What are the symptoms that manifest after a meniscus injury? What are the main treatments for meniscus injuries?
We often have friends ask about meniscus injury, today we will compile a detailed explanation about meniscus injury, I believe that after reading it, you will also have a preliminary understanding of your condition.
1.Where is the meniscus? What is the structure?
The meniscus, located in the knee joint, is a half-moon shaped plate of fibrocartilage that acts as a cushion between the femur of the thigh and the tibia of the lower leg.
There are two menisci in each knee joint, the medial meniscus and the lateral meniscus. The meniscus, which attaches to the upper tibia of the lower leg, is thicker in the peripheral portion and thinner in the central portion. The upper surface of the meniscus touches the femoral end of the thigh, which is slightly concave, and the lower surface touches the tibial end of the lower leg, which is flatter, thus reinforcing the stability of the spherical femoral end and the flatter tibial end and allowing the knee joint to move freely. The meniscus can move somewhat with the movement of the knee joint, moving forward when the knee is extended and moving backward when the knee is flexed.
2. What is the role of the meniscus?
The meniscus plays an important role in the normal physiological function of the knee joint, mainly in the following ways.
Force cushioning, shock absorption
When not bearing weight, the tibia of the lower leg is not in contact with the femur of the thigh, and the meniscal liner is in between. During weight-bearing, the meniscus takes up about 70% of the pressure, greatly reducing the forces on the upper end of the calf bone and preventing direct friction of the thigh and calf bones against each other, thus well protecting the cartilage and synovial membrane of the knee joint. If the meniscus is removed, the peak pressure on the upper tibia of the lower leg can rise by a factor of two, causing cartilage degeneration and resulting in osteoarthritis of the knee joint. When the meniscus is torn transversely, the weight-bearing function of the meniscus is completely lost.
Maintaining the stability of the knee joint and maintaining motor coordination
The meniscus adapts well to the anatomical shape of the knee joint and moves together with the lower leg during knee flexion and extension, maintaining knee joint stability and coordination of knee movement.
Lubrication of the joint
The meniscus also has the function of lubricating the joint. The meniscus can evenly coat the joint surface with joint fluid, so that the friction coefficient of the joint is greatly reduced.
It is because the meniscus plays a role in stabilizing the load, its integrity to ensure that the knee joint for years of weight-bearing sports without injury.
3. What is a meniscal injury?
Meniscus injury is a common injurious condition of the knee. The disease is caused by a sudden and violent force or chronic injury that tears the meniscus of the knee. Patients often experience severe pain and swelling in the knee joint during strenuous activities (such as running, jumping, and shooting in basketball), as well as painful pressure on the inside and outside of the knee joint. At present, the diagnosis of this disease mainly relies on MRI (magnetic resonance imaging) examination of the knee joint, and the main treatment method is minimally invasive arthroscopic surgery of the knee joint. If meniscal injury is not treated appropriately and in a timely manner, it can easily cause joint degeneration and is a common cause of osteoarthritis of the knee.
4. What are the symptoms of meniscal injury? Is there any damage to other structures in the knee joint?
Meniscus injury can be divided into acute injury and chronic injury.
In acute meniscal injuries, patients often have a clear history of trauma, usually suddenly during strenuous activity (e.g., when playing ball, heavy work). When the knee suddenly rotates or jumps to the ground, the patient suddenly feels severe pain in the joint, cannot straighten it, and quickly develops joint swelling, at which time blood may accumulate in the joint due to meniscal tears.
In chronic meniscal injuries, the patient may not have a clear history of trauma and the patient mainly presents with
Knee pain, more pronounced when walking and significantly reduced when sitting or lying down to rest.
There is a popping sound when the knee joint moves (when the joint moves, a “kata sound” is heard), and even joint interlocking (manifested as: when the joint moves, suddenly after hearing the “kata sound”, the joint cannot be straightened, and then swings the calf a few times with pain, and then hears the “kata sound” again). After the “kata sound” is heard again, the joint can be straightened again). Interlocking of the patient’s joints can occur occasionally or frequently. Frequent interlocking can interfere with daily activities in which the patient’s knee joint is involved, such as walking, standing up or squatting.
Patients may experience hitting weakness when walking up or down stairs, which is manifested by a sudden feeling of weakness in the affected knee (a feeling of unstable or slipping knee joints).
Patients may not have significant knee swelling and daily functions such as common knee flexion and extension, may not be affected.
Later in the injury, the patient may show atrophy of the quadriceps muscle, reduced muscle strength, and thinning of the leg.
Patients may experience knee pain when the lower leg is straightened or when squatting.
Patients can press around the knee joint and get a definite pressure pain in a more limited and fixed location.
Meniscal injuries due to strenuous activity are sometimes combined with rupture of other ligamentous structures within the knee joint due to the tremendous external forces. It is the presence of these intra-articular ligaments that allows the knee joint to remain stable and to perform daily activities such as flexion and extension successfully. When these ligaments are combined, the pain and swelling in the knee will become more intense, the joint will no longer be stable, and the joint will not be able to flex and extend.
5.Who is prone to meniscus injury?
Meniscus injuries are more common in young adults, more in men than women. It is more common in ball players, and heavy laborers such as miners and porters.
Research data shows that: 21-30 years old have a clear history of trauma, mostly caused by strenuous sports injuries, 31-40 years old have no clear history of trauma or have minor trauma, mostly chronic injuries. More male patients, and more men engaged in physical and sporting activities and accidental injuries related.
6.What are the causes of meniscal injury and the mechanism of injury?
Sudden movements and grinding forces are the main causes of meniscal injuries.
Under normal circumstances, when the knee joint is straight, the meniscus is pushed forward by the femoral condyles, while in flexion the meniscus moves backward.
When the knee joint is in semi-flexion, that is, when we usually squat and flex the knee, when doing calf abduction and external rotation or internal rotation, both sides of the meniscus are located in one front and one back, if the action is sudden, the meniscus can not slide in time, it will make the meniscus between the femoral condyles and tibial plateau grinding distance, thus leading to various types of injuries.
For example, when basketball players compete for the ball to cut into the basketball jumping up or landing, often accompanied by a change of body direction, in the landing due to instability of the center of gravity often cause the knee joint to flash sharply left and right, and flexion and extension twisting action, etc., may lead to meniscal tears.
Sudden hyperextension and hyperflexion of the knee joint can lead to damage to the anterior and posterior angles of the meniscus. In addition, repeated small traumas or abrasions over time can also lead to meniscus damage. If many coal miners often need to work in a semi-squatting or squatting position, so that the meniscus repeatedly repeatedly squeezed and worn, although not suffered acute injury violence, but still degenerative changes can occur, causing meniscus injury.
General meniscus injury shall have four factors: knee half flexion, adduction or abduction, gravity extrusion and rotation force.
7.What kind of examination is needed after meniscus injury?
A frontal and lateral x-ray of the knee. X-rays cannot be used to diagnose meniscal tears and are designed to rule out intra-articular fractures, osteochondral free bodies, exfoliative osteochondritis and other knee disorders that may resemble meniscal tears.
MRI (magnetic resonance imaging), is by far the most sensitive and accurate imaging tool for diagnosing positive meniscal injuries, ligament tears, etc., with an accuracy rate of 98%. MRI of meniscal tears mainly shows low-signal areas within the meniscus with linear or complex-shaped high-signal bands across the surface of the meniscus. Based on MRI performance, foreign scholars can classify meniscal degeneration and injury into 4 grades, which can provide reference for the treatment of meniscal injury as well as clinical prognosis.
Other diagnostic imaging methods such as high-resolution ultrasound and high-resolution CT of the knee joint are also helpful in the diagnosis of intra-articular disorders of the knee.
Arthroscopy, the arthroscopic technique is the most ideal means of diagnosis and surgical management of meniscal injuries. However, arthroscopy is not a routine means of examining meniscal tears. Arthroscopy can only show its superiority after the initial diagnosis of meniscus tear, in order to confirm the diagnosis and to perform arthroscopic surgical management at the same time.
8.What conditions would be diagnosed as meniscus injury? What diseases are similar to meniscal injuries?
Patients with meniscal injuries generally meet the criteria described in 1 to 4 below:
The patient has a history of acute or chronic knee injury or a long term occupation of heavy physical work.
The patient has sudden knee joint pain and swelling during strenuous activity, or symptoms such as joint interlocking, weak legs (noticeable when walking up or down stairs), and quadriceps atrophy.
There are fixed pressure points around the knee joint or signs of increased pain when standing up or squatting.
Typical MRI (Magnetic Resonance Imaging) imaging presentation of the knee joint.
Injury to the ligaments in the knee joint due to strenuous activity (such as anterior and posterior cruciate ligaments, lateral collateral ligaments, etc.) or trauma-induced patellar fracture has a slightly similar clinical presentation to meniscal injury, which requires hospital examination to determine the diagnosis or the presence of a combined injury.
9.What are the main treatment options for meniscal injuries?
Currently, the main treatment options for meniscal injuries include conservative treatment, arthroscopic meniscal repair, arthroscopic partial meniscectomy, arthroscopic subtotal meniscectomy, arthroscopic total meniscectomy, and meniscal transplantation.
10.Can the meniscus be conservatively treated and self-repaired after injury?
The central part of the meniscus has no blood supply, and its nutrition mainly comes from synovial fluid. Only the peripheral edge part (about 10%-30% of the meniscus), has blood supply. Therefore, except for the edge tears at the periphery of the meniscus, which heal easily, tears in other parts are difficult to heal because there is no blood supply.
Foreign scholars divide the meniscus into three zones, namely the red zone, the red-white zone and the white zone. The red zone has blood flow and has a strong ability to heal after tearing, while the red and white zones are located at the junction of blood flow and no blood flow and have some healing ability. The white zone has no hematopoiesis and is extremely difficult to heal after injury. Therefore, meniscus injury in the red zone and red and white zone, after proper repair can heal, but, if the meniscus injury area in the white zone, it is generally difficult to self-heal.
11.What are the consequences of untreated meniscus injury if left to develop?
In mild meniscus injury, the patient’s symptoms are not serious, the knee pain is mild, swelling is not obvious, does not affect the function of the knee joint, and can generally heal on its own.
For more serious meniscus injuries, the patient’s symptoms are obvious, with severe knee pain, swelling and limitation of daily activities, which indicates a more serious meniscal tear and possible intra-articular bleeding. If the patient is left alone, the pain and swelling of the knee joint will be reduced after the acute period, but there will often be joint pain, popping when moving, and even joint interlocking. In the long run, the patient’s knee joint will degenerate early, and osteoarthritis such as free body formation in the knee joint, bone superfluity formation, and joint deformity will occur, which will seriously affect the patient’s daily life. Therefore, early treatment after meniscal injury is recommended.
12.What kind of meniscus injury is suitable for non-surgical conservative treatment?
Meniscus injuries within the blood-rich and blood-marginal areas of the meniscus in adults can be considered for conservative treatment.
Incomplete, small (<5mm), stable marginal tears are generally considered to be left without surgical management if they are not combined with joint instability, and can heal after 3-6 weeks of protection. Intra-articular cavity injection of chondroprotective drugs and supplemental intra-articular viscosity drugs are effective.
Because there are more large blood vessels in the meniscus before 14 years old, after 14 years old, 75% of large blood vessels disappear from the body of the meniscus and there are only blood vessels in the surrounding area, so many scholars believe that conservative treatment for meniscal injuries under 14 years old is effective.
13.What are the main methods of non-surgical conservative treatment?
Immobilization of the knee joint, external fixation of the knee joint with splint or plaster brace in the straight position for 3 to 4 weeks to promote meniscus repair.
Pharmacological treatment, taking anti-inflammatory and pain-relieving drugs and applying anti-inflammatory and pain-relieving creams externally.
Injection of sodium vitreous acid into the joint cavity to increase the viscosity and elasticity of the joint fluid, which has the effect of lubrication and shock absorption, thus protecting the diseased meniscus.
Functional exercise according to the rehabilitation program to enhance the strength of muscle groups and increase the stability of the knee joint.
14.What is the case of meniscus injury surgery? What are the advantages and disadvantages of various surgeries?
Meniscal repair requires certain conditions, such as: meniscal tear located in the area with good blood supply around the meniscus; injury type is a completely vertical longitudinal tear >10mm in length; no degeneration or loss of the meniscus; during the acute phase of the injury; good knee stability or ligament reconstruction is required at the same time. Meniscal injuries with good blood supply are treated satisfactorily, while meniscal injuries located in areas with poor blood flow, even if they can be repaired with sutures, have poor healing ability due to the influence of blood supply.
Nowadays, most of the surgeries use arthroscopic partial meniscectomy to preserve the original meniscus structure, minimize the meniscus resection part and avoid the total meniscus removal. Partial meniscectomy has the advantages of minimal invasion, low risk, and early functional exercise after surgery, which can greatly reduce or delay the occurrence of long-term knee degeneration, and is therefore widely used in clinical practice.
Total meniscectomy, subtotal meniscectomy, and subtotal meniscectomy should only be considered as a last resort in the following cases: as a prior procedure for meniscal transplantation, or in cases where the meniscus has been severely damaged and its fragmentation has caused severe functional disorders of the knee joint. Although total meniscectomy can relieve the patient’s symptoms and effectively improve the function of the knee joint, after the meniscus is removed, the meniscus can be partially replaced by scar tissue in the knee joint, but the cushioning effect between the femoral and tibial ends is weakened, and the pressure on the upper tibia is increased by 3 to 5 times, which can easily cause osteoarthritis of the knee joint and other complications.
For young patients with intact joint structure and articular cartilage, but with severe meniscal damage that cannot be repaired or after meniscectomy, meniscal transplantation can be considered. The current technique of allogeneic meniscus transplantation is still immature and needs further research and improvement.
In conclusion, the meniscus treatment plan should be carefully selected after considering the degree of meniscus injury, the type of tear, and the location and extent of the tear.
15.What are the surgical principles that doctors follow when performing meniscus injury surgery in clinical practice?
In addition to improving the clinical symptoms, the main goal of meniscus injury treatment is to preserve the function of the original meniscus.
Meniscal surgery is performed to address knee stability issues such as cruciate ligament and collateral ligament injuries;
Meniscus injuries within the meniscus blood rich zone and blood marginal zone can be sutured;
If suturing is not possible, partial meniscectomy should be considered first;
In partial meniscectomy, more stable meniscus with a more complete shape and a more physiologically correct alignment should be preserved;
Meniscectomy is only suitable for meniscal injuries that cannot be sutured or shaped.
16.At present, meniscal injuries are usually treated by minimally invasive arthroscopic surgery, what advantages does it have over open surgery?
The advantages of arthroscopic surgery for meniscus injury are small incision, light trauma, and early functional exercise after surgery. It is also a good way to explore all parts of the knee joint to see if there is a compound injury such as articular cartilage or ligament damage, so that it can be treated together. Currently, arthroscopic surgery has replaced open surgery as the best means of treatment for meniscal injuries.
17.What do I need to do before the arthroscopic surgery?
Generally, you should start fasting 8 to 12 hours before surgery, and you should not drink water 4 hours before surgery (usually you should not eat or drink water from zero hour on the day of surgery).
It is best to take a shower the day before surgery to clean the skin in the operating area.