There is a meat bag above the knee commonly for the following reasons: first, irritative prepatellar bursitis, often caused by repeated friction in the kneeling position, in the past the incidence of underground miners is higher, so it is usually called miner’s knee, clinical manifestations for the front of the patella fluctuating mass, the boundary is clear, does not involve the knee joint, the acute phase puncture is bloody, the chronic phase becomes yellowish, the bursa wall is more hypertrophic. Second, septic local infection, usually with sharp object puncture or bacterial invasion, clinically manifests as local redness, swelling, heat, pain, limited pressure pain, and enlargement of inguinal lymph nodes, accompanied by generalized fever symptoms, and increased white blood cells in routine blood tests.