Computer-assisted Knee Arthroplasty Research Articles

Femoral coordinate system based on articular surfaces: Implications for computer-assisted knee arthroplasty

Osteoarthritis knee can be restored by total knee arthroplasty (TKA). Imageless TKA requires several anatomical points to construct a reference coordinate system to measure bone resections and implant placement. Inaccuracies in the definition of the coordinate system lead to malalignment and failure of the implant. While the surgical transepicondylar axis (sTEA) is a reliable anatomical axis to define the lateromedial axis for the femoral coordinate system (FCS), the presence of the collateral ligaments and deterioration of the medial sulcus (MS) make the registration of sTEA a challenging task. In this work, sTEA is assigned using the articular surfaces of the femoral condyles, independent of the lateral epicondyle (LE) and MS. A single 3D arc is marked on each condyle, which is transformed into a 2D arc to get the best-fit curve according to the profile of condyles. The turning point of each best-fit curve, when transformed back to 3D, defines an axis parallel to sTEA. The condyles-based sTEA is measured experimentally on a 3D-printed bone using an Optitrack tracking setup. Using the proposed method, the angle between the aTEA, sTEA, and Whiteside's line was (3.77, 0.55, and 92.72)°, respectively. The proposed method provides the same level of accuracy and improves the anatomical points registration efficiency, as there is no need to register the LE or MS.

Reduced Early Revision Surgery and Medical Complications in Computer-assisted Knee Arthroplasty Compared With Non-computer-assisted Arthroplasty.

Computer assistance can help surgeons achieve mechanical accurate alignment, but the clinical effect of this technology in different arthroplasty types remains controversial because of conflicting functional outcomes, revision rates, and complication rates. The goal of this study was to compare 90-day medical complications and 1 and 2-year revision surgeries after computer-assisted patellofemoral arthroplasty, unicompartmental knee arthroplasty (CA-UKA), bicompartmental knee arthroplasty (CA-BKA), and total knee arthroplasty (CA-TKA) with non-computer-assisted procedures. A retrospective cohort analysis was conducted using the Mariner data set of the PearlDiver Patient Records Database from 2010 to 2018. Current Procedural Terminology codes were used to identify patients who underwent patellofemoral arthroplasty, unicompartmental knee arthroplasty, bicompartmental knee arthroplasty, and total knee arthroplasty with or without computer assistance for osteoarthritis. All included patients were followed up for 2 years. Univariate and multivariable analyses were conducted. On multivariable analysis, revision within 1 year was decreased in patients who underwent computer-assisted patellofemoral arthroplasty (odds ratio [OR]: 0.541, P = 0.031), CA-UKA (OR: 0.798, P = 0.019), and computer-assisted bicompartmental knee arthroplasty (OR: 0.186, P = 0.025) compared with the same surgeries without technology assistance. CA-TKA had decreased odds of revision for aseptic loosening at 2 years (OR: 0.789, P < 0.001). CA-UKA and CA-TKA had decreased risk of overall 90-day medical complications (OR: 0.838, P < 0.001; OR: 0.903, P < 0.001, respectively) and major complications (OR: 0.750, P = 0.004; OR: 0.822, P < 0.001, respectively). Complication rates and revision surgeries for all arthroplasty types were equivalent or more favorable when computer assistance was used during surgery. Our results quantify some early benefits to using computer assistance in total and partial knee arthroplasties.

What's New in Adult Reconstructive Knee Surgery.

What's New in Adult Reconstructive Knee Surgery.

Accuracy of intraoperative bone registration and stereotactic boundary reconstruction during total knee arthroplasty surgery.

The intraoperative registration of the bones play a crucial role in image-based computer-assisted knee arthroplasty to achieve accurate implant placement and to create reliable stereotactic bone boundaries for robot-assisted surgical systems. This study assessed the intraoperative registration accuracy on six intact fresh frozen cadavers. Rotational errors around the mechanical axis were the largest, with a standard deviation of 1.2° and outliers up to 3.7°. The mean translational errors were lower than 1mm, with outliers up to 1.5mm. These errors were amplified to 2mm for the registration-based reconstruction of the posterior bone surface at the resection levels. Given the cumulative behaviour of surgical errors, registration errors can affect the final implant positioning. Furthermore, inaccuracies in the reconstructed bone boundary directly affect the virtual stereotactic boundaries used in robotic-assisted surgery and can result in an incomplete resection or inadvertent soft tissue damage.

Future implications of navigation in total knee arthroplasty

After more than two decades of experience with computer-assisted knee arthroplasty, extensive experience and study data are available, allowing aprofound evaluation. Undoubtedly, computer-assisted knee arthroplasty has been proven to achieve excellent results for implant positioning and long-leg axis reconstruction. Thus, computer-assisted knee arthroplasty represents the current gold standard to avoid unintended malpositioning of total knee components for neutrally aligned implants and individualized implant alignment (kinematic alignment, adjusted mechanical alignment, and others). Previous studies could not show significant differences in functional outcomes and patient satisfaction. However, recent meta-analyses showed relevant advantages of computer-assisted knee arthroplasty. These results could be based on further developments in software-assisted soft tissue balancing and more sensitive evaluation methods of follow-up examinations. Further, international registries show advantages of computer-assisted knee arthroplasty regarding long-term outcomes. In particular, the Australian arthroplasty registry describes asignificantly lower revision rate due to aseptic loosening/osteolysis in the computer-assisted knee arthroplasty group, analyzing aperiod of up to 17years. These positive effects can already be proven six months following surgery. However, despite demonstrated benefits, computer-assisted knee arthroplasty has not yet become established in daily routine, and wide regional variations in its use are observed. Newer developments such as robotic-assisted knee arthroplasty, primarily based on navigation techniques, are currently being heavily promoted. However, this new technology must justify its enormous additional costs and prove its advantages compared to computer-assisted knee arthroplasty. In the backdrop of the development of computer-assisted knee arthroplasty, this might be adifficult task.

Assistive technologies in knee arthroplasty: fashion or evolution? Rate of publications and national registries prove the Scott Parabola wrong

Most opponents of assistive technologies in orthopedic surgery consider them as a marketing ruse or fashion. Our hypothesis was that many innovations in modern knee arthroplasty are not following the Scott Parabola. This parabola represents the visual curve of a procedure or therapy showing great promise at the beginning, becoming the standard treatment after reports of encouraging results, only to fall into disuse due to adverse outcome reports. This study aimed to assess the interest in these assistive technologies by (1) their number of publications/year and (2) their actual surgical use reported in the National Joint Registries. The search was performed through PubMed, EMBASE, and MEDLINE databases from 1997 to 2021 inclusive to identify all available literature that described the use and results of assistive technologies or new surgical techniques in knee arthroplasty. In the Australian and Norwegian registries, the number of cases performed with these techniques in knee arthroplasty has been quantified year by year. Following the initial online search, a total of 4085 articles was found. After the assessment mentioned above, 2106 articles were included in the study. The orthopedic techniques assessed in this study are not following the "Scott's parabola" in the literature. Computer-assisted knee arthroplasty and patient-specific instrumentation have increased quickly to have reached a plateau, with a stable number of publications over the last 6 years. The number of publications concerning robotic surgery, accelerometers and sensors continue to rise. In the Australian registry, the proportion of primary TKA performed by computer-assisted systems increased from 2.4% in 2003 to 32% in 2019. In the Norwegian registry, the proportion of computer-assisted TKA remained between 8 and 12% of primary TKA since 2007. Most of the innovations in modern knee arthroplasty are not following the Scott Parabola. After a fast rise, these techniques do not disappear but continue to evolve. Their evolution is synergistic, and techniques appeared to be linked to each other's. Despite persisting concerns about the cost-efficiency of assisting technologies in knee arthroplasties, the interest and use do not decrease and seems to be directly linked to an exponential increase in interest for a better understanding of alignment targets and improved functional recovery.

Trends in Practice Patterns of Conventional and Computer-assisted Knee Arthroplasty: An Analysis of 570,671 Knee Arthroplasties Between 2010 and 2017.

Despite advances in computer-assisted knee arthroplasty (CAKA), little is known about the uptake of this technology in recent years. We aimed to explore the utilization trends and practice variation of CAKA from 2010 to 2017 and investigate the predictors of CAKA adoption. Patients undergoing conventional knee arthroplasty and CAKA were identified from the states of New York and Florida's administrative databases using the International Classification of Diseases version 9 and 10 procedure codes. Quarterly proportions of CAKA were calculated over the study period, and logistic regression was used to estimate predictors of CAKA utilization. Between 2010 and 2017, quarterly proportion of CAKAs increased from 4.89% in 2010Q1 to 9.45% in 2017Q3 in New York and from 4.03% in 2010Q1 to 5.73% in 2017Q3 in Florida. The general CA code was used to code most of the procedures (81%). Being Black (odds ratio [OR]: 0.63, 95% confidence interval [CI], 0.60 to 0.67), Hispanic (OR: 0.45, CI, 0.41 to 0.50), and having Medicaid coverage (OR: 0.46, CI, 0.40 to 0.53) were associated with lower likelihood of receiving CAKA in New York; similar findings were found in Florida. Utilization of CAKA has increased substantially in both New York and Florida from 2010 to 2017; however, with most CAKAs reported using the general code, understanding adoption rates of various modalities was not possible. Black and Hispanic patients and those with Medicaid insurance are least likely to receive this high-precision technology, illustrating the presence of disparities in the adoption of CAKA.

Computer Assisted Knee Replacement Surgery: Is the Movement Mainstream?

The first computer-assisted Total Knee Arthroplasty (TKA) was performed in 1997. The FDA approved computer assisted knee arthroplasty systems used in the early 2000s. Since then, surgeons and institutions all over the world have gradually adopted the technology. While the computer holds an importance place in the majority of workspaces across all industries, computer-assisted surgical technique has yet to become the preferred tool of the orthopaedic surgeon. Why has e-instrumentation not yet substituted conventional instrumentation in TKA orthopaedic surgery? In this article, we argue that main reasons which oppose the use of this technology are based on inaccurate or misleading observations. We isolated the factors likely to explain such opposition to this innovation: current results of total knee replacement, surgeon age, operative time, system ergonomics, cost for users, and cost for suppliers and disruptive innovations. Other factors such as surgeon habits, hospital environment and available assistance for support, although relevant, are not discussed. We assessed the advantages and drawbacks, costs and benefits of this technology to assess whether or not this opposition is justified. Finally, we explored the reasons why such a technology may impel surgeons to use this technique or any related technologies in the future. The main factors limiting TKA navigation spreading amongst orthopaedic surgeons are ergonomics and economics. Other factors, such as current TKA outcomes and surgeon's age are fallacious arguments in the rebuttal of CAS system use. Computer assisted knee arthroplasty surgery is not yet mainstream, but TKA will not escape technological progress.

Randomized Trial of Computer-Assisted Knee Arthroplasty: Impact on Clinical and Radiographic Outcomes

Computer-assisted surgery in knee arthroplasty is gaining popularity; however, the resulting outcome improvement is controversial. A double-blinded trial was performed with subjects randomized to undergo surgery with either computer-assisted or nonassisted instruments. Postoperatively, limb and implant alignment and rotation were assessed using both full-length radiographs and computed tomography in addition to clinical scores. One hundred twenty patients (141 knees) were randomized. No differences in Western Ontario MacMaster Osteoarthritis Score, Short Form-36, or flexion were seen. More varus limb alignment was seen in the computer-assisted group (1.9°) vs the nonassisted group (0.9°, P = .04) with no improvement in alignment precision. Rotational alignment of the components did not differ between groups. Computer-assisted surgery appeared to have minimal effect on knee implant arthroplasty with no improvement in limb alignment or early functional outcome.

Impact of hospital volume on the economic value of computer navigation for total knee replacement.

An aim of the use of computer navigation is to reduce rates of revisions of total knee replacements by improving the alignment achieved at the surgery. However, the decision to adopt this technology may be difficult for some centers, especially low-volume centers, where the cost of purchasing this equipment may be high. The purpose of this study was to examine the impact of hospital volume on the cost-effectiveness of this new technology in order to determine its feasibility and the level of evidence that should be sought prior to its adoption. A Markov decision model was used to evaluate the impact of hospital volume on the cost-effectiveness of computer-assisted knee arthroplasty in a theoretical cohort of sixty-five-year-old patients with end-stage arthritis of the knee to coincide with the peak incidence of knee arthroplasty in the United States. Computer-assisted surgery becomes less cost-effective as the annual hospital volume decreases, as the cost of the navigation increases, and as the impact on revision rates decreases. Centers at which 250, 150, and twenty-five computer-navigated total knee arthroplasties are performed per year will require a reduction of the annual revision rate of 2%, 2.5%, and 13%, respectively, per year over a twenty-year period for computer navigation to be cost-effective. Computer navigation is less likely to be a cost-effective investment in health-care improvement in centers with a low volume of joint replacements, where its benefit is most likely to be realized. However, it may be a cost-effective technology for centers with a higher volume of joint replacements, where the decrease in the rate of knee revision needed to make the investment cost-effective is modest, if improvements in revision rates with the use of this technology can be realized.

Positionnement acétabulaire assisté par ordinateur dans les prothèses totales de hanche: Étude prospective comparative randomisée

Purpose of the study Actetabular component malpositioning during total hip arthroplasty (THA) increases the risk of dislocation, reduces the range of motion, and can be the cause of early wear and loosening. There have been numerous reports on the optimal orientation of the acebaular component in THA. Lewinnek et al recommended an abduction angle of 40±10° and an anteversion of 15±10° for cup alignment in THA. In order to prevent malpostioned hip implants and improve the reproducibility of implant alignment in THA, numerous computer-assisted orthopedic systems have been described, using computed tomography (CT)-base or imageless navigation. Among the imageless systems available, one is based on Bone Morphing ® technology initially described by Stindel for computer-assisted knee arthroplasty and adapted for THA. The purpose of this study was to compare computer-assisted acetabular component insertion versus free hand placement. Material and methods A controlled randomized matched prospective study was performed in two groups of 30 patients. The study was approved by the French Ethics Committee. In the first group, cup positioning was assisted by an imageless computer-assisted orthopedics system based on Bone Morphing ® (CAOS+ group). In the control group, cup placement was free hand (CAOS- group). The same cementless cup was used in both groups. The same surgeon performed all procedures using an anterolateral approach. Cup anteversion and abduction angles were measured on 3D CT scan reconstructions obtained postoperatively for each patient by an independent observer using a special cup evaluation software. Results There were 16 males and 14 females in each group, mean age was 62 years (range 24-80) years, and mean body mass index was 25 in each group. Mean additional time of the CAOS procedure was 12 minutes (range 8-20). Intraoperative subjective agreement of the surgeon with the computer guidance system demonstrated a high correlation in 23 cases, a weak correlation in six cases and poor correlation in one case. There were no statistical differences between the CAOS+ and the CAOS- group regarding means of the abduction and anteversion angles, but a significant range of variance, the lowest variations being observed in the CAOS+ group. Discussion This study has shown the accuracy of cup positioning using a CT-free navigation system in a prospective randomized controlled protocol.

Improved knee kinematics after intraoperative soft tissue balanceing by computer assisted knee arthroplasty

Improved knee kinematics after intraoperative soft tissue balanceing by computer assisted knee arthroplasty

Computer assisted knee arthroplasty for osteoarthritis and other non-traumatic diseases

Computer assisted knee arthroplasty for osteoarthritis and other non-traumatic diseases

Computer-assisted knee arthroplasty versus a conventional jig-based technique

Sir, We read with interest the article in the April 2004 issue by Chauhan et al[1][1] entitled ‘Computer-assisted knee arthroplasty versus a conventional jig-based technique’. While we commend the authors on their study design, we would urge caution when recommending such an expensive system

An algorithm for locating the center of the ankle joint in knee navigation surgery

The primary aim of computer-assisted knee arthroplasty is to improve the alignment of the implanted prostheses. Accurate component alignment is dependent on the establishment of accurate anatomical reference points. Current techniques for establishing the center of the ankle joint, especially in the coronal plane, rely solely on clinical judgment in relation to the position of the center of the ankle joint. The aim of this study was to determine if an algorithm could be developed, based on establishing the most prominent points on the medial and lateral malleoli on 3D CT scans, to accurately and reproducibly establish the position of the center of the ankle joint. To determine this, images of 20 ankles were obtained and axial, coronal, and sagittal 2D reconstructions were manipulated on a workstation. Two observers independently performed relevant measurements and calculations. The calculated data was found to be reproducible with a very small standard deviation in each plane. This algorithm is able to provide accurate measurements of the ankle joint in knee navigation surgery. Caution must be exercised in anatomically abnormal ankles, as the calculations of the ankle center were found to be significantly different.

An algorithm for locating the center of the ankle joint in knee navigation surgery

The primary aim of computer-assisted knee arthroplasty is to improve the alignment of the implanted prostheses. Accurate component alignment is dependent on the establishment of accurate anatomical reference points. Current techniques for establishing the center of the ankle joint, especially in the coronal plane, rely solely on clinical judgment in relation to the position of the center of the ankle joint. The aim of this study was to determine if an algorithm could be developed, based on establishing the most prominent points on the medial and lateral malleoli on 3D CT scans, to accurately and reproducibly establish the position of the center of the ankle joint. To determine this, images of 20 ankles were obtained and axial, coronal, and sagittal 2D reconstructions were manipulated on a workstation. Two observers independently performed relevant measurements and calculations. The calculated data was found to be reproducible with a very small standard deviation in each plane. This algorithm is able to provide accurate measurements of the ankle joint in knee navigation surgery. Caution must be exercised in anatomically abnormal ankles, as the calculations of the ankle center were found to be significantly different.

Computer-Assisted Knee Arthroplasty Is Better Than a Conventional Jig-Based Technique in Terms of Component Alignment

Computer-Assisted Knee Arthroplasty Is Better Than a Conventional Jig-Based Technique in Terms of Component Alignment