ObjectiveTo investigate the effectiveness of interrupted suture under exercise position in total knee arthroplasty (TKA).MethodsEighty-four patients with osteoarthritis who were treated with TKA between July 2015 and July 2016 were enrolled in the study. All patients were randomly divided into control group and observation group with 42 cases in each group. There was no significant difference in gender, age, side, body mass index, and osteoarthritis grading between 2 groups (P>0.05). The incisions were interrupted sutured at the knee flexion position in control group and at the exercise position in observation group. Preoperative and postoperative treatments of 2 groups were same. The incision length, suture time, total tramadol usage, intraoperative blood loss, stitches removal time, hospitalization time, incidence of postoperative complication, the incision healing score (HWES), and satisfaction score of incisional self evaluation (Liktert score) were recorded and compared between 2 groups. The visual analogue scale (VAS) score was used to evaluate the incision pain at pre- and post-operation. The hospital for special surgery (HSS) score and range of motion (ROM) were also used to assess the knee function.ResultsThere was no significant difference in incision length, incidence of postoperative complication, HWES score, stitching time, and hospitalization time between 2 groups (P>0.05). The suture time, intraoperative blood loss, and Likter score were significantly lower in control group than those in observation group (P<0.05), but the total tramadol usage was significantly higher in control group than that in observation group (P<0.05). All patients were followed up. The follow-up time ranged from 12 to 24 months (mean, 14.7 months) in control group and from 12 to 23 months (mean, 15.3 months) in observation group. There was no significant difference in VAS scores between 2 groups before operation, before going to bed at the 1st day, and after suture removal (P>0.05). The VAS score of observation group after flexion and extension exercises at the 1st day was significantly lower than that of control group (P<0.05). There was no significant difference in HSS score and ROM between 2 groups before operation and at 12 months after operation (P>0.05). The HSS score and ROM in observation group at discharge and at 1, 3, and 6 months after operation were superior to those in control group (P<0.05).ConclusionCompared with interrupted suture at flexion knee position, the application of interrupted suture at exercise positon in TKA had the advantages of less postoperative pain and good incision healing, and can get satisfactory early joint function recovery. But significant difference in the long-term effectiveness of the two methods was not found.