Indications: 1. Diagnostic examination surgery of the knee joint. 2.Meniscal injury and degeneration. 3, Various types of synovitis. 4, Purulent arthritis debridement and irrigation and drainage. 5, Knee joint tuberculosis lesion removal. 6.Intra-articular free body or foreign body. 7.Joint cavity cleaning and irrigation for osteoarthritis. 8.Resetting and fixation of exfoliative osteoarthritis or intra-articular fracture. 9.Repair and reconstruction of cruciate ligament and lateral collateral ligament injury. 10 Gout stones in the knee joint. Contraindications: 1. Patients with obvious local or systemic foci of infection in the affected knee, which may cause joint infection after surgery; 2. Patients with particularly narrow or even disappearing joint space.