Synergistic Effects of Preoperative BRT Combined with Postoperative Time-Limited Cryotherapy on Early Swelling, Inflammation and Short-Term Rehabilitation after TKA

INTERVENTION: Combined intervention group:Standardized BRT pre‐relaxation training for 3 days before surgery, and standardized timed cold therapy implemented simultaneously 48 hours after surgery.;Postoperative limited‐time cold therapy group:Before surgery, only routine education is provided, and BRT is not carried out; within 48 hours after returning to the ward post‐surgery, standardized timed cold therapy is applied, with temperature, single session duration, and interval cycles uniformly controlled, and a dedicated person checks the skin condition.;Preoperative BRT‐only group:3 days before surgery, use the standardized Benson relaxation technique once a day for 20 minutes each time; after surgery, apply routine simple cold compresses.;Blank control group:Routine preoperative health education was given, but no BRT training; after surgery, simple ice packs were routinely used in the hospital, without standardized temperature control or duration.; CONDITION: Knee Osteoarthritis PRIMARY OUTCOME: Difference in knee swelling circumference at 24h, 48h, and 72h after surgery;Serum CRP, IL‐6, and TNF‐a levels; SECONDARY OUTCOME: VAS pain scores at each time point;knee joint active/passive range of motion;first time getting out of bed;length of hospital stay;short‐term knee function scores; INCLUSION CRITERIA: 1. Primary knee osteoarthritis, planned for unilateral first‐time TKA, completed by the same surgical team with standardized anesthesia, prosthesis, and tourniquet protocols; 2. Age 60–78, any gender; 3. MMSE >= 24, normal cognition, no severe vision or hearing problems, able to cooperate with BRT training, blood collection, joint measurements, and scale assessments; 4. Expected hospital stay >= 3 days, able to complete all tests at 24h, 48h, and 72h post‐surgery; 5. Patients and their families are informed and consent, voluntarily signing a written informed consent form.