关键词: 膝骨关节炎, 全膝关节置换, 后交叉韧带保留型假体, 膝关节功能, 步态, 下肢静脉回流

Abstract: BACKGROUND: Varus knee arthroplasty is an important treatment for osteoarthritis of the knee with varus deformity. Intraoperative joint replacement prostheses include the posterior cruciate ligament preserving type and the posterior cruciate replacement type, and there is some controversy about the therapeutic effects of the two groups of prostheses.  
OBJECTIVE: To investigate the effect of posterior cruciate ligament preserving knee prosthesis on gait and lower extremity venous return in varus knee arthroplasty.
METHODS: The medical records of 98 patients with varus knee osteoarthritis in Guizhou Provincial Orthopedics Hospital from October 2019 to October 2020 were retrospectively analyzed, all of whom were treated with total knee arthroplasty. According to the different intraoperative knee prostheses, they were divided into two groups (n=49). The control group used a posterior cruciate replacement knee prosthesis, and the test group used a posterior cruciate ligament preserving knee prosthesis. The two groups were compared in terms of surgical condition, postoperative complication rate, postoperative hospital stay, pre- and postoperative knee range of motion, maximum flexion angle, knee function, degree of joint obliteration, gait parameters, plasma fibrinogen, activated partial thromboplastin time, and D-dimer level.  
RESULTS AND CONCLUSION: (1) The operation time of the test group was longer than that of the control group. The intraoperative blood loss, postoperative drainage and postoperative hospital stay were less in the test group than those of the control group (P < 0.05). (2) The knee range of motion and maximum flexion angle at 3, 6 and 12 months after surgery were higher than those before surgery in both groups, and above indexes in the test group were higher than those in the control group (P < 0.001). (3) The percentages of gait speed, stride length, and support time were higher in both groups at 3, 6, and 12 months after surgery than before surgery, and the test group was higher than the control group (P < 0.05). (4) The knee joint scores of the Hospital for Special Surgery in the two groups at 3, 6, and 12 months after operation were higher than those before operation (P < 0.05), but there was no significant difference between the two groups (P > 0.05). (5) The scores of degree of joint obliteration in the test group were higher than those in the control group at 3, 6, and 12 months after operation (P < 0.05). (6) Plasma fibrinogen, activated partial thromboplastin time, and D-dimer levels were lower in the test group than those in the control group at 1 and 2 weeks after surgery (P < 0.05). (7) The overall complication rate was lower in the test group (4%) than that in the control group (17%) (P < 0.05). (8) It is suggested that the use of posterior cruciate ligament-preserving knee prosthesis in varus knee arthroplasty can significantly reduce surgical trauma and promote patients' recovery, and can more effectively improve knee range of motion, gait and lower limb venous return and reduce the incidence of postoperative complications, although the operation time is longer.

Key words: knee osteoarthritis, total knee arthroplasty, posterior cruciate ligament preserving prosthesis, knee function, gait, lower extremity venous return