Objective To design a new custom-made artificial semi-knee joint based on rapid prototyping(RP) technique and to explore a method to solve necroses of allocartilage in hemi-joint allotransplantation. Methods Based on the extracted 3D contour image of the articular cartilage of femoral condyle, the custom-made artificial semi-knee joint was designed with Surfacer 9.0 image processingsoftware. The artificial semi-knee joint design used the femoral condylar 3D contour of the patient as the outer face and the subchondral bone 3D contour of allograft bone as inner face. One dado for medullary nailand two for special designing cages which were used to fix the cartilage into the allograft were added on the inner face. After being converted into RP data format, the computerassisted design was imported into the LPS600 rapid prototyping machine, and the prototype was achieved. Furthermore, the prototype could be modified by hand according to the design. Then the RP model was used as a positive mould to build up a silica gel negativemould, and the negative mould was sent to the factory to manufacture Ti-6Al-4V alloy articular cartilage through ordinary mould-melted founding process. Finally, the whole metal cartilage was completed after melting two special cages on it andpolishing it. Results A new custom-made artificial semi-knee joint was made ad used to treat a 14-year old patient. The custom-made artificial semi-knee joint and the subchondral bone were a perfect match. The operative result was satisfactory. The patient could walk 5 weeks after operation. The bone healing of the auto-bone and allo-bone was achieved 6 months later. A follow-up period lasting 1 yearshowed that the knee joint played a good function. Conclusion The artificial semi-knee joint is a good match for the allograft boneand a good idea to solve necroses of allocartilage in hemijoint allotransplantation.
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 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 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 improve the accuracy of the acetabular component placement using the nonimage 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 nonimage 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 nonimage 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 nonimage based surgical navigation system, which can reduce the incidence of the loosening of the prostheses and has an important value in clinical practice.
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 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 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.
Post-stroke cognitive dysfunction is a common complication of stroke, and active rehabilitation therapy can effectively promote the recovery of patients. As a new treatment method, telecognitive rehabilitation is used in rehabilitation treatment of cognitive disorders. Its main technologies include computer-assisted cognitive rehabilitation, virtual reality technology, and artificial intelligence technology. It can use the Internet platform to provide homogeneous treatment, make patients more convenient for cognitive rehabilitation treatment, help to ensure the continuity of rehabilitation treatment, and save medical costs. This article describes the definition of cognitive telerehabilitation, the development and application of cognitive telerehabilitation technology, and summarizes the existing problems. The purpose is to provide a reference for the clinical application of cognitive telerehabilitation in China and future research directions.
【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.