The use of pneumatic tourniquet in total knee arthroplasty: a meta-analysis

Are tourniquets indicated in total knee arthroplasty in the era of tranexamic acid: A meta-analysis and systematic review

Introduction

There is conflicting evidence in the literature regarding the clinical utility of tourniquets in total knee arthroplasty (TKA), specifically in regards to perioperative blood loss. In this meta-analysis and systematic review, we aim to evaluate the clinical advantages and disadvantages associated with tourniquet use in the setting of TKA.

Methods

A systematic review was conducted through April 2017 using keywords: "tourniquet" and "total knee arthroplasty" or "total knee replacement". Perioperative variables including TXA use, blood loss, incidence of venous thromboembolism (VTE), and wound complications were either extracted from the studies or corresponding authors were contacted. A sub-analysis was conducted to evaluate the effects of TXA on intraoperative and total blood loss (TBL), and VTE incidence.

Results

After review of 558 articles, 19 studies reporting outcomes in 1094 patients were analyzed. Intraoperative blood loss was significantly lower in the tourniquet cohorts compared to non-tourniquet (p < 0.01). TBL was reduced in tourniquet groups but not significantly (p = 0.08). In contrast, calculated blood loss was greater in tourniquet groups, but this difference was not significant (p = 0.43). There was a greater likelihood for wound complications and VTE among tourniquet assisted TKA, albeit only significant for the former (p = 0.01). TXA sub-analysis demonstrated intraoperative blood loss was significantly reduced with tourniquet use regardless of TXA implementation (p < 0.01). In studies without TXA, tourniquet patients were at greater risk of developing VTE (p = 0.08). These risks decreased with TXA administration.

Conclusion

This meta-analysis demonstrates that tourniquets prevent intraoperative blood loss, yet within the postoperative period, there is no significant difference in TBL between tourniquet and non-tourniquet assisted TKA.

Level of evidence

Level II; Systematic Review and Meta-Analysis.

Tourniquet Effect on Patients Undergoing Total Knee Arthroplasty: A Single-Blind, Randomized Controlled Trail

BACKGROUND

Tourniquet is applied in Total Knee Arthroplasty (TKA) to reduce intraoperative blood loss and improve view of surgical field. However, tourniquet use in TKA is still in dispute. Some researchers find that tourniquet may lead to extra side effects such as aggravated pain and limb swelling, while others consider that tourniquet has no significant adverse impact on clinical outcomes of TKA patients. This trial is conducted to evaluate tourniquet effect on TKA patients.

METHODS

A prospective, single-blind, randomized controlled trail is adopted with a sample size of 130 knees from August 2020 to February 2023. Patients undergoing TKA are randomly allocated to tourniquet group and non-tourniquet group. Outcomes including quadriceps thickness and stiffness, operation time, total blood loss, intraoperative blood loss, postoperative blood loss, transfusion rate, thigh circumference, knee and thigh VAS, D-Dimer and CRP level, knee function score, patient satisfaction, and complications are evaluated in this trial. Student's t-test, Mann-Whitney U test, Pearson's chi-square test, and Fisher's exact test are used in this study.

RESULTS

No significant difference in demographic information and baseline outcomes were found (p > 0.05). Participants in the tourniquet group had significantly less total blood loss and intraoperative blood loss, more postoperative blood loss, and higher D-Dimer level on postoperative day 3 when compared with non-tourniquet group (p < 0.05). Other outcomes including quadriceps thickness and stiffness, operation time, postoperative blood loss, transfusion rate, thigh circumference, knee and thigh VAS, D-Dimer level on postoperative day 1, CRP level, knee function score, patient satisfaction, and complications showed no significant difference (p > 0.05).

CONCLUSION

Tourniquet application can effectively reduce intraoperative blood loss and total blood loss, without significant side effects. Hence, we advocate the regular use of tourniquet in primary TKA.

Risk factor analysis and establishment of a nomogram model to predict blood loss during total knee arthroplasty

PURPOSE

The risk factors for excessive blood loss and transfusion during total knee arthroplasty (TKA) remain unclear. The present study aimed to determine the risk factors for excessive blood loss and establish a predictive model for postoperative blood transfusion.

METHODS

This retrospective study included 329 patients received TKA, who were randomly assigned to a training set (n = 229) or a test set (n = 100). Univariate and multivariate linear regression analyses were used to determine risk factors for excessive blood loss. Univariate and multivariate logistic regression analyses were used to determine risk factors for blood transfusion. R software was used to establish the prediction model. The accuracy and stability of the models were evaluated using calibration curves, consistency indices, and receiver operating characteristic (ROC) curve analysis.

RESULTS

Risk factors for excessive blood loss included timing of using a tourniquet, the use of drainage, preoperative ESR, fibrinogen, HCT, ALB, and free fatty acid levels. Predictors in the nomogram included timing of using a tourniquet, the use of drainage, the use of TXA, preoperative ESR, HCT, and albumin levels. The area under the ROC curve was 0.855 (95% CI, 0.800 to 0.910) for the training set and 0.824 (95% CI, 0.740 to 0.909) for the test set. The consistency index values for the training and test sets were 0.855 and 0.824, respectively.

CONCLUSIONS

Risk factors for excessive blood loss during and after TKA were determined, and a satisfactory and reliable nomogram model was designed to predict the risk for postoperative blood transfusion.

Impact of tourniquet use in total knee arthroplasty on functional recovery and postoperative pain: a prospective study

BACKGROUND

Tourniquet use during total knee arthroplasty (TKA) remains controversial. The purpose of this study is to determine the impact of tourniquet use only during cementation compared with its use throughout the entire surgery concerning early outcomes in functional recovery, pain, quadriceps function, and rehabilitation.

METHODS

Between November 2019 and March 2020, 118 patients were enrolled in this study, with 59 patients undergoing TKA with a tourniquet during the entire surgery (group 1) and 59 patients with a tourniquet only during cementation (group 2). Twenty-eight patients were unable to complete follow-up leaving fifty in group 1 and forty in group 2. Primary endpoints were surgical time, postoperative knee and thigh pain, and functional recovery. Secondary endpoints were 6-month clinical scores and blood loss.

RESULTS

Patients in group 1 had statistically significantly increased knee pain on postoperative day 3 (p = 0.004), and thigh pain on postoperative day 1 (p < 0.001), 2 (p < 0.001), and 3 (p = 0.027), and longer time intervals to achieve straight leg raise maneuver (p = 0.006) compared to group 2. However, it did not affect overall narcotic consumption, knee pain (day 1-2), functional recovery, ROM, ability to do the first walk, Oxford knee score, length of stay, and complication rate. There was no statistically significant difference in terms of 6-month postoperative knee score, surgical time, and blood loss between the two groups.

CONCLUSION

Tourniquet use diminishes quadriceps function and increases postoperative thigh pain and, to a lesser extent, knee pain. We, therefore, recommend the use of a tourniquet only during cementing.

LEVEL OF EVIDENCE

1; prospective randomized study.

Tranexamic acid administration for the prevention of periprosthetic joint infection and surgical site infection: a systematic review and meta-analysis

INTRODUCTION

Tranexamic acid (TXA) has been widely utilized to reduce blood loss and allogeneic transfusions in patients who undergo lower limb arthroplasty. In recent years, there have been several articles reporting the incidence of periprosthetic joint infection (PJI) as a primary outcome of TXA administration, but no meta-analysis has been conducted to date. The present systematic review and meta-analysis evaluated the efficacy of TXA administration in preventing PJI and surgical site infection (SSI).

MATERIALS AND METHODS

Pubmed, CINAHL, and the Cochrane Library bibliographic databases were searched for studies published by May 24, 2022, that evaluated the effects of TXA on PJI and SSI. Two researchers screened the identified studies based on the PRISMA flow diagram. The quality of each randomized clinical trial was assessed using Version 2 of the Cochrane risk-of-bias tool for randomized trials (ROB2.0), and the quality of cohort and case-control studies was assessed by risk of bias for nonrandomized studies (ROBANS-I).

RESULTS

Of the 2259 articles identified from the database search, 31 were screened and selected. Treatment with TXA significantly reduced the incidence of overall infection, including PJI, SSI, and other infections (OR 0.55; 95% CI 0.49-0.62) (P < 0.00001), and that of PJI alone (OR 0.53; 95% CI 0.47-0.59) (P < 0.00001). TXA reduced the incidence of overall infection in patients who underwent total hip arthroplasty (THA; OR 0.51; 95% CI: 0.35-0.75) (P = 0.0005) and total knee arthroplasty (TKA; OR 0.55; 95% CI: 0.43-0.71) (P < 0.00001). Intravenous administration of TXA reduced the incidence of overall infection (OR 0.59; 95% CI 0.47-0.75) (P < 0.0001), whereas topical administration did not.

CONCLUSIONS

Intravenous administration of TXA reduces the incidence of overall infection in patients undergoing both THA and TKA.

LEVEL OF EVIDENCE

Level III.

The effects of tourniquet use on blood loss and perioperative complications in total knee arthroplasty

BACKGROUND

There has been ongoing debate about the use of tourniquets in total knee arthroplasty, and their application is widely studied. A comprehensive understanding of the advantages and disadvantages of tourniquet use during the procedure is crucial for optimizing surgical outcomes. This study aimed to investigate the effectiveness of tourniquet application, with a particular focus on blood loss and perioperative complications, providing valuable insights for clinical practice.

METHODS

Fifty patients who underwent total knee arthroplasty were randomized into tourniquet (n = 25) and nontourniquet (n = 25) groups. The same surgeon performed all surgical procedures. The follow-up time was 14 days after surgery. Primary outcomes were hemoglobin level changes, blood loss, operation time, and perioperative plasma D-dimer levels. Secondary outcomes were postoperative complications, including thrombotic and nonthrombotic events.

RESULTS

No significant differences were found in drainage, calculated blood loss, total blood loss, postoperative hemoglobin levels, or blood transfusion between the two groups (P > 0.05). No differences in D-dimer levels were observed on postoperative Days 1, 3, and 14 between the two groups, except on postoperative Day 7, when the D-dimer level in the tourniquet group was lower than that in the nontourniquet group (P = 0.03). The incidence of local complications (thigh bruising, blisters, pain, fat liquefaction, and superficial infections) in the tourniquet group was significantly higher than that in the nontourniquet group (P = 0.03), but no significant differences were found in thromboembolic and nonthromboembolic events or overall complications (P > 0.05).

CONCLUSION

We conclude that tourniquet use does not reduce the length of surgery or blood loss but does increase local complications in total knee arthroplasty.

Silicone ring tourniquet could be a substitute for a conventional tourniquet in total knee arthroplasty with a longer surgical field: a prospective comparative study in simultaneous total knee arthroplasty

INTRODUCTION

This study aimed to compare the clinical outcomes of silicon ring tourniquets and conventional pneumatic tourniquets in total knee arthroplasty (TKA). The study compared the operation time, total bleeding amount, length from the tourniquet distal end to the patella superior pole (L_TP), and complications related to the two tourniquet application methods and attempted to determine whether the silicon ring tourniquet has advantages over conventional pneumatic tourniquets.

MATERIALS AND METHODS

This prospective comparative study included 30 patients who underwent bilateral simultaneous TKA for degenerative osteoarthritis in August to December 2021. All patients underwent TKA on one side with a conventional pneumatic tourniquet, while TKA on the other side with a silicon ring tourniquet. The primary outcomes were the L_TP, operation time, tourniquet time, total bleeding amount, total drainage amount, and postoperative visual analog scale (VAS) score of the tourniquet applied site at 6, 24, and 48 h postoperatively. The secondary outcome was tourniquet-related complications in both groups.

RESULTS

L_TP was significantly longer in the silicon ring tourniquet group compared with that in the pneumatic tourniquet group (20.22 ± 2.74 cm versus 15.12 ± 2.40, p < 0.001). No significant difference was found in other results. The tourniquet applied site pain was less in the silicon ring tourniquet group (p = 0.037).

CONCLUSIONS

Silicon ring tourniquet application resulted in better clinical outcomes than conventional pneumatic tourniquets in TKA. Because we can obtain a wider surgical field using silicon ring tourniquets without complications, silicon ring tourniquets could be a substitute for conventional pneumatic tourniquets in total knee arthroplasty or distal femoral surgeries.

The use of tourniquet in primary total knee arthroplasty does not increase the risk of venous thromboembolism within 90 days of surgery: a Danish nationwide cohort study of 19,804 patients

PURPOSE

Existing evidence estimates a twofold risk of venous thromboembolisms (VTEs) if tourniquet is applied during total knee arthroplasties (TKAs). However, this estimate relies on multiple trials with a low number of patients analyzing VTEs as a secondary outcome. We hypothesized that tourniquet-use increases the risk of symptomatic VTE within 90 days of contemporary primary TKA and aimed to use the extensive Danish healthcare registries to quantify this risk.

METHODS

Prospectively collected registry data from Danish patients receiving primary TKAs between 2014 and 2018 were included in the study. Patients were divided by tourniquet-use during surgery. By merging information from four nationwide registries, the study included 44 baseline characteristics with the potential to confound the association between tourniquet-use and VTE. Incidence rate and odds ratios were used to compare the risk of VTE within 90 days of surgery.

RESULTS

19,804 patients of whom 10,111 (51%) were operated with tourniquet and 9693 (49%) without were included. The mean age (SD) was 70 (9) in both groups and 62% were females in the tourniquet group compared with 61% in the no tourniquet group. The groups were similarly comparable across all other baseline characteristics except type of post-operative thromboprophylaxis, type of anaesthesia, implant fixation, and year of surgery. The 90-days incidence of VTE was 0.77% (95% CI 0.60-0.94) in the tourniquet group compared with 1.10% (95% CI 0.90-1.31) in the no tourniquet group. Following adjustment for the unbalanced confounders, the odds ratio for VTE was 0.77 (95% CI 0.54-1.10) associated with tourniquet-use.

CONCLUSION

In contemporary TKAs the rate of VTE within 90 days is low and not significant altered by tourniquet-use. Thus, tourniquet can safely be applied during primary TKA-surgery without jeopardizing the risk of postoperative VTE.

LEVEL OF EVIDENCE

II-prospective cohort study.

Effect of tourniquet technique on postoperative delirium in elderly patients with total knee arthroplasty: a randomized single-blind controlled trial

BACKGROUND

The tourniquet technique is often used in total knee arthroplasty (TKA). However, its effect on postoperative delirium (POD) in elderly patients undergoing TKA is unknown.  METHODS: This prospective randomized controlled trial assessed the eligibility of 245 elderly patients. A total of 197 patients who met the inclusion criteria were randomly divided into a tourniquet group (n = 98) and a non-tourniquet group (n = 99). The primary outcome was the incidence of POD within 72 h after surgery. The secondary outcome was the quality of rehabilitation, including inflammatory reaction, postoperative pain, hypoproteinemia and anemia.

RESULTS

Of 245 patients, 184 patients completed this clinical trial, with 92 cases in each group. There were 14 patients (15.22%) with POD in the tourniquet group and 5 patients (5.43%) in the non-tourniquet group (95% CI 1.076 to 9.067, P = 0.029). The changes in white blood cell count (WBC), the proportion of neutrophils (NEUT%), c-reactive protein (CRP), interleukin-6 (IL-6) and middle patellar circumference in the tourniquet group were higher than those in the non-tourniquet group (P < 0.05). The visual analog scale (VAS) at rest and activity in the tourniquet group were higher than those in the non-tourniquet group (F = 170.102, P < 0.001 F = 75.391, P < 0.001). There were 41 (44.57%) patients with hypoproteinemia in the tourniquet group and 26 (28.26%) in the non-tourniquet group (95% CI 1.106 to 3.765, P = 0.022).

CONCLUSION

The application of the tourniquet technique in elderly patients with TKA procedures increased the incidence of POD. This may be attributed to the increased inflammatory reaction, severe postoperative pain and hypoproteinemia caused by the tourniquet technique.

TRIAL REGISTRATION

Clinical trial registration number: ChiCTR2100045711. Full date of the first registration: 23/04/2021.

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.

Comparison of Operative Times in Primary Bilateral Total Knee Arthroplasty Performed by a Single Surgeon

Purpose: Prolonged operative time (OT) is associated with adverse complications after total knee arthroplasty (TKA). The purpose of this study was to determine whether preoperative factors, such as sex, age, body mass index, body weight (BW), body height, American Society of Anesthesiologists grade, tibiofemoral angle, hospital for special surgery scores, surgical side, surgical order, and calendar year of surgery, affect OT. Methods: One hundred and nineteen patients (238 knees) with osteoarthritis who underwent staged bilateral primary TKA performed by a single surgeon were evaluated. The medical records of 15 males and 104 females were retrospectively reviewed. All variables were expressed as median (interquartile range). Results: The OT for all TKAs was 57 min (51, 65). The OT on the left side (59 min (52−67)) was longer than that on the right side (55 min (50−62)) (p = 0.015). Multiple regression analysis revealed that longer OT was related to BW (β = 0.488, p < 0.001), calendar year of surgery (β = −0.218, p< 0.001), and operative side (β = −0.151, p = 0.007). The Jonckheere−Terpstra test showed a trend toward decreasing OT with calendar year on the left side (p = 0.037) (surgeon’s non-dominant side), but not on the right (p = 0.795). Body height, BW, and body mass index showed weak correlations (r = 0.212, p = 0.001; r = 0.352, p < 0.001; r = 0.290, p < 0.001, respectively) with OT. Conclusion: Patients with a large physique, and especially obesity, with an affected knee on the surgeon’s non-dominant side may require a longer OT; OT decreased over time.

Tourniquet use in total knee arthroplasty and the risk of infection: a meta-analysis of randomised controlled trials

Purpose

The intra-operative use of tourniquets during Total Knee Arthroplasty (TKA) is common practice. The advantages of tourniquet use include decreased operating time and the creation of a bloodless visualisation field. However, tourniquet use has recently been linked with increased post-operative pain, reduced range of motion, and slower functional recovery. Importantly, there is limited evidence of the effect of tourniquet use on infection risk. The purpose of this systematic review and meta-analysis is to fill this gap in the literature by synthesising data pertaining to the association between tourniquet use and infection risk in TKA.

Methods

A systematic literature search was performed on Pubmed, Embase, Cochrane and clinicaltrials.gov up to May 2021. Randomized control trials were included, comparing TKA outcomes with and without tourniquet use. The primary outcome was overall infection rate. Secondary outcomes included superficial and deep infection, skin necrosis, skin blistering, DVT rate, and transfusion rate.

Results

14 RCTs with 1329 patients were included. The pooled incidence of infection in the tourniquet group (4.0%, 95% CI = 2.7–5.4) was significantly higher compared to the non-tourniquet group (2.0%, 95% CI = 1.1–3.1) with an OR of 1.9 (95% CI = 1.1–3.76, p = 0.03). The length of hospital stay, haemoglobin drop (0.33 95% CI =0.12–0.54), P = 0.002) and transfusion rates (OR of 2.7, 95%CI = 1.4–5.3, P = < 0.01) were higher in the tourniquet group than the non-tourniquet group. The difference in the length of inhospital stay was 0.24 days favouring the non-tourniquet group (95% CI = 0.10–0.38, P = < 0.01). The incidence of skin blistering (OR 2.6, 95% CI = 0.7–9.9, p = 0.17), skin necrosis (OR 3.0, 95% CI = 0.50–19.3, p = 0.25), and DVT rates (OR 1.5, 95% CI = 0.60–3.60, p = 0.36) did not differ between the two groups.

Conclusion

Quantitative synthesis of the data suggested tourniquet use was associated with an increased overall risk of infection, intraoperative blood loss, need for blood transfusion and longer hospital stay. Findings of this meta-analysis do not support the routine use of tourniquet in TKA and arthroplasty surgeons should consider any potential additional risks associated with its use.

Level of evidence

meta-analysis, Level II.

The knee position at tourniquet inflation does not affect the gap balancing during total knee arthroplasty

INTRODUCTION

The relationship between gap balancing and clinical outcome of total knee arthroplasty (TKA) has been researched. Tourniquet is widely used by most surgeons; however, there are little quantitative data about the gap depending on the tourniquet usage. We aimed to investigate whether the knee position at tourniquet inflation affected the gap measurement intra-operatively.

METHODS

TKA was performed for 104 knees and the tourniquet was inflated with the knee at full flexion and extension. The gap was measured in each static knee flexion status (0°, 30°, 45°, 60°, 90°, 120°, and in full flexion) using a tensor. We measured the gap twice; under the tourniquet inflation and release. The gap difference at each static knee flexion status was calculated by subtracting the gap under release from that under inflation.

RESULTS

When the tourniquet was inflated with the knee at full flexion, the mean gap differences were < 1 mm and < 1° in each static knee flexion status. When the tourniquet was inflated with the knee at full extension, the mean gap differences were < 1 mm and < 1°, respectively. All values of the gap difference were minimum, and were not affected by the tourniquet, whether the knee position at the tourniquet inflation was flexed or extended.

CONCLUSIONS

We postulated that the knee position at tourniquet inflation would affect the gap, which was refuted by our results. This shows that we can measure the gap without considering the knee position at tourniquet inflation.

Hyperbaric oxygen therapy does not alleviate tourniquet-induced acute ischemia-reperfusion injury in mouse skeletal muscles

During tourniquet application, blood flow is restricted to a limb to stop excessive limb hemorrhage in a trauma setting and to create a bloodless operating field in the surgical setting. During tourniquet-related ischemia, aerobic respiration stops, and ATP is depleted, and during subsequent reperfusion, there is an increase in reactive oxygen species (ROS) production and other endogenous substances, which leads to acute ischemia-reperfusion (IR) injuries, including tissue necrosis and skeletal muscle contractile dysfunction. Hyperbaric oxygen (HBO) therapy can increase the arterial oxygen tension in the tissues of patients with general hypoxia/anoxia, including carbon monoxide poisoning, circulatory arrest, and cerebral and myocardial ischemia. Here, we studied the protective effects of HBO pretreatment with 100% oxygen at 2.5 ATA against tourniquet/IR injury in mice. After one hour of HBO therapy with 100% oxygen at 2.5 ATA was administered to C57/BL6 mice, a rubber band was placed at the hip joint of the unilateral hindlimb to induce 3 h of ischemia and then released for 48 h of reperfusion. We analyzed gastrocnemius muscle morphology and contractile function and measured the levels of ATP and ROS accumulation in the muscles. HBO pretreatment did not improve tourniquet/IR-injured gastrocnemius muscle morphology and muscle contraction. Tourniquet/IR mice with HBO pretreatment showed no increase in ATP levels in IR tissues, but they did have a decreased amount of ROS accumulation in the muscles, compared to IR mice with no HBO pretreatment. These data suggest that one hour of HBO pretreatment with 100% oxygen at 2.5 ATA increases the antioxidant response to lower ROS accumulation but does not increase ATP levels in IR muscles and improve tourniquet/IR-injured muscle morphology and contractile function.

Change in the optic nerve sheath diameter after deflation of a pneumatic tourniquet: a prospective observational study

Applying a pneumatic tourniquet provides surgeons with a bloodless surgical field. However, application of the tourniquet induces various physiological changes. We evaluated the effect of tourniquet deflation on the intracranial pressure by using ultrasonography to measure the optic nerve sheath diameter (ONSD) in patients undergoing lower limb surgery. The ONSD was measured in 20 patients at five time points: after anesthetic induction (T0) and immediately before (T1), immediately after (T2), 5 min after (T3), and 10 min after tourniquet deflation (T4). Hemodynamic and respiratory variables were recorded. The ONSD showed significant differences at each point (P < 0.001). The ONSDs at T2 and T3 were significantly greater than that at T1 (P = 0.0007 and < 0.0001, respectively). The change in the end-tidal carbon dioxide partial pressure (EtCO2) was similar to the change in the ONSD. The change in the ONSD was significantly correlated with the change in the EtCO2 after tourniquet deflation (r = 0.484, P = 0.030). In conclusion, the ONSD, as an indicator of intracranial pressure, increased after tourniquet deflation in patients undergoing lower limb surgery. This was correlated with an increased EtCO2 and arterial carbon dioxide partial pressure.Trial registration: ClinicalTrials.gov (NCT03782077).

Tourniquet Use Does Not Affect Pain and Function after Total Knee Arthroplasty: Patient Evaluation According to Pain Threshold

We evaluated the effect of using a tourniquet on early-stage pain and 1-year postoperative functional outcomes when patients were divided into two groups according to the pain threshold (PT). Overall, 120 patients who were assessed preoperatively with an algometer were recruited for this prospective, double-blinded, randomized controlled trial. Patients were randomized to undergo total knee arthroplasty (TKA) with a tourniquet (group 1, 60 patients) and without tourniquet (group 2, 60 patients). Primary outcome measures were visual analog scale (VAS) pain scores at 24, 36, and 48 hours postoperatively and functional assessment with Knee Society Score (KSS) test at 1 year postoperatively. No significant differences were observed between groups in terms of gender (49 females and 8 males in group 1 vs. 53 females and 6 males in group 2; p = 0.201) and age (68.9 years in group 1 vs. 68.7 years in group 2; p = 0.811). There was no significant difference between groups in all the VAS and KSS 1 and KSS 2 scores. PT measurements ranged from 2.5 to 11.5 with a mean of 7.69 ± 1.70 and a median of 8. Total 54 patients with a median value of < 8 were defined as the low-PT group, and 62 patients with a median value of ≥ 8 were defined as the high-PT group. When the groups were evaluated according to using the tourniquet, 21 patients were operated on with a tourniquet and 33 patients without it in the low-PT group, while 36 patients were operated on with a tourniquet and 26 patients without it in the high-PT group. There was no significant difference in pain or functional scores between patients when comparing with-tourniquet and without-tourniquet or when comparing the low- and high-PT groups. This showed that the use of a tourniquet during TKA was not associated with either early-stage pain or 1-year postoperative functional outcomes according to algometer evaluation.Level of evidence: Level 1 prospective randomized study.

A comparison of acute mouse hindlimb injuries between tourniquet- and femoral artery ligation-induced ischemia-reperfusion

The tourniquet or femoral artery ligation is widely used to stop extremity hemorrhage or create a bloodless operating field in the combat scenario and civilian setting. However, these procedures with subsequent reperfusion also induce ischemia-reperfusion (IR) injuries. To fully evaluate animal models of limb IR injuries, we compared tourniquet- and femoral artery ligation-induced IR injuries in the hindlimb of mice. In C57/BL6 mice, 3 h of unilateral hindlimb ischemia was induced by placement of a rubber band at the hip joint or a surgical ligation of the femoral artery. The tourniquet or femoral artery ligation was then released, allowing for 24 h of reperfusion. Compared to the femoral artery ligation/IR, the tourniquet/IR induced more severe skeletal muscle damage, including muscle necrosis and interruption of muscle fibers. There was no gastrocnemius muscle contraction in tourniquet/IR, while femoral artery ligation/IR markedly weakened gastrocnemius muscle contraction. Motor nerve terminals disappeared, and endplate potentials (EPPs) were undetectable in tourniquet/IR, whereas femoral artery ligation/IR only induced mild impairment of motor nerve terminals and decreased the amplitude of EPPs. Additionally, western blot data showed that proinflammatory cytokine levels (IL-1β and TNF-α) were higher in the tourniquet/IR than that in femoral artery ligation/IR. Moreover, tourniquet/IR caused significant tissue edema and dilation of lymphatic vessels in the hindlimb, compared to femoral artery ligation/IR. The above data demonstrated that tourniquet/IR-induced acute hindlimb injuries are more severe than those induced by femoral artery ligation/IR. This suggests that future investigators should determine which hindlimb IR model (tourniquet/IR or femoral artery ligation/IR) is optimal depending on the purpose of their study.

Not using a tourniquet is superior to tourniquet use for high tibial osteotomy: a prospective, randomised controlled trial

PURPOSE

Tourniquets are routinely used in high tibial osteotomy (HTO). However, research on the necessity of tourniquets during HTO is lacking. This study was designed to investigate the necessity of tourniquets in HTO.

METHODS

This was a prospective study that included patients who underwent HTO at the same hospital. The patients were randomised into Group A (non-tourniquet, n = 45) and Group B (tourniquet, n = 45). Same surgical techniques and haemostatic methods were used in the two groups.

RESULTS

All patients were followed up for more than three months. There was no difference in operation time, and no intra-operative vascular or nerve damage occurred in either group. The hospital stay was shorter in group A than in group B (p < 0.05). There was no difference in post-operative blood loss, haemoglobin or haematocrit (p > 0.05). The post-operative visual analogue scale (VAS) pain scores and calf swelling were lower in group A (p < 0.05), and the early knee range of motion was higher in group A (p < 0.05). The use of morphine and the incidence of thigh complications were also lower in group A (p < 0.05). There was no difference in the VAS and knee function between the two groups at three months post-operatively (p > 0.05).

CONCLUSION

Tourniquet use during HTO does not reduce post-operative blood loss, operation time or intra-operative complications, but not using a tourniquet shortens the hospital stay and reduces the post-operative usage of morphine and tourniquet-related complications, which promotes early recovery of knee function.

Hybrid Oxford unicompartmental knee arthroplasty has lower residual cement extrusion than cemented arthroplasty in treating end-stage unicompartmental knee osteoarthritis

Background

Hybrid Oxford unicompartmental knee arthroplasty (OUKA) consists of cementless femoral prostheses and cemented tibial prostheses. Although a hybrid OUKA has been used in clinical practice, the clinical outcome has not been reported. The purpose of this study was to compare the short-term clinical outcomes and rate of residual bone cement extrusion between hybrid and cemented prostheses and analyse the possible reasons for differences between outcomes.

Methods

A total of 128 knees (118 patients) with end-stage osteoarthritis were included in this study, of which underwent consecutive operations using unicondylar Oxford phase 3 implants from July 2017 and September 2019 in our centre. Follow-up was performed at 6 weeks, 3 and 6 months, 1 year and every year after operation, and complications and changes in the Oxford knee score (OKS) were recorded. The OKS of the two groups was analysed by the generalized estimating equation approach. Prosthesis-based standard fluoroscopy was performed in a timely manner after each operation, and the rate of residual cement extrusion of the two groups was estimated using T-tests and a multivariate regression analysis.

Results

Excluding the cases that lost follow-up, a total of 120 knees (65 in hybrid group and 55 in cemented group) were included in the analysis. There was no statistically significant difference in patient characteristics between the two groups (p > 0.05). The average follow-up time was 23.4 months (and ranged from 12 to 38 months). As of the last follow-up, there were no complications, such as dislocation, fracture, prosthesis loosening and subsidence, but one patient in the cemented group experienced symptoms caused by residual loose cement. Postoperative OKS in both groups improved significantly (p < 0.001). There was no significant difference in the OKS at any point during the follow-up or in the improvement of the OKS between the two groups (p > 0.05). Residual cement was mainly extruded behind the tibial prosthesis. The rate of hybrid periprosthetic residual cement extrusion was significantly lower in the hybrid group than in the cemented group, and the difference was statistically significant (OR = 3.38; p = 0.014).

Conclusions

Hybrid OUKA is as effective as cemented OUKA in the short term after operation and can significantly reduce the residual cement extrusion rate around the tibial prosthesis.

Perioperative Blood Loss Can Be Reduced If Total Knee Arthroplasty Was Performed in the Si Hour-Period, Compared with the Wei Hour-Period: A Retrospective Cohort Study

OBJECTIVE

To investigate the efficacy and safety of performing primary unilateral total knee arthroplasty (TKA) in the "Si hour-period" meaning 09:00 a.m. to 11:00 a.m. (one of the 12 two-hour periods into which the day was traditionally divided, each being given the name of one of the 12 earthly branches), compared with the "Wei hour-period" (13:00-15:00).

METHODS

Patient documentations were studied for those who underwent a primary unilateral TKA performed by the same surgical team with a tourniquet between January 2018 and January 2021 at our medical center. Eighty-four patients were enrolled and assigned into group A (in Si hour-period) and group B (in Wei hour-period). The main outcomes were total blood cell loss (TBL), hidden blood loss (HBL), visible blood loss (VBL), maximum hemoglobin (Hb) drop, and transfusion rate. Secondary outcomes were length of hospital stay (LOS), postoperative femorotibial mechanical axis (FTMA), FTMA correction, platelet count, plasma D-dimer (D-D), prothrombin time (PT), international normalized ratio (INR), and the incidence of postoperative complications.

RESULTS

Group A showed statistical significance lower at the mean TBL, the mean HBL, and the maximum Hb drop (95% CI: -352.8 to -46.1,P=0.011, 95% CI: -348.0 to -40.1,P=0.014, and 95% CI: -9.5 to -0.7,P=0.023, respectively) after TKA than group B. The postoperative platelet count of group A was more significant than that of group B (95% CI:3.1 to 52.9, P=0.028). The VBL, transfusion rate, the LOS, postoperative FTMA, FTMA correction, plasma D-D, PT, INR, and the incidence of postoperative complications (wound complications, calf muscular vein thrombosis, infection, pulmonary embolism, and deep vein thrombosis) were similar between the two groups (P > 0.05, respectively).

CONCLUSION

Our study shows that blood loss can be reduced when TKA is performed in the "Si hour-period," which may be due to increasing platelet count, and postoperative complications did not increase, compared with the Wei hour-period. We recommend that the selective operation, such as TKA, should be performed in the "Si hour-period" in clinical practice between the two hour-period.

Effect of tourniquet application on cement penetration in primary total knee arthroplasty: a meta-analysis

Background

Tourniquet application is expected to improve surgery exposure and cementation process in total knee arthroplasty (TKA) but its effectiveness remains controversial and needs to be further explored. The aim of this meta-analysis was to assess the effect of tourniquet in primary TKA. The hypothesis is that the tourniquet application affects the cement penetration in TKA.

Methods

A search was conducted in PubMed, Embase, and the Cochrane Library for the potentially eligible articles. Two independent researchers reviewed the articles retrieved against the pre-designed inclusion and exclusion criteria. In primary TKA, cement penetration was assessed, and the data between the tourniquet-assisted and non-tourniquet-assisted TKAs were compared. Statistical significance was set at P < 0.05.

Results

A total of 4 randomized controlled trials and 3 non-randomized controlled trials (involving 675 patients) were included. There was no significant difference between the tourniquet-assisted and non-tourniquet-assisted TKAs in terms of cement penetration (P > 0.05). There were no significant differences in the total surgical time, blood loss, blood transfusion, the Knee Society Score, and the visual analogue scale (VAS) between the two kinds of procedures (P > 0.05).

Conclusions

Tourniquet application may not affect cement penetration in primary TKA and may not help reduce blood loss, ease knee pain or improve the knee function. A surgeon may choose to use a tourniquet or not according to his or her own preference.

Level of Evidence

Level Ib, meta-analysis.

Tourniquet use in primary total knee arthroplasty is associated with a hypercoagulable status: a prospective thromboelastography trial

STUDY DESIGN

Prospective study.

PURPOSE

The main purpose of this study was to investigate whether the use of a tourniquet changes the blood coagulation state following primary total knee arthroplasty (TKA) by means of conventional coagulation tests and thromboelastography (TEG) analyses.

METHODS

A total of 154 patients who underwent primary unilateral TKA from January 2018 to October 2020 were enrolled. Seventy-nine patients were randomized into a tourniquet group, and 75 were randomized into a no-tourniquet group. Demographic data, surgical time, intra-operative blood loss, transfusion rate, and wound complications were collected. Complete blood count, conventional coagulation tests, and TEG were performed the day before surgery, one day after surgery, three days after surgery, and seven days after surgery. Lower extremity Doppler ultrasound was performed the day before surgery and seven days after surgery.

RESULTS

The baseline characteristics of the patients were similar between the two groups. Hidden blood loss, transfusion rate, and wound complications were similar between the two groups, but the intra-operative blood loss of the tourniquet group was lower than that of the no-tourniquet group. The calculated total blood loss of the tourniquet group was higher than that of the no-tourniquet group. In terms of conventional coagulation tests and TEG, the tourniquet group had higher values of fibrin degradation products, D-dimer, maximum amplitude, and coagulation index (p < 0.001). The incidence of deep vein thrombosis (DVT) in the tourniquet group was higher than that in the no-tourniquet group (21.5% compared with 8%; p = 0.019).

CONCLUSION

The application of a tourniquet during TKA significantly increases the amount of calculated total blood loss and does not decrease the post-operative transfusion rate. Using a tourniquet in routine TKA exacerbates the early post-operative hypercoagulable status together with a higher incidence of below-knee asymptomatic DVT observed via conventional coagulation tests, TEG, and ultrasonic Doppler.

A comparison of thrombosis in total knee arthroplasty with and without a tourniquet: a meta-analysis of randomized controlled trials

Background

Tourniquets are widely used in total knee arthroplasty (TKA), but the issue of their safety remains controversial. Previous studies have focused on TKA blood loss, duration of surgery, and hemostatic drugs. The purpose of this meta-analysis was to analyze the effect of tourniquet use on postoperative deep venous thrombosis (DVT).

Methods

PubMed, SCOPUS, Web of Science, Embase, and the Cochrane Library were searched for randomized clinical trials published before April 17, 2020, that compared the effect of tourniquet use on postoperative DVT, knee circumference, D-dimers, and pain measured using the visual analog scale (VAS).

Results

Fourteen clinical trials that included 1321 unique participants were included in the meta-analysis. Among the total, 721 and 600 participants were randomized to the tourniquet and non-tourniquet groups, respectively. The incidence of postoperative thrombosis in the tourniquet group was significantly higher than in the non-tourniquet group (RR 2.30, 95% CI 1.51–3.49, P < 0.0001, I² = 0%). On the 1st, 3rd, and 5th to 21st days, and 3 to 6 weeks after surgery, the knee circumference difference of the tourniquet group was significantly larger than that of the non-tourniquet group (P < 0.05). However, 4 to 6 months after the surgery, no significant difference in knee circumference was found between the two groups (MD 0.14, 95% CI −0.02–0.31, P = 0.09, I² = 0%). The VAS score of the tourniquet group was higher than the non-tourniquet group on the 3rd and 5th days after surgery (P < 0.05). However, this difference was not significant (MD 0.31, 95% CI −0.05–0.66, P = 0.09, I² = 89%).

Conclusion

Results of this meta-analysis indicate that tourniquet application could increase the incidence of postoperative DVT and aggravate postoperative pain and swelling in the short term.

Level of evidence

Level III

Tourniquet use during knee arthroplasty: A Bayesian network meta-analysis on pain, function, and thromboembolism

BACKGROUND

The role of a tourniquet for knee arthroplasty remains controversial. The present Bayesian network meta-analysis investigated the role of various protocols for tourniquet inflation for knee arthroplasty, assessing data on pain control, clinical and functional outcomes, and the rate of deep vein thrombosis (DVT).

MATERIAL AND METHODS

The present Bayesian network meta-analysis was conducted according to the PRISMA guidelines. In March 2021, all clinical trials investigating the role of tourniquet use for knee arthroplasty were considered for inclusion. Groups were divided into those which used a tourniquet in knee arthroplasty procedures versus those which completed the procedure without tourniquet, or with varying protocols of tourniquet use. The hierarchical random-effects model analysis was adopted in all comparisons.

RESULTS

Data from 54 articles (5497 procedures) were retrieved. The absence of tourniquet group evidenced the lowest rate of DVT, and scored the lowest in the visual analogic scale (VAS) at 24-48 h, 1, 3, and 12 months follow-up. The same group evidenced the greatest gain of motion at 3-days, 1 week, 1 month, 3 months, 6 months, and 12 months follow-up, and the highest Knee Society Rating System scores at 1, 3, and 12 months follow-up. Of the outcome data assessed, the straight-leg-raise test was markedly inconsistent: therefore, no recommendations from this test can be made.

CONCLUSION

With regards to the endpoints considered in the present study, knee arthroplasties undertaken without the use of a tourniquet perform better overall.

Effect of Different Tourniquet Pressure on Postoperative Pain and Complications After Total Knee Arthroplasty: A Prospective, Randomized Controlled Trial

BACKGROUND

Tourniquet pressure inflation is commonly selected between 100 and 150 mm Hg above the systolic blood pressure (SBP). Given the lack of evidence to support a given inflation pressure, our study aimed to ascertain the lowest tourniquet pressure that facilitated total knee arthroplasty (TKA) and resulted in the least postoperative pain and complications.

METHODS

In a double-blind, randomized controlled trial of patients scheduled for unilateral primary TKA, 150 were assigned to use tourniquet pressures of SBP + 75 mm Hg (group I), SBP + 100 mm Hg (group II), and SBP + 150 mm Hg (group III). The quality of the bloodless field, total blood loss, and limb swelling were determined perioperatively. Clinical outcomes were evaluated by visual analog scale for pain at thigh and surgical site, serum creatinine phosphokinase levels, wound complications, range of motion, and Knee Society Score.

RESULTS

Visual analog scale for pain at thigh and surgical site were lowest in group I (P < .01) and highest in group III (P < .01). However, the quality of bloodless field at the tibial cutting surface was significantly better in group III compared to group I/II but not at the femoral cutting surface. The total blood loss and limb swelling showed no difference among 3 groups. Postoperative serum creatinine phosphokinase levels at 24 and 48 hours and wound complications in group III were significantly higher than group I (P < .01) and group II (P < .01). Nevertheless, postoperative knee range of motion and Knee Society Score were not significantly different among 3 groups.

CONCLUSION

Post TKA, the lowest tourniquet pressure was associated with significantly less postoperative tourniquet and surgical site pain, muscle damage, and wound complications.

Short-term outcomes of total knee arthroplasty performed with and without a tourniquet

INTRODUCTION

Not using a tourniquet could improve early postoperative pain, range of motion (ROM), length of stay (LOS), and thromboembolic risk in patients undergoing total knee arthroplasty (TKA). Our aim was to compare these factors, intraoperative blood loss, and gender-related outcomes in patients undergoing primary TKA with or without a tourniquet.

METHODS

We performed a retrospective cohort study of 97 patients undergoing TKA with or without tourniquet from 2018 to 2020. Revisions and bilateral TKAs were excluded. Blood loss was estimated using a validated formula. Postoperative pain was tested using the visual analogue scale (VAS). ROM and quadriceps lag were assessed by a physiotherapist on a postoperative day 2 and discharge. The index of suspicion for a thromboembolic event was defined as the number of embolic-related investigations ordered in the first 6 months post-surgery. The Shapiro-Wilk test was used to assess the distribution of the data, Mann-Whitney for the continuous variables, and Fischer's test for the categorical ones.

RESULTS AND DISCUSSION

There was a significant difference in blood loss. The non-tourniquet group lost on average 32% more blood (1291 mL vs. 878 mL, p<0.001 two-tailed). We found no difference in pain, ROM, LOS, and quadriceps lag on day 2 and at discharge. There was one thromboembolic event in the tourniquet group, but the thromboembolic index of suspicion did not differ (p=0.53). With tourniquet use, women had a significantly lower day 2 maximum flexion than men (71.56° vs. 84.67°, p=0.02). In this retrospective cohort study, the results suggest that tourniquet use is associated with lower blood loss and similar postoperative pain, range of motion, quadriceps lag, length of stay, and thromboembolic risk. There might be some differences between how men and women tolerate a tourniquet, with women having worse short-term outcomes compared to men.

Application of Tourniquet Does Not Influence Early Clinical Outcomes After Total Knee Arthroplasty

Introduction

The use of a tourniquet during total knee arthroplasty (TKA) is still a topic of debate, given the conflicting results in the literature with respect to complications, pain, functional outcome, and blood loss. However, due to a lack of convincing data on early patient-reported outcomes (PROMS), this study aims to compare pain and functional outcomes in total knee arthroplasty patients with and without a tourniquet.

Methods

A randomized controlled trial was set up at a tertiary care hospital that spanned from 1^st February 2015 to 31^st July 2018. We included all primary total knee arthroplasties performed for patients aged between 50 and 80 years. Oxford Knee Score (OKS), Numerical Pain Rating Score (NPRS), Visual Analogue Scale (VAS) for satisfaction, active range of knee motion, and Short Form-12 Survey (SF-12) scores were collected pre-surgery and then at six-weeks and six-months interval with a p-value of 0.05 considered to be significant.

Results

Two hundred and forty patients participated in the study; 117 patients were randomized to surgery with the tourniquet inflated and 123 to surgery with the tourniquet deflated. There were 43.4% males, and 56.6% females in the tourniquet inflated group with an average age of 62.29±9.63 years while in tourniquet deflated group, there were 46.7% males and 53.3% females with a mean age of 65.41±9.042 years (p-value for age is 0.404; the p-value for gender is 0.086). 

Despite the increase in intraoperative blood loss in both the groups, there was no significant increase in blood transfusions as both groups recorded the need for postoperative blood transfusion - 12 patients in the tourniquet group and 19 in the non-tourniquet group, but this difference was statistically insignificant (p=0.231). The perioperative blood loss was significantly lower (p<0.001) in the tourniquet group (490.29±47.752) compared to in the non-tourniquet group (526.18±12.796), while the duration of surgery was comparable in both groups (p=0.156).

The length of stay for the two groups did not statistically differ (p=0.976) - the mean length of stay for the tourniquet group was 6.16±2.38 days and for the non-tourniquet group it was 6.18±2.34 days.

There were no significant differences between the two groups regarding patient-reported outcomes (PROMS) at six-weeks and six-months. However, during the in-hospital stay, only the NPRS score for knee pain showed that the non-tourniquet patients had a lower NPRS compared to the tourniquet group and this difference was statistically significant (p=0.02). During the postoperative hospital stay, there was no significant difference among the two treatment groups for VAS, OKS, SF-12, and range of motion (flexion/extension).

At the six weeks follow-up, both groups had similar outcomes for the range of movements and pain scores. Besides, no difference was noted among the tourniquet and non-tourniquet groups even after a follow-up of six months. Regarding complications, 27 patients in the tourniquet group did complain of numbness during the study period compared to 10 in the non-tourniquet group (p=0.001).

Conclusion

In conclusion, a tourniquet application helps minimize intraoperative blood loss and results in a faster procedure. Furthermore, the application of the tourniquet is safe and effective and does not affect the functional outcomes and pain scale in total knee arthroplasty.

Impact of tourniquet during knee arthroplasty: a bayesian network meta-analysis of peri-operative outcomes

INTRODUCTION

The role of tourniquet during knee arthroplasty is controversial. The present study compares various tourniquet protocols using a Bayesian network meta-analysis of peri-operative data.

MATERIAL AND METHODS

The present study was conducted in accordance with the PRISMA extension statement for reporting systematic reviews incorporating network meta-analyses of health interventions. The literature search was conducted in September 2020. All clinical trials investigating the role of tourniquet in knee arthroplasty were considered for inclusion. Methodological quality was assessed using Review Manager 5.3. A Bayesian hierarchical random-effects model analysis was used in all comparisons.

RESULTS

Ultimately, pooled data from 68 studies (7413 procedures) were analysed. Significant inconsistency was found in the data relating to total estimated blood lost; no assumption could be made on this outcome. Full-time tourniquet resulted in the shortest surgical duration and lowest intra-operative blood lost, in both cases followed by incision-to-suture. The incision-to-suture protocol achieved the smallest drop in haemoglobin during the first 72 h post-operatively and the lowest rate of blood transfusion, both followed by full-time tourniquet. Hospitalisation was shortest in the absence (no-tourniquet) group, followed by the cementation-to-end group.

CONCLUSION

For knee arthroplasty, longer tourniquet use is associated with the shorter duration of surgery, lower intra-operative blood lost, lower drops in haemoglobin and fewer transfusion units. The shortest average hospitalisation was associated with no tourniquet use.

Effects of continuing use of aspirin on blood loss in patients who underwent unilateral total knee arthroplasty

PURPOSE

Concerning the ongoing debate on the effects of continuing aspirin therapy on blood loss in knee arthroplasty, we conducted a retrospective investigation to test the hypothesis that continuation of aspirin prior total knee arthroplasty (TKA) will not cause more blood loss.

METHODS

From a database of patients who underwent unilateral TKA between 2011 and 2016, we identified two groups: the aspirin group (patients continued aspirin during perioperative period) and the nonaspirin group (patients had no current or recent history of aspirin usage). We extracted and compared patient demographic information, comorbidity index, baseline serum hemoglobin (Hb), and creatinine level between the two groups. We also compared our primary outcomes, including the total blood loss, transfusion requirement, and length of hospitalization between the two groups. A multivariate logistic regression for analyzing the risk factors of requiring transfusion was performed.

RESULTS

We found that apart from preoperative serum creatinine level, there was no difference in the baseline Hb level, perioperative change in Hb, total blood loss, or length of hospitalization between the two groups. The percentage of transfusion utilization was also comparable between the two groups. Our regression analysis shows that the risk of requiring transfusion after TKA is not significantly associated with patients taking aspirin therapy before operation.

CONCLUSION

Patients who underwent TKA with continuation of low-dose aspirin did not result in more blood loss. Current blood loss management has provided sufficient reduction of blood loss to accommodate aspirin therapy perioperatively. We suggest that it is safe to continue aspirin prior to TKA.

Potential Risk Factors Contributing to Development of Venous Thromboembolism for Total Knee Replacements Patients Prophylaxed With Rivaroxaban: A Retrospective Case-Control Study

Rivaroxaban after total knee arthroplasty (TKA) is used to prevent postoperative venous thromboembolism (VTE); however, despite thromboprophylaxis, some patients still develop postoperative VTE. To determine whether tourniquet time, time to initiate rivaroxaban (TTI_RIV), or Body Mass Index (BMI) was associated with postoperative VTE. A retrospective case-control study was conducted. Those patients that developed VTE despite prophylaxis (cases) were compared to controls (no VTE). A univariate analysis was conducted (p < 0.05 statistically significant). Seven VTE cases were identified from 234 TKA-patients. Patients with and without VTE had BMI of 40.1 ± 9.1 and 32.8 ± 7.5, respectively (p = 0.064). TTI_RIV in VTE and control group was 28.2 ± 4.7 hours and 26.4 ± 4.2 hours, respectively (p = 0.39). Mean tourniquet time in VTE and control group was 65.0 ± 8.7 minutes and 49 ± 8.8 minutes, respectively (p = 0.0007). Statistically significant differences in tourniquet times were noted between VTE and non-VTE group but not for TTI_RIV and BMI. Prolonged tourniquet use could pose a potential risk factor for postoperative VTE. Thromboprophylaxis management may need to be adjusted, based on patient-specific factors that could include increasing doses of oral anticoagulants and/or mechanical prophylaxis. However, further large-scale studies are required to establish pathophysiology.

Tourniquet use in routine primary total knee arthroplasty is associated with a higher transfusion rate and longer postoperative length of stay: a real-world study

BACKGROUND

In an enhanced recovery after surgery program, a growing number of orthopedists are reconsidering the necessity of tourniquet use in total knee arthroplasty (TKA). However, the impact of tourniquet use on transfusion rate and postoperative length of stay (PLOS) in TKA remains controversial. Therefore, we carried out a study to investigate the effect of tourniquet application in routine primary TKA on transfusion rate and PLOS.

METHODS

We analyzed data from 6325 patients who underwent primary unilateral TKA and divided them into two groups according to whether a tourniquet was applied during the procedure, and a tourniquet was used in 4902 and not used in 1423. The information for transfusion and PLOS was extracted from patients' electronic health records, and the data were analyzed with logistic and linear regression analyses.

RESULTS

Following TKA, the transfusion rate and PLOS were 14.52% and 7.72 ± 3.54 days, respectively, in the tourniquet group, and 6.47% and 6.44 ± 3.48 days, respectively, in the no-tourniquet group. After adjusting for the different related variables, tourniquet use was significantly correlated with a higher transfusion rate (risk ratio = 1.888, 95% confidence interval (CI) 1.449-2.461, P < 0.001) and a longer PLOS (partial regression coefficient (B) = 0.923, 95%CI 0.690-1.156, P < 0.001).

CONCLUSIONS

Our findings suggested that tourniquet use in routine primary TKA was related to a higher transfusion rate and a longer PLOS. The impact of tourniquet use on transfusion rate and PLOS should be taken into account in clinical practice.

Comparison of local pain and tissue reaction between conventional pneumatic tourniquet and disposable silicone ring tourniquet during Total Knee Arthroplasty

BACKGROUND

To study the comparison of conventional pneumatic and disposable silicone ring tourniquet in Total Knee Arthroplasty.

MATERIAL AND METHODS

This is a prospective randomized control trial. We used conventional pneumatic tourniquet on one side of leg and disposable silicone ring tourniquet on the other side in consecutive 50 simultaneous bilateral TKR patients. Patients having peripheral vascular disease of the lower limb were excluded from the study. The patient demographics & characteristics are identical being the same patient with two different legs. We started the study with null hypothesis. An independent observer assessed the local tourniquet site pain (VAS score 1-10) and local tourniquet site skin reaction at 24 h and 48 h after the TKA. P value < 0.05 was considered significant.

RESULTS

There were no local skin complication with disposable tourniquet (0%). 8 out of 50 patients in whom the conventional tourniquet was applied showed local bruising, and two patients had blister formation making the local skin site complication rate 20% (statistically significant, p value0.0196, chi-squared test). The VAS score at 24 h was 4.3 ± 1.5 for disposable tourniquet group as against 5.6 ± 2.1 for conventional tourniquet group (statistically significant, p value = 0.0152, t statistic test for comparison of means). The VAS score at 48 h was 2.1 ± 1.5 and 3.3 ± 1.2 for disposable tourniquet group and conventional tourniquet group respectively (statistically significant p value = 0.003, student's t-test).

CONCLUSION

Use of disposable tourniquet has better outcome than the conventional tourniquet with minimal or no local complications. The advantages of the disposable tourniquet are: 1 less local pain, 2. no local skin problems, 3. accurate tourniquet pressure at the application site, 4.0% local contamination. Hence, we recommend use of the disposable tourniquet during the Total Knee Arthroplasty.

Finding the optimal control level of intraoperative blood pressure in no tourniquet primary total knee arthroplasty combine with tranexamic acid: a retrospective cohort study which supports the enhanced recovery strategy

Background

With the use of tranexamic acid and control of the blood pressure during the operation, total knee arthroplasty (TKA) without tourniquet can be achieved. There is no exact standard for the control level of blood pressure during no tourniquet TKA. We explored the optimal level of blood pressure control during no tourniquet TKA surgery with the use of tranexamic acid in this study.

Methods

Patients underwent TKA were divided into three groups: the mean intraoperative systolic blood pressure in group A was < 90 mmHg, 90–100 mmHg in group B, > 100 mmHg in group C. Total blood loss (TBL), intraoperative blood loss, hidden blood loss, transfusion rate, maximum hemoglobin drop, operation time, and postoperative hospitalization days were recorded.

Results

Two hundred seventy-eight patients were enrolled, 82 in group A, 105 in group B, and 91 in group C. Group A (663.3 ± 46.0 ml) and group B (679.9 ± 57.1 ml) had significantly lower TBL than group C (751.7 ± 56.2 ml). Group A (120.2 ± 18.7 ml) had the lowest intraoperative blood loss than groups B and C. Group C (26.0 ± 4.1 g/l) had the largest Hb change than groups A and B. Group A (62.3 ± 4.7 min) had the shortest operation time. The incidence rate of postoperative hypotension in group A (8, 9.8%) was significantly greater than groups B and C. No significant differences were found in other outcomes.

Conclusion

The systolic blood pressure from 90 to 100 mmHg was the optimal strategy for no tourniquet primary TKA with tranexamic acid.

Use of Tourniquet During Knee Arthroplasty in Patients With Radiographic Arterial Calcifications

BACKGROUND

Use of tourniquet during total knee arthroplasty (TKA) in patients with radiographic arterial calcifications is controversial. Intimal arterial calcifications are feared to be associated with ischemic complications such as delayed wound healing and arterial thrombosis, whereas medial calcifications stiffen the arterial wall, possibly leading to tourniquet failure and increased blood loss.

METHODS

We conducted a prospective cohort study to determine the incidence of tourniquet failure (inflated up to 300 mm Hg), blood transfusions, wound healing, and ischemic complications in thighs with and without arterial calcifications on preoperative radiographs, in 2548 consecutive primary TKAs conducted in our unit over a 5-year period. Eighty-six thighs showed vascular calcifications: 58 medial and 28 intimal.

RESULTS

Thighs with vascular calcifications had higher risk of tourniquet failure as compared to those without calcifications (P < .001), but with no significant increase in incidence of blood transfusions. All cases of tourniquet failure in the calcification group occurred in thighs with medial calcifications, whereas all cases of tourniquet failure in the control group occurred in obese patients. There was no difference in wound healing and ischemic complications in limbs with and without arterial calcifications.

CONCLUSION

The presence of arterial calcifications on preoperative radiographs increases the risk of tourniquet failure at 300 mm Hg in patients undergoing TKA, with no significant increase in rate of blood transfusions, wound healing or ischemic complications.

More pain and slower functional recovery when a tourniquet is used during total knee arthroplasty

PURPOSE

Although a tourniquet can effectively control intraoperative blood loss and offer clear surgical field in total knee arthroplasty (TKA), its optimal usage has been controversial. The aim of this research was to perform a systematic review and meta-analysis to compare and explore the best application of a tourniquet in TKA.

METHODS

MEDLINE, PubMed, EMBASE, the Cochrane Library, Wanfang database, and Web of Science were searched for randomized controlled trials (RCTs) comparing the four different strategies of tourniquet application in TKA. In Group I, a tourniquet was not used and was called the non-tourniquet (NT) group. In Group II, a tourniquet was only used during the cementation of implants and was called the specific duration tourniquet (SDT) group. In Group III, the tourniquet was only released before wound closure to control the bleeding sources and was called the majority duration tourniquet (MDT) group. In Group IV, a tourniquet was used throughout the procedure, from skin incision to wound closure and was called the whole duration tourniquet (WDT) group.

RESULTS

Forty-six RCTs were included in this systematic review and meta-analysis. In a comparison between the NT and WDT groups (25 RCTs), intraoperative blood loss (IBL) (P = 0.0001) and range of motion (ROM) (P = 0.0001) were significantly increased in the NT group, while the visual analog score (VAS) (P = 0.0001), rate of deep vein thrombosis (DVT) (P = 0.01), and all complications (AC) (P = 0.0001) were significantly decreased in the NT group. In a comparison between the SDT and WDT groups (10 RCTs), IBL (P = 0.0001), TBL (P = 0.009), and ROM (P = 0.0001) were significantly increased in the SDT group, while thigh pain (P = 0.04) and the rate of DVT (P = 0.03) were significantly decreased in the SDT group. There were no significant differences between the MDT and WDT groups (12 RCTs) except for the rate of all complications (P = 0.01).

CONCLUSION

Despite the decrease in IBL with a tourniquet, no difference was found in TBL. In conclusion, not using a tourniquet or only using it during the cementation of implants was preferable based on the faster functional recovery, lower rate of DVTs and complications compared with using a tourniquet throughout the TKA procedure.

LEVEL OF EVIDENCE

I.

Tranexamic Acid Is Associated With Reduced Periprosthetic Joint Infection After Primary Total Joint Arthroplasty

BACKGROUND

Previous studies have demonstrated preoperative anemia to be a strong risk factor for periprosthetic joint infection (PJI) in total joint arthroplasty (TJA). Allogeneic blood transfusion can be associated with increased risk of PJI after primary and revision TJA. Tranexamic acid (TXA) is known to reduce blood loss and the need for allogeneic blood transfusion after TJA. The hypothesis of this study is that administration of intravenous TXA would result in a reduction in PJI after TJA.

METHODS

An institutional database was utilized to identify 6340 patients undergoing primary TJA between January 1, 2013 and June 31, 2017 with a minimum of 1-year follow-up. Patients were divided into 2 groups based on whether they received intravenous TXA prior to TJA or not. Patients who developed PJI were identified. All PJI patients met the 2018 International Consensus Meeting definition for PJI. A multivariate regression analysis was performed to identify variables independently associated with PJI.

RESULTS

Of the patients included, 3683 (58.1%) received TXA and 2657 (41.9%) did not. The overall incidence of preoperative anemia was 16%, postoperative blood transfusion 1.8%, and PJI 2.4%. Bivariate analysis showed that patients who received TXA were significantly at lower odds of infection. After adjusting for all confounding variables, multivariate regression analysis showed that TXA is associated with reduced PJI after primary TJA.

CONCLUSION

TXA can help reduce the rate of PJI after primary TJA. This protective effect is likely interlinked to reduction in blood loss, lower need for allogeneic blood transfusion, and issues related to immunomodulation associated with blood transfusion.

Risk factors for periprosthetic joint infection after total knee arthroplasty

INTRODUCTION

Periprosthetic joint infection (PJI) is the most serious and feared complication in total knee arthroplasty (TKA) and can have catastrophic consequences. The number of total knee arthroplasties is increasing, so infections could also be greater in the future. The aim of this study is to identify the most relevant risk factors associated with infection after a total knee arthroplasty.

METHODS

This is a case-control study of patients who underwent total knee arthroplasty at the University Hospital of Salamanca. We included 66 TKA PJI patients and 66 control TKA patients. Demographic and clinical variables were collected. A descriptive and inferential analysis was performed by logistic regression and attributable risk fraction assessed.

RESULTS

Prolonged operative time (> 90') and tourniquet time (> 60') were the most relevant risk factors described (OR 40.77, AFE 0.97, p > 0.001 and OR 37.14, AFE 0.97, p < 0.001, respectively). The use of non-antibiotic-laded cement (OR 3.62), obesity (BMI > 30, OR 8.86), diabetes (OR 2.33), high ASA grade (III-IV, OR 15.30), and blood transfusion requirement (OR 4.60) were also statistically significant risk factors for TKA PJI.

CONCLUSIONS

Our study provides evidence concerning that operative time, tourniquet time, cement type, diabetes, obesity, ASA grade, and blood transfusion requirement as independently associated risk factors for TKA PJI. Modifiable risk factors were specifically relevant, so we should be able to reduce the infection rate.

Reduced length of stay and faster recovery after total knee arthroplasty without the use of tourniquet

INTRODUCTION

Total knee arthroplasty (TKA) is commonly performed using tourniquet despite being associated with several recognised complications that may affect patient's post-operative recovery and early rehabilitation. In this study we investigate whether or not use of a tourniquet during TKA was associated with shorter length of stay, faster recovery and lesser complications.

METHODS

29 patients, who underwent bilateral sequential TKA, had their first TKA under tourniquet and the second TKA 15 (11-32) months later without tourniquet.All operations were performed by the first author using the same technique and instrumentation with the same early rehabilitation protocol. All patients were followed prospectively for a minimum of 8 months.All patients had the following parameters measured which included surgical time, length of stay, post-operative pain using Visual analogue score (VAS), calf circumference, drop in haemoglobin, haematocrit level, oxford knee score (OKS), and range of motion (ROM).

RESULTS

TKA performed without the use of tourniquet had significantly shorter Length of hospital stay (3.6 vs 4.4, P < 0.05), significantly less pain on day 2 (1 vs 2; P < 0.05) and significantly smaller increase in calf circumference on day 2 (1.2 cm vs 2.3 cm; P < 0.05). Postoperative calf circumference increase of less than 2 cm in TKA without tourniquet was associated with shorter length of stay when compared with increase of more than 2 cm in TKA with tourniquet 2.9 days (SD 0.6) versus 3.9 days (SD 0.8) P < 0.05.ROM and OKS were significantly better in TKA without tourniquet at 6 weeks but no difference at 8 months.

CONCLUSIONS

TKA done without tourniquet was associated with shorter length of stay, lesser pain and swelling, in addition to improved range of motion in the early post-operative period.

Does tourniquet use decrease blood loss following primary total knee arthroplasty in Jehovah's Witness patients?

OBJECTIVES

This study aims to investigate the use of multiple blood management strategies and the effect of tourniquet on the estimated blood loss (EBL) in Jehovah's Witness (JW) patients who underwent primary total knee arthroplasty (TKA).

PATIENTS AND METHODS

Twenty-two self-reported JW patients (9 males, 13 females; mean age 66.8±8.6 years; range, 51 to 83 years) who underwent primary TKA between January 2014 and January 2020 in our institution were retrospectively reviewed. A standard blood management protocol that consisted of hypotensive anesthesia, local and systemic administration of tranexamic acid (TXA) and intraoperative cell salvage was applied to all patients. Patients were divided into two groups: with (n=11) and without (n=11) tourniquet use. The EBL was calculated according to Meunier's formula. Hemoglobin (Hgb), hematocrit (Hct), and EBL on the first and third postoperative days were compared statistically.

RESULTS

There was no significant difference between groups regarding postoperative Hgb (p=0.801 and p=0.767), Hct (p=0.617 and p=0.895), Hgb decline (p=0.311 and p=0.822), and EBL (p=0.067 and p=0.284) at first and third postoperative days. None of the patients required blood transfusion. No wound complication or symptomatic deep vein thrombosis was seen during the hospital stay.

CONCLUSION

Combined use of hypotensive anesthesia, intravenous administration of TXA, intraoperative periarticular injection, and cell salvage seem to be sufficient in controlling the blood loss in JW patients during TKA. Additional tourniquet use may not further decrease the EBL.

Tourniquet Use Does Not Affect Functional Outcomes or Pain After Total Knee Arthroplasty: A Prospective, Double-Blinded, Randomized Controlled Trial

BACKGROUND

The use of a tourniquet during total knee arthroplasty (TKA) is controversial. Pain and return to function are believed, by some, to be influenced by the use of a tourniquet. The hypothesis of this study was that use of a tourniquet would delay postoperative functional recovery and increase pain as compared with no tourniquet use.

METHODS

Two hundred patients were recruited for this prospective, double-blinded, randomized controlled trial. Patients were randomized to undergo TKA either with a tourniquet (100 patients) or without one (100 patients) and blinded to group allocation. Primary outcome measures were functional assessment testing using the Timed Up & Go (TUG) test and visual analog scale (VAS) pain scores. Secondary outcome measures included the stair-climb test, blood loss, surgical field visualization, and range of motion. Outcome measures were completed preoperatively, in the hospital, and postoperatively at a first and a second follow-up. The minimal detectable change, Student t test, Fisher exact test, and nonasymptotic chi-square analysis with an alpha of p < 0.05 were used to determine significance.

RESULTS

The no-tourniquet group had more calculated blood loss (1,148.02 mL compared with 966.64 mL; p < 0.001) and more difficulty with surgical field visualization (p < 0.0001). The tourniquet group had greater knee extension at the first follow-up (-7° compared with -9°; p = 0.044).

CONCLUSIONS

Tourniquet use during TKA significantly decreases blood loss and does not adversely affect early postoperative outcomes. Tourniquet use during routine TKA is safe and effective, and concerns about deleterious effects on function and pain may not be justified.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Influence of the Tourniquet on Pain and Function in Total Knee Arthroplasty: a Systematic Review and Meta-Analysis

BACKGROUND

The use of the tourniquet in total knee arthroplasty is still a subject of controversial discussion. Previous studies mainly focus on parameters like blood loss and operation time. The aim of this systematic review is to evaluate the postoperative outcome involving parameters such as pain intensity, analgesic consumption, knee function and complication rate with and without tourniquet use, to find a recommendation for future application in total knee arthroplasty.

MATERIAL AND METHODS

This review is based on the PRISMA Checklists. A systematic research was performed in PubMed using the key words "tourniquet", "total knee arthroplasty", "TKA" and "knee endoprosthesis" up to and including January 2018. The initial search revealed 686 Papers which were extracted by the parameters intensity of pain, analgesic consumption, function (range of motion, Hospital for Special Surgery Score, Knee Society Score) and complications (deep vein thrombosis, surgical side infection, pulmonary embolism). The program Review Manager Version 5.3 was used for statistical analysis. A significance level of p < 0,05 was defined.

RESULTS

18 studies were included in this review with 1279 total knee arthroplasties overall (646 with the use of tourniquet and 633 without). The analysis shows a significant lower pain intensity until the fifth postoperative day (p = 0,03) and also after one to three months (p = 0,04) without using the tourniquet. Range of motion is significantly higher in two to three days postoperatively (p < 0,00 001) when the surgery was performed without tourniquet. Knee Society Score shows no difference between the two groups. A deep vein thrombosis appears significantly more often when using a tourniquet (p = 0,04). There was no higher occurrence in pulmonary embolism and surgical side infections.

CONCLUSION

The use of a pneumatic tourniquet in total knee arthroplasty affects especially the early postoperative pain and functional recovery.

Microbial Colonization of Pneumatic Tourniquets in the Orthopedic Operating Room

Background The rate of surgical site infections following orthopedic procedures is approximately 2% globally. Potential sources of contamination in the operating room include pneumatic tourniquets, blood pressure cuffs, and stethoscopes, among others. Our study aims to investigate microbial colonization on reusable pneumatic tourniquets stored and used in the orthopedic department of our institution and evaluate the efficacy of the cleaning protocols employed. Methods Over a course of two weeks, 26 samples were obtained. A total of 14 pneumatic tourniquets were sampled preoperatively on Monday morning following the weekly cleaning protocol of soaking the tourniquets in sodium hypochlorite for 30 minutes while 12 tourniquets were cultured immediately following the postoperative cleaning protocol of wiping the tourniquet clean with a cloth soaked in sodium hypochlorite. Samples were cultured on MacConkey and sheep blood agar and incubated at 37-degrees centigrade for a total of 48 hours. Organisms were identified and colony count was documented. The analysis was performed using the Fisher Exact test on SPSS v23 (IBM Corp., Armonk, NY, US). Results All 14 samples obtained after being soaked in sodium hypochlorite for 30 minutes cultured negative. However, four out of 12 (33%) samples obtained after simply wiping the pneumatic tourniquet with a cloth soaked in sodium hypochlorite cultured coagulase-negative Staphylococci. The difference between the two was significant (p=0.002). Conclusion Postoperative tourniquets, wiped with a cloth soaked in sodium hypochlorite and ready to be used on the next patient, were found to be contaminated with coagulase-negative Staphylococcus. This species is notorious for causing surgical site infections following implant-related surgeries potentially through direct inoculation and cross-infections intraoperatively and in storage. Efforts to identify the relationship with postoperative surgical site infections need to be made to suggest more aggressive cleaning protocols.

Comparison of lower limb lifting and squeeze exsanguination before tourniquet inflation during total knee arthroplasty

Background

During total knee arthroplasty(TKA), tourniquet is widely used by most surgeons whereas the optimal application is still controversial. With this prospective randomized controlled study, we intend to investigate the effect of lower limb lifting and squeeze exsanguination methods on clinical outcomes in a series of TKAs.

Methods

Prospectively enrolled a total of 236 TKA patients from March, 2012 to November, 2016. Of which 118 patients randomly constitute Group A with lower limb lifting exsanguination technique; and the other 118 patients comprise Group B with squeeze exsanguination method. A year’s follow-up measurements were recorded in detail for analysis.

Results

The pre-tourniquet time of Group A was significantly shorter than that in Group B (P < 0.001). Significant difference was found on skin tension blister, 3 happened in Group A and 11 happened in Group B (P = 0.031), which resulted in a difference in total complications (P = 0.039). The VAS score was significantly lower in Group A at one and seven days postoperatively, P < 0.001 and P = 0.011, respectively. No significant differences were found regarding all other clinical outcome measurements.

Conclusion

The lower limb lifting exsanguination is a safe and effective technique. Compared with squeeze exsanguination method, it could decrease the incidence of skin tension blister and alleviate early postoperative pain reaction, no additional risks occurred regarding other clinical outcomes. Thus, it might have the potentiality to be commonly utilized in TKA procedure.

Trial registration

ClinicalTrials.gov Identifier: ChiCTR1800020471. Registered on 31 December 2018 Retrospectively registered.

Tourniquetless Total Knee Arthroplasty With Modern Perioperative Protocols Decreases Pain and Opioid Consumption in Women

BACKGROUND

This study examined whether a modern total knee arthroplasty (TKA) protocol without a tourniquet results in less patient-reported pain and in-hospital opioid consumption compared to TKA with a tourniquet.

METHODS

A retrospective study of 203 primary unilateral cemented TKAs consecutively performed with or without tourniquet was performed. Identical perioperative pain and blood loss protocols were used in all cases. In tourniquetless TKAs, the tourniquet was not inflated at any time, and sterile CO₂ gas compression maximized cement interdigitation.

RESULTS

After exclusions for scientific confounds, 184 TKAs (93 with tourniquet; 91 tourniquetless) were analyzed. Controlling for multiple covariates, females with a tourniquet reported significantly more pain (P = .002) and opioid consumption (P < .001) the first 24 hours after surgery compared to females without a tourniquet. There were no differences in pain (P = .192) or amount of opioids consumed (P = .203) among males with and without a tourniquet. Tourniquet use resulted in a significant reduction in blood loss for both females (P ≤ .040) and males (P ≤ .020), although the total blood savings of approximately 200 mL is of unknown clinical significance.

CONCLUSION

Avoiding tourniquet use during TKA for females may be a relatively risk-free adjunct to minimize opioid consumption during hospitalization. Further study is warranted to elucidate the factors accounting for different outcomes in females and males.