Objective To investigate a modified robotized hydraulictensor for management of the ligament balance in the total knee arthroplasty. Methods The effect of the modified robotized hydraulic tensor on the mechanical behaviour of the ligament system balance in the total knee arthroplasty was analyzed andthe related information was obtained. Results The robotized hydraulic tensor acted as a tensorsensor system, which could assist the surgeon by providing thequantitative information to align the lower limb in extension, equalize the articular spaces in extension and flexion, balance the internal and external forces, and define the femoral component rotation, and by providing the information toplan the releasing of the soft tissues and the rotating of the femoral component. Conclusion The modified robotized hydraulic tensor can enable the surgeon to properly manage the ligament balance in the total knee arthroplasty.
ObjectiveTo investigate the application and technical essentials of computer-assisted navigation in the surgical management of periacetabular fractures and pelvic fractures. MethodsBetween May 2010 and May 2011, 39 patients with periacetabular or anterior and posterior pelvic ring fractures were treated by minimally invasive fixation under computer-assisted navigation and were followed up more than 2 years, and the clinical data were analyzed retrospectively. There were 21 males and 18 females, aged 15-64 years (mean, 36 years). Fractures were caused by traffic accident in 23 cases, crush injury in 6 cases, and falling from height in 10 cases. Of them, 6 cases had acetabular fractures; 6 cases had femoral neck fractures; 18 cases had dislocation of sacroiliac joint; and 15 cases had anterior pelvic ring injuries. All patients were treated with closed or limited open reduction and screw fixations assisted with navigation. ResultsEighty-nine screws were inserted during operation, including 8 in the acetabulum, 18 in the neck of the femur, 33 in the sacroiliac joint, and 30 in the symphysis pubis and pubic rami. The mean time of screw implanted was 20 minutes (range, 11-38 minutes), and the average blood loss volume was 20 mL (range, 10-50 mL). The postoperative pelvic X-ray and three dimensional CT scan showed good reduction of fractures and good position of the screws. No incision infection, neurovascular injury, or implant failure occurred. All patients were followed up 27-33 months with an average of 29.6 months. The patients could walk with full weight loading at 6-12 weeks after operation (mean, 8 weeks); at last follow-up, the patients could walk on the flat ground, stand with one leg, and squat down, and they recovered well enough to do their job and to live a normal life. ConclusionMinimally invasive fixation under computer-assisted navigation may be an excellent method to treat some specific types of periacetabular and anterior and posterior pelvic ring fractures because it has the advantages of less trauma and blood loss, lower complication incidence, and faster recovery.
Objective To investigate application of medical digital imaging systems and computer technologies in orthpedics. Methods The main computer-assisted surgery systems comprise the four following subcategories. Results ①A collection and recording process for digital data on each patient, including preoperative images (CT scans, MRI, standard X-rays), intraoperative visualization (fluoroscopy, ultrasound), and intraoperative position and orientation of surgical instruments or bone sections (using 3D localisers). Data merging based on the matching of preoperative imaging (CT scans, MRI, standard X-rays) and intraoperative visualization (anatomical landmarks, or bone surfaces digitized intraoperatively via 3D localiser; intraoperative ultrasound images processed for delineationof bone contours). ②In cases where only intraoperative images are used for computer-assisted surgical navigation, the calibration of the intraoperative imaging system replaces the merged data system, which is then no longer necessary. ③A system that provides aid in decisionmaking, so that the surgical approach is planned on basis of multimodal information: the interactive positioning of surgical instruments or bone sections transmitted via pre- or intraoperative images, display of elements to guide surgicalnavigation (direction, axis, orientation, length and diameter of a surgical instrument, impingement, etc.). And ④ A system that monitors the surgical procedure, thereby ensuring that the optimal strategy defined at the preoperative stage is taken into account. Conclusion It is possible that computer-assisted orthopedic surgery systems will enable surgeons to better assess the accuracy and reliability of the various operative techniques, an indispensable stage in the optimization of surgery.
Objective To evaluate the feasibility and effectiveness of computer-assisted preoperative planning system—ACL Detector in anterior cruciate ligament (ACL) reconstruction. Methods Between March 2009 and January 2012, 80 patients with ACL rupture received arthroscopic ACL single-bundle reconstruction with autologous hamstring tendon transplantation. Before operation, the preoperative planning was done by computer-assisted preoperative planning system—ACL Detector (trial group, n=40) or by conventional method (control group, n=40). There was no significant difference in gender, age, disease duration, injury cause, preoperative Lysholm score, and preoperative International Knee Documentation Committee (IKDC) score between 2 groups (P gt; 0.05). After operation, the effectiveness was evaluated by Lachman test, pivot shift test, Lysholm score, and IKDC score; the digital three-dimensinal model of knee was reconstructed, and the impingement rate of ACL graft was measured. Results All incisions healed by first intention, and no complication was found. The patients were followed up 18-25 months (mean, 20 months) in trial group and 18-24 months (mean, 21 months) in control group. The Lysholm score and IKDC score were significantly increased at 18 months after operation when compared with preoperative scores (P lt; 0.05), but no significant difference was found between 2 groups (P gt; 0.05). The results of Lachman test and pivot shift test at 18 months after operation were significantly better than those before operation in 2 groups (P lt; 0.05), but no significant difference between 2 groups after operation (P gt; 0.05). MRI showed that impingement was observed in 1 case of trial group (2.50%) and in 8 cases of control group (20.00%), showing significant difference (χ2=4.51, P=0.03). Conclusion The computer-assisted preoperative planning system—ACL Detector could be successfully applied to ACL reconstruction. It has the same improvement in knee functional score as conventional surgery, but it is better than conventional surgery in reducing the impingement incidence.
【Abstract】 Objective To introduce several navigation systems in anterior cruciate l igament reconstructionand to investigate the appl ication of navigation systems for the improvement in reconstruction of the anterior cruciatel igament. Methods The related l iterature was reviewed extensively, and the main current computer assisted surgery systems(OthoPilot system, Bone Morphing system, Fluoroscopic-based system, etc) for util ization in the anterior cruciate l igament reconstructionwere analyzed. Results The computer-assisted systems can enhance the accurate placement of tunnels. Accordingto the anatomical and isometric parameters, graft impingement on the intercondylar notch could be avoided, and individualideal implantation using 3D visual ization local isers was achieved. Conclusion It is possible that computer-assisted systemswill enable surgeons to better acquire the accuracy and rel iabil ity of the various operative techniques, to meet the demand ofsurgeon’s surgical optimisation and to improve the cl inical results.
Objective To review the CT appearances and important differential diagnoses of various primary and secondary mesenteric neoplasms. Methods By describing the mesenteric anatiomy and major routes for the dissemination of metastatic mesenteric tumors, the article presents both the common and rare types of various primary and secondary mesenteric neoplasms, and addresses the characteristic CT appearances and important aspects of the differential diagnosis. Results CT study, especially the multislice spiral CT (MSCT), along with the clinical history and other related information, can nicely depict various mesenteric tumors and well differentiate them from infectious, inflammatory or vascular processes affecting the mesentery. Conclusion CT is the imaging method of choice for the evaluation of tumors of small bowel mesentery.
Objective To evaluate the security and effectiveness of minimal invasive fixation with fluoroscopybased navigation in the management of pelvic fractures. Methods From April 2007 to June 2008, 22 patients with pelvic fractures were treated with percutaneous screw fixation under the guidance of a fluoroscopy-based navigation system after closed reduction. There were 13 males and 9 females, aged 21-65 years old. Fractures were caused by traffic accident in 17 cases, andfall ing from height in 5 cases. According to AO classification, there were 2 cases of A2.2 type, 2 cases of A2.3 type, 7 cases of B1.2 type, 3 cases of B2.2 type, 1 case of B3.3 type, 2 cases of C1.2 type, 3 cases of C1.3 type, and 2 cases of C2.3 type. The interval from injury to hospital ization was 4 hours to 3 days (mean 1.2 days). After 3-13 days of skeletal traction through tibial tubercle, the operation was performed. Results Totally 42 screws were inserted. The average time for operation was 20.4 minutes per screw. Forty-one screws were inserted correctly with a successful insertion rate of 97.6%, only 1 hollow screw was reinserted for deviation. No incision problem and implant failure occurred. All 22 patients were followed up 7 to 21 months with an average of 14.5 months. At last follow-up, fracture union was achieved in all patients with satisfactory screw fixation. According to Majeed functional scoring, the results were excellent in 18 cases and good in 4 cases, with an excellent and good rate of 100%. Conclusion The minimal invasive fixation with fluoroscopy-based navigation makes the surgery for the pelvic fracture more precise and time-saving, and improves cl inical results without an increasing rate of compl ications.
Objective To achieve threedimensional (3D) contour image of boneand articular cartilage for fabricating custommade artificial semiknee joint as segment bone allograft.Methods The distal femora of human and pig were scanned with Picker 6000 spiral X-ray computed tomography with 1.0 mm thick slice. The data obtained were treated in Voxel Q image workstation for 3D reconstruction with volume rendering technique. After being downloaded to personal computer at 0.1 mm interval, the transaxial 2D image data were converted into 2D digitized contour data by using image processing software developed by the team. The 2D digitized data were inputted into image processing software of Surfacer 9.0 (Imageware Company, USA), then the 3D wire frame and solidimages of femoral condyle were reconstructed. Subsequently， based on the clinical experience and the requirement of the design of artificial knee joint, the 3Dcontour image of bone or articular cartilage was extracted from the surrounding.Results The 3D contour image of bone or articular cartilage presented was edited and processed easily for the computer aided design(CAD) of custom-madeartificial knee joint.Conclusion The 3D contour image of boneand articular cartilage can be obtained by spiral CT scanning, and the digitized data can beapplied directly to CAD of custom-made artificial joint and subsequently rapidprototyping fabricating. In addition, the reconstruction method is simple and can be applied widely to clinical implant fabricating practice of dentistry and orthopaedics.
Objective To investigate the clinical efficacy of computer-assisted cannulated screw internal fixation system based on error correction method for femoral neck fractures. Methods A retrospective analysis was made on the clinical data of 20 femoral neck fracture patients treated by computer-assisted cannulated screw internal fixation system based on error correction method between January 2014 and October 2015 (trial group), and 36 femoral neck fracture patients undergoing traditional manual surgery with closed reduction by cannulated screw fixation in the same period (the control group). There was no significant difference in gender, age, injury cause, side of fracture, types of fracture, and time from injury to operation between 2 groups (P>0.05). The operation time, intraoperative blood loss, intraoperative frequency of fluoroscopy and guide pin insertion, fracture healing time, fracture healing rate, and Harris hip score were compared between 2 groups. Results All incisions healed by first intention after operation, and no complication of blood vessel and nerve injury occurred. The operation time of trial group was significantly longer than that of control group (t=2.290,P=0.026), however, the intraoperative blood loss, intraoperative frequency of fluoroscopy and guide pin insertion of trial group were significantly less than those of control group (t=–10.650,P=0.000;t=18.320,P=0.000;t=–16.625,P=0.000). All patients were followed up 12-18 months (mean, 14.7 months). X-ray films showed that fracture healing was obtained in 2 groups, showing no significant difference in fracture healing time between 2 groups (t=0.208,P=0.836). No complication of ischemic necrosis of femoral head occurred during follow-up period. At last follow-up, the Harris hip score was 87.05±3.12 in trial group and was 86.78±2.83 in control group, showing no significant difference (t=0.333,P=0.741). Conclusion Computer-assisted cannulated screw internal fixation surgery based on error correction method for femoral neck fractures is better than traditional manual surgery in decreasing intraoperative radiation and surgical trauma during operation.
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.