2.1 Design: Randomized controlled clinical trial.
2.2 Time and venue: Completed in the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine from June 2018 to December 2019. Trial Registration: Chinese Clinical Trial Registry, ChiCTR1900026573. Registered on May 12, 2018.
2.3 Subjects:were randomly selected from 150 patients who underwent primary unilateral total knee arthroplasty in the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine from June 2018 to December 2019.
The study was approved by the Ethics Committee of the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine on May 17,2018(NT-5324). Any protocol modifications will be submitted to the Ethics Committee for review and participants will be informed. After eligibility screening, we will request signed consent from participants. Participants are also informed that their choice to participate or not participate in the study will not affect their access to health services or treatment, and that there is no penalty for not participating in the study.
2.3.1 Inclusion criteria:①Referring to the 2018 edition of the Guidelines for the Diagnosis of Osteoarthritis[5] ②Patients with knee osteoarthritis who need unilateral total knee arthroplasty due to ineffective conservative treatment ③General conditions can tolerate surgery④Mental status is normal and can cooperate with functional exercise ⑤Patients have informed consent for the treatment and trial program.
2.3.2 Exclusion Criteria:①Osteoarthrosis caused by other reasons, such as rheumatoid arthritis, traumatic arthritis, etc.②Severe varus and valgus deformity and ankylosis of the knee ③Patients with severe femoral and tibial defects ④Revision surgery ⑤History of thromboembolism ⑥Patients with liver and kidney dysfunction ⑦Patients with severe anemia before surgery ⑧Patients with hemorrhagic hematological diseases and patients receiving anticoagulant therapy ⑨Patients with tranexamic acid allergy ⑩Previous history of lower limb venous thrombosis, cardiovascular and cerebrovascular thrombosis and other peripheral vascular disease, combined with malignant tumors.
150 patients were treated according to SPSS software was randomly divided into 3 groups: limited tourniquet group , Second half tourniquet groupand no tourniquet group, 50 cases for each group.
2.4 Experimental methods
2.4.1 Preoperative preparation After admission, blood routine, biochemical and coagulation related examinations were perfected, and anteroposterior and lateral X-ray films of both knees and full-length anteroposterior X-ray films of both lower limbs in standing position were taken. The patient's surgical procedure was explained before surgery to relieve anxiety. Preemptive analgesia with oral seloxifene 200 mg was routinely administered 3 days before surgery twice daily, local skin disinfection was performed with local diluted iodophor wet compress of the affected knee, diet was prohibited 6 h before surgery, drinking was prohibited 2 h before surgery, and urinary catheters were routinely not placed.
2.4.2 Replacement methods: All operations were performed by the same senior joint surgeon in the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine and assisted by the same group of assistants. General anesthesia was used for anesthesia. Cefuroxime Sodium 2 g was intravenously infused 30 min before operation to prevent infection, and aminocyclic acid 1 g was intravenously infused 15 min before skin incision to stop bleeding. Controlled hypotension was routinely performed during the operation, mean arterial pressure was controlled at two-thirds of the basal blood pressure, and a tourniquet was tied at the root of all thighs. The anterior midline medial patellar approach was used. The posterior cruciate ligament substituting bone cement was used to fix the total knee prosthesis. The osteophyte was only removed without patellar replacement followed by peripheral denervation.
2.4.3 Method of tourniquet use:① Restricted tourniquet group: after the completion of osteotomy, tourniquet was applied only when the prosthesis was installed, and ended when the knee prosthesis was successfully placed and the bone cement hardened, that is, limited tourniquet was used; ② Tourniquet group was used in the second half (after the completion of osteotomy, tourniquet was started when the prosthesis was installed, until the incision was sutured and pressurized, that is, tourniquet was used in the second half; ③No tourniquet group: no tourniquet was used throughout. All patients were given "cocktail",[formula: lidocaine,betamethasone infiltration injection through the surgical incision and surrounding soft tissues, routine placement of drainage tube, injection of aminocyclic acid into the joint cavity through the drainage tube, elastic bandage compression bandaging.
2.4.4 Postoperative treatment:All patients were given Parecoxib for Injection for analgesia 3 d after operation, Tramadol for symptomatic analgesia, Estazolam for sleep assistance, and Mosapride for relieving nausea and vomiting. After the patient returned to the ward, ice compress was started. The drainage tube was clamped for 3 h and then opened. Additional tranexamic acid 1 g was intravenously infused. The drainage tube was removed within 24 h. On the first postoperative day, the patient was instructed to perform quadriceps strength and active and passive flexion and extension functional exercises of the knee. 6 h after operation, 4000u of enoxaparin was subcutaneously injected for routine anticoagulation. From the first day after operation to 2 weeks after operation, if the patient did not tolerate acupuncture, switch to oral rivaroxaban ,10 mg/d. If there was bleeding tendency, the anticoagulation was immediately stopped; venous blood C-reactive protein, hemoglobin levels and visual analogue scale and HSS score were reexamined on the 1st, 3rd, and 7th day after operation.
2.5 Primary outcome measures
2.5.1 Pain: The visual analogue scale of knee joint pain was measured at 1, 3, 7 d and 1 month after operation, and the score represented the degree of knee joint postoperative pain.
2.5.2 Knee function: The HSS score of the patients' knees was measured at 3, 7 d and 1 month after surgery, and the score represented the better the functional activity of the knee joint.
2.5.3 Inflammatory Index: The concentration of C-reactive protein (CRP) in upper limb veins was measured by immunonephelometry at 1, 3 and 7 d after operation.
2.5.4 Blood loss:The hemoglobin level of the upper limb veins of the patients was measured by colorimetry at 1, 3, and 7 d after surgery, and the lower the hemoglobin level, the greater the overall blood loss of the operation.
2.6 Statistical analysis was performed using SPSS 25.0 statistical software for data analysis. Measurement data conformed to normal distribution and were expressed as x ± s. One-way analysis of variance was used for comparison. LSD-t test was used for comparison of measurement data between the two groups. X2 test was used for comparison of enumeration data. P < 0.05 was considered significant.