Health economic value of CT scan based robotic assisted UKA: a systematic review of comparative studies

Current trends of unicompartmental knee arthroplasty (UKA): choosing between robotic-assisted and conventional surgeries and timing of procedures

BACKGROUND

With robotic advancements in UKA technology, we sought to explore if robotic-assisted UKA could translate to clinical benefits such as reduced hospital stays and lowered emergency readmissions. Also, current utilization trends of UKA and choice of procedure timing (unilateral [uUKA] vs. one-staged bilateral UKA [biUKA]) could be explored.

METHODS

This was a retrospective study utilizing the Clinical Data Analysis and Reporting System (CDARS) for data retrieval. All patients who had undergone primary UKA in all Hospital Authority (HA) hospitals in HK from 2021-2023 were included. Primary outcomes included utilization of UKA compared to TKA and percentage utilization of different UKA systems, namely, conventional, Mako, and Cori/Navio systems, from 2021-2023. Secondary outcomes involved: (1) patient demographics, (2) postoperative average length of stay (ALOS), (3) 30-day and 90-day postoperative Accident and Emergency Department (AED) attendance, (4) surgical times (skin-to-skin) and (5) 90-day mortality and reoperation. Differences in outcomes between uUKA and biUKA and between different robotic systems were examined. Regression analysis was performed to study if utilization of robotic-assisted systems could contribute to reduced hospital stays.

RESULTS

UKA accounted for 15.2% of primary knee arthroplasties throughout 2021-2023. Robotic-assisted UKA (Mako and Navio/Cori) has shown an increasing utilization since 2022 in both unilateral (16.0% to 25.9%) and bilateral operations (17.8% to 29.0%). Mako had shorter ALOS than Navio/Cori (2.9 ± 1.6 vs. 3.6 ± 2.6 days; P = 0.006) and significantly shorter ALOS than conventional UKA (2.9 ± 1.6 vs. 3.6 ± 2.6 days; P = 0.004). Utilization of Mako was predictive of shortened ALOS on multi-linear regression (β = - 0.056; P = 0.049). Interestingly, biUKAs, especially conventional ones, showed a lower attendance rate than uUKAs at 30-day (2.9% VS 6.9%; P = 0.036) and 90-days (7.8% VS 15.7%; P = 0.004). Robotic-assisted surgery was associated with a prolonged surgical time of 16.4 min in uUKA and 29.1 min in biUKA compared to conventional operations.

CONCLUSION

UKA utilization has dropped since 2021 but the percentage of robotic-assisted UKA has risen. Mako yielded promising results in reducing hospital stays compared to conventional operations. Sub-group analysis (Mako versus Cori/Navio) highlighted the importance of distinguishing between different robotic platforms. For patients with bilateral unicompartmental OA, biUKA was shown to be a safe and effective alternative to unilateral operations.

TRIAL REGISTRATION

Registered (HKU/ HA HKW IRB; Ref No: 24-373).

Pin-Related Complications in Computer Navigated and Robotic-Assisted Knee Arthroplasty: A Systematic Review

BACKGROUND

Computer-assisted navigation (CAN) and robotic-assisted (RA) knee arthroplasty procedures carry unique risks of tracking pin-related complications. This systematic review aimed to quantitatively assess the incidence, timing, treatment, and clinical outcomes of all tracking pin-related complications following CAN and RA knee arthroplasty.

METHODS

A systematic review was performed using PubMed, Cochrane Central and Scopus databases. All clinical studies that documented pin-related complications associated with the use of CAN or RA for total or partial knee arthroplasty were included. Descriptive statistics were analyzed when data were available.

RESULTS

Thirty-six studies were included: 18 case reports (25 cases) and 18 randomized controlled trials, cohort studies and case series i.e., non-case reports (7,336 cases). The most common pin-related complication among case reports was fracture (n = 22; 81%). The overall rate of pin-related complications among non-case reports was 1.4%. The intraoperative and postoperative complication with the highest incidence were pin dislodgement (0.6%) and superficial pin site infections (0.6%), respectively. Most postoperative complications were related to the tibial site (69%). All complications were effectively treated and resolved at follow-up.

CONCLUSION

Pin-related complications following CAN and RA knee arthroplasty are relatively uncommon. While pin loosening, superficial infections and fractures have been most commonly documented, other complications such as vascular injury, myositis ossificans, and osteomyelitis can also occur. The potential for pin-related complications should be considered by arthroplasty surgeons, especially during early stages of adoption. Further studies investigating patient risk factors for pin-related complications are warranted.

Robotic-Assisted Versus Manual Unicompartmental Knee Arthroplasty: A Time-Driven Activity-Based Cost Analysis

BACKGROUND

The cost-effectiveness of robotic-assisted unicompartmental knee arthroplasty (RA-UKA) remains unclear. Time-driven activity-based costing (TDABC) has been shown to accurately reflect true resource utilization. This study aimed to compare true facility costs between RA-UKA and conventional UKA.

METHODS

We identified 265 consecutive UKAs (133 RA, 132 conventional) performed at a specialty hospital in 2016-2020. Itemized facility costs were calculated using TDABC. Separate analyses including and excluding implant costs were performed. Multiple regression was performed to determine the independent effect of robotic assistance on facility costs.

RESULTS

Due to longer operative time, RA-UKA patients had higher personnel costs and total facility costs ($2,270 vs $1,854, P < .001). Controlling for demographics and comorbidities, robotic assistance was associated with an increase in personnel costs of $399.25 (95% confidence interval [CI] $343.75-$454.74, P < .001), reduction in supply costs of $55.03 (95% CI $0.56-$109.50, P = .048), and increase in total facility costs of $344.27 (95% CI $265.24-$423.31, P < .001) per case. However, after factoring in implant costs, robotic assistance was associated with a reduction in total facility costs of $235.87 (95% CI $40.88-$430.85, P < .001) per case.

CONCLUSION

Using TDABC, overall facility costs were lower in RA-UKA despite a longer operative time. To facilitate wider adoption of this technology, implant manufacturers may negotiate lower implant costs based on volume commitments when robotic assistance is used. These supply cost savings appear to offset a portion of the increased costs. Nonetheless, further research is needed to determine if RA-UKA can improve clinical outcomes and create value in arthroplasty.