Robotic Arm-Assisted versus Manual Total Knee Arthroplasty: A Propensity Score-Matched Analysis

Comparing a robotic imageless second-generation system to traditional instrumentation in total knee arthroplasty: A matched cohort analysis

Introduction

Robotic-assisted total knee arthroplasty (rTKA) has gained interest from patients and surgeons alike. Robotic systems assist with gap balancing and bone cut accuracy, which can theoretically minimize post-operative pain by decreasing soft tissue damage. This study compared perioperative results, 30- and 90-day complications, patient-reported outcomes (PROs), and survivorship to all-cause revisions between patients undergoing traditional versus rTKA.

Methods

A total of 430 TKAs (215 rTKA, 215 traditional) by two fellowship trained arthroplasty surgeons were retrospectively reviewed from 2017 to 2022. All rTKAs were performed using the CORI Surgical System (Smith & Nephew, Memphis, Tennessee). Cohorts were propensity score matched by age, sex, body mass index, and American Society of Anesthesiologist classification. Blood loss, surgical times, length of stays, 30- and 90-day complications, pain scores and PROs were compared with univariable analyses. Cox regression analyses evaluated survival to all-cause revisions.

Results

Patients undergoing rTKA had a higher incidence of discharge home (86.5 %-60.0 %) (p < 0.01). There was no difference in blood loss or surgical time. rTKA pain scores were lower in-hospital mean 2 (range, 0 to 9) vs 3 (range, 0 to 9) (p = 0.02) as well as at one-year post-operatively, mean 1 (range, 0 to 7) vs 2 (range, 0 to 10) (p = 0.02). Cox hazard ratio demonstrated no difference in survival to all-cause revisions (HR 1.3; CI 0.5 to 3.7) (p = 0.64).

Conclusion

This matched cohort analysis demonstrated potential short-term benefits associated with imageless second generation rTKA including improved early post-operative pain, without compromising survivorship to all-cause revisions.

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.

No Benefit of Robotic-Assisted over Computer-Assisted Surgery for Achieving Neutral Coronal Alignment in Total Knee Arthroplasty

The use of robotic-assisted surgery (RAS) in total knee arthroplasty (TKA) is becoming increasingly popular due to better precision, potentially superior outcomes and the ability to achieve alternative alignment strategies. The most commonly used alignment strategy with RAS is a modification of mechanical alignment (MA), labeled adjusted MA (aMA). This strategy allows slight joint line obliquity of the tibial component to achieve superior balancing. In the present study, we compared coronal alignment after TKA using RAS with aMA and computer-assisted surgery (CAS) with MA that has been the standard in the center for more than 10 years. We analyzed a prospectively collected database of patients undergoing TKA in a single center. Lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) were compared for both techniques. In 140 patients, 68 CASs and 72 RASs, we observed no difference in postoperative measurements (median 90 degrees for all, LDFA p = 0.676, MPTA p = 0.947) and no difference in outliers <2 degrees (LDFA p = 0.540, MPTA p = 0.250). The present study demonstrates no benefit in eliminating outliers or achieving neutral alignment of both the femoral and the tibial components in robotic-assisted versus computer-assisted TKA if MA is the target. To utilize the precision of RAS, it is recommended to aim for more personalized alignment strategies. The level of evidence is level III retrospective study.

Retrospective analysis of robotic unicompartmental and total knee arthroplasties: patient demographics and outcomes

CONTEXT

With the growing number of robotic knee arthroplasties being performed, new outcomes must be analyzed to provide a database for comparing robotic and nonrobotic surgeries. These results can be utilized in the future to properly assess the significance of utilizing robotic technology in the operating room regarding patient outcomes and cost.

OBJECTIVES

The aims of this study are to: (1) analyze adverse outcomes from robotic-assisted knee arthroplasty and its relation to sex, body mass index (BMI), and age; and (2) explore any possible differences in outcomes among robotic-assisted unicompartmental knee arthroplasty (UKA) and robotic-assisted total knee arthroplasty (TKA). It is hypothesized that sex, BMI, and age will play a role in adverse events experienced among robotic-assisted knee arthroplasty. It is hypothesized that adverse outcomes will differ in robotic-assisted TKA v UKA.

METHODS

A retrospective analysis was performed utilizing 1,300 patient cases from a single surgeon that underwent robotic-assisted UKA or TKA utilizing a robotic surgical system. Demographics were sorted by age, sex, and BMI. Outcomes were sorted by the type of adverse event. The most common adverse event was further statistically analyzed by age, sex, and BMI and then compared to the total cohort. The most common adverse event was also broken down by TKA vs. UKA.

RESULTS

The average age of the individuals undergoing this procedure was 63.6 years, with 52.3 % being female. The average BMI was 32.2. Of the 87 patients who experienced adverse events, 111 total events were documented. Manipulation under anesthesia (MUA) was the highest experienced adverse event. Among the MUA events, 79.5 % had a BMI over 30 (p=0.067), 72.8 % were female (p=0.014), and the average age was 59 years (p=0.019). Among the MUA adverse events, 76.9 % (n=30) were following a TKA and 23.1 % were following a UKA. When considering the entire sample (n=1,300), there was a statistically significant 12.6 times greater odds that an MUA occurred among those who had a TKA vs. UKA (p<0.001). Similar results were discovered when only considering those who had experienced an adverse event (n=87) because the odds of an MUA occurring among those who underwent a TKA was 4.67 times greater than those who underwent a UKA (p<0.001).

CONCLUSIONS

MUA was the most common adverse event in this cohort of robotic-assisted knee arthroplasties. The other adverse events did not yield large enough cohort sizes to analyze statistically in relation to specific patient demographics. Younger patients and females were at significantly greater odds of needing MUA. A BMI over 30 was not found to have a statistically significant risk of needing an MUA after robotic-assisted knee arthroplasty. Among the total cohort, those who underwent a TKA were at a 12.6 times greater odds of needing an MUA than those who received a UKA.

Robotic Arm-Assisted Total Knee Arthroplasty: Anatomical Alignment and Mid-Term Outcomes from the First Cohort Originating in Greece

Robotic arm-assisted total knee arthroplasty (RATKA) represents a haptic assistive robotic arm used for bone preparation. The purpose of this study was to present implant survivorship, complications and evaluate patients' satisfaction, clinical and functional outcome of RATKA with a minimum of 1-year follow-up. The Oxford Knee Score was recorded preoperatively and at last follow-up. Patients' satisfaction rates, as well as complications and re-operations were studied. Anatomical alignment including varus, valgus deformities and flexion, extension, pre-and postoperatively were evaluated. A total of 156 patients with mean age = 71.9 years were included in the study. The mean follow-up was 35.7 months, while one revision was performed due to infection. Statistically significant improvement of the Oxford Knee Score, as well as of the knee alignment deformities were recorded, while 99.4% of patients reported to be "very satisfied" or "satisfied" with the procedure. RATKA seems to be a safe, as well as reproductible procedure at short-and mid-term follow-up, while the accurate implant positioning may lead to favorable long-term outcomes.

Multicenter, prospective cohort study: immediate postoperative gains in active range of motion following robotic-assisted total knee replacement compared to a propensity-matched control using manual instrumentation

BACKGROUND

Range of motion (ROM) following total knee replacement (TKR) has been associated with patient satisfaction and knee function, and is also an early indicator of a successful procedure. Robotic-assisted TKR (raTKR) is considered to reproduce more precise resections, and, as a result, may be associated with improved early patient satisfaction compared to manual TKR (mTKR). The purpose of this study was to evaluate the early postoperative active ROM (aROM) between raTKR and mTKR.

METHODS

A total of 216 mTKR patients were propensity-matched, in terms of age, gender, comorbidities, and BMI, to 216 raTKR cases. Intraoperative and immediate postoperative adverse events were collected. Knee flexion and extension aROM were measured preoperatively and at one- and three months after operation.

RESULTS

Changes in flexion aROM were significantly greater in raTKR vs. mTKR at one- (6.9°, 95% CI: 3.5, 10.4°) and three months (4.9°, 95% CI: 2.1, 7.7°). Flexion aROM was greater at three postoperative months compared to preoperative aROM only in the raTKR group, and raTKR patients had higher odds of achieving ≥ 90° of flexion at one month after operation (OR: 2.15, 95% CI: 1.16, 3.99). There were no significant differences between groups in intraoperative (P > 0.999) or postoperative adverse events.

CONCLUSIONS

Compared with mTKR, raTKR resulted  in less loss of aROM immediately after operation and a faster recovery of aROM within three months after operation.

TRIAL REGISTRATION

Clinicaltrials.gov (NCT# 03737149).

When Do We Perform Elective Total Knee Arthroplasty? General and Demographic-Specific Trends of Preoperative Pain and Function among 10,327 Patients

Total knee arthroplasty (TKA) is the sole disease-modifying intervention for end-stage osteoarthritis. However, the temporal trends and stratification of age and patient demographics of pain and function levels at which surgeons perform TKA have not been characterized. The present investigation aimed to analyze the temporal trends of preoperative pain and functional patient-reported outcomes measures (PROMs) over the past 5 years when stratifying patient demographics. A prospective cohort of all patients who underwent primary elective TKA between January 2016 and December 2020 at a North American integrated tertiary health care system was retrospectively reviewed. The primary outcome was quarterly baseline (preoperative) pain and function PROM values before primary elective TKA. Evaluated PROMs included Knee Osteoarthritis Outcome Score (KOOS)-pain and KOOS-physical function shortform (PS) for the 5-year study period and were stratified by patient demographics (age, sex, race, and body mass index [BMI]). A total of 10,327 patients were analyzed. Preoperative pain levels remained unchanged over the study period for patients in the 45- to 64-year category (P-trend = 0.922). Conversely, there was a significant improvement in preoperative pain levels in the 65+ years group. Sex-stratified trends between males and females did not demonstrate a significant change in pre-TKA baseline pain over the study period (P-trend = 0.347 and P-trend = 0.0744). Both white and black patients demonstrated consistent KOOS-pain levels throughout the study period (P-trend = 0.0855 and P-trend = 0.626). Only white patients demonstrated improving preoperative KOOS-PS (P-trend = 0.0001), while black and "other" patients demonstrated consistent lower preoperative functional levels throughout the study period (P-trend = 0.456 and P-trend = 0.871). All BMI categories demonstrated relatively consistent preoperative KOOS-pain and KOOS-PS except for overweight and obese patients who demonstrated progressive improvement in preoperative KOOS-PS over the study period. Patients and surgeons are electing to perform primary TKA at higher levels of preoperative function. Stratification by race showed black patients did not experience a similar trend of improving function and exhibited a consistently lower functional level versus white patients. This disparity is likely to be multifactorial but may indicate underlying barriers to TKA access.

Improved perioperative narcotic usage patterns in patients undergoing robotic-assisted compared to manual total hip arthroplasty

BACKGROUND

Robot-assisted total hip arthroplasty (RA-THA) improves accuracy in achieving the planned acetabular cup positioning compared to conventional manual THA (mTHA), but optimal dosage for peri-RA-THA and mTHA pain relief remains unclear. This study aimed to compare pain control with opioids between patients undergoing direct anterior approach THA with the use of a novel, fluoroscopic-assisted RA-THA system compared to opioid consumption associated with fluoroscopic-assisted, manual technique.

METHODS

Retrospective cohort analysis was performed on a consecutive series of patients who received mTHA and fluoroscopy-based RA-THA. The average amount of postoperative narcotics in morphine milligram equivalents (MME) given to each cohort was compared, including during the in-hospital and post-discharge periods. Analyses were performed on the overall cohort, as well as stratified by opioid-naïve and opioid-tolerant patients.

RESULTS

The RA-THA cohort had significantly lower total postoperative narcotic use compared to the mTHA cohort (103.7 vs. 127.8 MME; P < 0.05). This difference was similarly seen amongst opioid-tolerant patients (123.6 vs. 181.3 MME; P < 0.05). The RA-THA cohort had lower total in-hospital narcotics use compared to the mTHA cohort (42.3 vs. 66.4 MME; P < 0.05), consistent across opioid-naïve and opioid-tolerant patients. No differences were seen in post-discharge opioid use between groups.

CONCLUSIONS

Fluoroscopy-based RA-THA is associated with lower postoperative opioid use, including during the immediate perioperative period, when compared to manual techniques. This may have importance in rapid recovery protocols and mitigating episode burden of care.

Length of stay and discharge dispositions following robotic arm-assisted total knee arthroplasty and unicompartmental knee arthroplasty versus conventional technique and predictors of delayed discharge

Aims

In-hospital length of stay (LOS) and discharge dispositions following arthroplasty could act as surrogate measures for improvement in patient pathways, and have major cost saving implications for healthcare providers. With the ever-growing adoption of robotic technology in arthroplasty, it is imperative to evaluate its impact on LOS. The objectives of this study were to compare LOS and discharge dispositions following robotic arm-assisted total knee arthroplasty (RO TKA) and unicompartmental arthroplasty (RO UKA) versus conventional technique (CO TKA and UKA).

Methods

This large-scale, single-institution study included patients of any age undergoing primary TKA (n = 1,375) or UKA (n = 337) for any cause between May 2019 and January 2023. Data extracted included patient demographics, LOS, need for post anaesthesia care unit (PACU) admission, anaesthesia type, readmission within 30 days, and discharge dispositions. Univariate and multivariate logistic regression models were also employed to identify factors and patient characteristics related to delayed discharge.

Results

The median LOS in the RO TKA group was 76 hours (interquartile range (IQR) 54 to 104) versus 82.5 (IQR 58 to 127) in the CO TKA group (p < 0.001) and 54 hours (IQR 34 to 77) in the RO UKA versus 58 (IQR 35 to 81) in the CO UKA (p = 0.031). Discharge dispositions were comparable between the two groups. A higher percentage of patients undergoing CO TKA required PACU admission (8% vs 5.2%; p = 0.040).

Conclusion

Our study showed that robotic arm assistance was associated with a shorter LOS in patients undergoing primary UKA and TKA, and no difference in the discharge destinations. Our results suggest that robotic arm assistance could be advantageous in partly addressing the upsurge of knee arthroplasty procedures and the concomitant healthcare burden; however, this needs to be corroborated by long-term cost-effectiveness analyses and data from randomized controlled studies.

Functional alignment with robotic‑arm assisted total knee arthroplasty demonstrated better patient-reported outcomes than mechanical alignment with manual total knee arthroplasty

PURPOSE

Given the improved accuracy of robot-assisted surgery, robotic-arm assisted functionally aligned total knee arthroplasty (RFA-TKA) aims to preserve the native pre-arthritic knee biomechanics, to achieve balanced flexion-extension gaps. The purpose of this study was to compare the accuracy of the implant position and short-term clinical outcomes of patients who underwent RFA-TKA vs. mechanically aligned total knee arthroplasty with manual technique (MA-TKA).

METHODS

A prospectively collected database was reviewed retrospectively for patients who underwent primary TKA. Sixty patients who underwent RFA-TKA between February 2020 and July 2020 were included in the RFA-TKA group. Sixty patients who underwent MA-TKA were included via 1:1 matching for age, sex, and body mass index based on the RFA-TKA group. For radiological evaluation, knee X-rays were used to assess the functional knee phenotype and implant position accuracy by measuring the coronal and sagittal alignment, and these measurements were compared between the two groups. Patient demographic characteristics and patient-reported outcomes including Knee Society scores, Western Ontario and McMaster Universities Arthritis Index, and forgotten joint score-12 were compared between the groups.

RESULTS

Statistically significant differences were observed in postoperative 2-year clinical outcomes in favor of RFA-TKA group which showed greater accuracy in the tibial component sagittal alignment than MA-TKA (1.0 ± 2.3 vs. 0.7 ± 1.6, respectively; P < 0.001). However, outliers in the component positions were more common in the MA-TKA group, which was statistically significant for the femoral coronal and tibial sagittal alignments (P = 0.017 and 0.015, respectively).

CONCLUSIONS

Functional alignment in TKA could be accurately obtained with the assistance of a robotic arm, and the results showed greater 2 year postoperative patient-reported outcome and satisfaction than mechanically aligned TKA using manual instruments.

LEVEL OF EVIDENCE

III.

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.

Is it prime time for robotic-assisted TKAs? A systematic review of current studies

Introduction

Less-than-optimum positioning of femoral and tibial components and improper soft tissue tension, with abnormal loads and reduced range of motion, may cause lower patient satisfaction rates. To reduce surgeon-related variables during TKA, technology-assisted TKA was introduced, including computer navigation and robotic-assisted surgery (RATKA). Although several studies show promising short- and long-term functional and radiological outcomes of RATKA, there are still concerns related to its absolute superiority over conventional TKA.

Methods

This review aims to provide an updated insight into the most recent articles reporting on outcomes (functional, radiological, and complications) of RATKA through a systematic search of major databases. A comprehensive English literature search was performed by both authors through four databases (Embase, PubMed, Web of Science, and Scopus). The full text of the final eligible studies was evaluated for inclusion, resulting in 13 studies that are included in this review.

Results

There were 2112 knees in the 13 studies, with a follow-up ranging from three months to 13 years; only three were randomized controlled trials (RCTs), and nine directly compared the results of RATKA with CTKA technique. Seven studies reported the operative time ranging from 76.8 to 156 min; six reported a longer operative time with RATKA. Length of hospital stay (LOS) was reported in six studies which ranged from 0.48 to 2.1 days; in four studies the LOS was shorter with RATKA. In seven of the nine studies comparing RATKA with CTKA, no difference in functional outcomes was found. Four out of six studies reported that the overall alignment had mechanical alignment within ±3° of neutral alignment in all RATKA patients with an HKA ranging from -0.3 to 1.8°. Only one study reported better radiological outcomes in the RATKA group. In six comparative studies, no difference was found in the incidence of complications between RATKA and CTKA.

Conclusion

Although robotic-assisted total knee arthroplasty is a promising technology that provides better component alignment and superior early functional outcomes, the justification for its widespread adoption needs more robust evidence through well-designed and better long-term studies demonstrating superior, predictable, and durable clinical results compared to conventional total knee arthroplasty techniques.

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.

Clinical results and patient-reported outcomes following robotic-assisted primary total knee arthroplasty : a multicentre study

Aims

The aim of this study was to report patient and clinical outcomes following robotic-assisted total knee arthroplasty (RA-TKA) at multiple institutions with a minimum two-year follow-up.

Methods

This was a multicentre registry study from October 2016 to June 2021 that included 861 primary RA-TKA patients who completed at least one pre- and postoperative patient-reported outcome measure (PROM) questionnaire, including Forgotten Joint Score (FJS), Knee Injury and Osteoarthritis Outcomes Score for Joint Replacement (KOOS JR), and pain out of 100 points. The mean age was 67 years (35 to 86), 452 were male (53%), mean BMI was 31.5 kg/m² (19 to 58), and 553 (64%) cemented and 308 (36%) cementless implants.

Results

There were significant improvements in PROMs over time between preoperative, one- to two-year, and > two-year follow-up, with a mean FJS of 17.5 (SD 18.2), 70.2 (SD 27.8), and 76.7 (SD 25.8; p < 0.001); mean KOOS JR of 51.6 (SD 11.5), 85.1 (SD 13.8), and 87.9 (SD 13.0; p < 0.001); and mean pain scores of 65.7 (SD 20.4), 13.0 (SD 19.1), and 11.3 (SD 19.9; p < 0.001), respectively. There were eight superficial infections (0.9%) and four revisions (0.5%).

Conclusion

RA-TKA demonstrated consistent clinical results across multiple institutions with excellent PROMs that continued to improve over time. With the ability to achieve target alignment in the coronal, axial, and sagittal planes and provide intraoperative real-time data to obtain balanced gaps, RA-TKA demonstrated excellent clinical outcomes and PROMs in this patient population.

Cite this article: Bone Jt Open 2022;3(7):589–595.