The impact of intraarticular injection of ropivacaine into knee joint on the postoperative analgesia and local inflammatory response after patellar fracture fixation

Abstract

To explore the impact of intraarticular injection of ropivacaine into knee joint on the postoperative analgesia and local inflammatory response after patellar fracture fixation is the main objective. The subjects of this study are 136 patients with patellar fracture who received selective open reduction Kirschner wire tension band fixation of patellar fracture in our hospital from March 2018 to November 2020 were divided into two groups on the basis of random number table, each with 68 cases. After operation, both groups were given patient controlled intravenous analgesia for 48 h and the observation group was also administrated with intraarticular injection of ropivacaine into knee joint, while the control group with the same dosage of normal saline. Both groups were assessed with visual analogue scale at different time points and in both resting and active states after operation. The two groups were compared in the aspects of analgesic pump dosage and active knee flexion, 48 h after operation. The interleukin 6 and tumor necrosis factor alpha levels were tested using enzyme linked immunosorbent assay by drawing 2 ml of arthrohydrops, 48 h after operation. And statistical analysis was conducted on adverse reactions of the two groups. The observation group had much lower visual analogue scale scores at resting state 6 h, 12 h, 24 h and 48 h after operation (p<0.05) and remarkably lower visual analogue scale scores at active state 1 d, 2 d, 3 d and 4 d after operation (p<0.05), than the control group did at identical time points. 48 h after operation, the observation group used much less analgesic pump (p<0.05) and obtained more active knee flexion than the control group did (p<0.05). The concentration of interleukin 6 and tumor necrosis factor alpha of the observation group in arthrohydrops 48 h after operation was much lower than that of the control group over the same period (p<0.05). The observation group saw obviously lower incidence of nausea, vomiting and urinary retention as well than the control group did (p<0.05). The application of intraarticular injection of ropivacaine into knee joint can effectively relieve the pain patients suffer after patellar fracture fixation and alleviate local inflammatory response without significant adverse reactions.