Computer-Assisted Musculoskeletal Surgery: Thinking and Executing in 3D PDF
Preview Computer-Assisted Musculoskeletal Surgery: Thinking and Executing in 3D
Computer-Assisted Musculoskeletal Surgery Thinking and Executing in 3D Lucas E. Ritacco Federico E. Milano Edmund Chao Editors 123 Computer-Assisted Musculoskeletal Surgery Lucas E. Ritacco (cid:129) Federico E. Milano Edmund Chao Editors Computer-Assisted Musculoskeletal Surgery Thinking and Executing in 3D Editors Lucas E. Ritacco Edmund Chao Computer-Assisted Surgery Unit Johns Hopkins University Hospital Italiano de Buenos Aires Baltimore , MD Buenos Aires USA Argentina Federico E. Milano Bioengineering Instituto Tecnologico de Buenos Aires Buenos Aires Argentina ISBN 978-3-319-12942-6 ISBN 978-3-319-12943-3 (eBook) DOI 10.1007/978-3-319-12943-3 Library of Congress Control Number: 2015953344 Springer Cham Heidelberg New York Dordrecht London © Springer International Publishing Switzerland 2016 T his work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifi cally the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfi lms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. T he use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specifi c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. T he publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. Printed on acid-free paper S pringer International Publishing AG Switzerland is part of Springer Science+Business Media (www.springer.com) Pref ace It is an honor and pleasure to have been asked to write the Preface of a book I regard as “intimate” since it deals with the topic, that has occupied much of my career for more than four decades! Instead of dwelling only on the subject material in each chapter, I choose a different approach to refl ect my personal view of the general topic using a commentary style, and with brief historical reviews. As computer- assisted surgery is subjected to both enthusiastic acceptance and cautious scrutiny, it is fare for me to express my thoughts by assessing its current status and future outlook. To end, I offered a provocative thought for us all to contemplate that may impact on medical technology now and years to come. C omputer-assisted surgery (CAS) by defi nition is a process in which a surgical procedure is planned and executed using computer simulation and navigation technology. From the engineering point of view, simulation was a relatively old innovation started in the late 1950s and early 1960s using the analog computer in the aerospace and automobile industry. The digital computer was then in its infancy with limited memory, inadequate processing speed, and the lack of numerical methods to solve differential equations. The basic practice of spatial navigation was already in existence in tracking aircraft and vehicular movements in high speed using triangular photogrammetry. It was interesting that applications of engineering principles to medicine and surgery were beginning to emerge at about the same time. This early development of simulation had a major drawback in that the models were primarily analytical and scaled prototypes, thus making analysis of results diffi cult to visualize and the optimal design process time-consuming and costly. T he explosion of digital computer technology with large core memory and pro- cessing speed in the 1970s stimulated the development of numerical methods, which had replaced the use of analog computer in data processing and the solution of the analytical models. With the advances in imaging technology, 3D graphics provided the unique capability of generating solid and surface models in the late 1980s. This advancement also enhanced the navigation technology by coordinating the virtual model with the real system monitored using different stereometric methods with sensors and markers, thus making computer-assisted surgery (CAS) possible. Subsequently, the development of surgical robot gave rise to the “Robodoc” in hip v vi Preface replacement surgery, which set the pace and laid down the standards for future CAS development. B efore commenting on the contents of this book, several historical developments should be mentioned to explain the evolutional passage of CAS technology. Computer-aided preoperative planning based on biomechanical analysis using 2D radiographic images for osteotomy of the knee and hip joints using the discrete ele- ment analysis (the Rigid Body Spring Modeling technique) was well established for clinical trial and eventually received reimbursement for the preoperative planning service for nearly a decade between the 1980s and the 1990s. The execution of these diffi cult procedures was less precise, however; but the need to expand this innova- tive concept to 3D laid down the impetus and foundation to build today’s CAS. For bone fracture reduction, adjustment and fi xation, under unilateral external fi xator, were extensively investigated in the late 1990s using kinematic theories and virtual models of the bone-fi xator complex for application planning and visualization. This developmental effort was short lived due to the overwhelming favor towards inter- nal fi xation devices at the turn of the Millennium. Fortunately, such trend may have effectually reversed by the improvement in external fi xator design and their applica- tion software, which will be discussed in detail in this book. The combination of virtual interactive anatomical model and biomechanical analysis was successfully developed in the latter part of 1990s owing to the remarkable advancement in com- puter graphics stimulated by the movie, video, gaming and advertisement industry! These progressive passages made CAS what it is today! This book is logically structured into six well-coordinated and balanced sec- tions. Their contents cover a broad spectrum of the current R&D status of CAS in musculoskeletal surgery and related fi elds. Brief comments on each section may help in guiding the readership in surgery, bioengineering and the related clinical fi elds. Preoperative Planning : Using computer-aided segmental allograft transplanta- tion in osteotomy and limb salvage surgery, the model-building process for the grafts available in bone banks and the recipient host skeletal structure are presented as a lead chapter to describe the preoperative planning process for CAS. Although precision may be less desirable due to the inevitable system and image data errors, human musculoskeletal structure is capable to adjust for the motion and load- bearing requirements. The computerized tools for allograft selection, size- matching, fi xation device selection, registration, and reconstruction have made the concept of “Digital Bone Bank and Computer-aided Graft Transplantation” fi rst conceived in the 1990s, now a clinical reality! Virtual testing under static and cyclic loading became a new concept more than a decade ago which allowed both time and cost saving. However, real models on a testing machine or a wear simulator are neces- sary to verify the results. To minimize long-term side effects caused by wear parti- cles, ex vivo and in situ animal models must be utilized. Finally, clinical trial studies of suffi cient follow-up length remain the gold standard to assure safety and effi cacy when new material or implant designs were fi rst introduced. Surgical Navigation: The contributors of this section have done a remarkable job of reviewing and introducing the fi eld of surgical navigation in orthopaedics. Preface vii Their comprehensive and clear deliberations on the potential pitfalls of this t echnology are worthy for the surgical robot industry to note and rectify their claims. To justify its medical application, this technology should be evaluated based on its effi cacy, safety, cost, and reliability. It should be noted that surgery is still regarded as an art by many. The ability to visualize the operative fi eld in 3D while able to feel and manipulate vital anatomical parts by the surgeons’ hands during surgery cannot be duplicated by the robot. Therefore, surgical navigation and robot technology is intended to aid the experienced surgeons, not to replace them. Local Ablation of Bone Tumor – Using heat or extreme cold to ablate local tumorous tissues en bloc leaving the devitalized bony structure as a scaffold to facil- itate biological reconstruction has been in clinical trial for decades. However, the optimal dosages of these physical energies, their practical and effective implemen- tation technique for different tumor types and extent to minimize local recurrence of the malignant process have not been worked out satisfactorily and thus prevented a wide utilization. In diffi cult anatomical locations, where en bloc resection of can- cer-affl icted region is impossible, local ablation using diffusible energy source to allow the therapeutic effect reaching beyond the anticipated resection volume while able to protect the adjacent vital organ function would be a monumental advance in orthopaedic oncology! The use of CAS technology can accomplish these goals through biomechanical and heat-transfer analyses to optimize the thermal energy delivery in the pretreatment planning and execution strategy. Ultimately, when such technology becomes successful and reliable in orthopaedic application, it can easily be transferred to other oncologic fi elds. Custom Implants : In revision surgery after failed joint replacement prosthesis with massive bone loss and after bone tumor resection, the use of custom implant is an important service to save the patient’s limb. The argument for patient-specifi c implant design and surgical guidance cannot be over emphasized due to the bone and soft tissue defi ciency heavy loading demands which may lead to implant failure and poor joint function. Although orthopaedic device companies have always regarded such service as an act of charity, disputes sometimes ensued due the high cost involved if the anticipated results and durability of the implant were less desir- able. Occasionally, the issue of inadequate implant fi t in diffi cult bone tumor cases due to intraoperative change of resection margin would lead to unacceptable recon- struction. Hence, it would be hard to expect that the technology of CAS will be able to resolve these diffi culties. It is time to explore biological reconstruction using patient’s own bone stock as scaffold after local en bloc tumor ablation. Validation in Computer-assisted Surgical Workfl ow : Virtual model forma- tion, the operative planning strategy, and surgical guidance of implant placement used in CAS must all be carefully evaluated for their accuracy and adequacy. In addition, the effi cacy of the proposed technology should be supported by the results of evidence-based clinical studies. In musculoskeletal reconstructive surgery, it is important that the planning strategy will be based on biomechanical analysis to assure the functional requirements in terms of safety and durability with no long- term side effects. In the justifi cation of any new technology, cost factors must also enter into the overall assessment process. viii Preface Emerging Trends and Applications: The 3D projection-based navigation using that consist in overlapping skeletal and soft tissue images with implant and pathol- ogy data is an attractive and powerful tool for operative guidance. This may even be more useful in a teaching or training scenario combined with tactile and sensory feedbacks. The inclusion of CMS (cranio-m axillofacial surgery) in this section is commendable due to its large patient population while the same technology and biomechanical analysis can be readily shared to save cost. The use of a pure-axial quasi-static tractive force to assess spinal fl exibility in scoliotic patients is an inter- esting concept which may be helpful to the recent development of the remote-con- trolled spinal curvature correction rod in adolescent idiopathic scoliosis (AIS) patients with severe deformity. However, there are other important factors and prob- lems in treating scoliosis patients both in the adolescent and adult population that need be addressed. In nonoperative management of AIS patients with mild to mod- erate deformity, adjustable braces that are designed and applied based on computer- assisted analysis and corrective strategy can be an exciting and benefi cial trend for CAS. Furthermore, some of the high-return and low-risk clinical applications of CAS in orthopaedics not mentioned in this book deserve brief introduction as follows. 1. Fracture Reduction and Deformity Correction using External Robot: In the 1970s and 1980s, the use of external fi xator (EF) of various designs and clinical applications became wide spread in trauma and orthopaedic fi elds. Computer- aided fracture reduction, adjustments, stimulation and callus distraction plan- ning and execution treating the fi xator as an external robot were introduced in the early 1990s. Unfortunately, owing to the strong development and marketing effort of the internal fi xation devices, the EF fi eld faced a dramatic decline. The revival of EF method in orthopaedics and traumatology is evidenced in the chap- ters presented in this section. Three-dimensional joint osteotomy has become a reality as presented here. With a single closed or open wedge through a gradual callus distraction (EF devices) or an one-step correction procedure performed open using a computer- aided quick prototyping custom wedge-cutting instru- ment block are now well in their clinical trial. This indeed is a remarkable land- mark achievement in orthopaedics! Although, consecutive hinge joints in a fi xator can achieve the needed single angular correction with respect to the screw axis, the extra space requirement makes it bulky and not convenient for clinical usage. Similar corrections can also be achieved using redundant linear displace- ment actuators, such as the Taylor Frame®. The application of the “virtual hinge” concept or an instrumented ball-and-socket joint can achieve the same angular correction and bone length adjustment while able to make the external robot slim, easy to adjust, and improve the patient’s daily activities. These advances are expected to bring the EF technology back to orthopaedics, thanks to the concept of computer-assisted surgery. Preface ix 2. Minimal Invasive Tissue Engineering – Based on the science and technology of bone fracture tendon to bone junction healing augmentation using biophysical stimulation, it would be quite possible that these connective tissues’ properties and composition can be manipulated to facilitate the highly sought for tissue engineering process. If the biomechanical and morphological properties of bone, tendon, cartilage, vessels, and even the nerve could be monitored noninvasively during distraction, compression or angular deformation under external immobi- lization, minimally invasive tissue, or structure regeneration will become a real- ity. All these could be worked using the fi xator as a robot. The energy fi eld of proper intensity and pulse frequency produced either by ultrasound or e lectromagnetic power may also carry a pain control effect making this diffi cult and painful procedure more acceptable to the patients. This innovative applica- tion can greatly enhance bioengineering’s contribution to health care. 3. Computer-Assisted Rehabilitation – Although it may seem that such application would be out of the scope of this book, it is a well-recognized fact that the suc- cess of any major orthopaedic procedure would depend on safe and effective postoperative care through rehabilitation. The same modeling, analysis, and execution technology used in CAS can easily be adapted here making it a new fi eld. In addition, the emphasis on conservative management and injury preven- tion will be the spin-off benefi ts for patients suffering pain and dysfunction due to skeletal and joint trauma, deformity, and degeneration. T o conclude this commentary essay in support of CAS in musculoskeletal sur- gery, it is pertinent to briefl y address some of the nonmedical issues related to these technical innovations. The concept of CAS and its technology were largely stimu- lated and complemented by the game and entertainment industry, although each carries an entirely different motivation and ethics. When medical technology is transformed from bench top to bedside and for general dispersion, the manufactur- ing fi rms cannot avoid being contaminated by bias and commercialism. Though such accusation may seem unfair and even altruistic, unproven and ill-justifi ed application with unsubstantiated claims have caused unpleasant and even serious consequences leading to legal and economic dispute, which had eroded their noble intent of do no harm to humankind. Bioengineering effort of the past, present, and future may also fall into this trap without recognizing its inherent limitations and primary obligations to medicine professionals! A special value concept based on the balance of effi cacy, safety, durability, education, and cost should be worked out and adhered to beyond the government enforced regulatory guidelines for any medical technology! Hence, it is of vital importance that CAS or any other technology- driven innovations be extremely cautious and take a rather conservative attitude in promoting their clinical claims. Therefore, a self-induced jurisprudence is neces- sary for the bioengineers, their collaborating physicians, and industry. Finally, I wish to leave three questions to the readership and the contributors of this book that
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