There is not a direct correlation between hip effusion and femoral head necrosis, but there may be an indirect link. Hip effusion mostly indicates the presence of synovitis, especially when excessive exercise causes increased weight-bearing on the hip joint, which results in synovial effusion, synovial inflammation, and joint pain at the same time. If synovitis exists for a long time, it means that the weight-bearing status of the joint has not been improved, which will cause the pressure on the femoral head to increase in the long run and may cause femoral head necrosis. Patients, especially if they have underlying diseases themselves or use certain medications, such as patients who use hormones for a long time or drink a lot of alcohol, can cause necrosis of the femoral head if combined with the long-term load on the femoral head.