Justin Cobb

Bio: Justin Cobb is an academic researcher from Imperial College London. The author has contributed to research in topics: Arthroplasty & Hip resurfacing. The author has an hindex of 43, co-authored 244 publications receiving 6372 citations. Previous affiliations of Justin Cobb include Royal National Orthopaedic Hospital & University College Hospital.

Hands-on robotic unicompartmental knee replacement: A PROSPECTIVE, RANDOMISED CONTROLLED STUDY OF THE ACROBOT SYSTEM

Abstract: We performed a prospective, randomised controlled trial of unicompartmental knee arthroplasty comparing the performance of the Acrobot system with conventional surgery A total of 27 patients (28 knees) awaiting unicompartmental knee arthroplasty were randomly allocated to have the operation performed conventionally or with the assistance of the Acrobot The primary outcome measurement was the angle of tibiofemoral alignment in the coronal plane, measured by CT Other secondary parameters were evaluated and are reported All of the Acrobot group had tibiofemoral alignment in the coronal plane within 2 degrees of the planned position, while only 40% of the conventional group achieved this level of accuracy While the operations took longer, no adverse effects were noted, and there was a trend towards improvement in performance with increasing accuracy based on the Western Ontario and McMaster Universities Osteoarthritis Index and American Knee Society scores at six weeks and three months The Acrobot device allows the surgeon to reproduce a pre-operative plan more reliably than is possible using conventional techniques which may have clinical advantages

Pseudotumors in association with well-functioning metal-on-metal hip prostheses: a case-control study using three-dimensional computed tomography and magnetic resonance imaging.

Abstract: Introduction: Many papers have been published recently on the subject of pseudotumors surrounding metal-on-metal hip resurfacing and replacement prostheses. These pseudotumors are sterile, inflammatory lesions within the periprosthetic tissues and have been variously termed masses, cysts, bursae, collections, or aseptic lymphocyte-dominated vasculitis-associated lesions (ALVAL). The prevalence of pseudotumors in patients with a well-functioning metal-on-metal hip prosthesis is not well known. The purpose of this study was to quantify the prevalence of pseudotumors adjacent to well-functioning and painful metal-on-metal hip prostheses, to characterize these lesions with use of magnetic resonance imaging, and to assess the relationship between their presence and acetabular cup position with use of three-dimensional computed tomography. Methods: We performed a case-control study to compare the magnetic resonance imaging findings of patients with a well-functioning unilateral metal-on-metal hip prosthesis and patients with a painful prosthesis (defined by either revision arthroplasty performed because of unexplained pain or an Oxford hip score of <30 of 48 possible points). Thirty patients with a painful hip prosthesis and twenty-eight controls with a well-functioning prosthesis were recruited consecutively. All patients also underwent computed tomography to assess the position of the acetabular component. Results: Thirty-four patients were diagnosed with a pseudotumor. However, the prevalence of pseudotumors in patients with a painful hip (seventeen of thirty, 57%) was not significantly different from the prevalence in the control group (seventeen of twenty-eight, 61%). No objective differences in pseudotumor characteristics between the groups were identified. No clear association between the presence of a pseudotumor and acetabular component position was identified. The Oxford hip score in the group with a painful hip (mean, 20.2; 95% confidence interval [CI], 12.7 to 45.8) was poorer than that in the control group (mean, 41.2; 95% CI, 18.5 to 45.8; p ≤ 0.0001). Conclusions: A periprosthetic cystic pseudotumor was diagnosed commonly (in thirty-four [59%] of the entire study cohort) with use of metal artifact reduction sequence (MARS) magnetic resonance imaging in this series of patients with a metal-on-metal hip prosthesis. The prevalence of pseudotumors was similar in patients with a well-functioning hip prosthesis and patients with a painful hip. Pseudotumors were also diagnosed commonly in patients with a well-positioned acetabular component. Although magnetic resonance imaging is useful for surgical planning, the presence of a cystic pseudotumor may not necessarily indicate the need for revision arthroplasty. Further correlation of clinical and imaging data is needed to determine the natural history of pseudotumors to guide clinical practice. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Unicondylar knee arthroplasty in the UK National Health Service: An analysis of candidacy, outcome and cost efficacy

Abstract: The viability of unicondylar knee arthroplasty (UKA) as a stand-alone or temporising option for the management of gonarthrosis is a topic of considerable contention. Despite recent advances in prosthesis design and surgical technique, as well as mounting evidence of long-term survivorship, UKA remains infrequently used, accounting for just 8-15% of all knee arthroplasties. Instead this group is more typically managed using total knee arthroplasty (TKA). For UKA to warrant increased usage the candidacy for UKA must be prevalent, the outcome must be equivalent or superior to that of TKA, and the costs should be comparatively low. Here we address three issues regarding UKA: 1) a prospective assessment of the proportion of knees needing arthroplasty that are candidates for UKA; 2) retrospective outcome measures comparing TKA, UKA and controls; and 3) an estimation of the difference in costs between TKA and UKA from a hospital perspective. We show in a series of 200 knees that candidacy for UKA is widespread; representing 47.6% of knees. Furthermore, we also show for the first time, that not only is UKA functionally superior to TKA (based on Total Knee Questionnaire (TKQ) scores), but scores in medial and lateral UKA knees do not differ significantly from normal, non-operative age- and sex-matched knees (t=1.14 [38], p=0.163; and t=1.16 [38], p=0.255 respectively). Finally, we report that UKA offers a substantial cost saving over TKA ( pound 1761 per knee) indicating that UKA should be considered the primary treatment option for unicompartmental knee arthritis.

Alignment options for total knee arthroplasty: A systematic review.

Abstract: In spite of improvements in implant designs and surgical precision, functional outcomes of mechanically aligned total knee arthroplasty (MA TKA) have plateaued. This suggests probable technical intrinsic limitations that few alternate more anatomical recently promoted surgical techniques are trying to solve. This review aims at (1) classifying the different options to frontally align TKA implants, (2) at comparing their safety and efficacy with the one from MA TKAs, therefore answering the following questions: does alternative techniques to position TKA improve functional outcomes of TKA (question 1)? Is there any pathoanatomy not suitable for kinematic implantation of a TKA (question 2)? A systematic review of the existing literature utilizing PubMed and Google Scholar search engines was performed in February 2017. Only studies published in peer-reviewed journals over the last ten years in either English or French were reviewed. We identified 569 reports, of which 13 met our eligibility criteria. Four alternative techniques to position a TKA are challenging the traditional MA technique: anatomic (AA), adjusted mechanical (aMA), kinematic (KA), and restricted kinematic (rKA) alignment techniques. Regarding osteoarthritic patients with slight to mid constitutional knee frontal deformity, the KA technique enables a faster recovery and generally generates higher functional TKA outcomes than the MA technique. Kinematic alignment for TKA is a new attractive technique for TKA at early to mid-term, but need longer follow-up in order to assess its true value. It is probable that some forms of pathoanatomy might affect longer-term clinical outcomes of KA TKA and make the rKA technique or additional surgical corrections (realignment osteotomy, retinacular ligament reconstruction etc.) relevant for this sub-group of patients. Longer follow-up is needed to define the best indication of each alternative surgical technique for TKA. Level I for question 1 (systematic review of Level I studies), level 4 for question 2.

The First Clinical Application of a "Hands-on" Robotic Knee Surgery System

Abstract: The performance of a novel "hands-on" robotic system for total knee replacement (TKR) surgery is evaluated. An integrated robotic system for accurately machining the bone surfaces in TKR surgery is described. Details of the system, comprising an "active constraint" robot, called Acrobot, a "gross positioning" robot, and patient clamps, are provided. The intraoperative protocol and the preoperative, CT-based, planning system are also described. A number of anatomical registration and cutting trials, using plastic bones, are described, followed by results from two preliminary clinical trials, which demonstrate the accuracy achieved in the anatomical registration. Finally, the first clinical trial is described, in which the results of the anatomical registration and bone cutting are seen to be of high quality. The Acrobot system has been successfully used to accurately register and cut the knee bones in TKR surgery. This demonstrates the great potential of a "hands-on" robot for improving accuracy and increasing safety in surgery.

Machine learning

Abstract: Machine Learning is the study of methods for programming computers to learn. Computers are applied to a wide range of tasks, and for most of these it is relatively easy for programmers to design and implement the necessary software. However, there are many tasks for which this is difficult or impossible. These can be divided into four general categories. First, there are problems for which there exist no human experts. For example, in modern automated manufacturing facilities, there is a need to predict machine failures before they occur by analyzing sensor readings. Because the machines are new, there are no human experts who can be interviewed by a programmer to provide the knowledge necessary to build a computer system. A machine learning system can study recorded data and subsequent machine failures and learn prediction rules. Second, there are problems where human experts exist, but where they are unable to explain their expertise. This is the case in many perceptual tasks, such as speech recognition, hand-writing recognition, and natural language understanding. Virtually all humans exhibit expert-level abilities on these tasks, but none of them can describe the detailed steps that they follow as they perform them. Fortunately, humans can provide machines with examples of the inputs and correct outputs for these tasks, so machine learning algorithms can learn to map the inputs to the outputs. Third, there are problems where phenomena are changing rapidly. In finance, for example, people would like to predict the future behavior of the stock market, of consumer purchases, or of exchange rates. These behaviors change frequently, so that even if a programmer could construct a good predictive computer program, it would need to be rewritten frequently. A learning program can relieve the programmer of this burden by constantly modifying and tuning a set of learned prediction rules. Fourth, there are applications that need to be customized for each computer user separately. Consider, for example, a program to filter unwanted electronic mail messages. Different users will need different filters. It is unreasonable to expect each user to program his or her own rules, and it is infeasible to provide every user with a software engineer to keep the rules up-to-date. A machine learning system can learn which mail messages the user rejects and maintain the filtering rules automatically. Machine learning addresses many of the same research questions as the fields of statistics, data mining, and psychology, but with differences of emphasis. Statistics focuses on understanding the phenomena that have generated the data, often with the goal of testing different hypotheses about those phenomena. Data mining seeks to find patterns in the data that are understandable by people. Psychological studies of human learning aspire to understand the mechanisms underlying the various learning behaviors exhibited by people (concept learning, skill acquisition, strategy change, etc.).

Antimicrobial prophylaxis for surgery: An advisory statement from the National Surgical Infection Prevention Project

Abstract: In January 2003, leadership of the Medicare National Surgical Infection Prevention Project hosted the Surgical Infection Prevention Guideline Writers Workgroup meeting The objectives were to review areas of agreement among the published guidelines for surgical antimicrobial prophylaxis, to address inconsistencies, and to discuss issues not currently addressed The participants included authors from most of the published North American guidelines for antimicrobial prophylaxis and several specialty colleges The workgroup reviewed currently published guidelines for antimicrobial prophylaxis Nominal group process was used to draft a consensus paper that was widely circulated for comment The consensus positions of the workgroup include that infusion of the first antimicrobial dose should begin within 60 minutes before surgical incision and that prophylactic antimicrobial agents should be discontinued within 24 hours of the end of surgery This advisory statement provides an overview of other issues related to antimicrobial prophylaxis including specific suggestions regarding antimicrobial selection

Medical robotics in computer-integrated surgery

Abstract: This paper provides a broad overview of medical robot systems used in surgery. After introducing basic concepts of computer-integrated surgery, surgical CAD/CAM, and surgical assistants, it discusses some of the major design issues particular to medical robots. It then illustrates these issues and the broader themes introduced earlier with examples of current surgical CAD/CAM and surgical assistant systems. Finally, it provides a brief synopsis of current research challenges and closes with a few thoughts on the research/industry/clinician teamwork that is essential for progress in the field.

What is a tutorial

Abstract: There are two kinds of tutorial articles: those that provide a primer on an established topic and those that let us in on the ground floor of something of emerging importance. The first type of tutorial can have a noted expert who has been gracious (and brave) enough to write a field guide about a particular topic. The other sort of tutorial typically involves researchers who have each been laboring on a topic for some years. Both sorts of tutorial articles are very much desired. But we, as an editorial board for both Systems and Transactions, know that there has been no logical place for them in the AESS until this series was started several years ago. With these tutorials, we hope to continue to give them a home, a welcome, and provide a service to our membership. We do not intend to publish tutorials on a regular basis, but we hope to deliver them once or twice per year. We need and welcome good, useful tutorial articles (both kinds) in relevant AESS areas. If you, the reader, can offer a topic of interest and an author to write about it, please contact us. Self-nominations are welcome, and even more ideal is a suggestion of an article that the editor(s) can solicit. All articles will be reviewed in detail. Criteria on which they will be judged include their clarity of presentation, relevance, and likely audience, and, of course, their correctness and scientific merit. As to the mathematical level, the articles in this issue are a good guide: in each case the author has striven to explain complicated topics in simple-well, tutorial-terms. There should be no (or very little) novel material: the home for archival science is the Transactions Magazine, and submissions that need to be properly peer reviewed would be rerouted there. Likewise, articles that are interesting and descriptive, but lack significant tutorial content, ought more properly be submitted to the Systems Magazine.

Surgical robot and robotic controller

Abstract: The present invention was developed by a neurosurgeon and seeks to mimic the results of primate neurological research which is indicative of a human's actual neurological control structures and logic. Specifically, the motor proprioceptive and tactile neurophysiology functioning of the surgeon's hands and internal hand control system from the muscular level through the intrafusal fiber system of the neural network is considered in creating the robot and method of operation of the present invention. Therefore, the surgery is not slowed down as in the art, because the surgeon is in conscious and subconscious natural agreement and harmonization with the robotically actuated surgical instruments based on neurological mimicking of the surgeon's behavior with the functioning of the robot. Therefore, the robot can enhance the surgeon's humanly limited senses while not introducing disruptive variables to the surgeon's naturally occurring operation of his neurophysiology. This is therefore also a new field, neurophysiological symbiotic robotics.