Evaluation of Blood Loss in Conventional vs MAKOplasty Total Knee Arthroplasty

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

Introduction

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

Materials and methods

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

Results

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

Conclusions

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

Robotic-assisted total knee arthroplasty reduces postoperative complications and length of stay without increased cost compared to navigation-guided techniques: A national analysis

INTRODUCTION

This study compares postoperative outcomes of robotic-assisted total knee arthroplasty (RA-TKA) versus navigation-guided total knee arthroplasty (NG-TKA). Using Nationwide Inpatient Sample (NIS) data, it provides an analysis of postoperative complications, mortality, hospital costs and duration of stay.

METHODS

The study analysed 217,715 patients (81,830 RA-TKA; 135,885 NG-TKA) using NIS data from 2016 to 2019. Elective TKA patients were identified through the International Classification of Diseases, 10th Revision codes. Statistical analyses, including logistic regression modelling, were performed using Statistical Package for the Social Sciences and MATLAB.

RESULTS

RA-TKA patients were younger (66.1 vs. 67.1 years, p < 0.0001) and had similar mortality rates (0.024% vs. 0.018%, p = 0.342) but shorter length of stay (LOS) (1.89 vs. 2.1 days, p < 0.0001). Mean total charges were comparable between RA-TKA ($66,180) and NG-TKA ($66,251, p = 0.669). RA-TKA demonstrated lower incidences of blood-related complications (11.67% vs. 14.19%, p < 0.0001), pulmonary oedema (0.0306% vs. 0.066%, p < 0.0001), deep vein thrombosis (0.196% vs. 0.254%, p = 0.006) and acute kidney injury (AKI) (1.356% vs. 1.483%, p = 0.016).

CONCLUSION

RA-TKA reduces postoperative complications and LOS without increasing costs, highlighting the relevance of this technology in patient care.

LEVEL OF EVIDENCE

Level III.

Robots on the Stage: A Snapshot of the American Robotic Total Knee Arthroplasty Market

» Computer-assisted robots aid orthopaedic surgeons in implant positioning and bony resection. Surgeons selecting a robot for their practice are faced with numerous options. This study aims to make the choice less daunting by reviewing the most commonly used Food and Drug Administration-approved robotic total knee arthroplasty platforms in the American arthroplasty market.» Modern total knee arthroplasty (TKA) robots use computer guidance to create a virtual knee model that serves as the surgeon's canvas for resection planning.» Most available robotic TKA (rTKA) systems are closed semiactive systems that restrict implant use to those of the manufacturer.» Each system has distinct imaging requirements, safety features, resection methods, and operating room footprints that will affect a surgeon's technique and practice.» Robots carry different purchase, maintenance, and equipment costs that will influence patient access across different socioeconomic groups.» Some studies show improved early patient-reported outcomes with rTKA, but long-term studies have yet to show clinical superiority over manual TKA.

Robotics in total knee replacement: Current use and future implications

Robotic total knee replacement (TKR) surgery has evolved over the years with the aim of improving the overall 80% satisfaction rate associated with TKR surgery. Proponents claim higher precision in executing the pre-operative plan which results in improved alignment and possibly better clinical outcomes. Opponents suggest longer operative times with potentially higher complications and no superiority in clinical outcomes alongside increased costs. This editorial will summarize where we currently stand and the future implications of using robotics in knee replacement surgery.

Robotic Total Knee Arthroplasty: An Update

Total knee arthroplasty (TKA) is a gold standard surgical procedure to improve pain and restore function in patients affected by moderate-to-severe severe gonarthrosis refractory to conservative treatments. Indeed, millions of these procedures are conducted yearly worldwide, with their number expected to increase in an ageing and more demanding population. Despite the progress that has been made in optimizing surgical techniques, prosthetic designs, and durability, up to 20% of patients are dissatisfied by the procedure or still report knee pain. From this perspective, the introduction of robotic TKA (R-TKA) in the late 1990s represented a valuable instrument in performing more accurate bone cuts and improving clinical outcomes. On the other hand, prolonged operative time, increased complications, and high costs of the devices slow down the diffusion of R-TKA. The advent of newer technological devices, including those using navigation systems, has made robotic surgery in the operatory room more common since the last decade. At present, many different robots are available, representing promising solutions to avoid persistent knee pain after TKA. We hereby describe their functionality, analyze potential benefits, and hint at future perspectives in this promising field.

The Effect of Tranexamic Acid With or Without Tourniquet on Blood Loss in Total Knee Arthroplasty at a Community Hospital

Tourniquets have long been used in total knee arthroplasty due to the theoretical improvement of bleeding control, integration of cement-bone interface, visibility, and efficiency of the overall surgery. However, this has become increasingly disputed. Comparative studies in total knee arthroplasty employing chemical prophylaxis, i.e., tranexamic acid, have been conducted. This retrospective cohort study evaluated the effect of tranexamic with or without a tourniquet on mean blood loss, hemoglobin, and length of stay in total knee arthroplasty patients. A total of 153 patients' records met the inclusion criteria, 95 patients (62%) were in the tranexamic acid-only group while 58 patients (38%) were in the tranexamic acid plus tourniquet group. Based on mean blood loss in mL (827.5 without vs. 810.1 with the tourniquet, p=0.805), hemoglobin counts in g/dL (12.6 without vs. 12.5 with the tourniquet, p=0.598), and length of stay in days (1.0 days without vs. 1.1 with the tourniquet, p=0.204), there was no statistical difference between the tranexamic alone vs. tranexamic plus tourniquet groups. There were no statistical differences in the mean BMI between groups (32.3 without vs. 32.4 with tourniquets, p=0.901). The patient population had more women (64.1%) than men (35.9%) (p=0.001), but no significant difference in gender based on tourniquet use (p=0.521). The tourniquet group averaged three years younger than the tranexamic alone group (age mean 68.2 without vs 65.3 with tranexamic, p=0.029). This study found no identifiable difference in the three observed variables, indicating that tourniquet provides limited to no additional benefit in reducing blood loss over tranexamic alone in total knee arthroplasty, while tranexamic alone has no deleterious decrease in mean hemoglobin or increase in length of stay.

The Use of Regional Anesthesia to Reduce Blood Loss in Isolated Limb Perfusion (ILP)-A Novel Approach

BACKGROUND

Isolated limb perfusion (ILP) for soft tissue sarcomas (STS) is usually performed with tumor necrosis factor alpha (TNF-α) and melphalan. ILP regularly leads to a total blood loss (BLt) of 1.5-2 L/patient. Blood inflow from the central blood circulation to the limb is influenced by unstable pressure gradients and pain reactions after the administration of melphalan. With perioperative regional anesthesia (RA), pain levels can be reduced, and the pressure gradient stabilized resulting in a reduced BLt. The aim of this study was to compare the BLt with and without RA in patients with ILP during circulation of drugs.

METHODS

Patients were treated according to the following protocol: After the establishment of limb circulation, ILP was started with the administration of TNF-α. Half the dose of melphalan was given as a bolus after 30 min, and the remaining dose was continuously administered in the following 30 min. The extremity was washed out after 90 min. ILP with perioperative RA (supraclavicular plexus block/peridural catheter) was performed prospectively in 17 patients and compared to a matched retrospective control group of 17 patients without RA. BLt was documented and perioperative anesthesiological data were analyzed for response rates after the application of melphalan (RaM).

RESULTS

BLt and RaM tended to be lower for the intervention group with RA if compared to the control group without RA in all analyses. The trend of lower BLt and RaM in ILP with RA was more pronounced for the upper extremity compared to the lower extremity. Results were not statistically significant.

CONCLUSION

These findings indicate that the use of RA can help to stabilize hemodynamic anesthetic management and reduce the BLt in ILP, especially during perfusion of the upper extremities.

Predicting Factors for Blood Transfusion in Primary Total Knee Arthroplasty Using a Machine Learning Method

INTRODUCTION

Acute blood loss anemia requiring allogeneic blood transfusion is still a postoperative complication of total knee arthroplasty (TKA). This study aimed to use machine learning models for the prediction of blood transfusion after primary TKA and to identify contributing factors.

METHODS

A total of 2,093 patients who underwent primary TKA at our institution were evaluated using data extracted from the hospital quality improvement database to identify patient demographics and surgical variables that may be associated with blood transfusion. A multilayer perceptron neural network (MPNN) machine learning algorithm was used to predict risk factors for blood transfusion and factors associated with increased length of stay. Statistical analyses including bivariate correlate analysis, Chi-Square test, and Student t-test were performed for demographic analysis and to determine the correlation between blood transfusion and other variables.

RESULTS

The results demonstrated important factors associated with transfusion rates, including preoperative hemoglobin level, preoperative creatinine level, length of surgery, simultaneous bilateral surgeries, tranexamic acid usage, American Society of Anesthesiologists Physical Status score, preoperative albumin level, ethanol usage, preoperative anticoagulation medications, age, and TKA type (conventional versus robotic-assisted). Patients who underwent a blood transfusion had a markedly greater length of stay than those who did not. The MPNN machine learning model achieved excellent performance across discrimination (AUC = 0.894).

DISCUSSION

The MPNN machine learning model showed its power as a statistical analysis tool to predict the ranking of factors for blood transfusion. Traditional statistics are unable to differentiate importance or predict in the same manner as a machine learning model.

CONCLUSION

This study demonstrated that MPNN for the prediction of patient-specific blood transfusion rates after TKA represented a novel application of machine learning with the potential to improve preoperative planning for treatment outcomes.

Comparison of conventional and robotic knee arthroplasty results: A retrospective observational study

OBJECTIVE

This study aimed to determine whether a standard anesthetic protocol consisting of combined spinal epidural anesthesia (CSEA) in conjunction with controlled hypotensive anesthesia (CHA), which was used for conventional total knee arthroplasty (cTKA), could provide equally effective anesthetic conditions for robotic total knee arthroplasty (rTKA).

METHODS

Data were collected from the medical records of 113 patients (median age=67 years; age range=55-84) who underwent elective unilateral cTKA (n=52) or rTKA (n=61) without a tourniquet from 2021 to 2023. The primary outcome measure was the rate of patients whose anesthetic method did not provide adequate motor and sensory block during the surgery and had to be converted to general anesthesia. The secondary outcome measure was to compare perioperative variables, including pain scores, analgesic consumption, blood loss, transfusions, and complications.

RESULTS

In 6 patients (11.5%) in group rTKA, it was required to convert CSEA to general anesthesia at 160-180 minutes due to the pain at the operative knee and/or to the movement of the operative leg during surgery compared to none / zero in group cTKA (P=.008). Motor and sensory blocks terminated earlier than the total surgery time in those patients. Mean total surgery time was significantly higher in group rTKA than in group cTKA (151.25 ± 24.51 (120-240) minutes vs. 116.72 ± 4.99 (105-125) minutes, P < .001). Total surgery times tended to decrease gradually in group rTKA after the 11th case, indicating a learning curve for surgical performance. Conversion to general anesthesia was required only in 1 patient after the 11th case compared to the previous 5 patients. Mean pain scores and rescue analgesic consumption were higher in group rTKA at postoperative 0 hour and between 0 and 4 hours (P < .05) but similar at the following time points (P > .05). Blood loss, transfusion, and complication rates were similar (P > .05). Hospital discharge times were higher in group rTKA (P < .05).

CONCLUSION

Although our standard CSEA protocol failed due to the regression of motor and sensory block during surgery in 11.5% of patients in rTKA, the CSEA technique combined with controlled hypotensive anesthesia provided similar anesthetic conditions in the remaining patients in group rTKA as in group cTKA. The CSEA may be considered an effective and safe anesthetic method for rTKA if interventions are applied to extend the duration of the CSEA for this novel surgical technique.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Effectiveness of Robotic Arm-Assisted Total Knee Arthroplasty on Transfusion Rate in Staged Bilateral Surgery

The transfusion rate in staged bilateral total knee arthroplasty (TKA) remains high despite the application of blood management techniques. The potential of robotic arm-assisted TKA (R-TKA) in reducing the transfusion rate in staged bilateral surgery has not yet been investigated. Therefore, we aimed to evaluate the effectiveness of R-TKA on transfusion reduction compared with conventional TKA (C-TKA) in staged bilateral surgery. This retrospective study involved two groups of patients who underwent 1-week interval staged bilateral TKA-the C-TKA group and the R-TKA group-using MAKO SmartRobotics (Stryker, Kalamazoo, MI, USA). Each group comprised 53 patients after propensity score matching and was compared in terms of nadir hemoglobin (Hb) level and transfusion rate after each stage of surgery. Both groups showed no significant differences in the propensity-matched variables of age, sex, body mass index, American Society of Anesthesiologists physical status score, and preoperative Hb level. The R-TKA group showed a significantly higher nadir Hb level than the C-TKA group after the second TKA (p = 0.002). The transfusion rate was not significantly different between the two groups after the first TKA (p = 0.558). However, the R-TKA group showed a significantly lower transfusion rate in the TKA (p = 0.030) and overall period (p = 0.023) than the C-TKA group. Patients who undergo staged bilateral R-TKA have lower transfusion rate than those who undergo C-TKA. R-TKA may be effective in minimizing unnecessary allogeneic transfusions in staged bilateral surgery.