关键词: 关节, 膝, 单髁, 全膝关节置换, 单间室, 骨关节炎, 肌力

Abstract: BACKGROUND: Lateral single compartment knee osteoarthritis has a low incidence of degenerative diseases of the knee. Total knee arthroplasty in the treatment of lateral single compartment knee osteoarthritis has achieved considerable clinical efficacy. As a new technology, lateral monocondylar knee replacement has seldom been reported in terms of surgical strategy and clinical efficacy in the treatment of lateral single compartment knee osteoarthritis. 
OBJECTIVE: To compare the clinical efficacy of lateral unicompartmental knee arthroplasty and total knee arthroplasty for lateral unicompartmental knee osteoarthritis.  
METHODS: Clinical data of 39 patients with lateral unicompartmental knee osteoarthritis were retrospectively analyzed from October 2016 to October 2018 in the PLA 960 Hospital. According to the surgical plan, the patients were divided into two groups, including 20 patients in the lateral unicompartmental knee arthroplasty group and 19 patients in the total knee arthroplasty group. Perioperative incision healing and postoperative prosthesis survival were followed up. The changes of femorotibial angle of the affected knee were measured before and after operation. The patients’ acceptance of the two methods was statistically compared. The operation time, total blood loss, muscle strength of quadriceps femoris before operation, and the time of going to the ground after operation were compared between the two groups. Visual analogue scale score and Hospital for Special Surgery score were recorded before and after surgery.  
RESULTS AND CONCLUSION: (1) Perioperative situation: Intraoperative exploration found that a patient scheduled undergoing lateral unicompartmental knee arthroplasty to change the total knee arthroplasty due to anterior cruciate ligament rupture. One patient with diabetes in the lateral unicompartmental knee arthroplasty group had delayed healing of the incision, and one patient in the total knee arthroplasty group had delayed healing due to the liquefaction of fat. The remaining incisions healed normally. (2) Follow up after discharge: One patient in the total knee arthroplasty group died of lung cancer in the second year after operation, and the remainder was normal. The two-year survival rate was 97%. (3) Changes in femorotibial angle before and after surgery: The postoperative valgus angles of the two groups were between 5°-10°, and the lower extremity vertical line recovered well. There was no statistical difference in the femorotibial angle changes between the two groups before and after surgery (P > 0.05). (4) 54% of patients were more willing to undergo lateral unicompartmental knee arthroplasty, and 41% of patients respected the doctor’s suggestion that both surgical methods could be accepted. (5) The operation time, intraoperative and postoperative total blood loss and postoperative time of going to the ground in lateral unicompartmental knee arthroplasty group were better than those in total knee arthroplasty group (P < 0.05). There was no significant difference in preoperative muscle strength of quadriceps femoris, preoperative and postoperative visual analogue scale score, and Hospital for Special Surgery score between the two groups (P > 0.05). (6) Two surgical schemes have considerable clinical effects in the treatment of lateral compartment osteoarthritis. Compared with total knee arthroplasty, the lateral unicompartmental knee arthroplasty has less blood loss and shorter operation time, quick recovery and other advantages, so lateral unicompartmental knee arthroplasty is more suitable for the treatment of patients with osteoarthritis who meet the indications of lateral unicompartmental knee arthroplasty.

Key words: joint, knee, single condyle, total knee arthroplasty, single compartment, osteoarthritis, muscle strength