Why is there pain or soreness in the affected knee at night and stiffness when waking up in the morning after surgery? During the postoperative rehabilitation process, with the increase of training intensity and frequency, some patients may experience soreness in the affected knee at night and stiffness when waking up in the morning, which is especially likely to occur after a large amount of activity during the day. This is a normal reaction during the rehabilitation process after total knee arthroplasty, and the intensity of pain is related to the patient’s preoperative functional status of the knee, and the lower the knee and functional scores are, the more pronounced the training-induced pain may be. If the activities and exercises are more intense during the day, you can take an oral tablet of Relifen or Fitalin or Fenpropidone after dinner, or use an anti-inflammatory pain suppository in the anus before going to bed to inhibit soft tissue edema and pain. Based on the exclusion of other complications, patients should establish the confidence to overcome the disease and achieve the best functional rehabilitation through active practice. Is it normal to feel tightness around the affected knee after surgery? Within 6-8 weeks after surgery, patients often feel “tightness” around the surgical incision, like the feeling of being bound by a metal hoop, which is mainly due to the formation of postoperative scar, and will disappear after it is gradually “pulled apart” and loosened through functional exercises. Why do I feel stiff or unnatural when I walk in the early postoperative period? After knee replacement surgery, as long as the patient is able to take care of his/her daily activities without joint pain, and the joint flexes and extends to the desired degree, the desired effect is considered to have been achieved. Early postoperative stiffness is usually within the normal range and can be relieved to varying degrees in 6-8 weeks, with knee mobility basically returning to normal 3 months after surgery. There are many reasons for postoperative knee stiffness, besides soft tissue scar formation and unrecovered soft tissue edema, it is also related to incomplete recovery of the muscles around the joint, which is often most obvious in the morning when you first walk on the ground. Whether the joint stiffness is relieved or not can be used as an indicator of the rehabilitation effect, and it is normal for the symptoms to appear during the above time. Is it normal for the patient to experience a “crunching sound” in the knee joint during postoperative activities? This sound is usually due to the fact that the soft tissues around the newly implanted prosthesis are still loose, the muscles are weak and lack sufficient strength to maintain balance. This sound occurs when the prosthesis is in motion after surgery, especially when there is a collision between the patella and the femoral condyle prosthesis. This rattle is rarely accompanied by clinical symptoms, but can cause tension in the patient. With the passage of time, the soft tissues repair themselves after the balance, these patients will gradually disappear the joint activities of the clucking phenomenon, do not need special treatment. Consultation with a physician should be made when symptoms are evident to rule out problems such as patellar luxation. What is the most important postoperative symptom that must be seen by a doctor immediately? Late postoperative infection is the most serious complication after artificial joint replacement, and in severe cases the prosthesis may even have to be removed, thus easily leading to complete failure of the artificial joint replacement. Symptoms of infection are usually obvious localized warmth, redness, swelling or more fluid accumulation in the affected knee joint. When the patient has a cold or an acute infection in other parts of the body, antimicrobials should be given to prevent late-stage infections; if the affected knee is found to be locally red, swollen, or with protrusions, intravenous antimicrobials should be administered and the patient should immediately go to a specialist hospital to see a specialist for medical treatment. How to use the walking frame correctly after surgery? On the 3rd day after surgery, the patient can use the walking frame to flex and extend the knee joint by walking with the leg elevated. On the 4th day after surgery, the patient can walk with the aid of the walking frame for 50-100 meters per day or longer, depending on the patient’s reaction after the exercise. Method: Hold the handles with both hands, stand upright, look forward, move the walking frame forward, then move the healthy leg, then move the affected leg. (Note that the walking frame should be stabilized before moving the leg) How to use crutches after surgery? Patients need help when they first get off the floor. Double crutches should be used in the early postoperative period; single crutches should not be used to avoid the formation of deformity over time. When standing or walking, the lower end of the crutches and the weight-bearing part of the crutches should be kept in an inverted triangle to avoid falling. When walking, the body should lean forward slightly, and the strength should be put on both hands and elbows. The length of crutches should be chosen as the length of the body minus 40cm, and the height of the handle should be adjusted so that the elbow is bent at 30° when the hand is loaded. When using crutches, the weight should be held in the hand, and the axillary handle of the crutch should be kept two fingers away from the armpit, and the weight should not be held in the armpit, so as to prevent the neurovascularity under the armpit from being pressed and injured. When the patient should pay attention to the car: ① should try to choose a car with a high seat, because the low seat will make it difficult for the patient to enter and exit the car door. ② The patient should choose the front seat of the car, and move the seat back as far as possible. ③The patient should stand on the right side of the seat outside the car when getting into the car; lean back slowly to the seat and bend the legs as little as possible until sitting down; then let the family help the patient to lift the legs, turn 90 degrees to the left with the upper body as the axis, and move to the usual sitting position. ④ The patient gets off the bus in reverse of the process of getting on the bus. ⑤ The patient’s continuous traveling time should not be more than 45 minutes, and the patient should get off the car in the middle of the journey to walk around or stretch the knees. When the patient takes the train or airplane, should pay attention to: ① Should be booked in advance to have a larger space of the cabin, and choose the seat by the bulkhead, in order to enable the patient to straighten the legs. ② It is better to use a wheelchair instead of walking, but before boarding the train or airplane, the patient should get out of the wheelchair and do leg extension exercises. ③If the journey is long, the patient should practice walking short distances on the train or airplane with the assistance of family members. ④ Due to the long time sitting position, the patient will experience joint stiffness, so the patient should move slowly when getting off the train or airplane, so that the affected knee joints have time to relieve the stiffness. What should the patient pay attention to in his/her daily life after going home? Patients should try to complete the rehabilitation program developed by the physical therapist at home. When walking, the patient should increase the number of times he/she walks each day, followed by a gradual increase in the distance walked. When walking, patients should use crutches or walking frames to protect the knee joint and should pay attention to turn around with small steps to avoid twisting the knee joint. At home, choose a firm, straight-backed chair with armrests, which is good for the patient to stand up or sit down; do not sit on a low, soft sofa or recliner. When taking a bath, it should be noted that it is better to have assistive equipment in the bathroom, such as a chair and handrails, and the patient should be accompanied by family members when taking a bath; pay special attention to the fact that even if there are handrails, it is still dangerous for the patient to get in and out of the bathtub when the bathtub is wet and slippery; do not sit in the bathtub because it is very difficult for the patient to stand up. Difficulty in sleeping is common in the weeks after surgery, and frequent short breaks every day can reduce fatigue; try to sleep on a firm flat bed, and do not put pillows or cushions under the knee joint to avoid difficulty in extending the knee in the future. After going home for a week, patients can go out for walks as appropriate; use static bicycles for rehabilitation; swimming is allowed, but breaststroke should be avoided, and wide steps should be used when entering and exiting the pool, rather than going up and down the ladder; dancing, sports, and other (other than swimming) activities with intensity should be avoided for 6 weeks after surgery. Avoid using high-frequency, high-magnetic and localized electrified instruments during physical therapy, as the prosthesis installed in the patient’s affected limb will absorb more heat and magnetism and easily cause internal burns. What recreational activities does the doctor recommend the patient to take part in when everything is normal after the 6-month postoperative review? Bicycling, boating, bowling, dancing, swimming (breaststroke should be avoided), golf, horseback riding, hiking, and walking. What recreational activities can cause damage to the replaced knee? Long walks, jumping, sprinting, tai chi, lifting heavy objects, climbing. In case of doubtful activities, you need to ask your doctor before deciding whether you are able to do them or not.