Objective To investigate the clinical effect of anterograde percutaneous screw fixation under robot navigation in the treatment of acetabular anterior column fractures.Methods A retrospective analysis was made on 7 cases of anterior acetabular column fractures from April 2021 to January 2023.The traction reduction was conducted by using pelvic"double reverse"traction table,the orthopedic robot-assisted design was carried out to plan the screw entry point and direction,and the antegrade channel cannulated screw was used for internal fixation.Results The operation time was 60-95 min(mean,78 min).The intraoperative blood loss was 5-20 ml(mean,8.6 ml).The number of fluoroscopy was7-11(mean,8.7).The guide needle was unadjusted in 3 cases and adjusted for 1-2 times in 4 cases(once in 2 cases and twice in 2 cases).The actual path deviated from the planned by 0.65-1.50 mm(mean,0.98±0.30 mm).The excellent and good rate of screw position was 100%.X-ray and CT examinations were performed at 48 h after the operation.According to the Matta reduction standard,anatomical reduction was achieved in 6 cases and satisfactory reduction in 1 case.All the 7 cases were followed up for 6-28 months(mean,15 months).At the last follow-up,the Harris score of the hip joint was85-96 points(mean,91.6 points)and the pain of visual analogue scale(VAS)was0.There were no complications such as infection,loosening of internal fixation,or neurological dysfunction.Conclusion Anterograde percutaneous screw fixation under robot navigation in the treatment of acetabular anterior column fractures is safe,effective,and satisfactory.

Objective To explore the learning curve of Bikini incision direct anterior approach total hip arthroplasty(Bikini-THA).Methods Clinical data of 80 cases of Bikini-THA initially completed by an operator skilled in posterolateral approach and direct anterior approach total hip arthroplasty from March 2020 to March 2023 were retrospectively analyzed,and the learning curve was observed by scatter plots of operative time and intraoperative bleeding.They were divided into groups A to D according to the order of surgery,with 20 cases in each group.The operative time,intraoperative bleeding,acetabular abduction angle,anteversion angle,angle between stem and femoral axis,postoperative hip Harris score and complications were compared among the 4 groups.Results After about 40 cases,the decreasing trend of operative time and intraoperative bleeding slowed down and stabilized.The operative time and intraoperative bleeding in the 4 groups were group A＞group B＞groups C and D(P＜0.05),and the differences between the group C and group D were not statistically significant(P＞0.05).The acetabular prosthesis was well-positioned in the 4 groups(abduction angle of 30°-50°,anteversion angle of 5°-25°).The femoral prosthesis center fixation rate(angle between stem and femoral axis ≤3°)was group A＜groups C and D(P=0.003,0.003).The differences in the Harris scores of the hip joints at 2 weeks,1 month,3 months,and 12 months postoperatively of the 4 groups were not statistically significant(P＞0.05),and the efficacy evaluations of the hip joints at 12 months postoperatively were all excellent.There were 5 cases of complications in the group A(2 cases of greater trochanter fracture and 3 cases of lateral femoral cutaneous nerve injury),3 cases of complications in the group B(1 case of greater trochanteric fracture,1 case of lateral femoral cutaneous nerve injury,and 1 case of incision infection),1 case of complications in the group C(lateral femoral cutaneous nerve injury),and no complications in the group D.The follow-up period lasted for 12-26 months,with a mean of(19.4±4.7)months.There were no complications such as dislocation or loosening of the prosthesis.Conclusion The Bikini-THA learning curve was approximately 40 cases.