniscii in the knee, the medial and lateral meniscus.The meniscii consist of cartilage and provide shock absorption and stability to the joint.
The meniscii are attached to the capsule on the periphery and are vascularized in their outer 1/3. The inner 2/3's has no blood supply and no healing 
potential.

Injuries
The meniscii can be injured in many ways including activities as simple as arising from a seated position to more spectacular athletic injuries. 
If the tear is simple (not shredded) and in the vascular zone, meniscal repair is preferable to partial meniscectomy. Most injuries seem to occur in the 
avascular zones and are therefore  irreparable. Loss of as little as 10% of the meniscus can lead to increased contact forces on the joint leading to changes 
in the articular cartilage that ultimately lead to degenerative arthritis.

Meniscal tear

Diagnosis
Meniscal tears can usually be diagnosed by means of history and physical exam. There will often be joint line tenderness, loss of motion and occasionally 
there may even be some swelling. All of these findings are not always present. X-rays do not show meniscii,  but are useful for evaluating the bone and 
joint space. MRI is occasionally helpful but because of its limitations evaluating articular cartilage it is not often helpful in distinguishing articular 
cartilage from meniscal cartilage injuries which have similar histories and physical findings.
Treatment
Meniscal tears can lead to pain, locking, swelling and wear on the articular cartilage surfaces. Most tears will not respond to non-operative treatment. 
Arthroscopy is the treatment of choice for meniscal tears. The meniscus should be repaired whenever possible or minimal meniscectomy performed.
To date there is no reliable meniscal replacement, allograft meniscal replacement may offer a promising alternative in the future. Most meniscal 
symptoms are reliably resolved with meniscectomy but continued high impact activity is not advisable due to the increased joint load leading to degenerative
arthritis.

After Partial Meniscectomy

 

 

 

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