There is a difference. Knee arthritis is wide-ranging and includes synovitis, which is only one of the manifestations of knee arthritis. Common types of knee arthritis include osteoarthritis, which is caused by degeneration of the joints; traumatic arthritis, which is caused by fractures of the knee joints and injuries to the articular cartilage and meniscus; and infectious arthritis, which is caused by bacterial invasion that leads to joint infections. Most of these types of arthritis are accompanied by synovial lesions, in addition to different manifestations. Synovitis is a sterile inflammatory condition that develops as a result of injury to the synovial membrane of the knee, inflammatory exudation, and edema. Synovitis can develop alone or be one of the manifestations of various other types of knee arthritis. If there is discomfort in the knee joint, it is recommended to consult a regular hospital in time and follow the doctor’s instructions.