The clinical manifestations of knee synovial crease syndrome are as follows: (1) weakness of the affected knee, leg weakness during activity, especially when standing after going up or down stairs or being sedentary; (2) pain in the medial knee joint, aggravated by overexertion from running or prolonged extension and flexion of the knee joint; (3) joint popping sound when extending and flexing the knee joint greater than 45°; (4) the patient has varying degrees of quadriceps atrophy, swelling of the knee joint (5) Positive knee hyperextension or hyperextension test; (6) Positive McDonald’s sign; (7) Positive knee flexion and extension test with compression of the medial femoral condyle.