Journal Article•
Computer assisted orthopaedic surgery with image based individual templates : Computer assisted orthopaedic surgery: Medical robotics and image guided surgery
TL;DR: An alternative technique for computerized tomographic image based preoperative three-dimensional planning and precise surgery on bone structures using individual templates has been developed and has been applied clinically for pelvic repositioning osteotomies in acetabular dysplasia therapy.
Abstract: Recent developments in computer assisted surgery offer promising solutions for the translation of the high accuracy of the preoperative imaging and planning into precise intraoperative surgery. Broad clinical application is hindered by high costs, additional time during intervention, problems of intraoperative man and machine interaction, and the spatially constrained arrangement of additional equipment within the operating theater. An alternative technique for computerized tomographic image based preoperative three-dimensional planning and precise surgery on bone structures using individual templates has been developed. For the preoperative customization of these mechanical tool guides, a desktop computer controlled milling device is used as a three-dimensional printer to mold the shape of small reference areas of the bone surface automatically into the body of the template. Thus, the planned position and orientation of the tool guide in spatial relation to bone is stored in a structural way and can be reproduced intraoperatively by adjusting the position of the customized contact faces of the template until the location of exact fit to the bone is found. No additional computerized equipment or time is needed during surgery. The feasibility of this approach has been shown in spine, hip, and knee surgery, and it has been applied clinically for pelvic repositioning osteotomies in acetabular dysplasia therapy.
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TL;DR: Computer-assisted preoperative planning is proved to provide patient-specific templates that can replace conventional instruments for total knee arthroplasty, and these templates are a practical alternative to conventional instrumentations.
Abstract: Current techniques used for total knee arthroplasty rely on conventional instrumentation that violates the intramedullary canals. Accuracy of the instrumentation is questionable, and assembly and disposal of the numerous pieces is time consuming. Navigation techniques are more accurate, but their broad application is limited by cost and complexity. We aimed to prove a new concept of computer-assisted preoperative planning to provide patient-specific templates that can replace conventional instruments. Computed tomography-based planning was used to design two virtual templates. Using rapid prototyping technology, virtual templates were transferred into physical templates (cutting blocks) with surfaces that matched the distal femur and proximal tibia. We performed 45 total knee arthroplasties on 16 cadaveric and 29 plastic knees, including a comparative trial against conventional instrumentations. All operations were performed using patient-specific templates with no conventional instrumentations, intramedullary perforation, tracking, or registration. The mean time for bone cutting was 9 minutes with a surgical assistant and 11 minutes without an assistant. Computer-assisted analyses of six random computed tomography scans showed mean errors for alignment and bone resection within 1.7 degrees and 0.8 mm (maximum, 2.3 degrees and 1.2 mm, respectively). Patient-specific templates are a practical alternative to conventional instrumentations, but additional clinical validation is required before clinical use.
297 citations
Cites background from "Computer assisted orthopaedic surge..."
...However, the broad application of such techniques is limited by cost, complexity, set-up time, and long learning curve.(31) We proposed a new concept of using computer-assisted preoperative planning to provide two-piece, patientspecific templates (cutting blocks) for TKA....
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...new generation of the previously reported templating techniques.(9,31) Clinical application of the patient-specific templating...
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TL;DR: The custom-fit approach to total knee arthroplasty in conjunction with removal of osteophytes and preservation of ligaments rapidly returned function; restored motion, stability, and postoperative mechanical axis alignment; effected high patient satisfaction; and had an acceptable clinical outcome.
Abstract: The custom-fit approach to total knee arthroplasty in conjunction with removal of osteophytes and preservation of ligaments rapidly returned function; restored motion, stability, and postoperative mechanical axis alignment; effected high patient satisfaction; and had an acceptable clinical outcome.
227 citations
TL;DR: Corrective osteotomy for a malunited fracture of the upper extremity with use of computer simulation and a custom-designed osteotomy template can accurately correct the deformity and improve the clinical outcome.
Abstract: Background: Three-dimensional anatomical correction is desirable for the treatment of a long-bone deformity of the upper extremity. We developed an original system, including a three-dimensional computer simulation program and a custom-made surgical device designed on the basis of simulation, to achieve accurate results. In this study, we investigated the clinical application of this system using a corrective osteotomy of malunited fractures of the upper extremity.
Methods: Twenty-two patients with a long-bone deformity of the upper extremity (four with a cubitus varus deformity, ten with a malunited forearm fracture, and eight with a malunited distal radial fracture) participated in this study. Three-dimensional computer models of the affected and contralateral, normal bones were constructed with use of data from computed tomography, and a deformity correction was simulated. A custom-made osteotomy template was designed and manufactured to reproduce the preoperative simulation during the actual surgery. When we performed the surgery, we placed the template on the bone surface, cut the bone through a slit on the template, and corrected the deformity as preoperatively simulated; this was followed by internal fixation. All patients underwent radiographic and clinical evaluations before surgery and at the time of the most recent follow-up.
Results: A corrective osteotomy was achieved as simulated in all patients. Osseous union occurred in all patients within six months. Regarding cubitus varus deformity, the humerus-elbow-wrist angle and the anterior tilt of the distal part of the humerus were an average of 2° and 28°, respectively, after surgery. Radiographically, the preoperative angular deformities were nearly nonexistent after surgery. All radiographic parameters for malunited distal radial fractures were normalized. The range of forearm rotation in patients with forearm malunion and the range of wrist flexion-extension in patients with a malunited distal radial fracture improved after surgery.
Conclusions: Corrective osteotomy for a malunited fracture of the upper extremity with use of computer simulation and a custom-designed osteotomy template can accurately correct the deformity and improve the clinical outcome.
Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.
224 citations
TL;DR: This cadaveric study has shown that overall operation time including the fluoroscopy time can be shortened by using the individual template for the pedicle bore, an alternative to the computer-assisted navigation systems with a good cost–performance ratio without excessive technical workload on the physicians or the surgical personnel.
Abstract: Study design Comparison was made of the accuracy of a pedicle bore performed by conventional technique and by using an individual template in the lumbar spine of cadavers. Objectives The fixation of pedicle screws necessitates a high amount of surgical skill and experience to avoid lesions of nerves and vessels. By using individual templates in a cadaver study the goal was to prove the accuracy and efficiency of this less-invasive image-guided surgery in comparison with the conventional technique by fluoroscopy and computed tomographic (CT) scan. Summary of background data Based on three-dimensional models generated from CT scans of the lumbar spine, precise preoperative planning of the position and trajectory of pedicle screws is possible. In comparison with other means of computer-assisted spine surgery with navigation systems, in which a time-consuming intraoperative matching of the bone surface structure is necessary, the use of individual templates enables the surgeon to reduce the operation time considerably. Methods Individual templates are customized on the basis of three-dimensional reconstructions of the bone structures extracted from CT image data and depending on the individual preoperative surgical planning, which uses the desktop image processing system for orthopedic surgery (DISOS). A desktop-computer-controlled milling device is used as a three-dimensional printer to automatically mold the shape of small reference areas of the bone surface into the body of the template. Postoperative CT scans were obtained and the accuracy of the pedicle bore rated by two independent observers. Results The preparation time with the individual template lasted slightly longer than with the conventional operation technique (555 seconds and 482 seconds, respectively). Fluoroscopic study took a mean time of 31.5 seconds, with the conventional operation technique and 5.5 seconds with the individual template. The assessment of the postoperative CT scans demonstrated a higher accuracy of the pedicle bore with the individual template. Conclusions This cadaveric study has shown that overall operation time including the fluoroscopy time can be shortened by using the individual template for the pedicle bore. The individual template is an alternative to the computer-assisted navigation systems with a good cost-performance ratio without excessive technical workload on the physicians or the surgical personnel. Further investigations must be conducted to validate the clinical applicability of this system.
194 citations
Cites methods from "Computer assisted orthopaedic surge..."
...A preoperative CT scan is mandatory to generate the individual templates and for a precise spatial correspondence between the individual bone structure in situ and the intended position of the tool guide.(8) The goal of this study was to evaluate practicability and accuracy of the image-based individual templates....
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01 Dec 1999
TL;DR: A system design concept has been elaborated which includes definitions of components, functionalities, and interfaces, and Approaches to the acquisition of calibrated X-rays will be presented in the paper together with design and evaluation of a first human-computer interface.
Abstract: The CRIGOS (compact robot for image-guided orthopedic surgery) project was set up for the development of a compact surgical robot system for image-guided orthopedic surgery based on user requirements. The modular system comprises a compact parallel robot and a software system for planning of surgical interventions and for supervision of the robotic device. Because it is not sufficient to consider only technical aspects in order to improve clinical routines the therapeutic outcome of conventional interventions, a user-centered and task-oriented design process has been developed which also takes human factors into account. The design process for the CRIGOS system was started from requirement analysis of various orthopedic interventions using information gathered from literature, questionnaires, and workshops with domain experts. This resulted in identification of conventional interventions for which the robotic system would improve the medical and procedural quality. A system design concept has been elaborated which includes definitions of components, functionalities, and interfaces, Approaches to the acquisition of calibrated X-rays will be presented in the paper together with design and evaluation of a first human-computer interface. Finally, the first lab-type parallel robot based on low-cost standard components is presented together with the first evaluation results concerning positioning accuracy.
162 citations
References
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TL;DR: Three golden rules have guided the computer assisted medical interventions project for about ten years: conceive systems for which the clinical value is well defined, develop generic tools that can be applied to many different clinical applications, and provide efficient collaboration between the surgeon and the system through simple interfaces.
Abstract: Many medical or surgical interventions can benefit from the use of computers. Through progress of technology and growing consciousness of the possibilities of real clinical improvements with computers, what was in the past the privilege of very few operations (mostly stereotactic neurosurgery) is now entering many surgical specialities. Although many technical issues remain to be solved, there is virtually no limit to the introduction of computers and robots in any surgical speciality. This tendency can take on the most varied forms. At the authors' institute, three golden rules have guided the computer assisted medical interventions (CAMI) project for about ten years: 1) conceive systems for which the clinical value is well defined; 2) develop generic tools that can be applied to many different clinical applications; and 3) provide efficient collaboration between the surgeon and the system through simple interfaces. >
213 citations
01 Jan 1984
173 citations
TL;DR: A computer-assisted model developed to improve the results of surgical techniques for reconstruction of hip dysplasia establishes both deficiencies of coverage and congruency of pathologic hips and thus may be used to create a more precise definition and treatment of multiple congenital abnormalities.
Abstract: A computer-assisted model has been developed to improve the results of surgical techniques for reconstruction of hip dysplasia This method assesses the coverage and congruency of the femoral head by evaluating multiple factors that may influence surgical planning It achieves a more reliable image because the measurements are based on a three-dimensional representation, and attention is focused on the cartilaginous coverage of the femoral head A method to simulate the operative correction helps the surgeon in planning osteotomies of the femur and pelvis This technique clearly establishes both deficiencies of coverage and congruency of pathologic hips and thus may be used to create a more precise definition and treatment of multiple congenital abnormalities
141 citations
"Computer assisted orthopaedic surge..." refers methods in this paper
...Open door decompression in the cervical spine: (A) design of an individual template (2) with a copying profile (6) limiting cutting depth of the milling head (7) to the anterior cortical layer of the lamina (1); a micromilling machine (4) is equipped with a sliding jig plate (8) ; (B) planning of the milling work on bone, arrows indicating the specified are of bone to be removed; (C) the reference to the bone structure is provided by an individual contact face (9); the two individual parts of the template are connected by a simple adapter (10); (D) intraoperative execution in the framework of a cadaver study; (E) result on the left side showing the intact dura; and (F) result on the right side with the intact cortical hinge....
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19 Mar 1997
TL;DR: Within the framework of the European IGOS-project a demonstrator for image guided pelvis surgery as an exemplary clinical application will be developed and aspects of the integration into clinical routine as well as laboratory investigations concerning accuracy and integrated manufacturing are discussed.
Abstract: Individual templates for Orthopedic Surgery provide a precise intraoperative reproduction of the geometries of work on bone planned preoperatively on the base of CT-image data. The general feasibility concerning the adaptation to different surgical applications has already been demonstrated in various in-vitro studies as well as within clinical application1,2,3,4,5. Within the framework of the European IGOS-project a demonstrator for image guided pelvis surgery as an exemplary clinical application will be developed. In contrast to initial feasibility studies with our first labtyp systems, the introduction into clinical routine induces additional constraints. To provide an adequate level of reliability and usability additional efforts are necessary especially concerning quality assurance, ergonomic design and standardisation of the related chain of image acquisition and surgical planning, manufacturing of individual templates and finally the intraoperative execution. Aspects of the integration into clinical routine as well as laboratory investigations concerning accuracy and integrated manufacturing are discussed.
136 citations
TL;DR: The robotic assistant functioned easily in the operating room environment; increased the accuracy; and decreased the time, equipment, and personnel required for the conduct of the geometrical part of this surgical procedure.
Abstract: The term "robot" refers to a precision mechanical device that is accurately controlled by a computer using intelligent software. The term "robotic assistance" refers to the use of such a device to aid a surgeon in the optimal conduct of a procedure, particularly one requiring specified geometrical relationships. The authors have been exploring the application of robotic assistance in situations in which accuracy and precision are required in orthopaedic surgery. The initial application concerned the planning, positioning, and orientation cuts and holes of the bone required for the femoral component of a total knee arthroplasty. A three-dimensional digitizing template allowed the surgeon to specify the desired position and orientation of the component's articular surfaces in relation to the distal femur. The robotic system used this spatial relationship, along with its knowledge of the geometry of the component selected by the surgeon, to plan the precise location of the required bone cuts and holes. Finally, the robotic assistant sequentially positioned saw and drill guides with respect to the distal femur so that the surgeon made these cuts and holes in the locations necessary for optimal component fit, position, and orientation. The robotic assistant functioned easily in the operating room environment; increased the accuracy; and decreased the time, equipment, and personnel required for the conduct of the geometrical part of this surgical procedure.
132 citations