Can robot-assisted total knee arthroplasty be a cost-effective procedure? A Markov decision analysis

Can Robotic Arm-assisted Total Knee Arthroplasty Remain Cost-effective in Volume-based Procurement System in China? A Markov Model-based Study

OBJECTIVE

The volume based procurement (VBP) program in China was initiated in 2022. The cost-effectiveness of robotic arm assisted total knee arthroplasty is yet uncertain after the initiation of the program. The objective of the study was to investigate the cost-effectiveness of robotic arm-assisted total knee arthroplasty and the influence of the VBP program to its cost-effectiveness in China.

METHODS

The study was a Markov model-based cost-effectiveness study. Cases of primary total knee arthroplasty from January 2019 to December 2021 were included retrospectively. A Markov model was developed to simulate patients with advanced knee osteoarthritis. Manual and robotic arm-assisted total knee arthroplasties were compared for cost-effectiveness before and after the engagement of the VBP program in China. Probability and sensitivity analysis were conducted.

RESULTS

Robotic arm-assisted total knee arthroplasty showed better recovery and lower revision rates before and after initiation of the VBP program. Robotic arm-based TKA was superior to manual total knee arthroplasty, with an increased effectiveness of 0.26 (16.87 vs 16.61) before and 0.52 (16.96 vs 16.43) after the application of Volume-based procurement, respectively. The procedure is more cost-effective in the new procurement system (17.13 vs 16.89). Costs of manual or robotic arm-assisted TKA were the most sensitive parameters in our model.

CONCLUSION

Based on previous and current medical charging systems in China, robotic arm-assisted total knee arthroplasty is a more cost-effective procedure compared to traditional manual total knee arthroplasty. As the volume-based procurement VBP program shows, the procedure can be more cost-effective.

Robotic Arm-assisted versus Manual (ROAM) total knee arthroplasty: a randomized controlled trial

Aims

The primary aim was to assess whether robotic total knee arthroplasty (rTKA) had a greater early knee-specific outcome when compared to manual TKA (mTKA). Secondary aims were to assess whether rTKA was associated with improved expectation fulfilment, health-related quality of life (HRQoL), and patient satisfaction when compared to mTKA.

Methods

A randomized controlled trial was undertaken, and patients were randomized to either mTKA or rTKA. The primary objective was functional improvement at six months. Overall, 100 patients were randomized, 50 to each group, of whom 46 rTKA and 41 mTKA patients were available for review at six months following surgery. There were no differences between the two groups.

Results

There was no difference between rTKA and mTKA groups at six months according to the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) functional score (mean difference (MD) 3.8 (95% confidence interval (CI) -5.6 to 13.1); p = 0.425). There was a greater improvement in the WOMAC pain score at two months (MD 9.5 (95% CI 0.6 to 18.3); p = 0.037) in the rTKA group, although by six months no significant difference was observed (MD 6.7 (95% CI -3.6 to 17.1); p = 0.198). The rTKA group were more likely to achieve a minimal important change in their WOMAC pain score when compared to the mTKA group at two months (n = 36 (78.3%) vs n = 24 (58.5%); p = 0.047) and at six months (n = 40 (87.0%) vs n = 29 (68.3%); p = 0.036). There was no difference in satisfaction between the rTKA group (97.8%; n = 45/46) and the mTKA group (87.8%; n = 36/41) at six months (p = 0.096). There were no differences in EuroQol five-dimension questionnaire (EQ-5D) utility gain (p ≥ 0.389) or fulfilment of patient expectation (p ≥ 0.054) between the groups.

Conclusion

There were no statistically significant or clinically meaningful differences in the change in WOMAC function between mTKA and rTKA at six months. rTKA was associated with a higher likelihood of achieving a clinically important change in knee pain at two and six months, but no differences in knee-specific function, patient satisfaction, health-related quality of life, or expectation fulfilment were observed.

Cost-Effectiveness of Robot-Assisted Total Knee Arthroplasty: A Markov Decision Analysis

BACKGROUND

Robot-assisted total knee arthroplasty (rTKA) may improve clinical outcomes for patients who have end-stage osteoarthritis of the knee. However, the costs of rTKA are high, and there is a paucity of data evaluating the cost-effectiveness of rTKA. We aimed to analyze the cost per quality-adjusted life-year (QALY) of rTKA relative to manual TKA.

METHODS

A Markov decision analysis was performed using known parameters for costs, outcomes, implant survivorships, and mortalities. The cost-effectiveness of rTKA relative to manual TKA was assessed for end-stage knee osteoarthritis patients who had a mean age of 65 years (range, 27 to 94 years). The rTKA costs were calculated for a pay-per-use contract robot.

RESULTS

Using the Markov Model with an annual case volume of 500 patients and a mean age of 65 years, the overall health gain per patient was 13.34 QALYs after rTKA and 13.31 QALYs after manual TKA. This resulted in an overall gain in QALYs of 0.03 for each patient undergoing an rTKA compared with manual TKA and an incremental cost of $128,526 Singapore Dollars per QALY.

CONCLUSION

Robotic TKA is not a cost-effective alternative to conventional TKA using a pay-per-use contract robot.

[Translated article] Current situation of robotics in knee prosthetic surgery: A technology that has come to stay?

Robotic surgery is a surgical technique that is on the rise. The goal of robotic-assisted total knee arthroplasty (RA-TKA) is to provide the surgeon with a tool to accurately execute bone cuts according to previous surgical planning to restore knee kinematics and balance of soft tissue, being able to precisely apply the type of alignment that we choose. In addition, RA-TKA is a very useful tool for training. Within the limitations, there is the learning curve, the need for specific equipment, the high cost of the devices, the increase in radiation in some systems and that each robot is linked to a specific type of implant. Current studies show, with RA-TKA, variations in the alignment of the mechanical axis are reduced, postoperative pain is improved and earlier discharge is facilitated. On the other hand, there are no differences in terms of range of motion, alignment, gap balance, complications, surgical time or functional results.

Robotic Arthroplasty Clinical and cost Effectiveness Randomised controlled trial (RACER-knee): a study protocol

INTRODUCTION

Robotic-assisted knee replacement systems have been introduced to healthcare services worldwide in an effort to improve clinical outcomes for people, although high-quality evidence that they are clinically, or cost-effective remains sparse. Robotic-arm systems may improve surgical accuracy and could contribute to reduced pain, improved function and lower overall cost of total knee replacement (TKR) surgery. However, TKR with conventional instruments may be just as effective and may be quicker and cheaper. There is a need for a robust evaluation of this technology, including cost-effectiveness analyses using both within-trial and modelling approaches. This trial will compare robotic-assisted against conventional TKR to provide high-quality evidence on whether robotic-assisted knee replacement is beneficial to patients and cost-effective for healthcare systems.

METHODS AND ANALYSIS

The Robotic Arthroplasty Clinical and cost Effectiveness Randomised controlled trial-Knee is a multicentre, participant-assessor blinded, randomised controlled trial to evaluate the clinical and cost-effectiveness of robotic-assisted TKR compared with TKR using conventional instruments. A total of 332 participants will be randomised (1:1) to provide 90% power for a 12-point difference in the primary outcome measure; the Forgotten Joint Score at 12 months postrandomisation. Allocation concealment will be achieved using computer-based randomisation performed on the day of surgery and methods for blinding will include sham incisions for marker clusters and blinded operation notes. The primary analysis will adhere to the intention-to-treat principle. Results will be reported in line with the Consolidated Standards of Reporting Trials statement. A parallel study will collect data on the learning effects associated with robotic-arm systems.

ETHICS AND DISSEMINATION

The trial has been approved by an ethics committee for patient participation (East Midlands-Nottingham 2 Research Ethics Committee, 29 July 2020. NRES number: 20/EM/0159). All results from the study will be disseminated using peer-reviewed publications, presentations at international conferences, lay summaries and social media as appropriate.

TRIAL REGISTRATION NUMBER

ISRCTN27624068.

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.

What is the Value of a Balanced Total Knee Arthroplasty? Getting it Right the First Time

INTRODUCTION

Instability is a leading cause of early failure following total knee arthroplasty. Enabling technologies can improve accuracy, but their clinical value remains undetermined. The purpose of this study was to determine the value of achieving a balanced knee joint at the time of TKA.

METHODS

A Markov model was developed to determine the value from reduced revisions and improved outcomes associated with TKA joint balance. Patients were modelled for the first 5 years following TKA. The threshold to determine cost-effectiveness was set at an Incremental Cost Effectiveness Ratio (ICER) of $50,000/quality-adjusted life year (QALY). A sensitivity analysis was performed to evaluate the influence of QALY improvement (ΔQALY) and Revision Rate Reduction (ΔRevision) on additional value generated compared to a conventional TKA cohort. The impact of each variable was evaluated by iterating over a range of ΔQALY (0 to 0.046) and ΔRevision (0 to 30%) and calculating the value generated while satisfying the ICER threshold. Finally, the impact of surgeon volume on these outcomes were analyzed.

RESULTS

The total value of a balanced knee for the first 5 years was $8,750, $6,575, and $4,417 per case, for low, medium, and high-volume surgeons, respectively. Change in QALY accounted for greater than 90% of the value gain with a reduction in revisions making up the rest in all scenarios. The economic contribution of revision reduction was relatively constant regardless of surgeon volume ($500/case).

CONCLUSIONS

Achieving a balanced knee had the greatest impact on QALY improvement over early revision rate. These results can help assign value to enabling technologies with joint balancing capabilities.

Clinical and radiological outcomes of robotic-assisted versus conventional total knee arthroplasty: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND PURPOSE

Robotic-assisted total knee arthroplasty (RATKA) is an alternative surgical treatment method to conventional total knee arthroplasty (COTKA) that may deliver better surgical accuracy. However, its impact on patient outcomes is uncertain. The aim of this systematic review of randomized controlled trials (RCTs) is to evaluate whether RATKA could improve functional and radiological outcomes compared with COTKA in adult patients with primary osteoarthritis of the knee.

METHODS

We searched Ovid MEDLINE, EMBASE, Scopus, and the Cochrane Library to identify published RCTs comparing RATKA with COTKA. 2 reviewers independently screened eligible studies, reviewed the full texts, assessed risk of bias using the Risk of Bias 2.0 tool, and extracted data. Outcomes were patient-reported outcomes, range of motion, and mechanical alignment (MA) deviation and outliers, and complications.

RESULTS

We included 12 RCTs involving 2,200 patients. RATKA probably results in little to no effect on patient-reported outcomes (mean difference (MD) in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score of -0.35 (95% confidence interval [CI] -0.78 to 0.07) and range of motion (MD -0.73°; CI -7.5° to 6.0°) compared with COTKA. However, RATKA likely results in a lower degree of MA outliers (risk ratio 0.43; CI 0.27 to 0.67) and less deviation from neutral MA (MD -0.94°; CI -1.1° to -0.73°). There were no differences in revision rate or major adverse effects associated with RATKA.

CONCLUSION

Although RATKA likely results in higher radiologic accuracy than COTKA, this may not be clinically meaningful. Also, there is probably no clinically important difference in clinical outcomes between RATKA and COTKA, while it is as yet inconclusive regarding the revision and complication rates due to insufficient evidence.

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.

Can Technology Assistance be Cost Effective in TKA? A Simulation-Based Analysis of a Risk-prioritized, Practice-specific Framework

BACKGROUND

Robotic, navigated, and patient-specific instrumentation (PSI) TKA procedures have been introduced to improve component placement precision and improve implant survivorship and other clinical outcomes. However, the best available evidence has shown that these technologies are ineffective in reducing revision rates in the general TKA patient population. Nonetheless, it seems plausible that these technologies could be an effective and cost-effective means of reducing revision risk in clinical populations that are at an elevated risk of revision because of patient-specific demographics (such as older age at index surgery, elevated BMI, and being a man). Since clinical trials on this topic would need to be very large, a simulation approach could provide insight on which clinical populations would be the most promising for analysis.

QUESTIONS/PURPOSES

We conducted a simulation-based analysis and asked: (1) Given key demographic parameters characterizing a patient population, together with estimates of the precision achievable with selected forms of technology assistance in TKA, can we estimate the expected distributions of anticipated reductions in lifetime revision risk for that population and the associated improvements in quality-adjusted life years (QALYs) that would be expected to result? (2) Are there realistic practice characteristics (such as combinations of local patient demographics and capital and per-procedure costs) for which applying a per-patient risk-prioritized policy for using technology-assisted TKA could be considered cost-effective based on projected cost savings from reductions in revision rates?

METHODS

We designed simulations of hypothetical practice-specific clinical scenarios, each characterized by patient volume, patient demographics, and technology-assisted surgical technique, using demographic information drawn from other studies to characterize two contrasting simulated clinical scenarios in which the distributions of factors describing patients undergoing TKA place one population at a comparatively elevated risk of revision (elevated-risk population) and the second at a comparatively reduced risk of revision (lower-risk population). We used results from previous systematic reviews and meta-analyses to estimate the implant precision in coronal plane alignment for patient-specific instrumentation, navigated, and robotic technology. We generated simulated TKA patient populations based on risk estimates from large clinical studies, structured reviews, and meta-analyses and calculated the patient-specific reduction in the revision risk and the change in QALYs attributable to the technology-assisted intervention in each of the two simulated clinical scenarios. We also incorporated a sensitivity analysis, incorporating variations in the effect size of deviations from overall coronal alignment on revision risk and difference in health state utilities acquired through a structured review process. We then simulated the outcomes of 25,000 operations per patient using the precisions associated with the conventional TKA technique, the three technology-assisted techniques, and a hypothetical technology-assisted intervention that could consistently deliver perfectly neutral overall coronal alignment, which is unachievable in practice. A risk-prioritized treatment policy was emulated by ordering the simulated patients from the highest to lowest predicted increase in QALYs, such that simulated patients who would see the greatest increase in the QALYs (and therefore the greatest reduction in lifetime revision risk) were the patients to receive technology-assisted TKA intervention in a practice. We used cost estimates acquired through a structured review process and calculated the net added costs of each of the three technology-assisted techniques as a function of the percent utilization (proportion of patients treated with technology assistance in a practice), factoring in fixed costs, per-procedure variable costs, and savings occurring from the prevention of future revision surgery. Finally, we calculated the incremental cost-effectiveness ratio (ICER) and marginal cost-effectiveness ratio (MCER) for each technology-assisted technique for the two clinical scenarios. We then used a Monte Carlo approach to simulate variations in key patient risk, health state, and economic factors as well as to obtain a distribution of estimates for cost-effectiveness. We considered an intervention to be cost effective if either the ICER or MCER values were below USD/QALY 63,000.

RESULTS

For the lower-risk population, the median reduction in the revision risk was 0.9% (0.4% to 2.2%, extrema from the sensitivity analysis) and 1.8% (0.9% to 4.4%) for PSI and robotic TKA, respectively, and 1.9% (1.0% to 4.6%) for ideal TKA. In contrast, the median reduction in the revision risk in the elevated-risk clinical scenario was 2.0% (1.2% to 3.4%) and 4.6% (2.7% to 8.5%) for PSI and robotic TKA and 5.1% (3.0% to 9.4%) for ideal TKA. Estimated differences in the cumulative gain in QALYs attributable to technology-assisted TKA ranged from 0.6 (0.2 to 1.8) to 4.0 (1.8 to 10.0) QALYs per 100 patients, depending on the intervention type and clinical scenario. For PSI, we found treating 15% of patients in the lower-risk population and 77% in the elevated-risk population could meet the threshold for being considered cost effective. For navigated TKA systems offering high alignment precision, we found the intervention could meet this threshold for practice sizes of at least 300 patients per year and a percent utilization of 27% in the lower-risk population. In the elevated-risk population, cost-effectiveness could be achieved in practice volumes as small as 100 patients per year with a percent utilization of at least 6%, and cost savings could be achieved with a percent utilization of at least 45%. We found that robotic TKA could only meet the threshold for being considered cost-effectiveness in the lower-risk population if yearly patient volumes exceeded 600 and for a limited range of percent utilization (27% to 32%). However, in the elevated-risk patient population, robotic TKA with high alignment precision could potentially be cost effective for practice sizes as small as 100 patients per year and a percent utilization of at least 20% if a risk-prioritized treatment protocol were used.

CONCLUSION

Based on these simulations, a selective-use policy for technology-assisted TKA that prioritizes using technology assistance for those patients at a higher risk of revision based on patient-specific factors could potentially meet the cost-effectiveness threshold in selected circumstances (for example, primarily in elevated-risk populations and larger practice sizes). Whether it does meet that threshold would depend significantly on the surgical precision that can be achieved in practice for a given proposed technology as well as on the true local costs of using the proposed technology. We further recommend that any future randomized trials seeking to demonstrate possible effects of technology assistance on revision risk focus on clinical populations that are at higher risk of revision (such as, patient populations that are relatively younger, have higher BMIs, and higher proportions of men).

CLINICAL RELEVANCE

This study suggests that technology assistance is only likely to prove cost effective in selected circumstances rather than in all clinical populations and practice settings. In general, we project that surgical navigation is most likely to prove cost effective in the widest range of circumstances, that PSI may be cost effective or cost neutral in a moderate range of circumstances, and that robotic surgery is only likely to be cost effective in moderately large practices containing patients who are on average at an intrinsically elevated risk of revision.

Comparative assessment of current robotic-assisted systems in primary total knee arthroplasty

Robotic-assisted total knee arthroplasty (TKA) has proven higher accuracy, fewer alignment outliers, and improved short-term clinical outcomes when compared to conventional TKA. However, evidence of cost-effectiveness and individual superiority of one system over another is the subject of further research. Despite its growing adoption rate, published results are still limited and comparative studies are scarce. This review compares characteristics and performance of five currently available systems, focusing on the information and feedback each system provides to the surgeon, what the systems allow the surgeon to modify during the operation, and how each system then aids execution of the surgical plan.Cite this article: Bone Jt Open 2023;4(1):13-18.

Cost-effectiveness analysis of robotic-arm assisted total knee arthroplasty

PURPOSE

Total knee arthroplasty (TKA) is widely recognized as an effective treatment for end-stage knee osteoarthritis (OA). Compared with conventional TKA, robotic-arm assisted TKA may improve patients' functionality and resulting quality of life by more accurate and precise component placement. Currently, the literature on cost-effectiveness of robotic-arm assisted TKA in the US is limited. The objective of this study was to assess the cost-effectiveness of robotic-arm assisted TKA relative to TKA in the Medicare-aged population including exploring the impact of hospital volume on cost-effectiveness outcomes.

METHODS

We developed a decision-analytic model to evaluate the costs, health outcomes, and incremental cost-effectiveness ratio (ICER) of robotic-arm assisted TKA vs TKA in Medicare population with OA. We evaluated cost-effectiveness at a willingness-to-pay (WTP) threshold of $50,000 per quality-adjusted life-year (QALY). We sourced costs from the literature including episode-of-care (EOC) costs from a Medicare study. We assessed cost-effectiveness of robotic-arm assisted TKA by hospital procedure volume and conducted deterministic (DSA) and probabilistic sensitivity analysis (PSA).

RESULTS

For the average patient treated in a hospital with an annual volume of 50 procedures, robotic-arm assisted TKA resulted in a total QALY of 6.18 relative to 6.17 under conventional TKA. Total discounted costs per patient were $32,535 and $31,917 for robotic-arm assisted TKA and conventional TKA, respectively. Robotic-arm assisted TKA was cost-effective in the base case with an ICER of $41,331/QALY. In univariate DSA, cost-effectiveness outcomes were most sensitive to the annual hospital procedure volume. Robotic-arm assisted TKA was cost-effective at a WTP of $50,000/QALY only when hospital volume exceeded 49 procedures per year. In PSA, robotic-arm assisted TKA was cost-effective at a $50,000/QALY WTP threshold in 50.4% of 10,000 simulations.

CONCLUSIONS

Despite high robotic purchase costs, robotic-arm assisted TKA is likely to be cost-effective relative to TKA in the Medicare population with knee OA in high-volume hospitals through lowering revision rates and decreasing post-acute care costs. Higher-volume hospitals may deliver higher value in performing in robotic-arm assisted TKA.

Where are We Now and What are We Hoping to Achieve with Robotic Total Knee Arthroplasty? A Critical Analysis of the Current Knowledge and Future Perspectives

Robotic-assisted total knee arthroplasty (rTKA) has been developed to improve knee kinematics and functional outcomes, expedite recovery, and improve implants long-term survivorship. Robotic devices are classified into active, semi-active, and passive, based on their degree of freedom. Their capacity to provide increased accuracy in implants positioning with reduced radiographic outliers has been widely proved. However, these early advantages are yet to be associated with long-term survivorship. Moreover, multiple drawbacks are still encountered including a variable learning curve, increased setup and maintenance costs, and potential complications related to the surgical technique. Despite recent technologies applied to TKA have failed to prove substantial improvements, robotic-assisted surgery seems to be here to stay and revolutionize the field of TKA. To support its consistent usage on a daily basis, long-term results are still awaited, and further improvements are necessary to reduce the expenses related to it.

Economic studies in medical research: 'Importance, targets, outcome evaluation'

Economic studies in healthcare are used to measure the cost and effectiveness of an intervention and are valuable in determining how healthcare resources can be distributed to achieve the greatest overall gain. Most economic studies in healthcare are cost-benefit analyses, cost-effectiveness analyses (CEAs), or cost-utility analyses (CUAs). CEAs and CUAs compare alternative interventions based on cost and effectiveness but are influenced by different methodologies and assumptions employed by researchers. The perspective from which an economic study is evaluated (the patient, the provider, the payor, or the society) should be carefully considered. The incremental cost effectiveness ratio (ICER) describes the difference between two interventions in cost and health outcomes and can be expressed in dollars per quality-adjusted life year (QALY). A threshold ICER <$50,000/QALY is often used to determine whether an intervention is cost-effective, in conjunction with patient factors, healthcare system factors, and opportunity cost associated with the intervention. The Consolidated Health Economic Evaluating Reporting Standards (CHEERS) statement provides guidelines for reporting healthcare economic studies. Key elements to be reported include the study design, target population and subgroups, time horizon, health outcomes, perspectives, comparison group, and sensitivity analyses performed. Economic studies are particularly important in orthopedics given the prevalence of musculoskeletal disease, high upfront costs, and potential quality of life improvements associated with orthopedic surgical procedures. An understanding of economic evaluations in healthcare is important to critically review the available literature.

The initial learning curve for the ROSA® Knee System can be achieved in 6-11 cases for operative time and has similar 90-day complication rates with improved implant alignment compared to manual instrumentation in total knee arthroplasty

Purpose

The purpose of this study was to determine the learning curve for total operative time using a novel cutting guide positioning robotic assistant for total knee arthroplasty (raTKA). Additionally, we compared complications and final limb alignment between raTKA and manual TKA (mTKA), as well as accuracy to plan for raTKA cases.

Methods

We performed a retrospective cohort study on a series of patients (n = 180) that underwent raTKA (n = 90) using the ROSA Total Knee System or mTKA (n = 90) by one of three high-volume (> 200 cases per year) orthopaedic surgeons between December 2019 and September 2020, with minimum three-month follow-up. To evaluate the learning curve surgical times and postoperative complications were reviewed.

Results

The cumulative summation analysis for total operative time revealed a change point of 10, 6, and 11 cases for each of three surgeons, suggesting a rapid learning curve. There was a significant difference in total operative times between the learning raTKA and both the mastered raTKA and mTKA groups (p = 0.001) for all three surgeons combined. Postoperative complications were minimal in all groups. The proportion of outliers for the final hip-knee-ankle angle compared to planned was 5.2% (3/58) for the mastered raTKA compared to 24.1% (19/79) for mTKA (p = 0.003). The absolute mean difference between the validated and planned resections for all angles evaluated was < 1 degree for the mastered raTKA cases.

Conclusion

As the digital age of medicine continues to develop, advanced technologies may disrupt the industry, but should not disrupt the care provided. This cutting guide positioning robotic system can be integrated relatively quickly with a rapid initial learning curve (6-11 cases) for operative times, similar 90-day complication rates, and improved component positioning compared to mTKA. Proficiency of the system requires additional analysis, but it can be expected to improve over time.

Level of evidence

Level III Retrospective Therapeutic Cohort Study.

Custom total knee: understanding the indication and process

Patient-specific total knee arthroplasty (TKA) is a copy of the bony knee morphology based on a pre-op computer tomography (CT). The images are segmented in 3D and software is utilized through a proprietary process to generate individual total knee implants to recreate the articulating surfaces. The distal condylar valgus angle of the prosthesis is matched anatomically to the distal femur and reversely matched on the tibia with a thicker lateral insert. The implant, a set of patient-specific jigs (PSJ), which are 3D printed in nylon, and a detailed surgical plan are sent to the hospital in one box. The system is available with one solid or two separated medial and lateral PE inserts. There is a cruciate retaining (CR) and posterior stabilized (PS) version available, including various insert thicknesses. The system allows the addition of two different cemented stem extensions if needed at the time of surgery.

[Robot-assisted joint arthroplasty-An emerging technology of the present and the future]

Objective

To review and evaluate the research progress of the robot-assisted joint arthroplasty.

Methods

The domestic and foreign related research literature on robot-assisted joint arthroplasty was extensively consulted. The advantages, disadvantages, effectiveness, and future prospects were mainly reviewed and summarized.

Results

The widely recognized advantages of robot-assisted joint arthroplasty are digital and intelligent preoperative planning, accurate intraoperative prosthesis implantation, and quantitative soft tissue balance, as well as good postoperative imaging prosthesis position and alignment. However, the advantages of effectiveness are still controversial. The main disadvantages of robot-assisted joint arthroplasty are the high price of the robot system, the prolonged operation time, and the increased radioactive damage of the imaging-dependent system.

Conclusion

Compared to traditional arthroplasty, robot-assisted joint arthroplasty can improve the accuracy of the prosthesis position and assist in the quantitative assessment of soft tissue tension, and the repeatability rate is high. In the future, further research is needed to evaluate the clinical function and survival rate of the prosthesis, as well as to optimize the robot system.