Tranexamic Acid Prophylaxis in Hip and Knee Joint Replacement

Development of machine learning models to predict perioperative blood transfusion in hip surgery

BACKGROUND

Allogeneic Blood transfusion is common in hip surgery but is associated with increased morbidity. Accurate prediction of transfusion risk is necessary for minimizing blood product waste and preoperative decision-making. The study aimed to develop machine learning models for predicting perioperative blood transfusion in hip surgery and identify significant risk factors.

METHODS

Data of patients undergoing hip surgery between January 2013 and October 2021 in the Peking Union Medical College Hospital were collected to train and test predictive models. The primary outcome was perioperative red blood cell (RBC) transfusion within 72 h of surgery. Fourteen machine learning algorithms were established to predict blood transfusion risk incorporating patient demographic characteristics, preoperative laboratory tests, and surgical information. Discrimination, calibration, and decision curve analysis were used to evaluate machine learning models. SHapley Additive exPlanations (SHAP) was performed to interpret models.

RESULTS

In this study, 2431 hip surgeries were included. The Ridge Classifier performed the best with an AUC = 0.85 (95% CI, 0.81 to 0.88) and a Brier score = 0.21. Patient-related risk factors included lower preoperative hemoglobin, American Society of Anesthesiologists (ASA) Physical Status > 2, anemia, lower preoperative fibrinogen, and lower preoperative albumin. Surgery-related risk factors included longer operation time, total hip arthroplasty, and autotransfusion.

CONCLUSIONS

The machine learning model developed in this study achieved high predictive performance using available variables for perioperative blood transfusion in hip surgery. The predictors identified could be helpful for risk stratification, preoperative optimization, and outcomes improvement.

Driving Forces for Outpatient Total Hip and Knee Arthroplasty with Enhanced Recovery After Surgery Protocols: A Narrative Review

PURPOSE OF REVIEW

To explore the recent developments and trends in the anesthetic and surgical practices for total hip and total knee arthroplasty and discuss the implications for further outpatient total joint arthroplasty procedures.

RECENT FINDINGS

Between 2012 and 2017 there was an 18.9% increase in the annual primary total joint arthroplasty volume. Payments to physicians falling by 7.5% (14.9% when adjusted for inflations), whereas hospital reimbursements and charges increased by 0.3% and 18.6%, respectively. Total knee arthroplasty and total hip arthroplasty surgeries were removed from the Medicare Inpatient Only in January 2018 and January 2020, respectively leading to same-day TKA surgeries increases from 1.2% in January 2016 to 62.4% by December 2020 Same-day volumes for THA surgery increased from 2% in January 2016 to 54.5% by December 2020. Enhanced Recovery After Surgery (ERAS) protocols have revolutionized modern anesthesia and surgery practices. Centers for Medicare Services officially removed total joint arthroplasty from the inpatient only services list, opening a new door for improved cost savings to patients and the healthcare system alike. In the post-COVID healthcare system numerous factors have pushed increasing numbers of total joint arthroplasties into the outpatient, ambulatory surgery center setting. Improved anesthesia and surgical practices in the preoperative, intraoperative, and postoperative settings have revolutionized pain control, blood loss, and ambulatory status, rendering costly hospital stays obsolete in many cases. As the population ages and more total joint procedures are performed, the door is opening for more orthopedic procedures to exit the inpatient only setting in favor of the ambulatory setting.

Intravenous application of tranexamic acid in intramedullary nailing for the treatment of geriatric intertrochanteric fractures: a systematic review and meta-analysis

BACKGROUND

Meta-analyses on the use of tranexamic acid (TXA) in intertrochanteric fractures have shown inconsistent results due to variations in inclusion criteria and clinical heterogeneity. To address these limitations, we conducted a rigorous analysis of recent randomized controlled trials (RCTs) with strict inclusion criteria. The aim of this study was to objectively evaluate the effects and safety of intravenous TXA administration in the treatment of geriatric intertrochanteric femoral fractures with intramedullary nailing.

METHODS

PubMed, Embase, and the Cochrane Library were searched for RCTs published from the database inception to August 2022. The date of total blood loss (TBL), intra-operative blood loss (IBL), hidden blood loss (HBL), transfusion rate, transfusion units, thromboembolic events, and mortality were extracted. Review Manager 5.3 was used for the analysis.

RESULTS

A total of six RCTs involving 689 patients were included. Meta-analyses indicated that TXA can significantly reduce TBL (WMD = -232.82; 95% CI -312.81 to -152.84; p < 0.00001), IBL (WMD = -36.33; 95% CI -51.38 to -21.28; p < 0.00001), HBL (WMD = -189.23; 95% CI -274.92 to -103.54; p < 0.0001), transfusion rate (RR = 0.53; 95% CI 0.33 to 0.85; p = 0.008), and transfusion units (WMD = -0.58; 95% CI -0.75 to -0.41; p < 0.01). No increase in thromboembolic events rate (RR = 0.75; 95% CI 0.38 to 1.50; p = 0.42) and mortality (RR = 1.36; 95% CI 0.61 to 3.04; p = 0.45) was observed.

CONCLUSIONS

Our meta-analysis provides robust evidence supporting the efficacy and safety of intravenous TXA administration in treating geriatric intertrochanteric femoral fractures with intramedullary nailing. TXA significantly reduces blood loss and transfusion requirements without increasing the risk of thromboembolic events or mortality.

Tranexamic Acid in Hip Hemiarthroplasty Surgery: A Retrospective Analysis of Perioperative Outcome

Introduction: Implantation of a dual-head hip prosthesis to treat medial femoral neck fractures is often associated with significant blood loss. In elective endoprosthetics procedures, it has already been demonstrated that administration of tranexamic acid (TXA) reduces blood loss and need for postoperative transfusions, as well as reducing the frequency of postoperative complications. The aim of this study is to show whether the administration of TXA also leads to a reduction in perioperative blood loss and haemorrhage-associated complications when applied as part of treatment of femoral neck fractures using a dual-head prosthesis. Methods: In a single-centre retrospective cohort study, 1 g TXA i.v. was administered preoperatively to 93 patients who had suffered from femoral neck fractures. This group was compared to a comparison group of 65 patients who did not receive TXA (nonTXA). Outcomes were evaluated on the basis of perioperative blood loss, frequency of transfusion, and frequency of specific complications occurring. Results: The transfusion rate in the TXA group was 6% lower, whereby the volume of blood transfused was 26.7% lower than in the nonTXA group. However, neither result was significant. The calculated perioperative blood loss remained the same. Similarly, the incidence of postoperative renal failure was not significantly lower in the TXA group, at 6.5%, as compared to the nonTXA group (7.7%). A higher rate of complications or deaths as a result of TXA administration was not observed. The tranexamic acid effect seems to be related to the dose. Conclusion: Preoperative administration of TXA during implantation of a dual-head prosthesis for treatment of a femoral neck fracture does not lead to an increased complication rate. The study revealed a trend towards fewer transfusions required, but a significant reduction in blood loss could not be demonstrated. There should be further investigation of other factors influencing blood loss, in particular the dosing regimen followed for perioperative administration of TXA. Level of Evidence: Level 4: retrospective case-control study.

Preoperative administration of local infiltration anaesthesia decreases perioperative blood loss during total knee arthroplasty - a randomised controlled trial

PURPOSE

Local infiltration anaesthesia (LIA) consisting of ropivacaine, epinephrine and ketorolac administered at the end of surgery has become the gold standard for postoperative analgesia as it provides improved postoperative pain relief compared to other methods. The use of LIA has retrospectively been shown to be associated with decreased perioperative blood loss. However, no randomised controlled trials have examined the effect of of preoperative LIA on blood loss. This study aimed to compare pre- vs perioperative LIA during TKA surgery, with a primary outcome of perioperative blood loss.

METHODS

The present study was performed as a prospective single-center randomised controlled trial. A total of 100 patients undergoing primary TKA between October 2016 and March 2018 were randomised to receive either pre- or perioperative LIA. Perioperative blood loss was measured, as well as pre- and postoperative haemoglobin levels. Postoperative pain was estimated at intervals approximately 24, 48 and 72 hours after surgery; analgesic drug consumption was recorded for each patient, as well as the total length of stay as an in-patient.

RESULTS

Ninety six patients received either pre- or perioperative LIA as part of the intervention and control group respectively. Average blood loss was 39% lower in the intervention group at 130 ml vs 212 ml in the control group (p=0.002). No significant difference in haemoglobin drop, postoperative pain or length of hospital stay was found.

CONCLUSIONS

Preoperative LIA resulted in a 39% decrease in perioperative blood loss during TKA surgery compared to perioperative administration while providing non-inferior postoperative pain relief.

The use of tranexamic acid reduces blood loss in osteotomy at knee level: a systematic review

PURPOSE

Aim of this systematic review was to evaluate the literature regarding the effect of tranexamic acid (TXA) on the outcome after knee osteotomy.

METHODS

A systematic literature search was carried out in various databases on studies on the use of tranexamic acid in osteotomies around the knee. Primary outcome criterion was the hemoglobin (drop). Secondary outcome criteria were total blood loss, drainage volume, adverse effects such as thromboembolic events, blood transfusions, wound complications and clinical scores. A meta-analysis was performed for quantitative measures. The present study was registered prospectively ( www.crd.york.ac.uk/PROSPERO ; no.: CRD42021229624).

RESULTS

Seven studies with 584 patients (TXA group: 282 patients, non TXA group: 302 patients) Hemoglobin decrease (1.54 g/dl vs. 2.28 g/dl), blood loss (394.49 ml vs. 595.54 ml) and drainage volume (266.5 ml vs. 359.05 ml) were significantly less in the TXA group compared to the non TXA group. No thromboembolic event was noted in any study. In the non TXA group four blood transfusions were given. Eleven wound complications occurred in the non TXA group in comparison to two wound complications in the TXA group.

CONCLUSIONS

The results of the present study show that the application of TXA reduces hemoglobin drop, blood loss and drainage volume. These effects could be responsible for the lesser rate of side effects after administration of TXA during knee osteotomy.

Tranexamic acid in pertrochanteric fractures: a retrospective analysis of perioperative outcomes after fixation with a proximal femoral nail

Background

Treatment of pertrochanteric femoral fractures is often associated with significant blood loss. It has already been demonstrated that the administration of tranexamic acid (TXA) for endoprosthetic procedures reduces blood losses and leads to a decreased frequency of postoperative complications. The aim of this study is to demonstrate whether the administration of TXA as part of osteosynthesis treatment for pertrochanteric fractures using a proximal femoral nail reduces perioperative blood losses and haemorrhage-related complications.

Methods

In a two-centre retrospective cohort study, 1 g TXA i.v. was administered preoperatively to 294 patients who had suffered from pertrochanteric femoral fractures. The subjects were compared clinically to a historical control group who did not receive TXA (nonTXA). Outcomes were evaluated on the basis of perioperative blood loss, transfusion requirement, and occurrence of complications.

Results

The TXA group showed evidence of a reduction in blood loss (TXA = 0.97 ± 0.47 l; nonTXA = 1.06 ± 0.47 l; p = 0.004) and a lower frequency of transfusion (TXA = 20%; nonTXA = 31%; p = 0.032) as compared to the nonTXA group. However, evidence of this therapeutic effect could only be demonstrated at one of the centres on subgroup comparison between the two centres. At the second centre, the data did not show a significant difference. A trend could be seen towards a reduction in postoperative renal failure. No complications occurred resulting from the administration of tranexamic acid.

Conclusion

Preoperative administration of TXA does not lead to an increased rate of thromboembolic complications when applied for treatment of pertrochanteric femoral fractures. Evidence of a positive effect could be seen in principle in relation to the reduction in perioperative blood loss and the frequency of transfusion. The difference in effect between the two centres remains to be clarified: for this reason, it is possible to assume that further factors influencing the efficacy of TXA administration are at play which were not taken into account in this study.

Use of tranexamic acid in medial open wedge high tibial osteotomy

PURPOSE

Aim of this study was to evaluate the effect of tranexamic acid (TXA) on the outcome after medial open wedge osteotomy.

MATERIAL AND METHODS

A prospective non-randomized comparative study with 52 patients has been performed. In both treatment groups, the same surgical technique for the medial open wedge HTO was used. In group 1 (N: 26) the patients received 1 g TXA i.v. preoperatively, in group 2 (N: 26) no TXA was given. Primary outcome measure was the decrease in hemoglobin concentration. Secondary outcome criteria were postoperative pain, intraarticular effusion (measured by ultrasound), range of motion (ROM) at discharge, peri- and postoperative complications and the KOOS PS (pre- and postoperatively at 1 year follow up).

RESULTS

Hemoglobin decrease was significantly less in the TXA group compared to the non TXA group. Postoperative pain and intraarticular effusion was also significantly lower and ROM at discharge was higher in the TXA group. There was no group difference in peri- and postoperative complications and the pre- and postoperatively KOOS PS.

CONCLUSIONS

The results of the present study show the systemic application of 1 g TXA reduces hemoglobin drop and postoperative morbidity (pain, intraarticular effusion, and ROM) after tibial open wedge HTO.

Tranexamic acid in total knee replacement and total hip replacement - a single-center retrospective, observational study

BACKGROUND

Numerous strategies are used to decrease the risk of the need for [allogeneic blood transfusion (ABT)], including [tranexamic acid (TXA)].

OBJECTIVE

In a single-center retrospective observational study, we have assessed the impact of TXA on the need and average volume of blood used during transfusion.

METHODS

We have reviewed medical records of a total of 491 patients undergoing arthroplasty in our hospital from Dec 2016 to Dec 2019.

RESULTS

226 patients were administered TXA IV, and 265 did not receive an additional intervention. In the TXA group, 7/226 patients required ABT vs. 41/265 in the non-TXA group (p<0,001). The Non-TXA group required a significantly higher blood transfusion volume than the TXA group (mean 82,42 mL vs. 12,74 mL; p<0,001).

CONCLUSION

We conclude that two doses of 1g TXA administered [intravenously (IV)] before incision and during skin suturing reduce the need for blood transfusion in patients undergoing JRS.

The role of tranexamic acid in breast and body contouring surgery: a review of the literature

Background: Postoperative seroma and haematoma are two of the most common complications follow-ing large surface area surgeries. A review of the literature was performed to evaluate evidence for the use of tranexamic acid in reducing postoperative seroma and haematoma formation in breast surgery and body contouring surgery. Methods A literature search was performed using MEDLINE, the Cochrane Database of Systematic Review, the Cochrane Central Register of Controlled Trials (CENTRAL), the Database of Abstracts of Reviews of Ef-fect (DARE) and PubMed in English from 1 Jan 1990–30 Mar 2020. The search terms ‘TXA’, ‘breast reduction’, ‘mammaplasty’, ‘breast implants’, ‘breast implantation’, ‘breast reconstruction’, ‘mastectomy’, ‘tissue ex-pansion’, ‘body contouring’, ‘breast’ and ‘abdominoplasty’ were used alone and in combination. Results: A total of six articles were found including three randomised controlled trials, two cohort studies and one retrospective study. Two ongoing trials were found on The Cochrane Central Register of Con-trolled Trials (CENTRAL). No systematic reviews were found. Conclusion: Literature surrounding the use of TXA in breast and body contouring surgery is sparse com-pared to what is available in other surgical sub-specialties. The literature available shows promising results with the use of TXA in controlling haematoma, drain output and seroma formation in breast surgery and body contouring surgery with minimal morbidity in these patient groups.

Prevention of early complications following total hip replacement

Total hip arthroplasty (THA) has been quoted as "the operation of the century", owing to its efficacy and the substantial improvements evidenced with respect to functional patient outcomes and quality of life. However, early postoperative complications are often inevitable, hence it is imperative to take every step to prevent them and minimise morbidity and mortality. This manuscript focuses on the most common early complications following THA, namely venous thromboembolism (VTE), prosthetic joint infection, periprosthetic fracture, instability, and leg length inequality. It aims to outline effective risk stratification strategies and prevention measures that could apply to the wider Orthopaedic community.

Institutionally Adopted Perioperative Blood Management Program Significantly Decreased the Transfusion Rate of Patients Having Primary Total Hip Replacement Surgery

Perioperative transfusion in patients undergoing orthopedic surgery increases the number of postoperative complications. Thus, we have introduced an institution-tailored perioperative blood management program (PBM) to decrease the amount of blood transfused in patients going through primary total hip replacement (THR) surgery. We have conducted a before-after observational cohort study in two predetermined observational periods. Demographic and clinical data, ASA scores, laboratory parameters, features of surgical procedure, and anesthesia were registered. Parameters of perioperative fluid administration, transfusion rate, and postoperative complications were also assessed. One hundred patients in the first and 108 patients in the second observational period were enrolled. Eventhough the ratio of posttraumatic THR procedures increased (9% vs. 17%), the PBM protocol has been utilized effectively and a significant decrease in perioperative blood transfusion rate has been observed (61% vs. 21%). The abolishment of routine preoperative LMWH prophylaxis (90% vs. 16%), intraoperative use of tranexamic acid (10% vs. 84%), and the encouraged exploitation of our postoperative observational facility (5% vs. 39%) were abided by our colleagues. Patients still requiring transfusion had lower preoperative hemoglobin levels (129 vs. 147 g/l), scored higher in ASA (ASA III: 46% vs. 19%), and more often presented postoperative hypotension (40% vs. 7%), oliguria (23% vs. 5%), and infections (9% vs. 2%). We conclude that the individualized perioperative blood management protocol was successfully implemented and yielded a lower transfusion rate and better outcomes. Our study suggests that a partial, institution-tailored PBM program may be suitable and beneficial in countries where the modalities of perioperative blood management are limited.

Clinical Effectiveness of Intraoperative Tranexamic Acid Use in Shoulder Surgery: A Systematic Review and Meta-analysis

BACKGROUND

Tranexamic acid (TXA) is widely used across surgical specialties to reduce perioperative bleeding. It has been shown to be effective in spinal surgery and lower limb arthroplasty. Among all languages, there are no systematic reviews or meta-analyses investigating its clinical effectiveness for all types of shoulder surgery.

PURPOSE

To investigate the clinical effectiveness of TXA in all types of shoulder surgery, including open and arthroscopic procedures. To investigate the effect of TXA on bleeding and non-bleeding-related outcomes.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A protocol for the study was designed and registered with PROSPERO (CRD42020185482). The literature search included the MEDLINE, Embase, PsycINFO, and Cochrane Library databases. All randomized controlled trials evaluating the use of TXA against placebo, in all types of shoulder surgery, were included. Assessments were undertaken for risk of bias and certainty of evidence. The primary outcome was total blood loss. Secondary outcomes included those not directly related to bleeding. Data from comparable outcomes were pooled and analyzed quantitatively or descriptively, as appropriate.

RESULTS

Eight randomized controlled trials were included in the systematic review, and data from 7 of these studies were pooled in the meta-analysis. Pooled analysis demonstrated a significant reduction in 2 of 3 outcomes measuring perioperative bleeding with TXA compared with controls: estimated total blood loss (mean difference, -209.66 mL; 95% CI, -389.11 to -30.21; P = .02) and postoperative blood loss as measured by drain output (mean difference, -84.8 mL; 95% CI, -140.04 to -29.56; P = .003). Hemoglobin reduction was reduced but not statistically significant (mean difference, -0.33 g/dL; 95% CI -0.69 to 0.03; P = .07). This result became significant with sensitivity analysis excluding arthroscopic procedures.

CONCLUSION

This systematic review and meta-analysis indicated that TXA was effective in reducing blood loss in shoulder surgery. Larger randomized controlled trials with low risk of bias for specific surgical shoulder procedures are required.

CLINICAL RELEVANCE

TXA can be used across shoulder surgery to reduced perioperative blood loss. The use of TXA may have other beneficial features, including reduced postoperative pain and reduced operative time.

[Efficacy and safety of intravenous combined with topical administration of tranexamic acid in reducing blood loss after intramedullary fixation of intertrochanteric femoral fractures]

Objective

To investigate the efficacy and safety of intravenous combined with topical administration of tranexamic acid (TXA) in reducing blood loss after intramedullary fixation of intertrochanteric femoral fractures by a prospective controlled trial.

Methods

Patients with intertrochanteric femoral fractures, who were admitted for intramedullary fixation between June 2015 and July 2019, were selected as the study subjects, 120 of whom met the selection criteria. The patients were randomly assigned to 3 groups: intravenous administration group (group A, 41 cases), topical administration group (group B, 40 cases), and combined administrations group (group C, 39 cases). In group A, 4 patients occurred deep vein thrombosis of lower extremity before operation, 1 patient died of myocardial infarction on the 5th day after operation, and 1 patient developed severe pulmonary infection after operation. In group B, 2 patients occurred deep vein thrombosis of lower extremity before operation and 1 patient had iatrogenic fracture during operation. In group C, 3 patients occurred deep vein thrombosis of lower extremity before operation and 1 patient developed pulmonary infection before operation and gave up surgical treatment. All the above patients were excluded from the study, and the remaining 107 cases were included in the analysis, including 35, 37, and 35 cases in groups A, B, and C, respectively. There was no significant difference in gender, age, height, body mass, injury cause, fracture side and type, the interval between injury and operation, and preoperative hemoglobin (Hb), hematocrit between groups ( P>0.05). Intraoperative TXA (15 mg/kg) was injected intravenously in group A at 30 minutes before operation, and 1 g of TXA was injected into the medullary cavity in group B after the proximal femur was grooted and before the intramedullary nail implantation, respectively. TXA was given in group C before and during operation according to the administration methods and dosage of groups A and B. Total blood loss, maximum Hb decrease, blood transfusion rate, operation time, fracture healing time, and the incidence of complications were recorded and compared between groups. The hip joint function were evaluated by Harris score.

Results

There was no significant difference in operation time between groups ( P>0.05). The total blood loss, the maximum Hb decrease, and the blood transfusion rate in group B were the highest, followed by group A and group C, and the differences between groups were significant ( P<0.05). No incision infection or pulmonary embolism occurred in the 3 groups after operation. The incidence of anemia in group C was significantly lower than that in groups A and B, the difference was significant ( P<0.05). There was no significant difference in the incidence of subcutaneous hematoma, aseptic exudation, and deep vein thrombosis of lower extremity between groups ( P>0.05). All patients in the 3 groups were followed up 8-35 months, with an average of 16.2 months. The fracture healing time of groups A, B, and C was (6.12±1.78), (5.89±1.63), and (5.94±1.69) months, respectively, and there was no significant difference between groups ( P>0.05). At last follow-up, the Harris scores of the hip joints in groups A, B, and C were 83.18±7.76, 84.23±8.01, and 85.43±8.34, and the difference was not significant ( P>0.05).

Conclusion

Preoperative intravenous injection combined with intraoperative topical application of TXA can effectively reduce blood loss and blood transfusion after intramedullary fixation of femoral intertrochanteric fracture, without increasing the risk of deep vein thrombosis, and the efficacy is better than that of intravenous injection or topical administration.

The use of intra-operative tranexamic acid in shoulder surgery: Protocol for a systematic review and meta-analysis

INTRODUCTION

Blood loss is an important consideration in all types of shoulder surgery. Excessive bleeding is associated with increased morbidity. Tranexamic acid (TXA) is an antifibrinolytic agent. It has been demonstrated to be effective in reducing blood loss across multiple surgical specialties. The aim of this systematic review and meta-analysis is to review the literature evaluating clinical outcomes associated with the use of TXA in shoulder surgery.

METHODS

The study protocol was designed and registered prospectively on PROSPERO (International prospective register for systematic reviews). Literature search will include the MEDLINE, EMBASE, PsycINFO, and Cochrane Library databases. Randomised controlled trials (RCTs) evaluating the use of TXA against placebo, in all types of shoulder surgery, will be included. Our primary outcome is total blood loss (ml). Secondary outcomes include patient-reported outcome measures (PROMs), adverse events, and number of blood transfusions required. Risk of bias will be assessed within each study using The Cochrane Risk of Bias Tool 2.0 and the Jadad score. Inconsistency and bias across included studies will be assessed statistically. Data from comparable outcomes will be pooled and analysed quantitatively or descriptively as appropriate.

ETHICS AND DISSEMINATION

No ethical clearances required for this study. This systematic review and meta-analysis will be published in a peer-reviewed journal. It will be presented a various national and international conferences.

[Fast track concepts in total knee arthroplasty: use of tranexamic acid and local intra-articular anesthesia technique]

OBJECTIVE

Fast track concepts are used to reduce the risk of perioperative and postoperative complications after total knee arthroplasty.

INDICATIONS

The described concepts are used for patients with indications for the implantation of a total knee prosthesis.

CONTRAINDICATIONS

Contraindications for fast track concepts are aged patients, dementia, American Society of Anesthesiologists (ASA) grade IV and implantation of large revision or tumor prostheses. Contraindications for tranexamic acid are bleeding in the urinary tract, caution in cases of known epilepsy, individual risk assessment in existing thromboses or increased thrombosis risk, fresh myocardial infarction, conditions following fresh pulmonary embolism, percutaneous transluminal coronary angioplasty (PTCA) and stent implantation. Contraindications for ropivacaine are hypersensitivity (allergy) to ropivacaine and other amide type topical anesthetics and hypovolemia.

SURGICAL TECHNIQUE

Preoperative administration of 1 g tranexamic acid and intraoperative local infiltration anesthesia are carried out. After femoral and tibial bone resection and before cementing the femoral and tibial components, approximately 40 ml of ropivacaine (2%) is injected into the posterior capsule. This is followed by injection of the medial and lateral collateral ligaments with approximately 20 ml each and infiltration of Hoffa's fat pad and the extensor apparatus also with approximately 20 ml local anesthetic. After cementing, the subcutaneous tissue is infiltrated with approximately 50 ml ropivacaine solution.

POSTOPERATIVE MANAGEMENT

On the same day as the operation the patient is mobilized with the help of a physiotherapist. The patient should, if possible, walk a few steps on crutches. Systemic analgesic treatment is carried out according to the World Health Organization (WHO) staged scheme II with a weak opioid and first stage non-opioid analgesic (nonsteroidal anti-inflammatory drug, NSAID and/or metamizole). Gabapentin can be used as an adjuvant comedication. Medicinal thrombosis prophylaxis is carried out with a low molecular weight heparin for 2 weeks postoperatively.

RESULTS

In 100 patients who preoperatively received 1 g tranexamic acid and intra-articular infiltration anesthesia, in the evening of the day of the operation the pain was on average 2.1 (±1.8) on the numeric pain rating scale (NPRS). In one patient, there was a sensitive deficit of the lower leg and foot. A motor deficit was not observed. A total of 90 patients were able to raise and straighten leg. On the day of surgery 68 patients were able to walk more than 10 steps and 22 patients could be mobilized to a standing position. The mean length of hospital stay was 6.6 days (5-11 days). No infections, thromboses or pulmonary embolisms occurred.