Meniscus and Cartilage Tears: Do you have to have surgery?

Steve A. Mora, MD

Introduction

You have injured your knee. This is one of the most common orthopaedic injuries seen in our practice. Many knee injuries occur after a sports related accident but they may also occur after a simple fall or even during daily activities such as bending or squatting down. Perhaps in your case, you have been living with the pain for years and in fact you cannot remember the last time your knee felt completely normal. Simple activities such as a short walk at the park, walking up and down the sideline of your child’s football game, or getting in and out of your car have become difficult. Whatever the scenario, the result is the same; your knee pain is making life difficult or maybe its just not physically enjoyable anymore.

Anatomy

The femur is the upper portion of the knee joint. Its ends are lined with a smooth thin covering called articular cartilage. This surface lining allows smooth and practically frictionless motion. The tibia below is also lined with articular cartilage on its surface. These bones along with the patella (knee cap) will articulate together to form the knee joint. There are 2 “shock absorbers” called meniscus sandwiched between these two bones. These are made out of the same soft tissue material, fibro-cartilage, as that which makes up the tip of your nose. These crescent-shaped structures, medial and lateral meniscus, sit on the surface of the tibia. Because of their poor blood supply, once torn these menisci rarely heal. For this reason, torn meniscus are usually treated by removing the torn pieces rather than stitching the tear together. The anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL) and lateral collateral ligament (LCL) are the 4 major ligaments. Their function is to keep the knee joint “in line” or stabilized by maintaining the anatomical alignment of the femur and the tibia. The ACL is frequently torn in sports and requires complete replacement (reconstruction) instead of suturing together.

What kind of cartilage does the knee joint contain? Two types: Meniscus and Articular

1. Meniscus cartilage is located between the femur and tibia. It serves to cushion and lessen friction at the junction of those two bones. They also serve to better distribute the load from walking and running. These soft tissue structures have poor blood supply and easily become torn.

2. Articular cartilage is the slick, durable, pearly white, substance that covers the ends of the femur, patella, and tibia. It allows smooth gliding and with almost no friction. Articular cartilage usually takes more force to injure than meniscus. It is not uncommon following major trauma to the knee. This type of cartilage also has poor healing capacity once injured. This is also the type of cartilage that becomes worn out in osteoarthritis as we age.

Of the two types, meniscus is more likely to be torn. Knee arthroscopy for the management of meniscus tears is the most common Orthopaedic procedure performed today. But either or both types of cartilage can be damaged by trauma, cumulative forces, or the aging process. Articular cartilage treatment is much more involved.

What causes tears?

Meniscus can tears are frequently seen following a bending or squatting movement. Cartilage tears can often occur in conjunction with other knee injuries, such as ligaments. There are also conditions where the cartilage becomes damaged for unclear reasons and with minimal trauma such as in osteochondritis dissecans (OCD) where the cartilage develops a crater like lesion. Osteoarthritis is a cartilage problem and is due to wear and aging.

Why is there pain?

Usually a patient with a torn meniscus will feel pain and grinding along the inner side of the knee joint. If it’s a significant tear, there may be other symptoms, such as stiffness, popping, clicking and locking. The more displaced or “out of position” the torn fragments are, the more severe the symptoms will be. The surgery goal is to remove these torn fragments.

** “The Take Home Message” **

It is thought that when a meniscus is damaged, the knee is painful for a couple of reasons. First, the torn fragments are loose, they move in and out of place, causing clicking, popping, locking, swelling and irritation. Second, the knee has lost meniscus support (remember that they are like “shock absorbers”). When a portion of the meniscus is torn it can no longer provide normal dampening of joint forces. The loss of support is proportional to the size of the tear. Arthroscopic surgery can usually improve the knee pain because the painful fragments are snipped out or removed. However, the meniscus became irreversibly damaged when it was torn and not when the fragments were excised. The torn meniscus does not regenerate itself, therefore, the small area with the tear will remain abnormal permanently. In cases of massive tears, loss of “meniscus support” becomes significant and despite surgery the knee remains painful to some degree.

Because of this fact, we cannot guarantee that your arthroscopic surgery will be 100% successful. The greater the loss of meniscus tissue, the greater the risk of having persistent pain or future degeneration (i.e. osteoarthritis). Studies have shown that if a total meniscus is torn and removed, the knee is destined to develop arthritis in 12-15 years. The good news is that the long-term results of arthroscopic partial meniscectomy is excellent. Also, it is rare to have a large tear and actually most of the time the tears are small and therefore respond well to surgery.

How is the injury diagnosed?

After the exam, an x-ray is usually done to check for arthritis, spurs, or calcifications. An MRI can be performed to assist in the diagnosis as well as identify cysts and degenerative changes of the joint.

How are cartilage tears treated and what are the options?

Firstly, there is no rush. The surgery is elective. It may be done any time. Think about a tear like a pebble in your shoe. It will be uncomfortable and even painful but satisfactory activity is sometimes achievable without having to take the pebble out. The treatment is predicated on the intensity of the symptoms but not merely the existence of a positive MRI. Therefore, with tears that cause considerable pain, the treatment may include surgery. Initial measures to reduce pain include: ice and non-steroidal anti-inflammatory drugs (NSAIDs). In some cases platelet rich plasma injections may be used augment the healing response. If the tear is not substantial enough for surgical intervention, then the patient may begin exercising to restore strength, range of motion, and overall function. There are no restrictions. The activity is guided by the pain. If there is persistent locking or significant catching it is probably not a good idea to leave alone. In some cases the catching leads to erosion of the surrounding surfaces.

Knee Arthroscopy and Meniscus/Articular Cartilage Treatment.

This option should be selected for those individuals who’s symptoms do not allow them to reach their functional goals. Today, the operation is performed using two small incisions, each 1/2 inch long in the front of the knee. It is performed as an outpatient and usually with a combination of local anesthetic with a intravenous sedation (MAC Anesthesia). Meniscus repair (stitching the edges of the torn meniscus together usually is done in young patients with a clean cut type of tear. Most of the time the torn fragments are cut out. The patient can return home (outpatient) the same day and begin rehabilitation exercises almost immediately. Patients will usually only a cane on the opposite arm for 7 days. The knee will be wrapped with an ACE wrap. A repair requires the use of crutches for up to 4 weeks and a brace to protect the healing meniscus.

What about Articular Cartilage Injury Management? One of our greatest challenges!

ACDGrade4 Remember that articular cartilage may also become damaged or torn similar to a meniscus tear. It is the lining which is a few millimeters thick and so lesions are graded depending on how deep the damage penetrates through the lining. The deepest lesion is one where there is bone exposed (see photo) in the center. Most tears are partial thickness and do not go down to bone. Articular cartilage repair is complex and challenging. Partial thickness articular cartilage tears (grade III and below) are treated with arthroscopic shaving of the loose unstable flaps and smoothing out the rough edges. Complex treatment is reserved for tears/lesions that reach the bony foundation or for tears that did not get better after the arthroscopic shaving. When the articular cartilage tear is full thickness; we call this situation a “grade IV defect”. An articular cartilage repair or re-surfacing option may have to be implemented. The treatment for this may include drilling, micro-fracture chondroplasty, abrasion chondroplasty, cartilage plug transfers, and cartilage transplantation. When the articular cartilage undergoes one of these complex procedure the need for crutches and special rehabilitation is likely. Patients who undergo these complex treatments are usually not back on the field for a couple of months .

What are the risks of surgery?

The risks below are uncommon but nonetheless must be known. By accepting the surgery you also accept these risks. Some of these risks may be minimized by maintaining a healthy lifestyle, eating well, not smoking, controlling diabetes and following your doctor’s instruction.

The list of possible risks is actually much longer, however, those listed below are some of the more common risks. Please discuss any specific concern with us.

Risks of anesthesia including death As a general rule all anesthesia options are safe and effective. Regardless of the option selected, complication rates are low. If you are healthy and able to exercise you should be able to tolerate general anesthesia without any problem. You will have a chance to speak to the anesthesiology before the surgery and make a well informed decision.
Major infection requiring more surgery including loss of graft. Most infections can be treated with short courses of antibiotics but there are cases where more surgery is necessary.
Persistent pain. There are no guarantees. If you have arthritis it increases the chances of having an average or poor outcome. The larger the tear, the greater chance of pain even after surgery.
Major Nerve and/or Blood Vessel injury. Rare to have a major nerve or artery injury. Most of the time the skin immediately around the incision will be partially numb but this is not a significant issue.
Deep Vein Thrombosis (blood clots) with dislodgement into lungs. Extremely rare in arthroscopy.

Making Your Decision

There is absolutely no rush to make a surgical decision. We remind our patients frequently that this is elective surgery. The surgery is done on your time-line and whenever the symptoms are no longer acceptable. The only exception usually applies to a displaced meniscus tear or a large loose fragment in the knee that locks the knee in one position. In these situations, the surgery should be expedited to allow the knee to move again and allow you function.

Anesthesia options

General: Widely accepted and used most commonly
MAC: Local plus IV. Usually done in arthroscopy for simple cases. Very comfortable and less risks. Good choice for patients with sleep apnea.
Spinal/Epidural: Accepted and used infrequently.

Physical Therapy

Started 1-2 weeks after surgery. Done 2x a week for 6 weeks. Set up following your first post operative appointment.

How soon can the patient return to full activities and sports?

Every patient is unique. Some patients are able to return to play in 6 weeks while others take 12 weeks.. One variable is the amount of de-conditioning prior to surgery, size of the tear, and pre existing arthritis. PT and a daily home exercise program therefore is imperative.

We hope this information helped. Please contact us with further questions.

About Steve A. Mora MD:

Dr. Mora is a native of Orange County. He graduated from Anaheim High School in Orange County CA. He completed his training at the UC Irvine where he finished in the top of his class with AOA Medical Society honors. He completed his Orthopedic Surgery training USC. He completed an extra year of training with a Sports Medicine, Cartilage, Shoulder, and Knee Fellowship at Santa Monica Orthopaedic and Sports Medical Group. He is currently practicing Orthopedic Surgery in Orange County. Dr. Mora’s practice focus on sports related trauma, knee ligament and cartilage repair, shoulder rotator cuff and instability, hip arthroscopy and partial knee replacement. He sees athletes of all levels including professional soccer and UFC/MMA. He is team doctor for the Anaheim Bolts pro indoor soccer team and Foothill High School. Dr. Mora performs Cartilage transplantation (Genzyme), partial custom knee replacement, OATS, tibial osteotomies, meniscus transplant, ACL reconstruction, shoulder reconstruction, elbow arthroscopy, hip arthroscopy, platelet rich plasma and adult stem cell injections. Dr. Mora’s family heritage is Peruvian. He speaks fluent Spanish.