There are several different ways to repair a meniscus. It is important that a surgeon is capable of employing various techniques in order to be able to carry out the best possible repair for any particular meniscal tear.
This is the ‘traditional’ method that was first used for meniscal repair. This technique involves passing stitches through the meniscus from the inside of the joint, with the needle and suture material passing out of the knee through small incisions, and with knots being placed on the outer side of the meniscus / capsule. A disadvantage of this technique is the risk of potentially causing nerve and / or blood vessel damage, particularly around the back of the knee.
This is similar to the inside-out technique. The surgeon makes cuts in the skin and passes a needle from the outside, into the knee joint, through the meniscus and across the tear, and back out of the knee. The knot is then tied on the outer side of the capsule. Special needles and lassos are available nowadays, making outside-in repair relatively easy. This technique is particularly suitable for anterior horn tears (at the front of the knee).
This is now the most popular and best surgical technique for repairing most meniscal tears. Using specially designed devices, the surgeon is able to repair a meniscus fully arthroscopically, without any additional incisions and without having to pass needles around the back of the knee. Until recently, the best of these devices was the Smith & Nephew Fast-Fix-360. However, Mr McDermott now uses the Stryker Air meniscal sutures, which are, in his opinion, even better. These sutures have a curved slotted needle loaded with two tiny plastic anchors, with sutures tied to each one. The needle is pushed through the meniscus one side of the tear and an anchor is fired, which lodges into the capsule of the joint. Attached to this anchor is a suture. The slotted needle is then pushed through the meniscus again, across the other side of the tear, and another anchor is fired with a suture attached. The two sutures are connected by a slip knot. The knot is tightened and the suture is cut, leaving a very strong stitch across the meniscal tear.
Mr McDermott was the first knee surgeon in London to use the Stryker Air meniscal suture device, and he now uses this very regularly in his knee practice:
The success rate for meniscal repairs varies depending on the papers you read, ranging from around 50% to 90%.
If a surgeon only attempts to repair easy tears, the ‘success’ rate will probably be higher. However, if a surgeon attempts to repair too many tears (including the really bad tears that are more likely to fail) then the surgeon will have a higher failure rate. Experience and judgement are major factors here.
The older someone is, the poorer the blood supply to their meniscus is likely to be, and also the more degenerate the meniscal tissue will most probably be, reducing the chances that a repair will heal successfully.
If a patient chooses a surgeon who is a dedicated specialist knee surgeon, who performs meniscal repair regularly, then they are likely to do a better job of the meniscal repair and the repair is more likely to heal.
It is important that a patient takes their rehabilitation seriously following a meniscal repair and that they protect their knee appropriately to allow the meniscus to heal before they start stressing the joint. This normally means spending 6 weeks on crutches, offloading the joint, with the knee in a hinged brace at 0 to 90 degrees flexion in order to avoid the heavy loading on the meniscus that occurs in deeper flexion.