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find Keyword "Computer-assisted" 17 results
  • CT Appearances of Mesenteric Tumors and the Differential Diagnosis

    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 multislice 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.

    Release date:2016-08-28 04:43 Export PDF Favorites Scan
  • EFFECTIVENESS OF COMPUTER-ASSISTED PREOPERATIVE PLANNING SYSTEM IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

    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.

    Release date:2016-08-31 10:53 Export PDF Favorites Scan
  • COMPUTER ASSISTED SYSTEMS FOR ARTHROSCOPIC RECONSTRUCTION OF ANTERIOR CRUCIATE LIGAMENT

    【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.

    Release date:2016-09-01 09:09 Export PDF Favorites Scan
  • BONE MORPHING SYSTEM FOR ROTATIONAL ALIGNMENT IN TOTAL KNEE ARTHROPLASTY

    【Abstract】 Objective To investigate the qual itative rotation al ignment of components in total knee arthroplastyand the accuracy and the effectiveness of Bone Morphing computer assisted system when qual itatively practicing. MethodsFrom November 2002 to June 2003, 21 patients with three compartments osteoarthritis(21 knees) were treated by primarytotal knee arthroplasty after the conservative medical treatment failed, with the assistance of a “Bone Morphing” CeravisionSystem, implanted posterior stabil ized total knee prosthesis. Twenty-one patients included 5 males (5 knees) and 16 females (16knees) with an average age of 72.4 years (64-79 years) . The locations were left knee in 10 cases and right knee in 11 cases. Thepatients suffered from knee pain and l imitation of movement from 2 to 10 years. There were 14 genu varum and 7 genu valgumpreoperatively. The relative preoperative, intraoperative and postoperative data from cl inical check-up, the X-ray films and theintraoperative components rotational al ignment real-time records in CD Rom were analyzed. Results All operative incisionshealed up by first intension. Twenty-one patients were followed up 12-16 months(mean 13.3 months). For the achievement ofproper lower l imb al ignment and normal frontal laxity of knee, rotational al ignment of femoral components was from internalrotation (IR)1° to external rotation (ER) 5°, tibial components from IR 0° to ER 5°. In patients with genu varum, the rotationalal ignment of the femoral components was ER 1°- ER 5°, of tibial components ER 2°- ER 5°. In patients with genu valgum, the rotationalal ignment of femoral components was IR 1°- ER 4°, of tibial components IR 0°-ER 4°. After 3 months of operation, themean flexion angle measured as range of motion (ROM) was 115°(105-130°), the frontal laxsity measured as 0.2-0.5 cm (mean0.27 cm) of internal laxity and 1.0-2.5 cm (mean 1.7 cm) for external laxity, there were no knee pain, paterllar instabil ity or dislocationand abnormal knee frontal laxity. Conclusion Using Bone Morphing computer-assisted system can optimise theindividual components rotation al ignment accurately.

    Release date:2016-09-01 09:09 Export PDF Favorites Scan
  • MINIMAL INVASIVE FIXATION FOR PELVIC FRACTURE WITH FLUOROSCOPY-BASED NAVIGATION

    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.

    Release date:2016-09-01 09:08 Export PDF Favorites Scan
  • ACCURACY IMPROVEMENT OF ACETABULAR COMPONENT PLACEMENT USING NONIMAGE BASED SURGICAL NAVIGATION SYSTEM

    Objective To improve the accuracy of the acetabular component placement using the nonimage based surgical navigation system. Methods Twenty-three patients (14 males, 9 females; age, 28-55 years;26 hips)with hip disease underwent the total hip arthroplasty (THA) using the nonimage based surgicalnavigation system from February 2004 to April 2006. Rheumatoid arthritis was found in 3 patients (3 hips), necrosis of the femoral head in 6 patients (6 hips), and osteoarthritis in 14 patients (16 hips). All the patients were randomly divided into the following 2 groups: the navigated group (11 patients, 13 hips), treated by THA using the nonimage based surgical navigation system; and the control group (12 patients, 13 hips), treated by the traditional THA. According to thedesign of the study, the acetabular component was placed in the best inclination angle (45°) and the anteversion angle (15°). The postoperative component position was examined. Results No fracture, dislocation, infection or injury to the sciatic nerve was found. In the navigated group, the inclination and the anteversion reached 15.4±1.4° and 45.5±1.3°, respectively. In the control group,the inclination and the anteversion were 13.9±7.6° and 43.7±6.4°, respectively. The inclination difference was considered statistically significant (Plt;0.01). All the patients were followed up for 10-40 months,averaged 26 months. In the navigated group, the postoperative average Harris hip score was 95 (range,85-110), with an excellent result in 11 hips and a good result in 2 hips. In the control group, the postoperative average Harris hip score was 92 (range,75-110), with an excellent result in 9 hips, a good result in 3 hips, and a fair result in 1 hip. The Harris hip score difference was considered statistically significant (Plt;0.05). There was a significantly better result obtained in the navigated group than in the control group. Conclusion The acetabular component can be implanted accurately by the nonimage based surgical navigation system, which can reduce the incidence of the loosening of the prostheses and has an important value in clinical practice.

    Release date:2016-09-01 09:20 Export PDF Favorites Scan
  • MODIFIED ROBOTIZED HYDRAULIC TENSOR FOR LIGAMENT BALANCE IN TOTAL KNEE ARTHROPLASTY

    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 tensorsensor 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.

    Release date:2016-09-01 09:20 Export PDF Favorites Scan
  • BASIC CONCEPT IN COMPUTER ASSISTED SURGERY

    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 decisionmaking, 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.

    Release date:2016-09-01 09:25 Export PDF Favorites Scan
  • BONE MORPHING SYSTEM FOR LIGAMENT BALANCEING IN TOTAL KNEE ARTHROPLASTY

    Objective To investigate effectiveness of applying the Bone Morphingbased image-free computer-assisted system for the ligament balancing managementin the total knee arthroplasty (TKA). Methods Between November 2002 and June 2003, twenty-one posterior stabilized total knee prostheses (Ceraver, France) were implanted in 21 patients using the Bone Morphing based image-free Ceravision system.This cohort included 5 men and 16 women with an average age of 72.4 years, two undergoing high tibial osteotomy and 1 undergoing distal femoral osteotomy before. The preoperative deviation was measured by the full-length AP X-rays. The knees were in varus deviation in 14 patients and in valgus deviation in 7 patients, with an average of 2.36°(varus 13°-valgus 13°). The frontal X-rays ofthe knee were assessed, the mean value of the varus force-stress test was 8.47°(varus 2°-varus 20°), and the mean value of the valgus forcestress test was 3.63°(varus 7°-valgus 12°). Results With the Ceravisionrecorded data, the intraoperative alignment was assessed, the mean lower limb axis was 3.33°(varus 12°-valgus 10°),and compared with the preoperative data, the difference was significant (Plt;0.05); the mean value of the varus force-stress test was 6.47°(varus 0°-varus 24°), the mean value of the valgus force-stress test was 4.32°(varus 8°- valgus 15°), and compared with the preoperative data, the difference was significant (Plt;0.05). The post-prosthetic alignment on Ceravision with a deviation of 0.175°(varus 2°- valgus 3°) was compared with the postoperative alignment by the full-length AP X-rays, with a deviation of 0.3°(varus 3.5°-valgus 1.5°), the difference wasn’t significant(Pgt;0.05).The clinical check-up performed 3 months after operation showed that the average range of movement (ROM) was 115°(105-130°), the mean frontal laxity was 0.27 mm(0.2-0.5 mm). The femoral and tibial components were implanted in the satisfactory 3 dimensional position without ligament imbalance in all the patients, andthere were no instability or patella complications.Conclusion Utilization of the Bone Morphing based image-free computer-assisted system can achieve an accurate component 3 dimensional alignment, optimal bone resection, optimal control of surgical decision in releasing the soft tissues, rotating the femoral component to gain an extension/flexion rectangular gap, and managing theligament balancing so as to achieve a satisfactory initial clinical outcome. This system can be routinely used in the TKA.

    Release date:2016-09-01 09:26 Export PDF Favorites Scan
  • FABRICATION OF CUSTOMMADE ARTIFICIAL SEMIKNEE JOINT BASED ON RAPID PROTOTYPING TECHNIQUE: THREEDIMENSIONAL RECONSTRUCTION OF FEMORAL CONDYLE

    Objective To achieve threedimensional (3D) contour image of boneand articular cartilage for fabricating custommade artificial semiknee 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. 

    Release date:2016-09-01 09:33 Export PDF Favorites Scan
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