A positive floating patella test generally indicates that the fluid in the knee cavity is relatively large and exceeds the normal amount. The floating patella test is performed by placing the patient in a supine position with the knee straight, the examiner’s left hand on the upper edge of the patella and squeezing downward, and the right hand on the lower edge of the patella and squeezing upward. At this time, use the index finger of the right hand to press the top of the patella, if a floating sensation appears, it means that the floating patella test is positive, suggesting more fluid in the knee joint. At this point, attention should be paid to further clarifying the nature of the fluid in the knee joint, because the nature of the fluid in the knee joint can determine the extent of the knee injury and the mechanism of the injury. There are two main types of clinical injuries: one is traumatic knee osteoarthritis; the other is degenerative knee osteoarthritis.