Robotic-assisted Total Knee Arthroplasty Research Articles

Robotic-assisted total knee arthroplasty is associated with the use of thinner polyethylene liners compared to navigation-guided and manual techniques.

The purpose of this study was to examine the effects of intraoperative technology use on the rate of using polyethylene liners 15 mm or greater during primary total knee arthroplasty (TKA). There were 103,295 implants from 16,386 primary unilateral TKAs performed on 14,253 patients at a single institution between 1 January2018, and 30 June2022, included in the current study. Robotic assistance and navigation guidance were used in 1274 (8%) and 8345 (51%) procedures, respectively. The remaining 6767 TKAs (41%) were performed manually. Polyethylene liners were manually identified and further subcategorised by implant thickness. Patients who underwent robotic-assisted TKA were younger (p < 0.001) and more likely to be male (p < 0.001) compared to patients who underwent navigation-guided or manual TKAs. Average polyethylene liner thickness was similar between groups (10.5 ± 1.5 mm for robotic-assisted TKAs, 10.9 ± 1.8 mm for navigation-guided TKAsand 10.8 ± 1.8 mm for manual TKAs). The proportions of polyethylene liners 15 mm or greater used were 4.9%, 3.8%and 1.9% for navigation-guided, manual and robotic-assisted procedures, respectively (p < 0.001). Multivariate regression analyses demonstrated that navigation-guided (odds ratio [OR]: 2.6, 95% confidence Interval [CI]: [1.75-4.07], p < 0.001) and manual (OR: 2.0, 95% CI: [1.34-3.20], p = 0.001) procedures were associated with an increased use of polyethylene liners 15 mm or greater. Robotic-assisted TKA was associated with a lower proportion of polyethylene liners 15 mm or greater used compared to navigation-guided and manual TKA. These findings suggest that robotic assistance can reduce human error via a more precise cutting system, limit over-resection of the tibia and flexion-extension gap mismatchand ultimately allow for more appropriately sized implants. Level III, retrospective cohort study.

Enhancing soft tissue balance: Evaluating robotic-assisted functional positioning in varus knees across flexion and extension with quantitative sensor-guided technology.

Functional implant positioning (FIP) for total knee arthroplasty (TKA) is an evolution of kinematic alignment based on preoperative CT scan and robotic-assisted technology. This study aimed to assess the ligament balancing of image-based robotic-assisted TKA in extension, mid-flexion and flexion with an FIP using intraoperative sensor-guided technology. The hypothesis was that image-based robotic-assisted TKA performed by FIP would achieve ligament balancing all along the arc of knee flexion. This prospective monocentric study included 47 consecutive patients with varus knees undergoing image-based robotic-assisted TKA performed with FIP. After robotic-assisted bone cuts, trial components were inserted, and soft tissue balance was assessed using sensor-guided technology at 10°, 45° and 90° of knee flexion. A mediolateral balanced knee was defined by an intercompartmental pressure difference (ICPD) ≤ 15 lbf and medial and lateral compartment pressure ≤60 lbf. The mean age was 71.6 years old ±6.7, the mean BMI was 29.0 kg/m2 ± 4.9 and the mean preoperative HKA was 174° ± 5 [159; 183]. The mean postoperative knee alignment was 177.0° ± 2.2° [172; 181]. There were 93.6% of balanced knees (n = 44) at 10 and 90° of knee flexion versus 76.6% (n = 36) at 45° of knee flexion with a significant difference (p = 0.014). Median ICPD at 10, 45 and 90° of knee flexion were, respectively, 7.0 (interquartile range [IQR]: 9), 11.0 (IQR: 9.5) and 8.0 (IQR: 9.0). Pairwise analyses revealed differences for ICPD at 45° versus ICPD at 10° (p = 0.003) and ICPD at 90° versus ICPD at 45° (p = 0.007). FIP with an image-based robotic-assisted system allowed the restoration of a well-balanced knee at 10° and 90° of flexion in varus knees. Nevertheless, some discrepancies occurred in midflexion, and more work is needed to understand ligament behaviour all along the arc of knee flexion. Level II.

Robot-assisted total knee arthroplasty system provides more precise control of the femoral rotation angle: A retrospective study.

Rotational alignment in total knee arthroplasty (TKA) is a crucial technical point that needs attention. We conducted a retrospective study to investigate whether a new robot-assisted TKA (RA-TKA) could improve the accuracy of rotational alignment and whether rotational alignment affects postoperative pain and functional evaluation of the knee. A total of 136 consecutive patients who underwent TKA were included in this study. Half of the patients underwent RA-TKA and the other half underwent conventional TKA (CON-TKA) by the same group of surgeons. Collect the relevant parameters. The postoperative femoral rotation angle (FRA) was -0.72±2.59° in the robot-assisted group and 1.13±2.73° in the conventional group, and were statistically significantly different (p<0.001). This study provides preliminary evidence that the RA-TKA provides more precise control of FRA than CON-TKA, and verifies that tibial rotation angle and combined rotation angle affect postoperative knee pain and functional evaluation.

ROBOTIC-ASSISTED TOTAL KNEE ARTHROPLASTY IS ASSOCIATED WITH EARLIER RETURN OF SYMMETRICAL LIMB FUNCTION COMPARED WITH CONVENTIONAL TOTAL KNEE ARTHROPLASTY

IntroductionRobotic-assisted total knee arthroplasty (TKA) has demonstrated significant benefits, including improved accuracy of component positioning compared to conventional jig-based TKA. However, previous studies have often failed to associate these findings with clinically significant improvements in patient-reported outcome measures (PROMs). Inertial measurement units (IMUs) provide a more nuanced assessment of a patient's functional recovery after TKA. This study aims to compare outcomes of patients undergoing robotic-assisted and conventional TKA in the early postoperative period using conventional PROMS and wearable sensors.Method100 patients with symptomatic end-stage knee osteoarthritis undergoing primary TKA were included in this study (44 robotic-assisted TKA and 56 conventional TKA). Functional outcomes were assessed using ankle-worn IMUs and PROMs. IMU- based outcomes included impact load, impact asymmetry, maximum knee flexion angle, and bone stimulus. PROMs, including Oxford Knee Score (OKS), EuroQol-Five Dimension (EQ-5D-5L), EuroQol Visual Analogue Scale (EQ-VAS), and Forgotten Joint Score (FJS-12) were evaluated at preoperative baseline, weeks 2 to 6 postoperatively, and at 3-month postoperative follow-up.ResultsBy postoperative week 6, when compared to conventional TKA, robotic-assisted TKA was associated with significant improvements in maximum knee flexion angle (118o ± 6.6 vs. 113o ± 5.4; p=0.04), symmetrical loading of limbs (82.3% vs.22.4%; p&lt;0.01), cumulative impact load (146.6% vs 37%; p&lt;0.01), and bone stimulus (25.1% vs 13.6%; p&lt;0.01). Whilst there were no significant differences in PROMs (OKS, EQ-5D-5L, EQ-VAS, and FJS-12) at any time point between the two groups, when comparing OKS subscales, significantly more robotic-assisted TKA patients achieved an ‘excellent’ outcome at 6 weeks compared to conventional (47% vs 41%, p= 0.013).ConclusionsIMU-based metrics detected an earlier return to function among patients that underwent robotic-assisted TKA compared to conventional TKA that PROMs were unable to detect within the first six weeks of surgery.

IN VIVO ACCURACY OF A NEW ROBOTICALLY ASSISTED SYSTEM FOR TOTAL KNEE ARTHROPLASTY: A PROSPECTIVE COHORT STUDY

IntroductionRecent technological advancements have led to the introduction of robotic-assisted total knee arthroplasty to improve the accuracy and precision of bony resections and implant position. However, the in vivo accuracy is not widely reported. The primary objective of this study is to determine the accuracy and precision of a cut block positioning robotic arm.MethodSeventy-seven patients underwent total knee arthroplasty with various workflows and alignment targets by three arthroplasty-trained surgeons with previous experience using the ROSA® Knee System. Accuracy and precision were determined by measuring the difference between various workflow time points, including the final pre-operative plan, validated resection angle, and post-operative radiographs. The mean difference between the measurements determined accuracy, and the standard deviation represented precision.ResultsThe accuracy and precision for all angles comparing the final planned resection and validated resection angles was 0.90° ± 0.76°. The proportion within 3° ranged from 97.9% to 100%. The accuracy and precision for all angles comparing the final intra- operative plan and post-operative radiographs was 1.95 ± 1.48°. The proportion of patients within 3° was 93.2%, 95.3%, 96.6%, and 71.4% for the distal femur, proximal tibia, femoral flexion, and tibial slope angles when the final intra-operative plan was compared to post-operative radiographs. No patients had a postoperative complication requiring revision at the final follow-up.ConclusionsThis study demonstrates that the ROSA Knee System has accurate and precise coronal plane resections with few outliers. However, the tibial slope demonstrated decreased accuracy and precision were measured on post-operative short-leg lateral radiographs with this platform.

Evaluating the cost of robotic-assisted total and unicompartmental knee arthroplasty.

As uptake of robotic-assisted arthroplasty increases there is a need for economic evaluation of the implementation and ongoing costs associated with robotic surgery. The aims of this study were to describe the in-hospital cost of robotic-assisted total knee arthroplasty (RA-TKA) and robotic-assisted unicompartmental knee arthroplasty (RA-UKA) and determine the influence of patient characteristics and surgical outcomes on cost. This prospective cohort study included adult patients (≥ 18years) undergoing primary unilateral RA-TKA and RA-UKA, at a tertiary hospital in Sydney between April 2017 and June 2021. Patient characteristics, surgical outcomes, and in-hospital cost variables were extracted from hospital medical records. Differences between outcomes for RA-TKA and RA-UKA were compared using independent sample t-tests. Logistic regression was performed to determine drivers of cost. Of the 308 robotic-assisted procedures, 247 were RA-TKA and 61 were RA-UKA. Surgical time, time in the operating room, and length of stay were significantly shorter in RA-UKA (p < 0.001); whereas RA-TKA patients were older (p = 0.002) and more likely to be discharged to in-patient rehabilitation (p = 0.009). Total in-hospital cost was significantly higher for RA-TKA cases (AU$18580.02 vs $13275.38; p < 0.001). Robotic system and maintenance cost per case was AU$3867.00 for TKA and AU$5008.77 for UKA. Patients born overseas and lower volume robotic surgeons were significantly associated with higher total cost of RA-UKA. Increasing age and male gender were significantly associated with higher total cost of RA-TKA. Total cost was significantly higher for RA-TKA than RA-UKA. Robotic system costs for RA-UKA are inflated by the software cost relative to the volume of cases compared with RA-TKA. Cost is an important consideration when evaluating long term benefits of robotic-assisted knee arthroplasty in future studies to provide evidence for the economic sustainability of this practice.

Robotic assisted Total Knee Arthroplasty (TKA) is not associated with increased patient satisfaction: a systematic review and meta-analysis.

Total knee arthroplasty (TKA) is a common orthopedic surgery, yet postoperative dissatisfaction persists in around 20% of cases. Robotic total knee arthroplasty (rTKA) promises enhanced precision, but its impact on patient satisfaction compared to conventional TKA remains controversial (cTKA). This systematic review aims to evaluate patient satisfaction post-rTKA and compare outcomes with cTKA. Papers from the following databases were identified and reviewed: PubMed, Scopus, Web of Science, and the Cochrane Online Library, using keywords like "Knee replacement," "Total knee arthroplasty," "Robotic," and "Patient satisfaction." Extracted data included patient satisfaction measures, Knee Society Score, Oxford Knee Score, Forgotten Joint Score, SF-36, HSS, and KOOS. Statistical analysis, including odds ratio and 95% CI was performed using R software. Heterogeneity was assessed using Cochrane's Q test. The systematic review included 17 articles, involving 1148 patients (571 in the rTKA group and 577 in the cTKA group) assessing patient satisfaction following rTKA. An analysis of proportions reveals rTKA satisfaction rate was 95%, while for cTKA, it was 91%. A meta-analysis comparing rTKA and cTKA found no statistically significant difference in patient satisfaction. Additionally, various patient-reported outcome measures (PROMs) were examined, showing mixed results across different studies and follow-up periods. The results of this study found no difference in patient satisfaction outcomes in the short to mid-term for rTKA compared to conventional methods. This study does not assert superiority for the robotic approach, highlighting the need for careful consideration of various factors influencing outcomes in knee arthroplasty.

Enhanced Recovery after Surgery Day Surgery for MAKO® Robotic-arm Assisted TKA; Better Outcome for Patients, Improved Efficiency

IntroductionRobotic-assisted Total Knee Arthroplasty (TKA) was designed to improve implant position accuracy by providing surgeons with real-time intra-operative data to tailor the operation to the patient. Proponents of robotic assisted TKA believe that this translates into meaningful improvements in outcomes. However, there are concerns that the longer surgical duration associated with robotic assisted TKA leads to longer length of stay (LOS). In this study, the authors investigated the outcome of MAKO® Robotic-arm Assisted TKA combined with ERAS protocol to assess its effect on LOS and short-term outcomes. MethodsAll patients who had undergone unilateral ERAS Day Surgery MAKO® TKA from August 2020 to July 2021 were prospectively followed up and matched to patients who underwent conventional ERAS Day Surgery TKA in the same time period. Factors such as surgical duration, LOS, immediate reduction in pain, 30-days complications, and 6-month PROMs and knee ROM were compared between the two groups. Results42 patients underwent MAKO® ERAS Day surgery TKA and were matched to 42 patients who underwent conventional ERAS Day surgery TKA. The study found that despite the longer surgical duration, LOS was comparable between both groups (1.1±0.9days in the MAKO® group vs 1.0±0.3days in the conventional group, p=0.755) with successful 24-hour discharge in 88.1% of patients in the MAKO® group. The MAKO® group achieved significantly better ROM compared to the conventional group 6-months post operatively. Post-operative PROMs were comparable between both groups. ConclusionERAS Day Surgery protocol can significantly reduce the LOS of patient undergoing MAKO® Robotic-arm Assisted TKA, conferring cost savings and making it a valid option for patients.

Patients undergoing robotic arm-assisted total knee arthroplasty have a greater improvement in knee-specific pain but not in function.

The aim was to assess whether robotic-assisted total knee arthroplasty (rTKA) had greater knee-specific outcomes, improved fulfilment of expectations, health-related quality of life (HRQoL), and patient satisfaction when compared with manual TKA (mTKA). A randomized controlled trial was undertaken (May 2019 to December 2021), and patients were allocated to either mTKA or rTKA. A total of 100 patients were randomized, 50 to each group, of whom 43 rTKA and 38 mTKA patients were available for review at 12 months following surgery. There were no statistically significant preoperative differences between the groups. The minimal clinically important difference in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score was defined as 7.5 points. There were no clinically or statistically significant differences between the knee-specific measures (WOMAC, Oxford Knee Score (OKS), Forgotten Joint Score (FJS)) or HRQoL measures (EuroQol five-dimension questionnaire (EQ-5D) and EuroQol visual analogue scale (EQ-VAS)) at 12 months between the groups. However, the rTKA group had significantly (p = 0.029) greater improvements in the WOMAC pain component (mean difference 9.7, 95% confidence interval (CI) 1.0 to 18.4) over the postoperative period (two, six, and 12 months), which was clinically meaningful. This was not observed for function (p = 0.248) or total (p = 0.147) WOMAC scores. The rTKA group was significantly (p = 0.039) more likely to have expectation of 'Relief of daytime pain in the joint' when compared with the mTKA group. There were no other significant differences in expectations met between the groups. There was no significant difference in patient satisfaction with their knee (p = 0.464), return to work (p = 0.464), activities (p = 0.293), or pain (p = 0.701). Patients undergoing rTKA had a clinically meaningful greater improvement in their knee pain over the first 12 months, and were more likely to have fulfilment of their expectation of daytime pain relief compared with patients undergoing mTKA. However, rTKA was not associated with a clinically significant greater knee-specific function or HRQoL, according to current definitions.

RESULTS OF ROBOTIC ASSISTED VS CONVENTIONAL TOTAL KNEE ARTHROPLASTY AT 1 YR FOLLOW UP

Background: Osteoarthritis (OA) of the knee is a prevalent condition among older individuals, causing significant discomfort and impairments in quality of life. Conventional total knee arthroplasty (COTKA) is a common treatment, but issues such as inadequate soft tissue balance and prosthesis misalignment can impact outcomes. Robotic-assisted total knee arthroplasty (RATKA) has emerged as a potential solution, offering enhanced precision in prosthesis placement. While observational studies suggest benefits, comprehensive reviews of randomized controlled trials (RCTs) are lacking. This study aims to fill this gap by evaluating the clinical, functional, and radiological outcomes of RATKA compared to COTKA in adult patients with primary knee OA. Methods: This prospective study was conducted at a specialized orthopedic center, involving patients diagnosed with symptomatic knee OA eligible for total knee replacement (TKR). Patients were allocated to either conventional TKR (Group A) or robotic-assisted TKR (Group B). Outcome measures included Visual Analog Scale (VAS) for pain, Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), patient satisfaction, and quality of life assessments. Radiological outcomes were assessed using standardized radiographs. Statistical analyses included descriptive statistics, group comparisons, and repeated measures analysis of variance (ANOVA). Results: Baseline characteristics showed similar distributions between Group A (n=30) and Group B (n=30). Clinical outcomes demonstrated significant improvements over time in both groups, with Group B consistently outperforming Group A across all measures. Notably, Group B exhibited lower pain scores (VAS), higher functional scores (KSS), lower disability scores (WOMAC), higher patient satisfaction, and better quality of life assessments. Radiological outcomes also favored Group B, with improved mechanical axis deviation and component positioning. Conclusion: Robotic-assisted TKR demonstrated superior clinical, functional, and radiological outcomes compared to conventional TKR in patients with knee OA. These findings support the growing body of evidence favoring the use of robotic technology in TKR procedures, particularly for optimizing implant placement and alignment. Future research should focus on cost-effectiveness and long-term outcomes to further inform clinical practice and enhance patient care.

[Clinical efficacy of intraarticular vancomycin in preventing early periprosthetic joint infection after primary knee arthroplasty].

Objective: To investigate the clinical effect of intraarticular vancomycin on early periprosthetic joint infection (PJI) in knee arthroplasty and the incidence of postoperative complications. Methods: This is a retrospective cohort study. The clinical data of 1 867 patients who underwent primary knee arthroplasty at Department of Joint Surgery, the Affiliated Hospital of Qingdao University from April 2022 to June 2023 were retrospectively analysed, including total knee arthroplasty (TKA), robotic-assisted total knee arthroplasty (RA-TKA) and unicondylar knee arthroplasty (UKA). There were 687 males and 1180 females, aged (68.0±11.2)years(range:45 to 87 years). Patients were divided into the vancomycin group and the control group according to whether or not intra-articular injection of 1 g of vancomycin powder dissolved in 30 ml of saline was performed after intraoperative joint capsule closure. In the vancomycin group, 925 patients were included, including 782 TKA, 27 RA-TKA and 116 UKA.In the control group, 942 patients were included, including 767 TKA, 99 RA-TKA and 76 UKA. Early PJI, wound complications, and vancomycin-related toxicity including acute renal collapse, ototoxicity, and allergic reactions were assessed within 3 months postoperatively. Results: No PJI was found in all patients in the vancomycin group.Five cases (0.7%,5/767) of early PJI were found in TKA patients in the control group, with a statistically significant difference (P=0.030); 1 case of early PJI was found in each RA-TKA and UKA patients, with non-significant difference compared with vancomycin group (all P>0.05). Two cases (0.3%,2/782) of incisional complications were found in TKA patients in the vancomycin group, and 4 cases (0.5%, 4/767) of incisional complications were found in TKA patients in the control group, with non-significant difference(P=0.449); no incisional complications were found in RA-TKA patients in the vancomycin group, and 1 case (1.0%,1/99) of incisional complications were found in RA-TKA patients in the control group, the difference was not statistically significant (P>0.05); no incisional complications were found in both groups of UKA patients.No vancomycin-related acute kidney injury, ototoxicity, or allergic reactions was observed in all patients. Conclusion: Intra-articular injection of 1 g of vancomycin suspension after arthrotomy closure during TKA maybe lower the risk of early PJI without increasing the risk of wound complication and vancomycin-associated systemic toxicity.

Comparison of surgical times of various total knee replacement techniques and assessment of learning curve of robotic total knee replacement: a retrospective study

Background: This study aims to compare the operating times of manual, computer-assisted and robotic- assisted TKA and to calculate the learning curve for image-less robotic-assisted TKA (RATKA). Methods: This retrospective observational study, conducted at the Centre of Excellence, Bone, Joint and Spine, Meitra Hospital, Kozhikode, Kerala, India, focused on patients aged 60 and above undergoing total                                                                       knee replacement for stage 4 osteoarthritis. The study included 75 consecutive cases of manual, computer- assisted, and robotic-assisted unilateral total knee arthroplasties performed between May 2021 and September 2022 (18 months). Data was collected from the hospital records. Results: The surgeon transitioned from learning to proficiency phase of RATKA after 14 cases. In the robotic learning phase, the overall operative time was 113.14 minutes (±8.96), significantly longer than the robotic proficiency phase's average of 98.24 minutes (±2.98) and that of CATKA (99.57±10.700 minutes) and manual TKAs (97.01±7.17 minutes). No statistically significant difference was observed in the global operative time between the proficiency phase RATKAs and the CATKA and manual groups (p=0.139). Conclusions: By optimizing techniques and modifying workflow, one can swiftly overcome the initial learning curve of RATKA and achieve operating times comparable to manual TKA. To enhance efficiency and productivity, the study proposes a revised workflow modifying various rate limiting surgical steps.

Operating room efficiency for a high-volume surgeon in simultaneous bilateral robotic-assisted total knee arthroplasty: a prospective cohort study.

Robotic-assisted total knee arthroplasty (RATKA) has been shown to achieve more accurate component positioning and target alignment than conventional jig-based instrumentation; however, concerns remain regarding its adoption since it is associated with steep learning curves, higher operational costs, and increased surgical time. This study aims to compare the operating times of three cohorts of patients undergoing simultaneous bilateral TKA, i.e., first 50 RATKA, last 50 RATKA (at the end of 1year), and 50 conventional TKA. This prospective cohort study was conducted at a single high-volume tertiary care center by a single experienced surgeon on 150 patients (300 knees), who were allotted into three equal cohorts of 50, between February 2020 and December 2021. Simultaneous bilateral TKAs were done in all three groups and operative times recorded. We describe the technique for optimizing the surgical time of SB-RATKA for efficient operative room logistics. The operating times of the two robotic-assisted TKA cohorts were compared with the operating times of the conventional SB-TKA cohort. The mean age of the study population was 59(±6.2) years with the majority of females (82%). The mean coronal deformity was comparable between the cohorts. The mean operating time in the conventional CTKA, initial 50 RATKA, and final 50 RATKA cohorts were 115.56 (±10.7), 127.8 (±26), and 91.66 (±13.5) min, respectively, all of which showed a statistically significant difference (p<0.001). The mean operating times of the final 50 RATKA at the end of 1year improved by about 36min with all the SB-RATKA cases being completed in under 120min. The efficiency of SB-RATKA improved significantly with time and experience, resulting in shorter operational times within a year, revealing the potential of robotic-assisted surgery to surpass conventional approaches in TKA in terms of operating room efficiency.

COMPUTER NAVIGATION AND ROBOTIC SURGERY DURING TOTAL KNEE ARTHROPLASTY

Total knee arthroplasty (TKA) is a successful treatment for knee osteoarthritis. The emphasis on optimal sizing and alignment of the components has led to an increase in the use of tools that allow for preoperative planning and verification of intraoperative steps. Computer navigation and robotic surgery have emerged as valuable tools for planning and performing surgery with greater precision and consistency. Objective. The aim of this paper is to organise information on the use of robotic systems in total knee arthroplasty based on own personal experience and analysis of contemporary literature sources. Methods. This study analysed professional articles that discussed the advantages and disadvantages of using robotic systems during knee arthroplasty. The information was obtained from electronic databases including PubMed, Scopus, Web of Science and Google Scholar, with a search span of over 20 years. Computerised or navigation devices allow the surgeon to enter anatomical data via an interface and receive feedback on the alignment of the implant and the knee as a whole, but cannot be programmed to perform additional tasks. Currently, several patented systems are available, and rapid technological advances in computer processing power have allowed for the rapid development of robotic surgical systems. Robotic systems usually provide feedback similar to navigation systems, but they can also be programmed to assist in specific surgical tasks. It is expected that these systems will become more reliable and accurate in the future, potentially leading to a reduced role for physicians in certain aspects of the surgical process, limiting their involvement to supervision, and thus improving the workflow of the operating room. The integration of new technologies, such as mixed reality, which overlays simulated images on real-life images, is expected to further expand the range of capabilities of these devices. But for now, it is crucial to establish the long-term outcomes of robotic-assisted total knee arthroplasty as a process to determine the viability of widespread adoption of these devices.

Comparison of Alignment Accuracy and Clinical Outcomes between a CT-Based, Saw Cutting Robotic System and a CT-Free, Jig-guided Robotic System for Total Knee Arthroplasty.

The different cutting mode of robot-assisted TKAs may influence the accuracy of alignment. The purpose of this study was to compare alignment accuracy and early clinical outcomes between a CT-based, saw cutting robotic system (MAKO) and a CT-free, jig-guided robotic system (ROSA) for total knee arthroplasty (TKA). A total of 20 MAKO TKAs and 20 ROSA TKAs from June 2021 to June 2022 were retrospectively analyzed. Differences in the postoperative hip-knee-ankle (HKA) angle, lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), posterior tibial slope (PTS) and 3° outlier frequency of the HKA, LDFA, MPTA and PTS were studied at 3 months and 1 year of follow-up. The operative time and total blood loss (TBL) were compared between these two groups. Clinical outcomes at 1 year after surgery, including range of motion (ROM), Western Ontario McMaster University Osteoarthritis Index (WOMAC) score, and Knee Society Score-2011 (KSS-2011), were also compared between these two groups. The baseline characteristics of the two groups were comparable. There were no significant differences in the mean deviations of postoperative HKA, LDFA, MPTA or PTS between the two groups at 3 months or 1 year (all ps > 0.05). Moreover, there was no significant difference in the percentage of 3° outliers for HKA, LDFA, MPTA, or PTS between the two groups at 3-month or 1-year follow-up (all ps > 0.05). The mean operation time of MAKO was longer than that of ROSA (112.7 ± 12.8 min vs 94.8 ± 23.0 min, p = 0.001), but the mean TBL (1356.7 ± 648.5 mL vs 1384.5 ± 676.3 mL) and transfusion rate (15.0% vs 5.0%) were not significantly different between the two groups (all ps > 0.05). No significant differences were found in postoperative ROM, WOMAC score or KSS score at 1 year (all ps > 0.05). The MAKO and ROSA had similar accuracy and precision in TKA alignment. The clinical outcomes at 1 year after surgery were also comparable.

Impact of change in coronal plane alignment of knee (CPAK) classification on outcomes of robotic-assisted TKA

BackgroundMechanical alignment with total knee arthroplasty (TKA) has been widely used since the implantation of the first prosthetic knee. Multiple studies have reported 80% patient satisfaction with TKA. However, the reported patients’ dissatisfaction is believed to be caused by having to convert different knee alignments to neutral alignments. It is postulated that a change in the CPAK classification of knees leads to patient dissatisfaction.Thus, we hypothesized that a change in CPAK classification with robot-assisted TKA with mechanical alignment does not significantly lead to patient dissatisfaction.MethodsWe retrospectively analyzed 134 patients who underwent robot-assisted mechanical alignment total knee arthroplasty (MA-TKA) using cementless implants and classified them into CPAK system pre- and post-operatively. One year after TKA surgery, we recorded binary responses to patients’ satisfaction with the outcome of surgery and analyzed if a change in CPAK classification is associated with the outcome of surgery.ResultsWe found that 125 out of 134 patients (93.28%) were happy with the outcome of surgery. CPAK classification was changed in 116 patients (86.57%) and maintained in 18 patients (13.43%). Our results also showed that 111 (95.7%) out of 116 patients who had a change in CPAK and 14 (77.8%) out of 18 patients who maintained their CPAK post-surgery were happy with the outcome of surgery (OR = 6.3, CI 1.741–25.17, P value = 0.019).ConclusionWe concluded that changing the patient’s native joint line and CPAK classification does not significantly change the outcome of surgery in terms of satisfaction. The dissatisfaction rate of 20% as published by previous researchers may be confounded by other reasons and not just due to changes in alignment and joint line.

Small deviations between planned and performed bone cuts using a CT-based robotic-arm-assisted total knee arthroplasty system.

Computed tomography (CT)-based robotic system for total knee arthroplasty (TKA) has shown improved accuracy compared to conventional. This study was designed to(1) confirm the accuracy of the robotic system in achieving the planand (2) establish the alignment and positioning deviation between final components and planning, by measuring the discrepancy between final implant alignment and the corresponding planned cut. Ninety-six cementless robotic-arm assisted (RA) TKAs were assessed. Bone resections were performed using the haptically controlled robotic arm. Alignment in the coronal and sagittal plane and resection depth of the distal femoral and proximal tibial cuts were recorded with a navigation planar probe. After final components were impacted, the probe was positioned on each implant surface to determine its alignment and positioning. The mean tibial resections and implanted tibial component's positioning were 0.4 mm (standard deviation, SD: 0.6) and 0.9 mm (SD: 0.8), respectively, higher than planned (p < 0.01). The tibial sagittal cut had 19/96 cases (19.8%) of ±1° outliers from plan. In 40/96 cases (41.7%), the tibial component was more prominent than planned of more than 1 mm. The mean femoral resections and impacted femoral component's positioning was 0.1 mm (SD: 0.8) and 0.2 mm (SD: 0.7), respectively, higher than planned. In 23/96 cases (24.0%), the femoral sagittal cut and femoral component coronal alignment deviated more than ±1° from plan. The computed tomography-based robotic-assisted TKA system showed good accuracy regarding bone preparation and component's positioning relative to the planning. Cementless tibial component impaction resulted in the most deviation from plan, with a large proportion of cases resulting in being more prominent than planned. Level III.

Comparison of imageless robotic assisted total knee arthroplasty and conventional total knee arthroplasty: early clinical and radiological outcomes of 200 knees.

The aim of this study was to compare the short term clinical and radiological outcomes of imageless robotic and conventional total knee arthroplasty (TKA) and to estimate the accuracy of the two techniques by analysing the outliers after TKA. We have evaluated 200 consecutive knees (158 patients), 100 knees undergoing robotic TKA, and 100 knees treated with conventional TKA. Demographic parameters like age, gender, body mass index, diagnosis and range of motion were obtained. Knee society score (KSS) and Knee society functional score (KSS-F) were used for clinical evaluation. Mechanical alignment (Hip-knee-ankle angle), proximal tibial angle (MPTA), distal femoral angle (LDFA) and tibial slope were analysed for radiological results and outliers were compared between both groups. Outliers were defined when the measured angle exceeded ± 3° from the neutral alignment in each radiological measurement on the final follow-up radiograph.The minimum follow-up was 6months (range, 6 to 18months). The preoperative mean HKA angle was 169.7 ± 11.3° in robotic group and 169.3 ± 7.3° in conventional group. There was significant improvement in HKA, LDFA, MPTA and tibial slope compared to the preoperative values in both the groups (p < 0.01). The number of HKA, LDFA and tibial slope outliers were 31, 29 and 37, respectively, in the conventional group compared to 13, 23 and 17 in the robotic group (p < 0.01). There was a significant improvement in the KSS and KSS-F functional scores postoperatively in both the groups (p < 0.01). However, there was no significant difference in the functional scores between the groups postoperatively (p = 0.08). This study showed excellent improvement with both imageless robotic and conventional TKA, with similar clinical outcomes between both groups. However, radiologically robotic TKA showed better accuracy and consistency with fewer outliers compared with conventional TKA.

Associations of postoperative outcomes with geriatric nutritional risk index after conventional and robotic-assisted total knee arthroplasty: a randomized controlled trial.

The association between postoperative outcomes of robotic-assisted total knee arthroplasty (RA-TKA) and nutrition status among elderly adults remained unclear. The authors aimed to evaluate these associations and provide a nutrition status reference for the surgical technique selection of TKA. In the present study, the authors used data from a multicenter, prospective, randomized controlled project, which recruited patients underwent TKA therapy. A total of 88 elderly adults (age ≥65 years old) were included in this study. Their preoperative and postoperative demographic data and radiographic parameters were collected. Clinical outcomes, including postoperative hip-knee-ankle (HKA) angle deviation, knee society score (KSS), 10cm visual analog scale, and so on, were observed and compared between the RA-TKA group and the conventional TKA group. Logistic regression was performed to adjust several covariates. In addition, according to the results of restricted cubic splines analyses, all participants were categorized into two groups with GNRI≤100 and GNRI >100 for further subgroup analyses. Our results showed despite having a lower postoperative HKA angle deviation, the RA-TKA group had a similar postoperative KSS score compared with the conventional TKA group in elderly adults. Among elderly patients with GNRI>100, RA-TKA group achieved significantly more accurate alignment (HKA deviation, P =0.039), but did not obtain more advanced postoperative KSS scores because of the compensatory effect of good nutrition status. However, among elderly patients with GNRI≤100, RA-TKA group had significantly higher postoperative KSS scores compared to the conventional TKA group ( P =0.025) and this association were not altered after adjustment for other covariates. Considering the clinical outcomes of conventional TKA may be more susceptible to the impact of nutrition status, elderly patients with GNRI≤100 seem to be an applicable population for RA-TKA, which is more stable and would gain significantly more clinical benefits compared with conventional TKA.

Robotic‐assisted total knee arthroplasty is not associated with improved accuracy in implant position and alignment compared to conventional instrumentation in the execution of a preoperative digital plan

AbstractPurposeThe primary objective of the present study was to evaluate if robotic‐assisted total knee arthroplasty (RO‐TKA) results in improved accuracy compared to conventional TKA (CO‐TKA) with respect to alignment and component positioning executing a preoperative digital plan. The secondary objective was to compare patient‐reported outcome measures (PROMs) between the two groups at 6 months of follow‐up (FU).MethodsPatients who underwent primary TKA using the concept of constitutional alignment were identified from the database. Each patient underwent preoperative digital planning as well as postoperative evaluation of the preoperative plan (alignment and component position) using mediCAD® software (Hectec GmbH). Two groups were formed: (i) The RO‐TKA group (n = 30) consisted of patients who underwent TKA with a robotic surgical system (ROSA®, Zimmer Biomet) and (ii) the CO‐TKA group (n = 67) consisted of patients who underwent TKA with conventional instrumentation. To assess accuracy, all qualitative variables were analysed using the χ2 test. Tegner activity scale, Oxford Knee Score and visual analogue scale were assessed preop and at 6‐month FU. To assess differences between the two groups, a 2 × 2 repeated measures analysis of variance was performed.ResultsThere was no significant (p &gt; 0.05) difference in the accuracy of alignment as well as tibial and femoral component position between the two groups. At the 6‐month FU, there was no significant (p &gt; 0.05) difference in PROMs between the two groups.ConclusionWhile robotic TKA may have some potential advantages, no significant difference was found between robotic and conventional TKA with respect to limb alignment, clinical outcomes and component positioning.Level of EvidenceLevel III.