Patients considering artificial knee replacement are concerned about how long it will take to regain function after surgery, mainly the flexion of the knee.

• 65º, walking
• 70º, picking things from the ground
• 85º, climbing stairs
• 95º, getting up from a seated position
• 105º, tying shoes
• Above 115º, cross-legged, squatting or cycling

The above angle can meet the basic daily needs, if it reaches 125º The above can almost satisfy the full range of motion of the knee. The ideal goal of artificial knee replacement is to restore to 120º, but not all patients can achieve this angle. In a study of 108 patients undergoing total knee arthroplasty, the mean flexion after surgery was 111°. In short, after the specific situation has been evaluated by the doctor, the patient will be informed in advance. Try to choose an experienced doctor.

The following is a post-operative knee flexion recovery schedule that will work for most patients.

Day 1 to week 2, At this stage, the patient is still using a walker and cannot do large-angle movements, just keep moving, The main thing is to avoid stiffness, reduce swelling and reduce inflammation. Knee flexion target 65-90º, can stand, walk, go up stairs.

Week 2 to 6, During this stage, some patients can switch to crutches, reduce the amount of painkillers or even stop taking them. The intensity and frequency of rehabilitation exercises gradually increase, and patients need some endurance and perseverance, and this stage is especially critical for rehabilitation. Flexion target 90-115°, walk without crutches, go up stairs, sit down, and stand up from seat.

Weeks 6 to 12, 115°+ flexion target, bend over, sit down, and even tie shoes.

The first three months of rehabilitation exercises basically determine the degree of flexion, flexibility, extension and movement of the knee after surgery. Without active exercise at this stage, the knee may become stiff, causing permanent problems. If you continue to exercise after three months, the flexion of the knee may increase to 125° or even 135°.

This timetable is based on the average number of patients. It is different for each patient. Let’s look at a patient’s recovery experience. He only used 2 months to 121°.

Day 6 after surgery -88°. Day 9 -95°. 10 days -98°. 12 days -100°.

Post-operative day 14-110°, day 27-115°.

The eighth week after surgery, 121°.

How did he do it? In addition to following the doctor’s orders, these exercises were also carried out.

Seated knee flexion

Sitting in chair , slide the operated leg on the floor, slide it back, and hold for 10 seconds, repeat 10 times. If the ground is not smooth, you can put a plastic bag.

Short arc

Lie on your back on the bed, roll up the towel under your knees, keep Stick your thighs on the towel, slowly lift your calves, try to straighten them as much as possible, do this 20 times a day.

Heel slide

Lie on your back on the bed with your legs straight and the operated leg slowly Bend, slide the heel back, or use the strap over the operated leg and pull back slowly.

Ankle Pump

Lie on your back on the bed, straighten your legs, slowly lift the operated leg, move your toes up and down 20 times, or twist your ankle clockwise and counterclockwise.

knee fully straight It is 0 degrees when it is fully flexed, and about 135 degrees when it is fully flexed. However, specific to each patient, the angle after surgery will be affected by the angle before surgery, which is usually smaller than the angle before surgery. For example, the patient above has 123° of flexion before surgery. , 110° after seven weeks of post-operative evaluation, and finally recovered to 121° after his efforts.

Medical popular science, for reference only.

References:

“Maximum Bend After Knee Replacement” Myknee, 2018.

“Range of Motion After Joint Replacement Surgery”Peerwell,2017