INTRODUCTION

Allograft reconstruction after resection of primary bone sarcomas has a non-union rate of approximately 20%. Achieving a wide surface area of contact between host and allograft bone is one of the most important factors to help reduce the non-union rate. We developed a novel technique of haptic robot-assisted surgery to reconstruct bone defects left after primary bone sarcoma resection with structural allograft.

Introduction. Innovations in surgical robotics and navigation have significantly improved implant placement accuracy in total knee arthroplasty (TKA). However, many comparative studies have not been shown to substantially improve revision rates or other clinical outcome scores. We conducted a simulation study based on the reported distribution of patient-specific characteristics and estimated potential effect of coronal plane alignment (CPA) on risk of revision to evaluate the hypothesis that most published study designs in this area have been too underpowered to detect improvements in revision rates. Methods. To model previously reported studies, we generated a series of simulated TKA patient populations, assigning each patient a set of patient-specific factors (age at index surgery, BMI, and sex (Fig.1a)), as well as one surgeon-controlled factor (CPA) (Fig.1b) based on registry data and published literature. We modelled the survival probability for an individual patient at time t as a Gaussian function (exp[-(t/(k∗τ. max. )). 2. ]), where τ. max. (99.5 years) is selected to ensure the mean survival probability of the patient population matched 92% at 15 years. The value of k was adjusted for simulated patients within a range of 0 to 1 as a function of their patient and surgeon-specific factors (Fig.2). To evaluate power associated with a study design, we ran a Monte Carlo simulation generating 10,000 simulated populations of ten different cohort sizes. We divided the patient population into two groups: one group was assigned CPAs governed by the precision of a navigated/robotic approach (σ=1.5°), and the other CPAs governed by the precision of a conventional approach (σ=3°). We then simulated the time to failure for each patient, computed the corresponding Kaplan-Meier survival curves, and applied a Log-Rank test to each study to test for statistical difference. From the 10,000 simulations associated with each cohort size, we determined the percentage of simulated studies that found a statistically significant difference at each time point. Results. Figure 3 shows a contour plot illustrating the probability that a survival analysis with a specific study design would find statistical significance between the conventional and navigated/robotic patient groups. Entries from recently published literature are overlaid for context. No studies achieved statistical significance (p<0.05). Discussion. The effectiveness of navigated/robotic surgery is one of the most controversial debates in orthopedic surgery. The results from this simulation suggest that most revision studies aiming to settle this debate are likely significantly underpowered, falling below the normal 80% threshold. Limitations of this analysis include using only a single surgeon-controlled variable in the survival simulation, and only a single precision for the navigated/robotic approaches. Further studies will include more implant-related risk factors and a wider range of precisions for navigated/robotic procedures. Based on this simulation, it appears the effect size afforded by navigated/robotic surgeries on revision rates in TKA surgery is too small to recommend broad application, especially since adoption could involve added costs and unforeseen risks associated with novelty. Clinically, it may be beneficial to examine the use of robotics/navigation on high-risk patients, where studies are likely to have higher power due to larger effect sizes. For any figures or tables, please contact the authors directly

Robotic surgical systems reduce the cognitive workload of the surgeon by assisting in guidance and operational tasks. As a result, higher precision and a decreased surgery time are achieved, while human errors are minimised. However, most of robotic systems are expensive, bulky and limited to specific applications. In this paper a novel semi-automatic robotic system is evaluated, that offers the high accuracies of robotic surgery while remaining small, universally applicable and easy to use. The system is composed of a universally applicable handheld device, called Smart Screwdriver (SSD) and an application specific kinematic chain serving as a tool guide. The guide mechanism is equipped with motion screws. By inserting the SSD into a screw head, the screw is identified automatically and the required number of revolutions is executed to achieve the desired pose of the tool guide. The usability of the system was evaluated according to IEC 60601-1-6 using pedicle screw implementation as an example. The achieved positioning accuracies of the drill sleeve were comparable to those of fully automatic robotic systems with −0.54 ± 0.93 mm (max: − 2.08 mm) in medial/lateral-direction and 0.17 ± 0.51 mm (max: 1.39 mm) in cranial/caudal- direction in the pedicle isthmus. Additionally, the system is cost-effective, safe, easy to integrate in the surgical workflow and universally applicable to applications in which a static position in one or more DOF is to be adjusted

Total knee arthroplasty is a successful procedure with good long-term results. Studies indicate that 15% – 25% of patients are dissatisfied with their total knee arthroplasty. In addition, return to sports activities is significantly lower than total hip arthroplasty with 34% – 42% of patients reporting decreased sports participation after their total knee arthroplasties. Poor outcomes and failures are often associated with technical errors. These include malalignment and poor ligament balancing. Malalignment has been reported in up to 25% of all revision knee arthroplasties, and instability is responsible for over 20% of failures. Most studies show that proper alignment within 3 degrees is obtained in only 70% – 80% of cases. Navigation has been shown in many studies to improve alignment. In 2015, Graves examined the Australian Joint Registry and found that computer navigated total knee arthroplasty was associated with a reduced revision rate in patients under 65 years of age. Navigation can improve alignment, but does not provide additional benefits of ligament balance. Robotic-assisted surgery can assist in many of the variables that influence outcomes of total knee arthroplasty including: implant positioning, soft tissue balance, lower limb alignment, proper sizing. The data on robotic-assisted unicompartmental arthroplasty is quite promising. Cytech showed that femoral and tibial alignment were both significantly more accurate than manual techniques with three times as many errors with the manually aligned patients. Pearle, et al. compared the cumulative revision rate at two years and showed this rate was significantly lower than data reported in most unicompartmental series, and lower revision rates than both Swedish and Australian registries. He also showed improved satisfaction scores at two years. Pagnano has noted that optimal alignment may require some deviation from mechanically neutral alignment and individualization may be preferred. This is also likely to be a requirement of more customised or bi-cruciate retaining implant designs. The precision of robotic surgery may be necessary to obtain this individualised component alignment. While robotic total knee arthroplasty requires further data to prove its value, more precise alignment and ligament balancing is likely to lead to improved outcomes, as Pearl, et al. and the Australian registry have shown. While it is difficult to predict the future at this time, I believe robotic-assisted total knee arthroplasty is the future and that future begins now

Knee OA affects more frequently both joints. The involvement of the medial compartment involves an axis deviation of both limbs. The solution allows unicompartmental prosthetic restoration of articular defect and the axis of the patient's physiological load. Many studies have shown that the simultaneous prosthetic solution, compared to excellent results as regards the functional rehabilitation, increases the perioperative risks. Our experience with robotic surgery (Makoplasty), allowed us to show that this procedure reduces maximally perioperative risks, given the less invasive procedure compared to traditional methods, and how can ensure the same clinical result in the two joints in terms of restoration of joint biomechanics that of the axis of load

Treatment of osteoarthritis of the knee remains a challenging problem since the evolution of the disease may be different in each compartment of the knee, as well as the state of the ligaments. Total knee arthroplasty may provide a reliable long-lasting option but do not preserve the bone stock. In another hand, compartmental arthroplasty is a bone and ligament sparing solution to manage limited osteoarthritis of the knee affecting the medial, lateral or the patello-femoral compartment.1, 2, 3. Patient's selection and surgical indication are based on the physical examination and on the radiological analysis including full-length x-rays and stress x-rays. Clinical experience has shown the need for high flexion in patients who have both high flexibility and a desire to perform deep flexion. Additionally the shape differences related to anatomy or the patient expectations after the surgery may also affect the surgeon decision. 4. The limited incision into the extensor mechanism allows a quicker recovery which represents a functional improvement for the patient additionally to the cosmetic result. A dedicated physiotherapy starting on the following day allowing weight bearing exercises protected by crutches and focusing on early mobilization and range of motion combined to a multimodal pain management approach is critical despite the type of individualized solution chosen for the patient knee. 5. Since bony landmarks may be different form a patient to another one as well as anatomical shapes, several tools have been developed in order to provide the surgeons an assisted tool during the surgery adapted to each knee, this include navigation, patient specific instrumentation and robotic surgery

Introduction and aims. The International Orthopaedic community is eagerly adopting Robotic Assisted Arthroplasty (RAA) technology. However, the evidence for the benefits of this technology are unproven and at best equivocal. This study is a comprehensive bibliometric analysis of all published research in the field of RAA. Methods. A systematic literature search was conducted to retrieve all peer-reviewed, English language, publications studying robot- assisted hip and knee arthroplasty between 1992 and 2017. Review articles were excluded. Articles were classified by type of study and level of evidence according to the Oxford Centre for Evidence-based Medicine (OCEBM) Levels of Evidence System. The number of citations, authorship, year of publication, journal of publication, and country and institution of origin were also recorded for each publication. Results. We identified 73 original studies published since 1992 in the field of RAA. The procedures reported were total hip and total knee replacement, and uni-compartmental knee replacement. Publications originated from 17 countries and 117 organisations. Fifty percent of studies identified were published in the last 5 years at an average of 7 publications per year, compared to an average of 2.7 publications per year from 1992 to 2012. Thirty-six percent of original studies were of level 5 evidence or below, with a preponderance of biomechanical and cadaveric studies. The most cited paper was Bargar, Bauer and Borner's original RCT proving efficacy and safety of the Robodoc system for total hip replacement. Most publications originated in the US (36.9%) and more than 15% were published in the Journal of Arthroplasty. Conclusions. Analysis of publication patterns in robotic orthopaedic surgery allow us a unique insight into the qualities, characteristics, clinical innovations and advances in the evolution of RAA research

Introduction. Technology in Orthopaedic surgery has become more widespread in the past 20 years, with emerging evidence of its benefits in arthroplasty. Although patients are aware of benefits of conventional joint replacement, little is known on patients' knowledge of the prevalence, benefits or drawbacks of surgery involving navigation or robotic systems. Materials & Methods. In an outpatient arthroplasty clinic, 100 consecutive patients were approached and given questionnaires to assess their knowledge of Navigation and Robotics in Orthopaedic surgery. Participation in the survey was voluntary. Results. 98 patients volunteered to participate in the survey, mean age 56.2 years (range 19–88; 52 female, 46 male). 40% of patients thought more than 30% of NHS Orthopaedic operations involved navigation or robotics; 80% believed this was the same level or less than the private sector. A third believed most of an operation could be performed independently by a robotic/navigation system. Amongst perceived benefits of navigation/robotic surgery was more accurate surgery(47%), quicker surgery (50%) and making the surgeon's job easier (52%). 69% believed navigation/robotics was more expensive and 20% believed it held no benefit against conventional surgery, with only 9% believing it led to longer surgery. Almost 50% would not mind at least some of their operation being performed with use of robotics/navigation, with a significantly greater proportion of these coming from patients aged under 50 years. Conclusions. Although few patients were familiar with this new technology, there appeared to be a strong consensus it was quicker and more accurate than conventional surgery. Many patients appear to believe navigation and robotics in Orthopaedic surgery is largely the preserve of the private sector. This study demonstrates public knowledge of such new technologies is limited and a need to inform patients of the relative merits and drawbacks of such surgery prior to their more widespread implementation

Introduction. Technology in Orthopaedic surgery has become more widespread in the past 20 years, with emerging evidence of its benefits in arthroplasty. Although patients are aware of benefits of conventional joint replacement, little is known on patients' knowledge of the prevalence, benefits or drawbacks of surgery involving navigation or robotic systems. Materials and methods. In an outpatient arthroplasty clinic, 100 consecutive patients were approached and given questionnaires to assess their knowledge of Navigation and Robotics in Orthopaedic surgery. Participation in the survey was voluntary. Results. 98 patients volunteered to participate in the survey, mean age 56.2 years (range 19–88; 52 female, 46 male). 40% of patients believed more than 30% of NHS Orthopaedic operations involved navigation or robotics; 80% believed this was the same level or less than the private sector. A third believed most of an operation could be performed independently by a robotic/navigation system. Amongst perceived benefits of navigation/robotic surgery was more accurate surgery(47%), quicker surgery (50%) and making the surgeon's job easier (52%). 69% believed navigation/robotics was more expensive and 20% believed it held no benefit against conventional surgery, with only 9% believing it led to longer surgery. Almost 50% would not mind at least some of their operation being performed with use of robotics/navigation, with a significantly greater proportion of these coming from patients aged under 50 years. Conclusions. Although few patients were familiar with this new technology, there appeared to be a strong consensus it was quicker and more accurate than conventional surgery. Many patients appear to believe navigation and robotics in Orthopaedic surgery is largely the preserve of the private sector. This study demonstrates public knowledge of such new technologies is limited and a need to inform patients of the relative merits and drawbacks of such surgery prior to their more widespread implementation

INTRODUCTION:. Unicompartmental knee replacement (UKR) facilitates the use of smaller sized implants that require less bone resection and allows preservation of the anterior and posterior cruciate ligaments (ACL and PCL)[1]. Therefore, UKR preserves the intact kinematics and may improve the clinical outcomes especially compared to the outcomes of total knee replacement (TKA). Despite the known benefits of UKR in arthritis limited to one compartment, in multicompartment disease TKA remains the gold standard. Current TKA designs require the sacrifice of the ACL in all cases, whereas the surgeon can decide to use a cruciate sparing or substituting design altering normal knee kinematics. Performing bi-UKR or tri-UKR with traditional instruments is very challenging and rarely done due to the difficulty in establishing the correct spatial relationship of the separate components. Recent advances in robotic surgery have provided the opportunity to utilize partial knee replacements. The MAKO Rio platform is a surgeon-interactive robotic arm with haptic guidance that allows computer assisted planning and intraoperative accurate placement of multiple unicompartmental components including the bi-UKR. Currently there is a lack of understanding about the short-term and long-term clinical outcomes of the bi-UKR compared to the traditional TKA. OBJECTIVES:. The objective of the current study was to investigate the differences in the clinical outcomes of bi-UKR and TKA. METHODS:. In the current study the clinical outcomes of the patients in three groups were obtained who were operated by the same surgeon. Table-1 shows the demographics of the participants. All patients were evaluated via Knee Injury Osteoarthritis Outcome Score (KOOS) and the scores were compared to reported scores from standard TKA. One-way ANOVA was performed to determine significance within demographics. The signed consent was obtained from each participant. RESULTS:. Post-operative data were collected at a mean followup time of 12.3 months. The results indicated higher KOOS in individuals in group-1 compared to TKA individuals. No intraoperative complications during implantation were noted for the bi-UKR group. At the latest followup, no revision surgery was required for any of the subjects. CONCLUSION:. Our experience with the bi-UKR has shown promising clinical outcomes with no post-operative complications. These outcomes may be explained by the less invasive nature of bi-UKR surgeries that preserves of the integrity of the both the ACL and PCL ligaments. Additionally, there is a more accurate joint line reconstruction compared to TKA which may reproduce the functional capabilities of the intact knee more closely. Considering these advantages in addition to preservation of bone and less soft tissue destruction, robotically assisted multi-compartment knee replacement may be a viable alternative treatment in select patients

Introduction. Many uncemented femoral implant designs have had successful outcomes in total hip arthroplasty (THA). Different uncemented stem designs achieve initial and long term stability through shape, size, coating and fit. There is increasing emphasis on bone preservation, particularly in younger and more active patients. The desire to optimize load transfer has led to the development of short stems that seek to achieve fixation in the proximal femur. Short stems designed to achieve stability by engaging the metaphysis or the proximal femoral necks are currently in clinical use. The purpose of this study was to examine the extent to which five stems designed to achieve proximal fixation contact the bone in the proximal femur. Using three-dimensional CT models of 30 femurs, we assessed the fit, fill and contact of each of the five different implants. Methods. Using three-dimensional computerized templating software designed to navigate robotic surgery, pre-operative CT scans of 30 patients were analyzed. Each of five femoral implant designs (TRILOCK, ARC, ABGII, CITATION, ACCOLADE) was then optimized for size and fit based on manufacturer technique guide and design rationale. The proximal femoral metaphysis was divided into four zones in the axial plane. Five contact points were determined on the frontal plane using anatomical landmarks. Each zone was assessed for cortical contact and fill of the bone-implant interface. We graded contact from 1 to 5, with 5 being 100% contact. Results. In the 150 different templates analyzed significant variability existed in contact areas of the proximal femur depending on implant design and femoral morphology. High femoral neck resection design (ARC) had the greatest contact area in the most proximal zones (Figure 1). The ABG II and Trilock stems had comparable contact in the antero-medial zones, while the ABG II had greater fill in the sagittal plane (Figures 2 & 3). The Trilock was the only stem that consistently achieved lateral cortical contact at the distal landmarks. All stems showed a pattern of mostly posteromedial contact proximally and mostly anteromedial distally. Discussion. To our knowledge, this is the first study to examine the contact points of metaphyseal engaging stems in the proximal femur. By directly comparing implant contact points in the same femur we found significant variability in the extent of fit, fill and contact of the metaphysis. These differences in proximal femoral contact are like to have implications for fixation in bone of varying quality and for long term proximal bone remodeling

Background:. Numerous studies have reported the importance of acetabular component positioning in decreasing dislocation rates, the risk of liner fractures, and bearing surface wear in total hip arthroplasty (THA). The goal of improving acetabular component positioning has led to the development of computer-assisted surgical (CAS) techniques, and several studies have demonstrated improved results when compared to conventional, freehand methods. Recently, a computed tomography (CT)-based robotic surgery system has been developed (MAKO™ Robotic Arm Interactive Orthopaedic System, MAKO Surgical Corp., Fort Lauderdale, FLA, USA), with promising improvements in component alignment and surgical precision. The purpose of this study was to compare the accuracy in predicting the postoperative acetabular component position between the MAKO™ robotic navigation system and an imageless, CAS system (AchieveCAS, Smith and Nephew Inc., Memphis, TN, USA). Materials and Methods:. 30 THAs performed using the robotic navigation system (robotic cohort) were available for review, and compared to the most recent 30 THAs performed using the imageless, CAS system (CAS cohort). The final, intraoperative reading for acetabular abduction and anteversion provided by each navigation system was recorded following each THA. Einsel-Bild-Roentgen analysis was used to measure the acetabular component abduction and anteversion based on anteroposterior pelvis radiographs obtained at each patient's first, postoperative visit (Figure 1). Two observers, blinded to the treatment arms, independently measured all the acetabular components, and the results were assessed for inter-observer reliability. Comparing the difference between the final, intraoperative reading for both acetabular abduction and anteversion, and the radiographic alignment calculated using EBRA analysis, allowed assessment of the intraoperative predictive capability of each system, and accuracy in determining the postoperative acetabular component position. In addition, the number of acetabular components outside of the “safe zone” (40° + 10° of abduction, 15° + 10° of anteversion), as described by Lewinnek et al., was assessed. Lastly, the operative time for each surgery was recorded. Results:. In the robotic cohort, the mean, absolute difference between the intraoperative reading and the postoperative alignment was 4.3° + 2.3° for acetabular abduction, and 3.2° + 2.3° for acetabular anteversion. In comparison, in the CAS cohort, the mean, absolute difference was 3.7° + 2.8° for acetabular abduction (p = 0.4), and 3.8° + 2.7° for acetabular anteversion (p = 0.4). In both cohorts, all of the acetabular components were placed within 40° + 10° of abduction. In the robotic cohort, 27 of 30 components were placed within 15° + 10° of anteversion, versus 25 of 30 components in the CAS cohort (p = 0.7). The interobserver correlation coefficients for measurement of both the acetabular abduction and anteversion were good (p = 0.83 and 0.79, respectively). A statistically significant difference was appreciated between the two cohorts for operative times, with a mean operative time of 120.2 + 8.9 minutes in the robotic cohort (vs. 73.6 + 17.1 minutes in the CAS cohort, p < 0.01). Discussion:. This study demonstrates the robotic navigation system to require significantly increased operative times, while providing no significant advantage over the imageless, CAS system with regards to predicting the postoperative acetabular component position

Navigation has been felt to play a role in a number of THA issues. These issues include: 1) Instability-Dislocation; 2) Leg Length discrepancy; 3) Impingement and its impact on range of motion and wear; 3) gait mechanics; and 4) less invasive surgery. Navigation requires that anatomic landmarks be accurately identified. This can be done using images obtained either pre-operatively or intra-operatively (image-based navigation) or using intra-operative techniques for registering the relevant bony anatomy (image-free). The suggested advantages of imaged-based navigation are that is potentially very accurate, makes registering bone landmarks relatively easy and provides information about relevant anatomic landmarks that are not visible during surgery. The disadvantages of image-based navigation are that the acquisition of pre-operative imaging may be inconvenient or cumbersome, the imaging may be associated with increased radiation exposure, the imaging may be associated with additional costs and the pre-operative planning carried out on the imaging may be elaborate and time consuming. The advantages of image-free navigation are that no special pre-operative planning is required, no special imaging is necessary and the intra-operative workflow is consistent with the routine performance of a THA. However, image free registration techniques may be unreliable or inaccurate and the information obtained with image-free registration techniques is limited. When surgeons proficient in the technique perform image free navigation, positioning of the acetabular component is more accurate and consistent than that achieved using manual techniques. However, this increased accuracy has not been associated with a reduction in hip dislocations and has not had a measurable impact on short-term clinical outcomes. However, navigation is an accurate measurement tool that can be used to validate other computer-based technologies (e.g. patient specific guides). Navigation is also essential to the performance of robotic hip surgery. It is in this latter capacity that navigation may prove most useful to the hip surgeon

The use of robots in orthopaedic surgery is an emerging field that is gaining momentum. It has the potential for significant improvements in surgical planning, accuracy of component implantation and patient safety. Advocates of robot-assisted systems describe better patient outcomes through improved pre-operative planning and enhanced execution of surgery. However, costs, limited availability, a lack of evidence regarding the efficiency and safety of such systems and an absence of long-term high-impact studies have restricted the widespread implementation of these systems. We have reviewed the literature on the efficacy, safety and current understanding of the use of robotics in orthopaedics.

Cite this article: Bone Joint J 2015; 97-B:292–9.