The meniscus is a triangular shaped piece of cartilage within the knee joint. Each knee has two menisci, one medial and one lateral. The medial meniscus is widely spaced and “C” shaped, with the edges connected to the joint capsule and the deeper layer of the medial collateral ligament. The lateral meniscus is “O” shaped, with the popliteal tendon separating the meniscus from the joint capsule in the middle and posterior 1/3, forming a gap, and the lateral meniscus is separate from the lateral collateral ligament.
The functions of the meniscus are as follows.
1, the role of the ball, so that the knee joint is easy to flexion and extension rotation and other activities.
2, shock-absorbing and cushioning effect, protecting the articular cartilage and absorbing the impact force on the knee joint when jumping and landing.
3, filling role, wedge-shaped filling the gap at the edge of the joint, making the knee joint more tight and stable.
4.Preventing excessive forward movement of the femur.
5.Prevent excessive flexion and rotation.
6.Regulate the intra-articular pressure and distribution of synovial fluid.
I. Meniscus injury
Injury to the meniscus of the knee is mainly caused by indirect violence. In extension movements, the meniscus is closely related to the tibial plateau. In knee extension, the meniscus moves forward, and in flexion, it moves backward. In turn, it moves together with the femoral condyles during knee rotation in internal and external rotation, causing friction between the meniscus and the tibial plateau. Therefore, if there is simultaneous twisting and turning of the knee during knee extension, there is inconsistent activity of the meniscus itself, which is the so-called contradictory movement, and it is easy to cause meniscal injury at this time.
Clinical manifestations
1. There is a clear history of knee sprain.
2. swelling of the joint and limitation of movement during the acute phase.
3. instability or slippage of the knee joint in chronic patients.
4. significant pressure pain in the joint space.
5. often unable to unlock themselves when interlocking occurs
6. A popping sound can be heard.
7. Different degrees of muscle atrophy may occur.
Diagnosis
1. There is a clear history of injury.
2.There are typical symptoms after meniscus injury.
3, there are obvious physical signs.
4.After the auxiliary examination: MRI and arthrography can make a clear diagnosis.
IV. Treatment
The treatment of knee meniscus injury is divided into acute treatment and chronic treatment.
In the acute phase, the accumulated blood can be extracted and wrapped with a cotton leg with pressure for 2-3 weeks to reduce the inflammatory response. If the injury is marginally separated, it can accelerate its healing. Interlocking is clearly an indication for surgery, and arthroscopic surgery should be performed early.
If the symptoms are not obvious in the chronic phase, conservative treatment is feasible, and if the symptoms are obvious and interlocked, surgical treatment is feasible.
Currently, meniscus surgery is performed under the microscope. The treatment methods include complete meniscectomy, meniscus revision, meniscus suture, and meniscus transplantation.
V. Prevention
1. Prepare the mind before exercise to make the joint hot and responsive.
2, do not exercise in a fatigued state, so that the response is sluggish and the movements are not easily coordinated.
3, strengthen the exercise of lower limb strength to ensure the stability and flexibility of the knee joint.
4. In sports, prevent accidental injuries caused by rough movements.
VI. Pre-operative care
Arthroscopic surgery requires strict skin requirements. In addition to routine preoperative care before surgery, special attention should be paid to protect the patient’s skin to avoid breakage, boils and folliculitis.
1.Psychological care
Medical staff should be patient and meticulous in all explanatory work to eliminate patients’ fears, and doctors and patients should cooperate closely to achieve the best treatment effect.
2.General care
General nursing care includes, understanding any past history, drug allergy history and medication use; supervising the patient to improve the preoperative examinations; if the patient has interlocked and has difficulty in moving, special care and assistance should be given in life.
3.Muscle strength exercise
Pre-operative muscle strength exercises are a very important task. The quadriceps muscle is an important structure to maintain the stability of the knee joint, and patients have already experienced different degrees of muscle atrophy before surgery, so they should be taught how to practice as soon as possible after admission.
4.Skin care
Arthroscopic surgery has extremely strict skin requirements, if the skin is broken, boils, folliculitis can not be operated. Therefore, after admission, patients should be told to strengthen the protection of the skin of the affected limb, avoid scratching, bruising, and mosquito bites. In summer, patients can be asked to wear long clothes and pants to sleep at night to avoid mosquito bites. If there is skin scratching, redness and swelling, etc., you should immediately notify the doctor to give treatment, do not solve the problem by yourself. At the same time, do not eat irritating and spicy food before surgery to prevent skin allergy causing rash and delaying the surgery.
5. Crutches use
The height of the crutches should be adjusted according to the patient’s height. The general height is that the patient holds the crutches with both hands, and the top of the crutches is 5 to 10 cm from the armpit and the same width as the shoulder.
6.Pre-operative preparation
Since the patient cannot get out of bed for 24 hours after surgery, the patient should be taught to use a commode and practice urination in bed before surgery to prevent difficulty in urination and urinary retention caused by postoperative postural discomfort, and to teach the patient methods to promote urination. In addition, since the affected limb is fixed after surgery, the patient should also be taught the method of elevating the affected limb and padding it when going to the toilet to relieve urination and defecation under fixed conditions before surgery to ensure a comfortable position. Older patients should also be taught how to use bedside toilet chairs and walkers.
VII. Postoperative care
Six hours after surgery, the affected limb should be elevated above the heart to facilitate reflux. At the same time, a perfect functional exercise program should be developed to help the affected limb recover and prevent muscle atrophy.
1.General care
After the patient returns to the ward, reasonable arrangements should be made for the patient’s transportation, attention should be paid to the patient’s safety and protection of the patient’s privacy during the transportation process, precautions should be explained to the patient, vital signs should be measured in a timely manner, and nursing records should be made.
2.Limb care
After surgery, the affected limb should be elevated above the patient’s heart to facilitate blood circulation and prevent swelling of the affected limb. The most important point of the affected limb care is to closely observe the blood flow of the affected limb, skin temperature, nerve sensation, filling of the peripheral circulation, blood seepage from the wound and the pulsation of the dorsalis pedis artery of the affected limb. Patients who wear splints after suturing should pay attention to whether the splint is fixed firmly and whether the tightness is appropriate.
3.Functional exercise
Early post-operative exercises should be aimed at avoiding adhesions and muscle atrophy, and should not be used too much as a method of exercise, otherwise it will easily cause joint swelling and joint effusion, which will affect functional recovery and tissue healing.
On the day of surgery, after the anesthesia subsides, you can start to move your toes and ankle joint, i.e., do the ankle pump exercise carefully, specifically by slowly and forcefully extending the ankle joint in full range for 5 minutes per group. At the same time, quadriceps exercises can also be performed.
On the first postoperative day, straight leg raising exercises and leg raising exercises in all directions were performed. The straight leg raise is performed by straightening and raising the straight leg until the heel is 15 cm above the bed and holding it for 5 seconds, 30 reps per set, 3 to 4 sets per day. Also, it is possible to get out of bed and perform weight-bearing balance exercises. However, the patient is required to perform the activities under the protection of a health care provider.
Functional exercise after meniscectomy revision: In addition to ankle pump and straight leg lift exercises, the patient can get out of bed on the first day after surgery, the cotton leg can be removed in 3 days, and the functional knee flexion is required to reach 90°, the stitches are removed in one week after surgery, and the patient can resume normal life one month after surgery, and the athlete can resume training 3 months after surgery.
Functional exercise after meniscectomy: active flexion up to 90° in one week after surgery, active flexion up to 120°~130° in 2 weeks, going up and down stairs and cycling in 6-8 weeks, and resuming training and normal life in 2-3 months.
Functional exercise of meniscus suture: passive flexion reaches 90° one week after surgery, passive flexion increases by 10° in 2 to 4 weeks, partial weight bearing starts in 4 weeks, the load is about 1/3 or 1/2 of body weight, full weight bearing can be done in 6 weeks, and fixed bicycle exercises can be done after 8 weeks.
The meniscus can be discharged from the hospital after 3 days of surgery, and the stitches will be removed for review at the outpatient clinic one week after surgery. If there is significant joint swelling and temperature increase after discharge, you should visit the hospital at any time. Functional exercises will be performed as planned and you can return to normal life 3 months after surgery.