【Abstract】 Objective To determine the three-dimensional stabil ity of atlantoaxial reconstruction withanterior approach screw fixation through C2 vertebral body to C1 lateral mass and Gall ie’s technique (ASMG) for C1,2instabil ity. Methods Twenty-five human cadaveric specimens (C0-3 ) were divided randomly into 5 groups (n=5). Thethree-dimensional ranges of motion C1 relative to C2 were measured under the five different conditions：the intact state group (group A), type II odontoid fracture group (group B), posterior C1,2 transarticular screw fixation group (group C), ASM group (group D) and ASMG group (group E). The three-dimensional ranges of motions C1 relative to C2 by loading ± 1.5 Nm were measured under the six conditions of flexion/extension, left/right lateral bending, and left/right axial rotation. The obtained data was statistically analyzed. Results In each group, the three-dimensional ranges of motion C1 relative to C2 under the six conditions of flexion/extension, left/right lateral bending, and left/right axial rotation were as follows: in group A (8.10 ± 1.08), (8.49 ± 0.82), (4.79 ± 0.47), (4.93 ± 0.34), (28.20 ± 0.64), (29.30 ± 0.84)°; in group B (13.60 ± 1.25), (13.80 ± 0.77), (9.64 ± 0.53), (9.23 ± 0.41), (34.90 ± 0.93), (34.90 ± 1.30)°; in group C (1.62 ± 0.10), (1.90 ± 0.34), (1.25 ± 0.13), (1.37 ± 0.28), (0.97 ± 0.14), (1.01 ± 0.17)°; in group D (2.03 ± 0.26), (2.34 ± 0.49), (1.54 ± 0.22), (1.53 ± 0.30), (0.80 ± 0.35), (0.76 ± 0.30)°; in group E (0.35 ± 0.12), (0.56 ± 0.34), (0.44 ± 0.15), (0.55 ± 0.16), (0.43 ± 0.07), (0.29 ± 0.06)°. Under the six conditions, there were generally significant differences between group A and other four groups, and between group B and groups C, D and E (P lt; 0.001), and between group E and groups C, D in flexion/ extension and left/right lateral bending (P lt; 0.05). There was no significant difference between group E and groups C, D in left/right axial rotation (P gt; 0.05). Conclusion In vivo biomechanical studies show that ASMG operation has unique superiority in the reconstruction of the atlantoaxial stabil ity, especially in controll ing stabil ity of flexion/extension and left/right lateral bending, and thus it ensures successful fusion of the implanted bone. It is arel iable surgical choice for the treatment of the obsolete instabil ity or dislocation of C1, 2 joint.
Objective To investigate the methods of establishing 3-dimensional skull model using electron beam CT(EBCT) data rapid prototyping technique, andto discuss its application in repairing crainomaxillofacial trauma. Methods The data were obtained by EBCTcontinuous volumetric scanning with 1.0 mm slice at thickness. The data were transferred to workstation for 3-dimensional surface reconstruction by computeraided design software and the images were saved as STL file. The data can be usedto control a laser rapid-prototyping device(AFS-320QZ) to construct geometricmodel. The material for the model construction is a kind of laser-sensitive resinpower, which will become a mass when scanned by laser beam .The design and simulation of operation can be done on the model. The image data were transferred to the device slice by slice. Thus a geometric model is constructed according to the image data by repeating this process. Preoperative analysis, surgery simulation and implant of bone defect could be done on this computer-aided manufacture d3D model. One case of craniomaxillofacial bone defect resulting from trauma wasreconstructed with this method. The EBCT scanning showed that the defect area was 4 cm×6 cm. The nose was flat and deviated to left. Results The -3dimensional -skull was reconstructed with EBCT data and rapid prototyping technique. The model can display the structure of 3-dimenstional anatomyand their relationship.The prefabricated implant by 3-dimensional model was well-matched with defect .The deformities of flat and deviated nose were corrected. The clinical result wassatisfactory after a follow-up of 17 months. Conclusion The 3-dimensional model of skull can replicate the prototype of disease and play an important role in the diagnosis and simulation of operation for repairing craniomaxillofacial trauma.
ObjectiveTo explore a method of three-dimensional (3D) printing technology for preparation of personalized rat brain tissue cavity scaffolds so as to lay the foundation for the repair of traumatic brain injury (TBI) with tissue engineered customized cavity scaffolds.
MethodsFive male Sprague Dawley rats[weighing (300±10) g] were induced to TBI models by electric controlled cortical impactor. Mimics software was used to reconstruct the surface profile of the damaged cavity based on the MRI data, computer aided design to construct the internal structure. Then collagen-chitosan composite was prepared for 3D bioprinter of bionic brain cavity scaffold.
ResultsMRI scans showed the changes of brain tissue injury in the injured side, and the position of the cavity was limited to the right side of the rat brain cortex. The 3D model of personalized cavity containing the internal structure was successfully constructed, and cavity scaffolds were prepared by 3D printing technology. The external contour of cavity scaffolds was similar to that of the injured zone in the rat TBI; the inner positive crossing structure arranged in order, and the pore connectivity was good.
ConclusionCombined with 3D reconstruction based on MRI data, the appearance of cavity scaffolds by 3D printing technology is similar to that of injured cavity of rat brain tissue, and internal positive cross structure can simulate the topological structure of the extracellular matrix, and printing materials are collagen-chitosan complexes having good biocompatibility, so it will provide a new method for customized cavity scaffolds to repair brain tissue cavity after TBI.
With the developing of three-dimensional (3D) printing technology, it is widely used in the treatment of bone tumors in the clinical orthopedics. Because of the great individual differences in the location of bone tumor, resection and reconstruction are difficult. Based on 3D printing technology, the 3D models can be prepared to show the anatomical part of the disease, so that the surgeons can create a patient-specific operational plans based on better understand the local conditions. At the same time, preoperative simulation can also be carried out for complex operations and patient-specific prostheses can be further designed and prepared according to the location and size of tumor, which may have more advantages in adaptability. In this paper, the domestic and international research progress of 3D printing technology in the treatment of limb bone tumors in recent years were reviewed and summarized.
ObjectiveTo review the current research status of in situ three-dimensional (3-D) printing technique and future trends.
MethodsRecent related literature about in situ 3-D printing technique was summarized, reviewed, and analyzed.
ResultsBased on the cl inical need for surgical repair, in situ 3-D printing technique is in the preliminary study, mainly focuses on in situ dermal repair and bone and cartilage repair, and succeeds in experiments, but there are still a lot of problems for cl inical application.
ConclusionWith the development of in situ 3-D printing technique, it will provide patients with real-time and in situ digital design and 3-D printing treatment with a timely and minimally invasive surgical repair process. It will be widely used in the future.
Objective
To study digitize design of custom-made radial head prosthesis and to verify its matching precision by the surgery of preoperative three-dimensional (3-D) virtual replacement.
Methods
Six healthy adult volunteers (3 males and 3 females, aged 25-55 years with an average of 33 years) received slice scan of bilateral elbow by Speed Light 16-slice spiral CT. The CT Dicom data were imported into Mimics 10.0 software individually for 3-D reconstruction image, and the left proximal radial 3-D image was extracted, the mirror of the image was generated and it was split into 2 pieces: the head and the neck. The internal diameter and the length of the radial neck were obtained by Mimics 10.0 software measurement tools. In Geomagic Studio 12 software, the radial head was simulated to cover the cartilage surface (1 mm thickness) and generated to an entity. In UG NX 8.0 software, the stem of prosthesis was designed according to the parameters above and assembled head entity. Each custom-made prosthesis was performed and verified its matching precision by the surgery of preoperative 3-D virtual replacement.
Results
Comparing the morphology of 6 digitize custom-made prostheses with ipsilateral radial heads by the 3-D virtual surgery, the error was less than 1 mm. The radial head prosthesis design on basis of the contralateral anatomy was verified excellent matching.
Conclusion
The 3-D virtual surgery test and the digitized custom-made radial head prosthesis will be available for clinical accurate replacement.
ObjectiveTo study the clinical value of digital technology assisted minimally invasive surgery in diagnosis and treatment of hepatolithiasis. MethodsThe image data of 64-slice spiral CT scanning were obtained from five patients of complicated hepatolithiasis and introduced into medical image three-dimensional visualization system (MI-3DVS) for three-dimensional reconstruction. On the basis of the data of three-dimensional reconstruction, minimally invasive surgical planning of preoperation was made to obtain reasonable hepatectomy and cholangiojejunostomy, and then preoperative emulational surgery was carried out to minimize the extent of tissue damage and provide guidance to actual operation. ResultsLiver, biliary system, stone, blood vessel, and epigastric visceral organ were successfully reconstructed by MI-3DVS, which showed clearly size, number, shape, and space distribution of stone, and location, degree, length, and space distribution of biliary stricture, and anatomical relationship of ducts and vessels. The results of three-dimensional reconstruction were successfully confirmed by actual operation, which was in accordance with emulational surgery. There was no operative complication. No retained stone in internal and external bile duct was found by Ttube or other supporting tube cholangiography on one month after operation. ConclusionThree-dimensional digitizing reconstruction and individual emulational surgery have important significance in diagnosis and treatment of complicated hepatolithiasis by minimally invasive technique.
ObjectiveTo explore the value and role of post-processing techniques such as 3D reconstruction in the online education mode in neurosurgery undergraduate clinical probation teaching.MethodsA retrospective analysis method was used to collect 120 clinical 5-year medical students who were trained in neurosurgery at West China Hospital of Sichuan University from January 2019 to May 2020, including 40 students receiving traditional imaging materials offline (control group 1), 40 students being taught on image post-processing technology offline (control group 2), and 40 students being taught on-line image post-processing technology during the novel coronavirus epidemic (observational group). The students’ scores of departmental rotation examination and feedback survey results on teaching satisfaction were collected, and multiple comparison was conducted between the observational group and the two control groups respectively.ResultIn the control group 1, the control group 2, and the observational group, the theoretical test scores were 36.80±3.22, 38.17±2.61, and 38.97±2.79, respectively; the case analysis scores were 37.05±2.01, 38.40±2.62, and 39.25±2.88, respectively; the total scores were 73.85±5.06, 76.57±4.29, and 78.10±4.53, respectively; the scores of interest in teaching were 84.47±3.71, 86.05±2.87, and 86.82±2.60, respectively; the scores of mastery of knowledge were 82.85±4.39, 84.90±2.72, and 85.78±2.36, respectively; and the scores of overall satisfaction with teaching were 84.17±3.45, 85.97±2.64, and 86.37±2.59, respectively. The differences among the three groups were all statistically significant (P<0.05). The observational group differed significantly from the control group 1 in all the above scores (P<0.05), while did not differed from the control group 2 in any of the above scores (P>0.05).ConclusionsIn neurosurgery internship activities, the online application of image post-processing techniques such as 3D reconstruction will help students establish 3D spatial concepts, better understand the brain anatomy, and improve students’ academic performance and acceptance.
Objective To develop hepatic surgical planning software for hepatic operation on deciding the rational operational scheme and simulating procedures before the operation to accomplish the precise liver resection and decrease the operational risk. Methods3D-econstruction of liver was restored from spiral computed tomography (CT) data by using LiVirtue software. The liver and its anatomic structures were reconstructed to illuminate the location of the tumor and its related vessels to design a rational operational scheme. The virtul results, such as liver volume, hepatic sections, anatomy of portal vein and hepatic veins or possible operation plans, were compared with the actual situations during the operations. Results3D models of liver, tumor and their relative vessels were reconstructed successfully. Preoperative planning and intra-perative navigation based on the models ensured the safety of liver resection in our 32 cases of right lobe tumors. This preoperative simulation allowed surgeons to dissect the liver with reduced complications. These models could be also viewed and manipulated on personal computers.ConclusionThe LiVirtue is very helpful in the hepatic surgery, for clearly disclosing hepatic structures, rationally deciding operation schemes, virtually simulating the operations. This preoperative estimation from 3D model of liver benefits a lot to complicated liver resection.
Objective To review the research progress on the three-dimensional (3D) reconstruction and visual ization of peri pheral nerve. Methods Literature about the research on the 3D reconstruction and visual ization of peripheral nerve both at home and abroad were extensively reviewed and thoroughly analyzed. Results The appl ication of 3D reconstruction and visual ization technology was capable of not only reappearing the 3D outer contour and spatial adjacent relationship of peripheral nerve veritably but also displaying, rotating, zooming, dividing and real-time measuring their 3D internal structure and the del icate pathways in any direction either separately or totally. Prel iminary achievements were achievedin terms of brachial plexus, lumbosacral plexus, the functional cluster of nerve trunk, intramuscular nerve distribution pattern, peripheral nerve regeneration and the 3D reconstruction and visual ization research of complex tissue including peripheral nerve. However, the research on the visual ization of peripheral nerve was still in the initial stage since such problems as recognition, segmentation, registration and fusion of the peripheral nerve information were not resolved yet. Conclusion Researching 3D reconstruction and visual ization of the peripheral nerve is of great value for updating the diagnosis and treatment principle of peripheral nerve injury, improving its diagnosis and treatment method and launching a new way for the studying and teaching, which may be a new growing point for the peripheral nerve surgery.
