Our knees are a crucial part of many physiological functions. One of the most important aspects of cushioning the knee is the meniscus, which acts as the “shock absorber.” The meniscus can be damaged in traumatic twisting events, but more commonly with time as it begins to weaken with repetitive use. This can lead to pain and discomfort, typically on the inside (medial) or outside (lateral), joint line of the knee.
As a general rule, younger patients suffer from more trauma-induced injuries that tend to do better with surgery. Patients in their 30s and above tend to suffer from more micro-trauma-induced injuries that often can be treated without surgery.
A knee injury has the potential to derail many daily functions from driving to walking. Once an injury begins to disrupt daily life, consult a doctor to find out what is happening and how to resolve the issue.
Anatomy of the Knee
Inside the knee joint, there are a couple of major structures: the femur, patella, femur, meniscus, and the stabilizing ligaments (ACL and PCL). The femur is the thigh bone, the patella is the kneecap, and the tibia is the shin bone.
The meniscus is two pieces of cartilage (“medial” and “lateral”) between the femur and tibia that cushion the bones during activity so that they don’t collide. Every joint in the body has a piece of cartilage between the bones for this reason; they serve a very important role in the body’s ability to function.
Injury to the Meniscus
Due to the important location and shock absorbing mechanism of the meniscus, it is prone to tearing. Individuals who participate in sports that involve changing direction quickly, such as tennis or basketball, are at a higher risk.
Tears in the meniscus can begin as a small tear and increase over time, or a significant tear can occur all at once. There are 6 different types of meniscus tears:
- Radial tear: A radial tear is the most common type of meniscus tear. Because this sort of tear develops in a part of the knee that isn’t supplied with blood, it won’t mend on its own. If the tear is significant, surgery may be necessary. The surgeon will trim away the injured section of the meniscus in the case of a radial tear.
- Horizontal tear: One of the easiest tears to heal in the knee is a horizontal meniscus tear. Rather than removing the injured section of the meniscus, the surgeon will attempt to reattach the circumferential fibers of the meniscus. When it comes to meniscus repair, the location is crucial. The more vascular parts of the meniscus, along the outside border, have a higher chance of healing than those closer to the center of the knee.
- Intrasubstance/incomplete tear: On an MRI, physicians frequently observe partial tears of the meniscus in persons in their 20s and 30s. These tears are frequently indicative of early degenerative alterations in the meniscus. Meniscus tears that are just partially torn are called “stable” injuries. That is to say, they are usually not surgically treated.
- Flap tear: A meniscus flap tear is a unique tear pattern. A piece of cartilage is ripped away and might become lodged in the joint, causing it to “catch” or lock up. A surgeon can generally correct the problem without removing much tissue if the flap causes the knee to catch.
- Complex tear: A complex tear has several tear patterns. A complex tear, for example, frequently includes both radial and horizontal tear patterns. Because of the intricate nature of the tear, surgical repair is rarely used to treat it. In certain rare cases, a surgeon may be able to remove some of the torn menisci while mending the rest.
- Bucket-handle tear: A bucket-handle tear is a common form of a horizontal meniscus tear. Because the torn component of the meniscus prevents normal knee mobility, these injuries frequently cause the knee to become stuck. Bucket-handle tears frequently need more immediate surgical intervention to allow the knee to flex again.
A tear in the meniscus can be caused by many factors. The most common reason someone experiences a meniscus tear is because of an injury or repetitive micro-trauma.
These occur most often during sports or exercise, but depending on an individual’s overall health, they can also occur from a task as simple as walking around or a simple twisting motion.
It is more likely that a tear will occur if an individual is experiencing degeneration in the joint. Degeneration is what happens when soft tissue is worn down over time and slowly becomes smaller. “Degenerative tears,” most often begin to occur in patients that are above 40 years of age.
Conditions such as arthritis are a result of chronic, slowly evolving degeneration – when cartilage, both the meniscus and articular cartilage, can no longer protect bones, they begin to rub against one another, causing damage to the bone integrity and pain in the area.
Signs and Symptoms
Tearing the meniscus can feel like a sharp pain, or cause no sensation at all initially. Some individuals can hear or feel a “popping” sensation as the cartilage tears. It may not be readily apparent that a tear has occurred, but the knee typically becomes painful and swollen in the days following the injury.
Some individuals may continue to exercise without yet knowing that they have a tear. Common symptoms of a meniscus tear are:
- Pain in the knee
- Stiffness or inability to bend the knee
- Weakness or inability to put weight on the knee
Symptoms can be chronic or only occur during certain activities depending on the severity of the tear. Once the symptoms begin to impact daily life, a doctor should be consulted.
Diagnosing a Meniscus Tear
Consulting with a doctor allows the recovery process to begin. They will ask about symptoms and family history, and it is important to be as honest as possible during this meeting. Symptoms that may not seem relevant could be important indicators of what is causing pain.
They may observe how a patient walks, squats, or how far they can move their knee. Discussion and observation alone cannot often result in an accurate diagnosis, however, so doctors turn to proven diagnostic techniques to be certain of the cause:
- McMurray test: With the patient lying on their back, doctors will bend the knee in a way that indicated a meniscus tear. Doctors will listen for a popping or clicking sound, often indicative of a tear. This test is often accurate if performed correctly, though some doctors prefer to use imaging techniques to be certain.
- MRI: Magnetic Resonance Imaging can create an image of a patient’s internal soft tissue. If there is a tear in the meniscus or any other soft tissue, an MRI can detect most meniscus tears.
- X-ray: These are not often used for meniscus tears as they do not show soft tissue. They are useful for determining abnormalities in the bone, which could be contributing to knee pain.
There can be more than one condition occurring simultaneously. Doing more than one diagnostic test can indicate all of the causes of knee pain. Knowing exactly what is going on under the surface allows doctors to create an effective recovery plan that is individual to each patient’s needs.
Recovering From a Meniscus Tear
The recovery process will vary depending on the severity of the tear, where it is located, and how the tear is positioned in relation to the cartilage and bone. Some minor tears do not require surgery, but in many cases, this injury leads to surgical intervention. Nonsurgical treatments may include:
- RICE Method: Rest, Ice, Compression, and Elevation. Resting the injury allows it to heal without added stress. Icing the knee can reduce inflammation, swelling, and pain. Compression prevents further damage and blood loss by reducing swelling. Elevating the injury can prevent blood clots and reduce swelling – the knee must be above the heart, which can be achieved by laying down and placing a pillow under the knee.
- Anti-Inflammatory Medication: over-the-counter drugs such as ibuprofen or naproxen can reduce inflammation and pain.
- Physical Therapy: the goal of physical therapy is to restrengthen muscles, which in turn provides more support for the joint. The exercises in physical therapy can also improve blood flow, which sends the body’s healing properties to the injury and can lead to repair over time.
These treatments have the potential to heal minor injuries, but may not always work. Once these have been attempted with little to no pain relief, doctors will often turn to surgery to repair an injury. In some cases, the injury is so severe initially that surgery is the first option.
Surgical Techniques for Meniscus Tear
There are several types of surgery that may be done to repair a torn meniscus.
The most common type of knee surgery is called a partial Meniscectomy performed through arthroscopy. Arthroscopy is considered minimally invasive because it involves small incisions that allow a camera with a light to locate the injury.
Once the injury has been found, surgeons enter the knee with the small tools that are necessary to make repairs. Types of arthroscopy that may be used are:
- Arthroscopic or meniscus repair: Only about 15% of Meniscus tears can be “repaired.” Doctors can attempt to repair the meniscus by stitching the torn meniscus back together. This form of surgery requires that the meniscus heal and therefore has a longer recovery time. This requires 6 weeks on crutches and is typically performed on younger patients.
- Partial meniscectomy: By far, the most common meniscus surgery. Using an arthroscope, doctors can cut away or remove parts of the meniscus that would not be able to heal on their own or with stitches.
- Total meniscectomy: In this day and age, this is an increasingly rare surgery because it causes early-onset arthritis. This surgery is not often necessary as it is considered quite drastic by removing the entire portion of the meniscus.
Once the surgery is complete, doctors will have a recovery plan set that ensures each patient can heal as quickly as possible. Postoperative plans often include the use of a walker, cane, crutches, or other assistive devices that help pain levels by reducing the amount of pressure on the knee. Recovery also involves physical therapy or certain exercises that will ensure that the knee heals properly.
The recovery time for knee surgery is typically short, 4-6 weeks. Most patients report decreased pain and an ability to walk within two weeks. In approximately two months, patients can begin to enjoy exercise again. This may vary depending on the severity of the injury and the patient’s commitment to the recovery process.
Though this recovery time is short relative to more invasive surgeries, some patients cannot afford to take so much time off of work. Before deciding to undergo surgery, it is important to consider all of the options available that may help heal the injury.
Alternative Therapies for Recovery: Cell-Based Therapies
The burgeoning field of Regenerative Medicine and Cell-Based Proceduresoffers new hope to patients suffering from meniscus tears. These therapies work particularly well on soft tissue, which gives them an advantage in repairing this specific injury. There are two types of regenerative therapy offered at CELLAXYS:
- Autologous Stem Cell Procedures: Autologous stem cell procedures begin with taking cells from a patient’s adipose (fat) tissue, blood cells, or bone marrow. These cells are then processed so that they are concentrated and reinjected into the injury site. These cells contain healing properties that the body is already using naturally to repair minor damages. Increasing the concentration of these cells could lead to a faster recovery.
- Cell-Based Therapy or Autologous Stem Cell Procedures begins with an extract of stem cell-rich adipose (fat) tissue or bone marrow. This tissue is then minimally manipulated and prepared to be transplanted into the knee. The transplantation will be performed under live x-ray called fluoroscopy and Ultrasound together while you are under anesthesia.
- Stem Cell rich tissues are used in the body’s natural healing process to stimulate and re-initiate the healing process. At Cellaxys, a specific procedure called Minimally Manipulated Adipose Tissue Transplant tends to be the most requested procedure for meniscus tears in patients above 40, and bone marrow-derived stem cells for patients under 40.
- Treatments like these are important to consider when faced with all of the options, as they are some of the only treatments on the market that seek to address and correct the actual cause of injury, rather than just managing symptoms.
- Cell-Based Medicine can be a good option to prevent the need for surgery in many patients, but it can also be used after an operation to help repair tissue that gets damaged in the process, specifically in patients suffering from pain after meniscus surgery.
- Clinical studies have demonstrated thicker, stronger appearing meniscus one-year post-procedure. This has been demonstrated using both adipose and bone marrow-derived stem cells.
- Platelet-Rich Plasma (PRP) Therapy: this form of therapy begins with a simple blood draw. The patient’s blood is then placed in a centrifuge to isolate the platelets from other components in the blood. Once the solution is processed, it is injected into the injury site. Platelets contain proteins and healing factors, namely 10 different growth factors, that the body uses to repair damaged tissue. Undergoing this form of therapy can allow an injury or tear to heal more quickly with an increased amount of healing properties.
All Cell-Based procedures are performed as outpatient procedures. The recovery time is much shorter than surgery. Patients who receive these procedures commonly return to normal activities within a few days.
Meniscus tear injuries may need surgical intervention depending on the severity of the tear. In these cases, Cell-Based procedures can be used as an adjunct to surgery as a sort of “boost” to help their injury heal post-op. In many cases, regenerative Cell-Based procedures improve pain and function to the point where surgery is no longer necessary.