Not All Robotic-assisted Total Knee Arthroplasty Are the Same

Comparative analysis of acute blood loss anemia in robotic assisted vs. manual instrumented total knee arthroplasty

Introduction

Robotic assisted total knee arthroplasty has become an increasingly popular technique over the past several years. Manual total knee arthroplasty can be associated with acute blood loss anemia. Instrumentation of the femoral canal with the alignment guide may in part contribute to this blood loss. Because the femoral canal is not entered during robotic assisted total knee arthroplasty, the blood loss may be lower compared to that seen in manual total knee arthroplasty. The purpose of this study was to determine if acute blood loss is greater in manually instrumented total knee arthroplasty versus robotic assisted total knee arthroplasty.

Materials and methods

This retrospective cohort study was performed in a large tertiary academic hospital network by two fellowship trained surgeons. Patients underwent either robotic assisted or manually instrumented total knee arthroplasty and were assessed for postoperative acute blood loss anemia, defined as hemoglobin <13 g/dL for males or <12 g/dL for females plus a 2 g/dL drop from preoperative levels, as well as postoperative drop in hemoglobin.

Results

A total of 75 patients were included in each study arm. There was no significant difference (p > 0.05) in postoperative hemoglobin in robotic assisted (2.1 g/dL) compared to manually instrumented total knee arthroplasty (2.1 g/dL). There was no significant difference in the incidence of postoperative acute blood loss anemia between robotic assisted (45 %) and manually instrumented total knee arthroplasty (39 %). Higher BMI and increased age were protective against postoperative drop in hemoglobin. These protective effects were not significant when controlling for confounding variables. Surgical time was significantly longer for robotic assisted (99 min) versus manually instrumented total knee arthroplasty (86 min) (p < 0.001).

Conclusions

There is no significant difference in acute blood loss when comparing patients undergoing robotic assisted and manually instrumented total knee arthroplasty.

Complications and Learning Curve Associated with an Imageless Burr-Based (CORI) Robotic-Assisted Total Knee Arthroplasty System: Results from First 500 Cases

Background

The use of robotic-assisted total knee arthroplasty (RA-TKA) is gaining traction. There is evidence to suggest that RA-TKA can help to optimize the precision and accuracy of implant positioning and that there may be protective effects on surrounding bony and soft tissues. Yet, there are important differences between the various RA-TKA systems currently on the market. One such newly introduced RA-TKA system uses imageless technology and performs bony cuts with the use of a burr-based device. The learning curve and complications unique to this system have yet to be assessed.

Methods

We evaluated 500 consecutive RA-TKA cases using a newly developed burr-based and imageless system which were done by a single surgeon between the months of October 2021 and February 2023. Operative times were recorded and compared to the previous 150 conventional TKA cases allowing for the learning curve to be calculated using the CUSUM method. Intraoperative and postoperative complications were categorically profiled.

Results

The learning curve of this RA-TKA system was found to be 6 cases. Intraoperative complications included unintended bony over resection (n = 3), soft tissue injury (n = 2), and robotic system hardware (n = 2) or software (n = 2) malfunction. Postoperative complications consisted of superficial pin site infection (n = 1) and periprosthetic fracture near the pin sites (n = 1). There were no identified cases of prosthetic joint infection, instability events, or wound complications.

Conclusions

The learning curve and the complication profile of a newly introduced imageless and burr-based RA-TKA system were described. This information serves to guide surgeons in adopting this technology and can counsel them regarding the potential pitfalls and challenges associated with its integration into practice. The work sheds light on the complexity and learning curve of the recently released imageless burr-based RA-TKA system. This important information is intended to help surgeons accept this cutting-edge technology by providing advice on any errors and difficulties that can occur when integrating it into clinical practice. This information can help surgeons navigate the complexities of integrating this new burr-based robotic technology into knee replacement procedures, enabling them to make well-informed decisions and receive guidance.

Understanding economic analysis and cost-effectiveness of CT scan-guided, 3-dimensional, robotic-arm assisted lower extremity arthroplasty: a systematic review

Aim: The overall goal of this review was to examine the cost-utility of robotic-arm assisted surgery versus manual surgery. Methods: We performed a systematic review of all health economic studies that compared CT-based robotic-arm assisted unicompartmental knee arthroplasty, total knee arthroplasty and total hip arthroplasty with manual techniques. The papers selected focused on various cost-utility measures. In addition, where appropriate, secondary aims encompassed various clinical outcomes (e.g., readmissions, discharges to subacute care, etc.). Only articles directly comparing CT-based robotic-arm assisted joint arthroplasty with manual joint arthroplasty were included, for a resulting total of 21 reports. Results: Almost all twenty-one studies demonstrated a positive effect of CT scan-guided robotic-assisted joint arthroplasty on health economic outcomes. For studies reporting on 90-day episodes of costs, 10 out of 12 found lower costs in the robotic-arm assisted groups. Conclusion: Robotic-arm assisted joint arthroplasty patients had shorter lengths of stay and cost savings based on their 90-day episodes of care, among other metrics. Payors would likely benefit from encouraging the use of this CT-based robotic technology.

Intraincisional Pin Placement is Safe for Robotic-Assisted Total Knee Arthroplasty

BACKGROUND

While robotic-arm assisted total knee arthroplasty (RA-TKA) has seen a major increase in its utilization, it requires bone array pins to be fixed into the femur and tibia, which intrinsically carries a risk. As it is currently off-label with some robotic platforms to place pins intraincisional, we aimed to evaluate the safety of intraincisional pin placement during RA-TKAs.

METHODS

A prospective cohort of 2,343 patients who underwent RA-TKA at a North American Healthcare System between January 2018 and March 2022 was included. Primary outcomes included periprosthetic fracture or infection (eg, superficial or deep). Secondary outcomes included 1-year reoperation rate due to any cause. Cases were retrospectively reviewed to determine whether complications could be attributed to metaphyseal intraincisional pin placement (4.0 mm pins; two tibial and two femoral). The 90-day follow-up was 100% and the 1-year follow-up rate was 70.6% (n = 1,655).

RESULTS

The pin-site related periprosthetic fracture incidence at 90 days was 0.09% (2 out of 2,343). The 90-day infection incidence was 1.4% (superficial: 22; deep: 13). The 1-year reoperation rate was 1.8% (29 out of 1,655). The most common causes of reoperation at 1-year were deep infection (n = 14; 0.83%), superficial infection (n = 3; 0.18%), periprosthetic fracture, mechanical symptoms, instability, and hematoma (n = 2; 0.12% for each).

CONCLUSIONS

One in 1,172 patients may experience a pin-related periprosthetic fracture after RA-TKA with intraincisional bone array pin placement. There was a low 90-day infection incidence and reoperations within 1-year after RA-TKA were rare.

Disparities in Access to Robotic Knee Arthroplasty: A Geospatial Analysis

BACKGROUND

The utilization of robotic knee arthroplasty (RKA) continues to increase across the United States. The aim of this geospatial analysis was to elucidate if RKA is distributed uniformly across the United States or if disparities exist in patient access.

METHODS

Publicly available provider-finding functions for 5 major manufacturers of RKA systems were used to obtain the practice locations of surgeons performing RKA along with their associated RKA system manufacturer. The average travel distance for each county to the nearest RKA surgeon was calculated and Moran's index clustering analysis was used to find hotspots and coldspots of RKA access. A logistic regression model was used to identify the predictive odds ratios between robotic hotspots and coldspots with county-level sociodemographic variables. Of the 34,216 currently practicing orthopedic surgeons in 2022, 2,571 have access to robotic assistance for knee arthroplasty.

RESULTS

Hotspots of increased travel time were predominantly in West South Central and West North Central census regions. Hotspots were significantly more rural and consisted of predominantly White populations, with lower median income and health insurance coverage.

CONCLUSIONS

The results of the current study align with existing literature, demonstrating absolute geographic access disparities for rural and economically disadvantaged populations. Additionally, relative access disparities persist for minority populations and individuals with high comorbidity burdens residing in urban areas.

Forty-Six Years of Technological Innovation in Musculoskeletal Medicine: An Analysis of a Patent Database (1973 to 2018)

BACKGROUND

Technological innovation in orthopaedics is key to advancing patient care. As emerging technologies near maturity, clinicians must be able to objectively assess where and when these technologies can be implemented. Patent databases are an underappreciated resource for quantifying innovation, especially within orthopaedic surgery. This study used a patent database to assess patent activity and relative growth of technologies in musculoskeletal medicine and orthopaedics over a period of 46 years.

METHODS

A total of 121,471 patent records were indexed from Lens.org , a patent database. These patents were grouped into subspecialty clusters and technology clusters using patent codes. Five-year (2014 to 2018), 10-year (2009 to 2018), and 30-year (1989 to 2018) compound annual growth rates were calculated and compared for each cluster.

RESULTS

Annual patent activity increased from one patent in 1973 to 4,866 patents in 2018. Of the eight subspecialty clusters, the largest number of patents were related to 'Inflammation' (n = 63,128; 40.57%). The 'Elbow', 'Shoulder', and 'Knee' clusters experienced increased annual patent activity since 2000. Of the 12 technological clusters, the largest number of patents were related to 'Drugs' (n = 55,324; 39.75%). The 'Custom/patient-specific instrumentation, 'Computer Modeling', 'Robotics', and 'Navigation' clusters saw growth in the average annual patent activity since 2000.

DISCUSSION

Innovation, as measured by patent activity in musculoskeletal medicine and orthopaedics, has seen notable growth since 1973. The 'Robotics' cluster seems poised to experience exponential growth in industry investment and technological developments over the next 5 to 10 years. The 'Diagnostics', 'Computer Modeling', 'Navigation', and 'Design and Manufacturing' clusters demonstrate potential for exponential growth in industry investment and technological developments within the next 10 to 20 years.

Joint Replacement Technology in the Ambulatory Surgery Center: Current and Future Applications

Total joint replacement (TJR) surgery in the ambulatory surgery centers (ASCs) has grown significantly over the past several years, along with the ability to improve the value of care. Standardization of high-quality, perioperative care is pivotal to the success of a TJR ASC program. As surgeons are experiencing increasing overhead with decreasing reimbursement, technology integration can provide major advantages. In this article, we will therefore highlight several examples of technologies that are changing the field and improving care in the preoperative, intraoperative, and postoperative settings.

Intra-operative Safety of an Autonomous Robotic System for Total Knee Replacement: A Review of 500 Cases in India

Background

Manual total knee arthroplasty (TKA) has been documented several times for their safety and complications data. In contrast, there is a limited evidence-based analysis for safety and complications of autonomous robotic-assisted (RA)-TKA. This study aimed to evaluate the safety features and intra-operative surgical complications associated with the use of Cuvis Joint™ autonomous robotic system for TKA.

Methods

The study included 500 consecutive patients who underwent TKA using the Cuvis Joint™ autonomous robotic system from November 2020 to November 2021. All surgeries were performed by a senior surgeon. Patients in whom the surgery was abandoned midway due to technical errors, were excluded from the analysis. In case of unilateral abandonment of the robotic arm during a bilateral RA-TKA, data of the side on which the surgery was completed with robotic assistance was recorded.

Results

There was no incidence of neurological injury, vascular injury, extensor mechanism disruption, or medial collateral ligament injury. There was one case of superficial abrasion of the patellar tendon; however, it did not require any intervention. There were no cases of midway abandonment due to threatened soft tissue injury. There was no intra-operative pin loosening or stress-related fractures at the pin sites. There was one case of Steinmann pin breakage and another case of drill bit breakage, which were removed without any damage to the bone.

Conclusion

The Cuvis Joint™ autonomous robotic system for TKA is safe with no significant intra-operative complications.

Higher revision rates in patients with preoperative contralateral pes planovalgus deformity following total knee arthroplasty

PURPOSE

The purpose of this study was to compare the incidence of revision in those with pes planovalgus deformity to those without using a large national database. Given the reciprocal changes in lower extremity alignment associated with planovalgus foot deformity, it has been suggested that patients with this deformity has worse outcomes following total knee arthroplasty (TKA).

METHODS

A retrospective cohort analysis of patients undergoing elective TKA was conducted using the PearlDiver database. Patients were stratified into three cohorts: those without pes planovalgus, patients with ipsilateral or bilateral pes planovalgus relative to the TKA, and patients with contralateral pes planovalgus. Patients with prior foot reconstructive surgery were excluded. The cohorts were each matched to those without pes planovalgus. Bivariate analysis was performed comparing 90-day medical complications and 2- and 4-year revisions following TKA. An adjusted number needed to be exposed for one additional person to be harmed (NNEH) was calculated using the adjusted odds ratio (OR) and unexposed event rate.

RESULTS

Following matched analysis, those with contralateral pes planovalgus had similar odds (OR 3.41; 95% CI 0.93-12.54; p = n.s.) for aseptic revision within 2 years but significantly higher odds (OR 3.35; 95% CI 1.08-10.41; p = 0.03) within 4 years when compared to those without a pes planovalgus deformity. Within 4 years, there was no significant difference in the incidence of aseptic revision (p = n.s.) in patients with ipsilateral/bilateral pes planovalgus. No patients in any cohort underwent septic revision within 4 years of TKA.

CONCLUSION

This study found that patients with contralateral pes planovalgus deformity had higher odds of aseptic revision within 4 years following primary TKA in a national database, suggesting that the change in gait kinematics associated with this deformity could possibly be associated with increased revision rates.

LEVEL OF EVIDENCE

Level III.

Identifying Trends and Quantifying Growth for Technological Innovation in Knee Arthroplasty: An Analysis of a Patent Database (1990 to 2020)

Technological innovation is the key for surgical progress in knee arthroplasty and improvement in patient outcomes. Exploring patented technologies can help elucidate trends and growth for numerous innovative technologies. However, patent databases, which contain millions of patents, remain underused in arthroplasty research. Therefore, the present study aimed to: (1) quantify patent activity; (2) group patents related to similar technologies into well-defined clusters; and (3) compare growth between technologies in the field of knee arthroplasty over a 30-year period. An open-source international patent database was queried from January 1990 to January 2020 for all patents related to knee arthroplasty A search strategy identified 70,154 patents, of which 24,425 were unique and included analysis. Patents were grouped into 14 independent technology clusters using Cooperative Patent Classification (CPC) codes. Patent activity was normalized via a validated formula adjusting for exponential growth. Compound annual growth rates (CAGR) were calculated (5-year, 10-year, and 30-year CAGR) and compared for each cluster. Overall yearly patent activity increased by 2,023%, from 104 patents in 1990 to 2,208 patents in 2020. The largest technology clusters were "drugs" (n = 5,347; 23.8%), "components" (n = 4,343; 19.0%), "instruments" (n = 3,130; 13.7%), and "materials" (n = 2,378; 10.4%). The fastest growing technologies with their 5-year CAGR were: "user interfaces for surgical systems" (58.1%); "robotics" (28.6%); "modularity" (21.1%); "navigation" (15.7%); and "computer modeling" (12.5%). Since 1990, overall patent growth rate has been greatest for "computer modeling" (8.4%), "robotics" (8.0%), "navigation" (7.9%), and "patient-specific instrumentation" (6.4%). Most patents in knee arthroplasty for the last 30 years have focused on drugs, components, instruments, and materials. Recent exponential growth was mainly observed for user interfaces for surgical systems, robotics, modularity, navigation, and computer-assisted technologies. Innovation theory would suggest that these rapidly growing technologies are experiencing high innovation output, increased resource investments, growing adoption by providers, and significant clinical impact. Periodic monitoring of technological innovation via patent databases can be useful to establish trends and future directions in the field of knee arthroplasty.

Mapping knowledge landscapes and emerging trends of robotic-assisted knee arthroplasty: A bibliometric analysis

The robotic-assisted knee arthroplasty has gained increasing attention in the research field. To date, no comprehensive bibliometric analysis has been carried out on this topic. The present study aimed to introduce the research status and hotspots and explore the field of robotic-assisted knee arthroplasty from a bibliometric perspective. The Web of Science Core Collection database was utilized to retrieve articles and reviews on robotic-assisted knee arthroplasty published between 1993 and 2023. CiteSpace, VOSviewer, Scimago Graphica, Pajek, and a bibliometric online analysis platform (http://bibliometric.com/) were employed to analyze the regions, institutions, journals, authors, and keywords, aiming to predict the latest trends in research related to robotic-assisted knee arthroplasty. This study encompasses 697 records. The annual publication count pertaining to robotic-assisted knee arthroplasty demonstrates consistent growth. The United States leads with the highest number of studies (298), trailed by the United Kingdom (110) and France (49). The Hospital for Special Surgery emerges as the most prolific institution, while Professor Mont, Michael A holds significant author influence. The Journal of Arthroplasty reigns supreme in this field, boasting the highest publication and citation figures. Funding sources predominantly include Stryker (34), Smith Nephew (19), and the National Natural Science Foundation of China (17). Noteworthy research themes within robotic-assisted knee arthroplasty encompass patient satisfaction, kinematic alignment, and clinical benefits. The landscape of robotic-assisted knee arthroplasty research is thriving. Anticipated trajectories of research will be geared toward refining the precision of robotic technology and enhancing clinical outcomes within the realm of robotic-assisted knee arthroplasty.

Robotic-Assisted Conversion of a Failed Medial Unicompartmental Knee Arthroplasty to Total Knee Arthroplasty: A Case Report

CASE

An 81-year-old man with a history of left medial unicompartmental knee arthroplasty (mUKA) 8 years prior presented to the outpatient clinic with gradually increasing medial left knee pain of 6 years of duration. He underwent left conversion robotic-assisted total knee arthroplasty (RA TKA). At 1-year follow-up, the patient reported satisfactory clinical outcomes and excellent component alignment on x-rays.

CONCLUSION

This case highlights using RA TKA for failed mUKA as a viable and promising conversion arthroplasty alternative technique that may improve surgical outcomes by enhancing implant alignment and positioning, protecting the soft tissues, and preserving bone stock.

Comparison of Femoral Component Rotation between Robotic-Assisted vs. Soft-Tissue Tensor Total Knee Arthroplasty with Anatomic Implants

Background and Objectives: Total knee arthroplasty (TKA) is the most effective treatment method for end-stage osteoarthritis. One of the most important aspects of this surgery is adequate implant positioning, as it guarantees the desired outcome of restoring limb biomechanics. Surgical technique is being continuously improved along with hardware development. There are two novel devices designed to help establish proper femoral component rotation: soft-tissue tensor and robotic-assisted TKA (RATKA). This study compared the femoral component rotation achieved with the use of three methods: RATKA, soft tissue tensioner and the conventional measured-resection technique, all of them utilizing anatomical design prosthesis components. Materials and Methods: A total of 139 patients diagnosed with end-stage osteoarthritis underwent total knee arthroplasty between December 2020 and June 2021. After the surgery, they were divided into three groups depending on procedure technique and implant type: Persona (Zimmer Biomet) + Fuzion Balancer, RATKA + Journey II BCS or conventional TKA + Persona/Journey. Postoperatively, a computed tomography examination was performed in order to measure femoral component rotation. All three groups were compared independently during statistical analysis. Fisher's exact, Kruskal-Wallis and Dwass-Steel-Crichtlow-Fligner tests were used for particular calculations. Results: Statistically significant differences in femoral component rotation between groups were noticed. However, in terms of values other than 0° in external rotation, no significant variance was revealed. Conclusions: Additional total knee arthroplasty instruments seem to improve the outcomes of the surgery, providing better component positioning than in the conventional measured-resection technique based only on bone landmarks.

Robotic-Assisted Total Knee Arthroplasty is Safe in the Ambulatory Surgery Center Setting

BACKGROUND

Robotic-assisted total knee arthroplasty (RA-TKA) has become more popular in the United States. With the significant trend towards performing TKA in outpatient and ambulatory surgery center (ASC) settings, this study was implemented to determine the safety and efficacy of RA-TKA in an ASC.

METHOD

A retrospective review identified 172 outpatient TKAs (86 RA-TKAs and 86 TKAs) performed between January 2020 and January 2021. All surgeries were performed by the same surgeon at the same free-standing ASC. Patients were followed for at least 90 days after surgery; complications, reoperations, readmissions, operative time, and patient-reported outcomes were recorded.

RESULTS

In both groups, all patients were successfully discharged home from the ASC on the day of surgery. No differences were noted in overall complications, reoperations, hospital admissions, or delays in discharge. RA-TKA had slightly longer operative times (79 vs 75 min [p = 0.017]) and total length of stay at the ASC (468 vs 412 min [p < 0.0001]) than conventional TKA. No significant differences were noted in outcome scores at 2-, 6-, or 12-week follow-ups.

CONCLUSIONS

Our results showed that RA-TKA can be successfully implemented in an ASC, with similar outcomes compared with TKA using conventional instrumentation. Initial surgical times were increased secondary to the learning curve of implementing RA-TKA. Long-term follow-up is necessary to determine implant longevity and long-term outcomes.

METHOD

A retrospective review identified 172 outpatient TKAs (86 RA-TKAs and 86 TKAs) performed between January 2020 and January 2021. All surgeries were performed by the same surgeon at the same free-standing ASC. Patients were followed for at least 90 days after surgery; complications, reoperations, readmissions, operative time, and patient-reported outcomes were recorded.

RESULTS

In both groups, all patients were successfully discharged home from the ASC on the day of surgery. No differences were noted in overall complications, reoperations, hospital admissions, or delays in discharge. RA-TKA had slightly longer operative times (79 vs 75 min [p = 0.017]) and total length of stay at the ASC (468 vs 412 min [p < 0.0001]) than conventional TKA. No significant differences were noted in outcome scores at 2-, 6-, or 12-week follow-ups.

CONCLUSIONS

Our results showed that RA-TKA can be successfully implemented in an ASC, with similar outcomes compared with TKA using conventional instrumentation. Initial surgical times were increased secondary to the learning curve of implementing RA-TKA. Long-term follow-up is necessary to determine implant longevity and long-term outcomes.

The Impact of Robotic-Assisted Total Knee Arthroplasty on Resident Training

BACKGROUND

As robotic-assisted total knee replacement (rTKA) continues to gain popularity, the impact of this technology on resident education remains unknown. The purpose of this study was to describe trainee experience and perceptions of rTKA and its effect on surgical training.

METHODS

Two hundred and twenty two senior orthopaedic residents attending a national board review course completed a 17-question survey regarding their experience and perceptions regarding rTKA. Mean and standard deviations were calculated for Likert scale questions, and bivariate analyses were utilized to compare answer groups.

RESULTS

Seventy percent of respondents reported exposure to rTKA during their training. Of those with robotic exposure, 20% reported that greater than half of their TKA experience involved robotics. Only 29% percent agreed that robotics improved outcomes, whereas 21% disagreed and the remainder were unsure. Over half of respondents agreed that robotics are used primarily for marketing purposes. Of those who trained with rTKA, 45% percent believed that robotics improved their understanding of the surgical procedure; however, 25% felt robotics negatively compromised their training with traditional instrumentation. Higher robotic case exposure (P = .001) and attending an industry-sponsored course (P = .02) was associated with the belief that robotics improved outcomes. Robotic case volume and percentage was associated with the belief that robotics improved understanding of the surgical procedure, however, it also was associated with reduced comfort performing traditional knee arthroplasty (P = .001).

CONCLUSION

Current resident training experience varies greatly within the United States with regards to rTKA. While exposure to rTKA may be beneficial for a well-rounded surgical education, over-exposure likely results in decreased comfort with traditional instrumentation.

Index surgery and ninety day re-operation cost comparison of robotic-assisted versus manual total knee arthroplasty

INTRODUCTION

This study looks to compare early costs of index surgery and re-operations of robotic-assisted total knee arthroplasties (rTKA) and manual total knee arthroplasty (mTKA) re-operations within 90 days.

MATERIAL AND METHODS

The Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) database was queried for patients undergoing rTKA and mTKA at our institution from January 1st, 2018, to March 31st, 2021. Primary outcomes were the day of surgery and overall encounter variable direct costs (VDC). Secondary outcomes included 90-day re-operations and costs.

RESULTS

One thousand two hundred seventy-six (21.2%) patients were in the rTKA cohort, while 4740 (78.8%) were in the mTKA cohort. When comparing rTKA to mTKA, rTKA had higher median total encounter costs (p < 0.001) and higher encounter VDC costs (p < 0.001). TKA had higher day of surgery total VDC (p < 0.001), VDC supplies (p < 0.001), and VDC of post-op recovery (p < 0.001). Multivariate linear regression showed no relationship with age, BMI, OR time, or LOS with cost for rTKA or mTKA.

CONCLUSION

Results from our study show that rTKA is associated with a higher index surgery costs, and no difference in 90-day re-operation costs. The main factor driving increased cost is supply cost, with other variables between too small in difference to make a significant financial impact. Future studies should focus on post-operative costs including readmission and episode of care costs and should consider cost to the payor as opposed to VDC. rTKA will become more common, and other institutions may need to take a closer financial look at this more novel instrumentation before adoption.

LEVEL OF EVIDENCE

III, retrospective cohort.

The Reverse Fragility Index: Interpreting the Current Literature on Long-Term Survivorship of Computer-Navigated Versus Conventional TKA: A Systematic Review and Cross-Sectional Study of Randomized Controlled Trials

BACKGROUND

Despite the most recent American Academy of Orthopaedic Surgeons clinical practice guideline making a "strong" recommendation against the use of intraoperative navigation in total knee arthroplasty (TKA), its use is increasing. We utilized the concept of the reverse fragility index (RFI) to assess the strength of neutrality of the randomized controlled trials (RCTs) comparing the long-term survivorship of computer-navigated and conventional TKA.

METHODS

A systematic review was performed including all RCTs through August 3, 2021, comparing the long-term outcomes of computer-navigated and conventional TKA. Randomized trials with mean follow-up of >8 years and survivorship with revision as the end point were included. The RFI quantifies the strength of a study's neutrality by calculating the minimum number of events necessary to flip the result from nonsignificant to significant. The RFI at a threshold of p < 0.05 was calculated for each study reporting nonsignificant results. The reverse fragility quotient (RFQ) was calculated by dividing the RFI by the study sample size.

RESULTS

Ten clinical trials with 2,518 patients and 38 all-cause revisions were analyzed. All 10 studies reported nonsignificant results. The median RFI at the p < 0.05 threshold was 4, meaning that a median of 4 events would be needed to change the results from nonsignificant to significant. The median RFQ was 0.029, indicating that the nonsignificance of the results was contingent on only 2.9 events per 100 participants. The median loss to follow-up was 27 patients. In all studies, the number of patients lost to follow-up was greater than the RFI.

CONCLUSIONS

The equipoise in long-term survivorship between computer-navigated and conventional TKA rests on fragile studies, as their statistical nonsignificance could be reversed by changing the outcome status of only a handful of patients--a number that was always smaller than the number lost to follow-up. Routine reporting of the RFI in trials with nonsignificant findings may provide readers with a measure of confidence in the neutrality of the results.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Understanding rates, risk factors, and complications associated with manipulation under anesthesia after total knee arthroplasty (TKA): An analysis of 100,613 TKAs

BACKGROUND

Considering the growing adoption of technology-assisted total knee arthroplasties (TKA), previous database studies evaluating post-operative stiffness may be outdated. The present study aimed to: (1) evaluate the incidence of manipulation under anesthesia (MUA) after primary TKA; (2) determine independent risk factors for MUA; and (3) assess complications after MUA.

METHODS

Primary TKAs, with at least 6-month follow-up, were identified from the Florida State Inpatient Database (January 2016-June 2018) and linked to outpatient records from the Florida State Ambulatory Surgery and Services Database. Multivariable regression analyses were performed to compare patient factors and complications (e.g., mechanical, non-mechanical, infectious) associated with MUA, while adjusting for baseline demographics, comorbidities, use of robotic- and computer-technologies, time to MUA (0-3, 3-12, or >12 months), and need for repeat MUA (one-time vs >1).

RESULTS

The MUA rate was 2.8% (2821 of 100,613). Being younger, a woman, Black or Hispanic; having private or self-pay insurance; and conventional TKA were associated with significantly higher odds of undergoing MUA. Higher rates of mechanical complications and acute posthemorrhagic anemia were observed in the MUA cohort. Time to MUA, repeat MUA, and baseline demographics were not associated with complication rates among the MUA cohort.

CONCLUSION

Overall, 1 in 36 patients underwent MUA after primary TKA. Several non-modifiable patient characteristics, such as Black or Hispanic race, female sex, and younger age were associated with an increased risk of MUA. However, technology-assisted TKA might help to decrease the risk of MUA.

Status and future of modern technologies in arthroplasty : Results of a survey of the German Society for Orthopedics and Trauma Surgery (DGOU)

BACKGROUND

The orthopedic community is divided on the question of whether modern technologies in arthroplasty improve outcomes. Therefore, the aim of this initiative of the working group on intraoperative imaging and technology integration (Arbeitsgemeinschaft intraoperative Bildgebung und Technologieintegration, AGiTEC) is to initiate the collection of additional data for the scientific evaluation of modern technologies.

QUESTION

To what extent are modern technologies currently used and which implementations are planned? Do the members of the German Society for Orthopedics and Trauma Surgery (DGOU) consider the acquisition of additional data for scientific assessment necessary?

METHODS

Members of the DGOU were asked via an e‑mail survey about the distribution and projected introduction of modern technologies in arthroplasty. They were also asked whether sufficient data were collected for scientific evaluation and whether acquisition of additional data in studies or arthroplasty registries were considered necessary.

RESULTS

Of the 7923 probands surveyed, 428 completed the questionnaire in full (5.4%). It was found that individual implants and navigation are currently the most frequently used (31% and 29%, respectively). The largest increases in the next 2 years are projected for virtual reality and robotics (+30% and +23%, respectively), 85% of respondents indicated that insufficient data were collected for scientific evaluation, and 89% each requested initiation of multicenter studies and inclusion of technologies in the arthroplasty registry.

CONCLUSION

The results of this study should motivate the scientific community, industry, and those responsible for the arthroplasty registries to collect and analyze data for the scientific assessment of modern technologies.

Use of intraoperative technology in total knee arthroplasty is not associated with reductions in postoperative pain

PURPOSE

Our systematic review and meta-analysis sought to assess how technology-assistance impacts (1) post-operative pain and (2) opioid use in patients undergoing primary total knee arthroplasty (TKA).

METHODS

Four online databases were queried for studies published up to October 2021 that reported on pain and opioid usage between technology-assisted and manual TKA (mTKA) patients. Mantel-Haenszel (M-H) models were utilized to calculate pooled mean difference (MDs) and 95% confidence interval (CIs). Subgroup analyses were conducted to isolate robotic-arm assisted (RAA) and computed-assisted navigation (CAN) cohorts. Risk of bias was assessed for all included non-randomized studies with the Methodological Index for Non-Randomized Studies (MINORS) tool. For the randomized control trials included in our study, the Detsky scale was applied.

RESULTS

Our analysis included 31 studies, reporting on a total of 761,300 TKAs (mTKA: n = 753,554; Computer-Assisted Navigation (CAN): n = 1,309; Robotic-Arm Assisted (RAA): n = 6437). No differences were demonstrated when evaluating WOMAC (MD: 0.00, 95% CI - 0.69 to 0.69; p = 1.00), KSS (MD: 0.01, 95% CI - 1.46 to 1.49; p = 0.99), KOOS (MD - 2.91, 95% CI - 6.17 to 0.34; p = 0.08), and VAS (MD - 0.54, 95% CI - 1.01 to - 0.007; p = 0.02) pain scores between cohorts. There was mixed evidence regarding how opioid consumption differed between TKA techniques.

CONCLUSION

The present analysis demonstrated no difference in terms of pain across a variety of utilized patient-reported pain measurements. However, there were mixed results regarding how opioid consumption varied between manual and technology-assisted cohorts, particularly in the immediate post-operative period.

LEVEL OF EVIDENCE

III.

Occupational Hazards to the Joint Replacement Surgeon: How Can Technology Help Prevent Injury?

Occupational hazards pose varying threats to the joint replacement surgeon. Musculoskeletal pain due to the repetitive nature of performing joint arthroplasty is felt daily by most surgeons. The purpose of this paper is to offer a basic introduction and demonstrate the many ways technology utilized during total joint arthroplasty can help mitigate common occupational hazards for the arthroplasty surgeon. This paper guides readers through the evolution and drivers behind technology in joint arthroplasty, describes several technologies currently available, and discusses how certain aspects of this technology may work to improve surgeon and patient outcomes. We review how advanced technologies in arthroplasty may reduce physical and mental demand, improve reproducibility, and decrease complications. The decision to utilize advanced technology in joint arthroplasty is ultimately made on an individual level after careful consideration of available literature.

Potential New Treatments for Knee OA: A Prospective Review of Registered Trials

We aimed to evaluate potential new treatments for knee osteoarthritis (OA). The National Institute of Health ClinicalTrials.gov database was searched for “Osteoarthritis, Knee”. We found 565 ongoing interventional studies with a total planned enrollment of 111,276 subjects. Ongoing studies for knee OA represent a very small fraction of the registered clinical trials, but they are over a quarter of all knee trials and over two thirds of all OA studies. The most researched topic was arthroplasty, with aspects such as implant design changes, cementless fixation, robotic guidance, pain management, and fast track recovery. Intraarticular injections focused on cell therapies with mesenchymal stem cells sourced from adipose tissue, bone marrow, or umbilical cord. We could see the introduction of the first disease modifying drugs with an impact on knee OA, as well as new procedures such as geniculate artery embolization and geniculate nerve ablation.

Robotic Arm-Assisted Total Knee Arthroplasty in the Setting of Severely Deficient Distal Femoral Bone Stock: A Case Report

CASE

A 26-year-old woman with a complex sequelae of open distal femoral fracture at 4 years of age presented to the office with severe knee pain from posttraumatic osteoarthritis. Robotic arm-assisted total knee arthroplasty (RA-TKA) with the elevation of previous free-flap was performed because of the following: (1) anatomic deformity, (2) small femoral size, and (3) compromised soft-tissue envelope.

CONCLUSION

This case highlights the complexity of planning and performing TKA in a young patient with these unique considerations. The successful outcome demonstrates the viability of RA-TKA techniques.

A new robotically assisted system for total knee arthroplasty: A sheep model study

BACKGROUND

We investigated the accuracy and safety of a new HURWA robotic-assisted total knee arthroplasty (TKA) system in a sheep model.

METHODS

Ten male small-tailed Han sheep were used in this study. Sheep were imaged by computed tomography scan before and after bone resection and the cutting errors between actual bone preparation and preoperative planning of the femur and tibia in three dimensions were measured.

RESULTS

The overall accuracies after surgery compared with that from preoperative surgical planning of the left and right femurs were 1.93 ± 1.02° and 1.93 ± 1.23°, respectively. Additionally, similarly high overall accuracies for the left and right tibia of 1.26 ± 1.04 and 1.68 ± 0.92°, respectively, were obtained. The gap distances of the distal cut, anterior chamfer, anterior cut, posterior chamfer and posterior cut on the medial side were 0.47 ± 0.35 mm, 0.41 ± 0.37 mm, 0.12 ± 0.26 mm, 0.41 ± 0.44 mm and 0.12 ± 0.23 mm, respectively. No intraoperative complications, such as intraoperative fracture, massive bleeding or death, occurred.

CONCLUSION

This new HURWA robotic-assisted TKA system is an accurate and safe tool for TKA surgery based on the sheep model.