Objective To investigate the significance of three dimensional (3D) visualization and virtual surgery system in liver transplantation surgery. Methods Two patients suffered from cholangiolithiasis were scanned by 64 slice helical-CT on livers and the data were collected. Man-made segmentation and true up on the image from the data were carried out. 3D moulds of the liver and the intrahepatic vessels were reconstructed by VTK software respectively. And then, the moulds were imported to the FreeForm Modeling System for modifying. At last, auxiliary partial orthotopic liver transplantation was simulated with the force-feedback equipment (PHANTOM). Results ①It had greatly verisimilar image for the reconstructed 3D liver moulds with artery, vein, portal vein and bile duct; By liver seeing through, it had high fidelity and b 3D effect for the intrahepatic artery, vein, portal vein and bile duct, and their spatial disposition and course and correlationship were shown clearly. ②In the virtual surgery system, the virtual scalpel could be manipulated on 3D liver mould with PHANTOM. The simulating effect was the same as the clinic operation for auxiliary partial orthotopic liver transplantation. Plane visualization of hepatic resection and intrahepatic vessel cutting was achieved by adjusting the transparency of the resection part. Life-like could be felt and power feeling could be touched during virtul operation. Conclusion ①The visualized liver mould reconstructed is 3D and verisimilar, and it is helpful to design reasonable scheme for liver transplantation. ②It not only can improve the surgical effect and decrease the surgical risk, but also can reduce the complications and enhance the communication between doctor and patient through designing surgical plan and demonstrating visualized operation before surgery. ③Visualized liver transplantation surgery is helpful for medical workers to train and study.
Objective To evaluate the effectiveness of unstable femoral neck fracture with posteromedial comminutations treated by cannulated screws and medial bracing plate combined with bone allograft. MethodsThe clinical data of 18 patients with unstable femoral neck fracture with posteromedial comminutations treated by cannulated screws and medial bracing plate combined with bone allograft between July 2016 and March 2020 were retrospectively analyzed. The age ranged from 22 to 64 years, with a median age of 43 years. The causes of injury included 11 cases of falling injury, 3 cases of traffic accident injury, and 4 cases of fall from height injury. According to Garden classification, the femoral neck fracture was classified as type Ⅲ in 3 cases, type Ⅳ in 15 cases, and all patients were type Ⅲ according to Pauwels classification. The time from injury to operation was 1-5 days, with an average of 2.3 days. The fracture healing time and complications were recorded. The quality of fracture reduction was evaluated by Garden index immediately after operation; at last follow-up, the degree of femoral neck shortening was determined by Zlowodzki method, Harris score was used to evaluate hip function. Results The operation time was 62-98 minutes (mean, 75 minutes); intraoperative blood loss was 101-220 mL (mean, 153 mL). Cannulated screws guide wire was inserted 3-5 times (mean, 4 times). Intraoperative fluoroscopy was performed 9-21 times (mean, 15 times). The hospital stay was 5-11 days (mean, 7.2 days). All the patients were followed up 12-40 months with an average of 17.3 months. There was no postoperative complication such as accumulated pneumonia, lower extremity deep venous thrombosis, nail cutting, nail withdrawal, internal fixation fracture, and so on. There was no fracture nonunion and osteonecrosis of the femoral head during the follow-up; the fracture healing time was 7-15 weeks, with an average of 12.1 weeks. The quality of fracture reduction was evaluated immediately after operation, the results were grade Ⅰ in 15 cases and grade Ⅱ in 3 cases. At last follow-up, there were 2 cases with femoral neck shortening less than 5 mm and 1 case with 5-10 mm. The incidence of femoral neck shortening was 16.7%. The Harris score of hip joint was 73-97, with an average of 93.5; among them, 12 cases were rated as excellent, 3 cases as good, and 3 cases as fair, with an excellent and good rate of 83.3%. ConclusionFor the treatment of unstable femoral neck fracture with posteromedial comminutations, cannulated screws and medial bracing plate combined with bone allograft are dramatically effective due to earlier weight bearing, faster fracture healing, and better hip function recovery.