Meniscus Repair Surgery for Torn Knee Cartilage

Once diagnosed with a meniscus tear, a decision needs to be made regarding the treatment of this problem. Many meniscal tears, particularly chronic tears, can be treated non-operatively. non-operative treatments may include:

• Physical therapy
• Strengthening exercises
• Anti-inflammatory medications
• Cortisone injections

However, some meniscus tears may require surgical treatment.

Why Meniscus Repair Surgery Is Needed

Your surgeon may offer a meniscus repair as a possible treatment option for damaged or torn cartilage. Years ago, if a patient had torn cartilage, and surgery was necessary, the entire meniscus was removed. These patients actually did quite well after the surgery. The problem was that over time, the cartilage on the ends of the bone was worn away more quickly. This is thought to be due to the loss of the cushioning effect and the diminished stability of the knee joint that is seen after a meniscus is removed.

When arthroscopic surgery became more popular, more surgeons performed partial meniscus removal, called a partial meniscectomy. A partial meniscectomy is performed to remove only the torn segment of the meniscus. This works very well over the short, and long-term if the meniscus tear is relatively small. But for some large meniscus tears, a sufficient portion of the meniscus is removed such that problems can again creep up down the road.

Who Needs Repair?

Tears of the meniscus that cause so-called "mechanical symptoms" tend to respond best to surgical treatment. A mechanical symptom is caused by the meniscus physically impeding the normal movement of the knee. Common "mechanical symptoms" include:

• Locking of the knee (unable to bend)
• Inability to fully straighten the knee
• A popping or clicking sound or sensation

In the operating room, the surgeon has two primary options, either remove the torn meniscus (a partial meniscectomy) or perform a meniscus repair to place the edges together with sutures or tacks.

Is Meniscus Repair Better?

The meniscus is a circular piece of cartilage with its blood supply coming from the outer rim. In order for the meniscus repair to heal, the tear must be near this outer edge in an area of good blood supply (nutrients from the blood vessels are necessary for healing)--this is the so-called red (vascular)-white (non-vascular) region of the meniscus.

Tears in the central portion of the meniscus will not heal even if a meniscus repair is performed. This part of the meniscus does not have a blood supply. When looking at this nonvascular part of the meniscus, it looks white, and therefore tears in this zone of the meniscus are not repaired. These tears are within the white-white zone where there is no blood supply to either side of the tear in the meniscus. These central tears will be removed by your surgeon. However, studies seem to show that if a meniscus repair is possible, the long-term outcome is better for the patient because of a decreased risk of arthritis later in life.

Performing the Surgery

Techniques of meniscus repair include using arthroscopically placed tacks or suturing the torn edges. Both procedures function by reapproximating the torn edges of the meniscus to allow them to heal in their proper position and not get caught in the knee causing the symptoms described above.

The success of a meniscus repair is most dependent on two factors. First, if the meniscus repair is attempted on a tear in the central portion of cartilage (where the blood supply is poor), it is likely to fail. Second, patients must be compliant with the postoperative rehabilitation after a meniscus repair.

If the meniscus repair fails (i.e. the repaired meniscus does not heal), which happens to 20 to 40% of the time, a second surgery may be necessary to remove the re-torn meniscus.

Rehab After Repair

Rehab following meniscus repair surgery is more extensive than rehab after a partial meniscectomy (surgery to remove the meniscus tear). Because you have to allow the torn meniscus to heal, certain activities must be restricted to avoid placing excessive stress on the healing meniscus.

In particular, deep flexion (bending) of the knee must be avoided as this movement is known to place high stresses on the repaired meniscus. For this reason, most patients who undergo meniscus repair surgery are placed in a brace for several months following their procedure.