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 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.
【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.
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 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 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 forcestress 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.
【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.
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 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 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.