What is a meniscus?
Meniscus is a cushion made of cartilage which fits within the knee joint between tibia and femur. Each knee has two such cushions the outer known as lateral meniscus and inner cushion is known as medial meniscus.
Each Menisci has - Two ends (Anterior Horn and Posterior horn); Two borders (inner and outer); and Two surfaces ( upper and lower).
The lateral meniscus is mobile hence saved during an injury and medial meniscus is more fixed which causes more tears to occur in medical meniscus.
Lateral meniscus is sometimes associated with discoid meniscus and meniscal cysts. Lateral meniscus is also associated with acute injury to the ACL ( Anterior Cruciate Ligament).
Medial Meniscus tears are more likely degenerative tears that happen because of wear and tear.
Meniscus are living structures and healing potential is decided by the amount of blood supply to the torn area. The outer one-third of the meniscus is vascular. It can heal if immobilized or repaired. The inner one-third is not having any blood supply and hence does not heal if injured or torn. The middle third is the red/white junction and healing of this area is also not that good compared to the outer zone.
- The Meniscus acts as a Shock Absorber inside the knees by providing load sharing across knees and increasing the contact area and decreasing the contact stress.
- Act as joint filler
- Joint Lubrication: help to distribute Synovial fluid through the joint and aid the nutrition of articular cartilage.
So how do we come to know if we have a Meniscus tear?
- Person is usually a young person who sustains twisting injury to the knee or has suffered from a accident
- Knee pain
- Swelling of the knee
- “Locking” : Sudden inability to extend the knee fully
- Popping or clicking within the knee.
- Limited motion of the knee joint.
So what are different types of Meniscus tears?
- Tears can be partial ( grade I and grade II) or complete (Grade III).
- Tears can be in inner or outer Meniscus.
- Tears can be divided into zones to decide possibilities of healing ( Red Zone, Red-White Zone, White Zone)
- Tears can be divided based On Pattern
- Vertical/Longitudinal - Common, esp. with ACL tears
- Bucket Handle - Vertical tear which may displace into notch
- Horizontal - More common in older population - May be associated with meniscal cysts
So what tests are necessary in case of a knee Meniscus or a knee cushion tear?
- Clinical checkup by Knee Specialist
- Xrays
- MRI scan ( good quality)
So do all Meniscus injuries require operation or surgery?
- 90% the tears heal by non operative methods only. Most require immobilization by braces and ice packs and medicines by orthopedic specialist doctor.
- Few of the large tears or severe variety of the meniscus tears require a surgery.
Meniscus tears are repaired by an arthroscopic trained surgeon only who can fulfil the surgery entirely via small key holes inside the knee. Dr Merchant has been specially trained and accredited to perform such a surgery from various International and National centres. Some parts of meniscus which are torn in zones of poor blood supply and have no potential to heal have to be trimmed and rest of the tissue of meniscus is repaired by various arthroscopic stitching techniques. After surgery, there are varying periods of immobilization in a brace and use of walker as per the tear.
It takes 2 to 3 months to recover from a meniscus repair surgery and furthermore may be required if any sports need to be played.