The causes of medial knee projection may include collateral ligament injury, bone degeneration and hyperplasia, and goosefoot bursitis. 1. Collateral ligament injury: The injury to the medial collateral ligament of the knee will cause bruising, swelling and pain in the medial side of the joint, and the hematoma formed may cause the medial side of the knee to bulge out. Patients with mild symptoms should pay more attention to rest, through ice, pressure bandage and so on to alleviate the symptoms, while patients with more serious symptoms need to be protected by a brace to limit the angle of joint activities. 2. Bone Degeneration and Hyperplasia: With age, the elderly will experience bone degeneration and hyperplasia, and the hyperplasia will stimulate the surrounding soft tissues, causing the inner side of the knee to protrude and have a sense of pressure and pain. Patients can reduce the symptoms through hot compresses, physical therapy, massage, etc., and at the same time, they can follow the doctor’s instructions to take medicines such as Celecoxib capsules, Erythroxib tablets, etoricoxib tablets, etc. for anti-inflammatory and analgesic treatment. 3. Goosefoot bursa: As the bursa on the inside of the knee will cause bursal edema after being stimulated, there will be fluid in the bursa, resulting in a protruding manifestation. Patients should reduce the stimulation of the lesion area, local braking, and at the same time can follow the doctor’s instructions for the use of prednisolone acetate and lidocaine for pain point closure injection. If the symptoms of medial knee joint protrusion persist without relief, it is necessary to seek medical treatment in time to avoid delaying the condition.