A discoid (literally: disc-like meniscus) meniscus is a type of regular meniscus. The pathology concerns mainly the lateral meniscus and is most common in young people and adolescents. Some people with discoid meniscus never experience any knee problems, but in most cases this pathology makes itself felt. This includes pain and clicking in the knee.
The discoid meniscus is more susceptible to injury than the normal shaped meniscus. This is due to its shape - when the knee moves, it is more likely to get stuck and injured. The risk of damage increases if there is no attachment to the tibia.
Epidemiology/Etiology
The discoid meniscus is the result of a developmental abnormality. Due to the high number of asymptomatic patients, it is difficult to estimate the actual incidence of this pathology. The incidence rate for the lateral discoid meniscus ranges from 0.4 to 17%, and for the medial one - from 0.06 to 0.3%. The Asian population has a slightly higher occurrence rate.
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There are three types of discoid menisci: a) incomplete (the lateral meniscus is slightly thicker and wider than the normal meniscus); b) complete (the tibia is completely covered by the meniscus); c) hypermobile meniscus (the meniscus is of normal shape, but has no attachment to the tibia). Hypermobile meniscus or hypermobile Risberg type is a very rare pathology, the prevalence of which is only 0.2%.
Clinic of Dr. Glazkov. Treatment of the knee and shoulder joint
Clinic of Dr. Glazkov.
Treatment of the knee and shoulder joint Pathological changes usually develop in older people against the background of dystrophy and degeneration (destruction) affecting cartilage tissue. They occur when trophism (nutrition) deteriorates.
Sometimes weakening of the menisci can be congenital due to a violation of the functional state of the genetic material, and changes can be observed already in childhood.
A long-term inflammatory process affecting components of the musculoskeletal system, as well as being a consequence of autoimmune processes (rheumatism, rheumatoid arthritis) or chronic infection, can also cause gradual weakening of cartilage and their pathological damage.
Diagnostics
Discoid meniscus on MRI
Magnetic resonance imaging provides clear images of soft tissue, so it can be used to visualize the meniscus. The most accurate criteria for diagnosing discoid meniscus on MRI are the ratio of the minimum width of the meniscus and the maximum width of the tibia (more than 20%), as well as the ratio of the total width of both lateral horns to the diameter of the meniscus (more than 75%). Therefore, an MRI may show an abnormal shape of the meniscus as well as tears within the meniscus. MRI cannot detect meniscus hypermobility (Riesberg hypermobility type) because the problem occurs during movement.
Biochemical content
By wet weight, the meniscus is primarily composed of water (72%), with the remaining 28% consisting of organic matter, mainly extracellular matrix and cells. Overall, collagens make up the majority (75%) of this organic matter, followed by glycosaminoglycans (17%), DNA (2%), adhesion glycoproteins (<1%), and elastin (<1%). These proportions may vary depending on age, injury and other pathological conditions.
Proteoglycans are molecules that constitute the main component of the extracellular matrix of the meniscus. These molecules are composed of heart-shaped proteins associated with glycosaminoglycans. The main types of glycosaminoglycones found in normal human meniscus tissue are various types of chondroitin sulfates. Aggrecan is the main large proteoglycan of the meniscus. Aggrecan plays a very important role in the interaction of chondrocytes and their extracellular matrix due to its ability to bind hyaluronic acid. The main function of proteoglycans is to allow the meniscus to absorb water, the retention of which supports the tissue during compression.
Inspection
During physical examination, swelling may be detected in the area of the lateral joint space, which is painful to palpation. To test your knee for discoid meniscus, you need to twist it in flexion or extension.
A clicking/popping or stepping sensation may occur as you bend and straighten your knee. This is usually associated with the less common type of Reisberg injury.
There may also be a feeling of limited movement during flexion/extension. When fully flexed, an anterolateral convexity may be detected. It is possible to find a positive McMurray test, but it is not typical, especially in young children.
The accuracy of clinical examination ranges from 29% to 93% compared with knee arthroscopy. This may be explained by variation in symptoms, descriptions of them as intermittent or vague, and constant change.
Causes of meniscus tear
In young people, the main cause of meniscal tears is injury. The knee is usually injured during sports or during outdoor activities. The most common situations that lead to a torn meniscus are:
- a blow to the side or front of the knee, causing the knee joint to move to the side;
- displacement of the knee when landing during a jump;
- disproportionate load on the knees when moving in uneven terrain;
- unexpected and rapid application of force (for example, during a collision).
With age, the cartilage that makes up the meniscus becomes less elastic, which increases the likelihood of damage even under relatively light loads. Thus, gonarthrosis (degenerative disease of the knee joint) is a factor favoring meniscal rupture. Another such factor is activities associated with the need for frequent squats (such as, for example, some types of construction work). Diseases such as rheumatism and gout also increase the risk of meniscus tears, as they usually occur with damage to the knee joints.
Treatment
Traditionally, treatment for stable or unstable discoid meniscus has been open total meniscectomy.
But recent studies have shown that partial meniscectomy of normal-shaped menisci increases stress on the articular surfaces in proportion to the amount of meniscus removed. Those. Total meniscectomy of the nondiscoid meniscus often results in osteoarthritis. Given the negative impact of meniscectomy on normal knee function, the goal of treatment planning should be to preserve meniscal tissue.
A discoid meniscus without any symptoms or physical signs should not be treated with surgery. However, it is important to carry out periodic monitoring in order to detect any worsening of the condition early and plan appropriate treatment.
Currently, arthroscopic partial meniscectomy is the preferred treatment for symptomatic stable, complete or incomplete discoid meniscus. As mentioned above, removing the entire meniscus accelerates degenerative changes within the joint, so the current standard therapy is to remove the abnormal central portion and preserve the meniscus rim to maintain proper knee biomechanics.
Symptoms of a meniscus tear
At the time of injury, the person experiences severe pain. But after a while, many discover that, despite the injury, they can easily walk, leaning on the injured leg. However, in this case, it is very likely that over the next day the problems will accumulate and movement in the knee will become increasingly difficult.
Main symptoms of a meniscus tear
The main symptoms of a meniscus tear are:
- knee pain, which can vary in severity—mild, severe, constant, or occasional;
- edema. As a rule, the knee does not swell immediately, but several hours after a meniscus injury;
- the feeling that movement in the knee is not free, as if something is clinging to it, usually occurs when the knee is bent. You can feel something clicking in it;
- the knee becomes unstable (a feeling of “looseness” in the joint)
- inability to bend and fully extend the knee.
Physical therapy
There is currently insufficient evidence to support the development of a specific rehabilitation program after partial meniscectomy.
What might a treatment program include?
- Control pain, swelling and inflammation with cryotherapy, NSAIDs.
- As rehabilitation progresses, continued use of the above techniques may be necessary to manage residual pain and swelling.
- Restoring range of motion with exercises within the limits specified by the surgeon.
- If surgery has been performed to repair the meniscus, it is necessary to limit flexion and rotation at the extreme points (period from 8 to 12 weeks).
- Restore muscle function with specific strengthening exercises targeting the quadriceps, hamstrings and glutes. for quadriceps - squats;
- for hamstrings - bending the legs with resistance;
- for the gluteal muscles - a bridge.
- it is also necessary to strengthen the muscles acting on adjacent joints, especially if weight bearing was limited before and after surgery;
- In addition to strengthening the muscles, it is necessary to restore their flexibility and elasticity.
Complications of meniscal injuries
If a person does not immediately consult a doctor, after a while the pain may subside, which is perceived as recovery. Actually this is not true. From an acute form, the injury becomes chronic, most often this happens within 2-3 weeks. A person believes that the problem with the knee has subsided, but any careless movement can cause pain, swelling, and even blockage of the knee joint to reappear. This can happen with varying frequencies - for some people every day, for others 1-2 times a week or less, depending on the degree of damage and activity.
If left untreated, ruptures result in progressive cartilage damage due to loss of shock-absorbing function, which can lead to arthrosis and constant pain. The latter in advanced cases ends with endoprosthetics. In the presence of small horizontal tears, parameniscal cysts often form.
Arthroscopic surgery on the meniscus
The meniscus is a cartilage pad that acts as shock absorption and stabilization for the joint. In humans, menisci are also present in the acromioclavicular, sternoclavicular, and temporomandibular joints, but meniscal tears requiring treatment occur only in the knee joints. As the knee moves, the menisci compress, changing their shape. Each knee joint has two menisci: the outer (lateral) is more mobile, so its traumatic injuries occur less frequently, and the inner (medial) is less mobile and is connected to the internal collateral ligament of the knee joint, which often causes their joint damage. Each meniscus has a body, anterior and posterior horns. In the anterior part of the joint, the menisci are connected by a transverse ligament.
Causes of tears and damage to the menisci of the knee joint
Most meniscus tears happen out of the blue. The reason for this is degenerative changes in the menisci. Degenerative changes are changes in the physico-chemical properties of the cartilaginous tissue of the meniscus as a result of chronic microtraumatization, tissue malnutrition, and inadequate loads.
An equally common cause of meniscus damage is traumatic tears. But the most common cause is a combination of meniscal injury and its degenerative changes.
Classification
Meniscal injuries vary in appearance, location, shape and extent. A special group consists of congenital diseases.
By type of damage there are:
Longitudinal tears, watering can handle tears, flap tears, degenerative tears, radial tears, horizontal tears, ramp tears (the most posterior tears), meniscal cysts, meniscal hypermobility, discoid meniscus.
Clinical picture
Most often, patients indicate a rotational nature of the injury or sudden pain and a sensation of tearing that occurs when performing a squat. Meniscus tears are also characterized by transient disturbances in movement in the joint (knee joint blockades) and clicking sounds.
Old tears are accompanied by quadriceps atrophy, accumulation of joint effusion, and limitations in knee flexion, either transient or permanent. Acute meniscal tears are usually accompanied by clinical signs of acute trauma, hemarthrosis (collection of blood inside the knee joint), and damage to the capsule and ligaments (collateral, posterior and anterior cruciate).
Diagnostics
There are a large number of methods available to differentiate meniscal injuries from other injuries. Since there is no generally accepted universal method, it is recommended to use several tests at once. Negative results of a clinical study do not rule out a meniscus tear; the sensitivity of the tests is 60-90%, depending on the clinical experience of the doctor.
The method of choice for diagnosing meniscal injuries is magnetic resonance imaging (MRI). It is widely used in this area and is sometimes superior to clinical examination in its value, as a result of which patients with unclear symptoms are often referred for MRI examination even before a thorough clinical examination. MRI is a highly sensitive, specific method for diagnosing meniscal injuries, which can be detected in most cases provided that the MRI images are of good quality.
Treatment
Meniscal injuries are the most common diseases of the knee joint and one of the main indications for knee arthroscopy. Traumatic ruptures of the meniscus often occur in athletes who experience significant axial loads in combination with rotation (football, basketball, alpine skiing, martial arts, artistic gymnastics, hockey, figure skating). But surgery for meniscal injuries is not always indicated. Small radial tears of the anterior or posterior horn, longitudinal tears of the outer and inner surface of the meniscus, penetrating not to the full thickness (up to 10 mm), as well as transverse tears up to 4 mm are considered stable, do not require arthroscopic intervention, and can be treated quite successfully with conservative treatment.
Its essence, in this case, is to temporarily limit the load on the knee joint, improve the trophism (nutrition) of the knee tissues and further restore and strengthen the muscles responsible for the stability of the knee joint and improve proprioceptive sensitivity and motor control during sports activity. When undergoing rehabilitation programs under the guidance of a specialist, athletes are excluded from performing movements that provoke tension in the meniscus and significant direct and axial load. At the same time, most people involved in sports themselves feel and understand what movements provoke further damage to the meniscus. Please note that the wrong tactic for ruptures that can be treated conservatively is to apply a cast. When there is no other damage to the joint, this contributes to the development of contracture (stiffness) of the joint, which significantly lengthens the recovery time.
One of the key roles of conservative therapy for meniscus damage is rehabilitation treatment. Its main purpose is to create a muscle corset around the joint. While the muscles do not have sufficient tone, it would not be superfluous to immobilize the joint with a knee brace.
The main indications for arthroscopy in case of meniscus damage are serious tears causing blockages, persistent pain, limited mobility, fluid in the joint that appears again after puncture, failure of conservative therapy and concomitant pathology, which itself serves as an indication for surgery (ligament ruptures, bone and joint damage, etc.).
Why Medalp
Diagnosis and treatment of meniscus injuries is a delicate process that requires highly qualified specialists and, if the patient is an athlete, an understanding of the specifics of this sport.
Medalp has everything you need to diagnose and treat meniscus injuries and injuries at all stages
1) clinical diagnosis by an orthopedic doctor and ample opportunities for conservative orthopedic therapy in a convenient area of the city;
2) complete pre- and postoperative management, individual anesthesiological support;
3) arthroscopic treatment by surgeons specializing in sports joint injuries. Since the establishment of the clinic, the surgical team has performed more than 3,000 arthroscopic operations on the knee joint;
4) specialized postoperative rehabilitation until complete restoration of joint function and the person’s return to usual activities, including high-performance sports.