Efficacy and safety of low-molecular-weight heparin after knee arthroscopy: A meta-analysis

The efficacy and safety of low-molecular-weight heparin in patients undergoing knee arthroscopic surgery and anterior cruciate ligament reconstruction

Purpose

To inveatigate how effective LMWH was at preventing venous thromboembolism (VTE), major bleeding events, and minor bleeding events after simple knee arthroscopic surgery and anterior cruciate ligament reconstruction (ACLR).

Methods

We conducted a comprehensive search of PubMed, EMBASE, Cochrane Library, and the CNKI database for potentially eligible articles. The outcomes were evaluated in terms of odds ratio (OR) and the associated 95% confidence intervals (CIs). Meta-analysis was performed using the Stata software and subgroup analyses were performed based on the surgical setting including ACLR and simple knee arthroscopic surgery.

Results

A total of eight studies with 2249 patients and 1794 controls were included in this meta-analysis. In patients undergoing simple knee arthroscopic surgery, LMWH prophylaxis did not bring a significant reduction in the risk of symptomatic deep venous thrombosis (DVT), symptomatic pulmonary embolism (PE), symptomatic VTE, and did not increase the risk of major bleeding events, but did have a higher risk of minor bleeding events (OR = 1.95, 95% CI 1.34-2.84, P = 0.000) and a lower risk of asymptomatic DVT (OR = 0.14, 95% CI 0.04-0.53, P = 0.004) in comparison with non-LMWH prophylaxis. In patients undergoing ACLR, LMWH prophylaxis did not bring a significant reduction in the risk of symptomatic DVT, symptomatic PE, symptomatic VTE, and did not increase the risk of major bleeding events and minor bleeding events, but did have a lower risk of asymptomatic DVT (OR = 0.43, 95% CI 0.23-0.78, P = 0.006).

Conclusion

When compared to a control group, this meta-analysis found that LMWH had little potential benefit in preventing major VTE (symptomatic VTE, symptomatic DVT, and symptomatic PE) after simple knee arthroscopy and ACLR. As a result, LMWH should not be considered routinely in patients undergoing knee arthroscopic surgery.

Interventions for preventing venous thromboembolism in adults undergoing knee arthroscopy

BACKGROUND

Knee arthroscopy (KA) is a routine orthopedic procedure recommended to repair cruciate ligaments and meniscus injuries and, in suitable cases, to assist the diagnosis of persistent knee pain. There is a small risk of thromboembolic events associated with KA. This systematic review aims to assess if pharmacological or non-pharmacological interventions may reduce this risk. This is an update of an earlier Cochrane Review.

OBJECTIVES

To evaluate the efficacy and safety of interventions - whether mechanical, pharmacological, or a combination of both - for thromboprophylaxis in adults undergoing KA.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 1 June 2021.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and controlled clinical trials (CCTs), blinded or unblinded, of all types of interventions used to prevent deep vein thrombosis (DVT) in men and women aged 18 years and older undergoing KA.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were pulmonary embolism (PE), symptomatic DVT, asymptomatic DVT, and all-cause mortality. Our secondary outcomes were adverse effects, major bleeding, and minor bleeding. We used GRADE criteria to assess the certainty of the evidence.

MAIN RESULTS

We did not identify any new studies for this update. This review includes eight studies involving 3818 adults with no history of thromboembolic disease. Five studies compared daily subcutaneous low-molecular-weight heparin (LMWH) versus no prophylaxis; one study compared oral rivaroxaban 10 mg versus placebo; one study compared daily subcutaneous LMWH versus graduated compression stockings; and one study compared aspirin versus no prophylaxis. The incidence of PE in all studies combined was low, with seven cases in 3818 participants. There were no deaths in any of the intervention or control groups. Low-molecular-weight heparin versus no prophylaxis When compared with no prophylaxis, LMWH probably results in little to no difference in the incidence of PE in people undergoing KA (risk ratio [RR] 1.81, 95% confidence interval [CI] 0.49 to 6.65; 3 studies, 1820 participants; moderate-certainty evidence). LMWH may make little or no difference to the incidence of symptomatic DVT (RR 0.61, 95% CI 0.18 to 2.03; 4 studies, 1848 participants; low-certainty evidence). It is uncertain whether LMWH reduces the risk of asymptomatic DVT (RR 0.14, 95% CI 0.03 to 0.61; 2 studies, 369 participants; very low-certainty evidence). LMWH probably makes little or no difference to the risk of all adverse effects combined (RR 1.85, 95% CI 0.95 to 3.59; 5 studies, 1978 participants; moderate-certainty evidence), major bleeding (RR 0.98, 95% CI 0.06 to 15.72; 1451 participants; moderate-certainty evidence), or minor bleeding (RR 1.79, 95% CI 0.84 to 3.84; 5 studies, 1978 participants; moderate-certainty evidence). Rivaroxaban versus placebo One study with 234 participants compared oral rivaroxaban 10 mg versus placebo. There were no cases of PE reported. Rivaroxaban probably led to little or no difference in symptomatic DVT (RR 0.16, 95% CI 0.02 to 1.29; moderate-certainty evidence). It is uncertain whether rivaroxaban reduces the risk of asymptomatic DVT because the certainty of the evidence is very low (RR 0.95, 95% CI 0.06 to 15.01). The study only reported bleeding adverse effects. No major bleeds occurred in either group, and rivaroxaban probably made little or no difference to minor bleeding (RR 0.63, 95% CI 0.18 to 2.19; moderate-certainty evidence). Aspirin versus no prophylaxis One study compared aspirin with no prophylaxis. There were no PE, DVT or asymptomatic events detected in either group. The study authors reported adverse effects including pain and swelling, but without clarifying which groups these occurred in. There were no bleeds reported. Low-molecular-weight heparin versus compression stockings One study with 1317 participants compared LMWH versus compression stockings. LMWH may lead to little or no difference in the risk of PE compared to compression stockings (RR 1.00, 95% CI 0.14 to 7.05; low-certainty evidence), but it may reduce the risk of symptomatic DVT (RR 0.17, 95% CI 0.04 to 0.75; low-certainty evidence). It is uncertain whether LMWH has any effect on asymptomatic DVT (RR 0.47, 95% CI 0.21 to 1.09; very low-certainty evidence). The results suggest LMWH probably leads to little or no difference in major bleeding (RR 3.01, 95% CI 0.61 to 14.88; moderate-certainty evidence), or minor bleeding (RR 1.16, 95% CI 0.64 to 2.08; moderate-certainty evidence). We downgraded the certainty of the evidence for imprecision due to overall small event numbers, for risk of bias due to concerns about lack of blinding, and for indirectness due to uncertainty about the direct clinical relevance of asymptomatic DVT detection.

AUTHORS' CONCLUSIONS

There is a small risk that healthy adults undergoing KA will develop venous thromboembolism (PE or DVT). We found moderate- to low-certainty evidence of little or no benefit from LMWH, or rivaroxaban in reducing this small risk of PE or symptomatic DVT. The studies provided very low-certainty evidence that LMWH may reduce the risk of asymptomatic DVT compared to no prophylaxis, but it is uncertain how this directly relates to incidence of DVT or PE in healthy people undergoing KA. There is probably little or no difference in adverse effects (including major and minor bleeding), but data relating to these outcomes were limited by low numbers of events in the studies reporting these outcomes.

Thromboprophylaxis after knee arthroscopy does not decrease the risk of deep vein thrombosis: a network meta-analysis

PURPOSE

The primary aim of this network meta-analysis (NMA) is to compare the incidence of venous thromboembolisms (VTE) and bleeding risk following the use of pharmacological and non-pharmacological thromboprophylaxis for arthroscopic knee surgery (AKS). This study assumed the null hypothesis which was that there will be no difference in the incidence of VTE and bleeding risk when comparing no treatment, pharmacological treatment, and non-pharmacological treatment for preventing VTE events following AKS.

METHODS

A systematic electronic search of CENTRAL, Medline, Embase, and ClinicalTrials.gov was carried out. All English language prospective randomized clinical trials published from date of database inception to November 21, 2021 were eligible for inclusion. All papers addressing arthroscopic knee surgery were eligible for inclusion regardless of timing of surgery, operation, surgical technique, or rehabilitation. Multiple random effects NMAs were conducted to compare all treatments for each outcome. The primary outcome was the incidence of pulmonary embolism (PE) and secondary outcomes consisted of overall deep vein thrombosis (DVT), symptomatic DVT, asymptomatic DVT, and all-cause mortality. Adverse outcomes consisted of major and minor bleeding, as well as adverse events.

RESULTS

A total of nine studies with 4526 patients were included for analysis. There were 1054 patients in the no treatment/placebo group (NT/Placebo), 1646 patients in the graduated compression stockings, 810 patients in the extended-duration (> 10 days) low molecular weight heparin (Ext-LMWH) group, 650 patients in the short-duration (< 10 days) LMWH group (Short-LMWH), and 356 patients in the rivaroxaban group. GCS, Ext-LMWH, Short-LMWH and rivaroxaban all demonstrated low risks of PE, symptomatic DVT, asymptomatic DVT, combined DVT and all-cause mortality. Similarly, all interventions demonstrated a low risk of major bleeding.

CONCLUSION

There is no significant difference in the risk reduction of PEs, symptomatic DVTs, major/minor bleeding, and/or all-cause mortality when using LWMH (including short or extended regimens), rivaroxaban, graduated compression stockings or no treatment following arthroscopic knee surgery. Future primary research on the efficacy of thromboprophylaxis following arthroscopic knee surgery should stratify outcomes based on key patient (i.e., age, sex, comorbidities) and surgical (i.e., major vs. minor surgery) characteristics and should include acetylsalicylic acid as an intervention.

LEVEL OF EVIDENCE

I, network meta-analysis of Level I studies.

Vascular Complications in Sports Surgery: Diagnosis and Management

Orthopedic sports surgery of the knee and shoulder is generally considered to be safe and effective. Vascular complications can occur during or after arthroscopy of either joint. A thorough understanding of anatomy, particularly when placing portals in non-routine locations, is extremely important. Prompt recognition of any vascular complication is of significant importance. This review will discuss the potential vascular complications for both knee and shoulder sports surgery, review the relevant anatomy, and discuss the treatment and expected outcome of each.

Prophylaxis for preventing venous thromboembolism in knee arthroscopy and soft tissue reconstruction: consensus statements from an international panel of experts

PURPOSE

There is a lack of consensus regarding need for Venous Thrombo Embolism (VTE) prophylaxis following arthroscopic knee surgery and open soft tissue knee reconstruction. Clear cut guidelines like ones for trauma surgery and arthroplasty do not exist and the published literature is limited to case reports with a few society guidelines. Given this lack of consensus, we conducted a modified Delphi questionnaire of international experts to provide recommendations on this topic.

METHODS

The consensus statements were generated using an anonymised 3 round modified Delphi questionnaire, sent to an international panel of 38 knee surgeons, with an 80% agreement being set as the limit for consensus. The responses were analysed using descriptive statistics with measures like mode, median and box plots. Feedback was provided to all panelists based on responses from the previous rounds to help generate the consensus.

RESULTS

Six consensus statements were generated after the three rounds of Delphi. Patient factors, prolonged surgery duration and family history of thrombogenic events emerged as the main points to be taken into consideration for prophylaxis.

CONCLUSION

It was established through this study, that there exists a select group of patients undergoing arthroscopic surgery that justify the usage of VTE prophylaxis. The expert responses to most of the questions in different scenarios favoured usage of VTE prophylaxis based on patient factors like advanced age, past history of VTE, smoking, oral contraceptive use etc. LEVEL OF EVIDENCE: Level V.

Not Using a Tourniquet May Reduce the Incidence of Asymptomatic Deep Venous Thrombosis After ACL Reconstruction: An Observational Study

Background

Deep venous thrombosis (DVT) and pulmonary embolism are serious potential complications after anterior cruciate ligament reconstruction (ACLR). Little is known about the influence of tourniquet use on the incidence of DVT after ACLR.

Purpose

To compare the incidence of DVT after ACLR with and without the use of a tourniquet.

Study Design

Cohort study; Level of evidence, 3.

Methods

Between November 2018 and May 2020, a total of 60 consecutive ACLRs in 60 patients, including 7 revision surgeries, were performed without tourniquet use at our hospital and were enrolled in this study (T- group). In addition, 55 consecutive ACLRs in 55 patients, including 10 revision surgeries, were performed with tourniquet use between April 2017 and September 2018 and were enrolled as the control group (T+ group). DVT was diagnosed using ultrasonography of both legs performed preoperatively and at postoperative week 1. The incidence of postoperative DVT was compared between the T- and T+ groups. Logistic regression analysis was performed to evaluate the effect of older age (≥40 vs <40 years) and tourniquet use on the occurrence of DVT.

Results

No DVTs were detected preoperatively. The incidence of postoperative DVT was significantly lower in the T- group compared with the T+ group (1 patient [1.7%] vs 9 patients [16.4%]; P = .005). All patients with DVT were asymptomatic. Although the mean operative time was not significantly different (80.8 minutes in the T+ group vs 78.5 minutes in the T- group; P = .461), the mean blood loss from the drain was significantly lower in the T- group than in the T+ group (149.9 vs 201.9 mL; P < .001). Age ≥40 years and tourniquet use were significantly related to the occurrence of DVT (odds ratio, 8.3 [95% CI, 1.9-36.8]; P = .005; and odds ratio, 8.8 [95% CI, 1.0-75.3]; P = .047, respectively).

Conclusion

ACLRs performed without tourniquet resulted in a significantly lower incidence of DVT after ACLR and significantly less bleeding from drains. If adequate visibility of the surgical field is obtained, ACLR without tourniquet use may reduce the incidence of DVT.

Bilateral pulmonary embolism without deep venous thrombosis was observed after knee arthroscopy: a case report

Background

Symptomatic pulmonary embolism (PE) after knee arthroscopy is extremely rare. If the embolism is not treated promptly, the patient may die. Bilateral pulmonary embolism with associated pulmonary infarct without concomitant deep vein thrombosis has never been reported following routine knee arthroscopy.

Case presentation

A 50-year-old female patient with no other risk factors other than hypertension, obesity, varicose veins in the ipsilateral lower extremities and elevated triglyceride (TG) presented to our ward. She had experienced sudden chest tightness, polypnea and fainting after going to the bathroom the morning of the second postoperative day and received emergency medical attention. Colour ultrasonography of the extremities showed no deep vein thrombosis. Lung computed tomography angiography (CTA) showed multiple embolisms scattered in both pulmonary artery branches. Thus, emergency interventional thrombolysis therapy was performed, followed by postoperative symptomatic treatment with drugs with thrombolytic, anticoagulant and protective activities. One week later, lung CTA showed a significant improvement in the PEs compared with those in the previous examination. Since the aetiology of PE and no obvious symptoms were discerned, the patient was discharged.

Conclusion

Although knee arthroscopy is a minimally invasive and quick procedure, the risk factors for PE in the perioperative period should be considered and fully evaluated to enhance PE detection. Moreover, a timely diagnosis and effective treatment are important measures to prevent and cure PE after knee arthroscopy. Finally, clear guidelines regarding VTE thromboprophylaxis following knee arthroscopy in patients with a low risk of VTE development are needed.

A rare case of pulmonary embolus after arthroscopic meniscus surgery

Although there is consensus that thromboprophylaxis is necessary for major orthopedic surgeries such a joint replacement, there is no widespread consensus on the need for thromboprophylaxis for minor arthroscopic surgery. Here, we present a case of deep vein thrombosis (DVT) and pulmonary embolism (PE) after a common arthroscopic meniscectomy in a healthy 20-year-old female collegiate athlete. The patient had no risk factors except for prior use of combined oral contraceptive pills (COCPs). Twenty hours after an uncomplicated right knee meniscectomy, patient presented to ED with right calf pain and cramping, and DVT was confirmed using ultrasound. One week later, patient presented again to ED with dyspnea and chest pain. PE was diagnosed on CT angiography. Despite the rarity of thromboembolic complications in minor arthroscopy surgery, the broadened use of thromboprophylaxis in patients with even few risk factors could prevent thromboembolic complications from occurring.

Interventions for preventing venous thromboembolism in adults undergoing knee arthroscopy

BACKGROUND

Knee arthroscopy (KA) is a routine orthopedic procedure recommended to repair cruciate ligaments and meniscus injuries and in eligible patients, to assist the diagnosis of persistent knee pain. KA is associated with a small risk of thromboembolic events. This systematic review aims to assess if pharmacological or non-pharmacological interventions may reduce this risk. This review is the second update of the review first published in 2007.

OBJECTIVES

To assess the efficacy and safety of interventions, whether mechanical, pharmacological, or in combination, for thromboprophylaxis in adult patients undergoing KA.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, the CENTRAL, MEDLINE, Embase and CINAHL databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registries, on 14 August 2019.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and controlled clinical trials (CCTs), whether blinded or not, of all types of interventions used to prevent deep vein thrombosis (DVT) in males and females aged 18 years and older undergoing KA. There were no restrictions on language or publication status.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion, assessed trial quality with the Cochrane 'Risk of bias' tool, and extracted data. A third author addressed discrepancies. We contacted study authors for additional information when required. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

This update adds four new studies, bringing the total of included studies to eight and involving 3818 adult participants with no history of thromboembolic disease undergoing KA. Studies compared daily subcutaneous (sc) low-molecular-weight heparin (LMWH) versus control (five studies); oral rivaroxaban 10 mg versus placebo (one study); daily sc LMWH versus graduated compression stockings (GCS) (one study); and aspirin versus control (one study). The incidence of pulmonary embolism (PE) in all trials combined was low, with seven cases in 3818 participants.There were no deaths in any of the intervention or control groups. LMWH versus control When compared with control, LMWH probably results in little to no difference in the incidence of PE in patients undergoing KA (risk ratio (RR) 1.81, 95% confidence interval (CI) 0.49 to 6.65; 1820 participants; 3 studies; moderate-certainty evidence). LMWH showed no reduction of the incidence of symptomatic DVT (RR 0.61, 95% CI 0.18 to 2.03; 1848 participants; 4 studies; moderate-certainty evidence). LMWH may reduce the risk of asymptomatic DVT but the evidence is very uncertain (RR 0.14, 95% CI 0.03 to 0.61; 369 participants; 2 studies; very low-certainty evidence). There was no evidence of an increased risk of all adverse events combined (RR 1.85, 95% CI 0.95 to 3.59; 1978 participants; 5 studies; moderate-certainty evidence). No evidence of a clear effect on major bleeding (RR 0.98, 95% CI 0.06 to 15.72; 1451 participants; 1 study; moderate-certainty evidence), or minor bleeding was observed (RR 1.79, 95% CI 0.84 to 3.84; 1978 participants; 5 studies; moderate-certainty evidence). Rivaroxaban versus placebo One study with 234 participants compared oral rivaroxaban 10 mg versus placebo. No evidence of a clear impact on the risk of PE (no events in either group), symptomatic DVT (RR 0.16, 95% CI 0.02 to 1.29; moderate-certainty evidence); or asymptomatic DVT (RR 0.95, 95% CI 0.06 to 15.01; very low-certainty evidence) was detected. Only bleeding adverse events were reported. No major bleeds occurred in either group and there was no evidence of differences in minor bleeding between the groups (RR 0.63, 95% CI 0.18 to 2.19; moderate-certainty evidence). Aspirin versus control One study compared aspirin with control. No PE, DVT or asymptomatic events were detected in either group. Adverse events including pain and swelling were reported but it was not clear what groups these were in. No bleeds were reported. LMWH versus GCS One study with 1317 participants compared the use of LMWH versus GCS. There was no clear difference in the risk of PE (RR 1.00, 95% CI 0.14 to 7.05; low-certainty evidence). LMWH use did reduce the risk of DVT compared to people using GCS (RR 0.17, 95% CI 0.04 to 0.75; low-certainty evidence). No clear difference in effects was seen between the groups for asymptomatic DVT (RR 0.47, 95% CI 0.21 to 1.09; very low-certainty evidence); major bleeding (RR 3.01, 95% CI 0.61 to 14.88; moderate-certainty evidence) or minor bleeding (RR 1.16, 95% CI 0.64 to 2.08; moderate-certainty evidence). Levels of thromboembolic events were higher in the GCS group than in any other group. We downgraded the certainty of the evidence for imprecision resulting from overall small event numbers; risk of bias due to concerns about lack of blinding, and indirectness as we were uncertain about the direct clinical relevance of asymptomatic DVT detection.

AUTHORS' CONCLUSIONS

There is a small risk that healthy adult patients undergoing KA will develop venous thromboembolism (PE or DVT). There is moderate- to low-certainty evidence of no benefit from the use of LMWH, aspirin or rivaroxaban in reducing this small risk of PE or symptomatic DVT. There is very low-certainty evidence that LMWH use may reduce the risk of asymptomatic DVT when compared to no treatment but it is uncertain how this directly relates to incidence of DVT or PE in healthy patients. No evidence of differences in adverse events (including major and minor bleeding) was seen, but data relating to this were limited due to low numbers of events in the studies reporting within the comparisons.

Combination of Traditional Chinese Medicine and Low-Molecular-Weight Heparin Prevents Deep Vein Thrombosis After Surgery: A Meta-Analysis

At present, there is no consistent understanding of the effect of traditional Chinese medicine (TCM) prescription in the prevention of the deep vein thrombosis (DVT), though TCM has been widely used in China. To evaluate the efficacy of TCM prescription combined with low-molecular-weight heparin (LMWH) for preventing DVT after major orthopedics surgery. All the retrieved articles were evaluated using specific inclusion and exclusion criteria. Then, data were extracted and evaluated for inclusion in a randomized controlled trial. In this study, variables included relative risk (RR), mean difference (MD), and their corresponding 95% confidence intervals (95% CIs). Overall, 16 articles were included with 1538 patients, 768 in the combination group (combination of TCM prescription and LMWH) and 770 in the LMWH group. The results indicated that in the combination group, the incidence of DVT (RR: 0.34, 95% CI: 0.23-0.50, P < .00001) and d-dimer levels (standardized mean difference: -1.19, 95% CI: -1.80 to -0.58, P = .0001) was significantly lower than that in the LMWH group. Furthermore, the combination treatment obviously decreased the concentration of fibrinogen (MD: -1.19, 95% CI: -2.13 to -0.25, P = .01). The combination of TCM prescription and LMWH could significantly reduce the incidence of DVT, suggesting that it may be a more effective prophylaxis measure for DVT after major orthopedics surgery.

Symptomatic Deep Vein Thrombosis Following Elective Knee Arthroscopy Over the Age of 40

Thromboprophylaxis following arthroscopic knee surgery (AKS) is not clear in the literature. The purpose of this study was to present the incidence of symptomatic deep vein thrombosis (DVT) following elective AKS over the age of 40. The secondary purpose was to investigate risk factors associated with venous thromboembolic events (VTEs). Surgical database and outpatient clinic follow-up charts of the patients who underwent AKS for any reason were included in the study. Odds for risk factors such as previous medical history of thrombosis, any family history for clotting disorders, diabetes mellitus (DM), oral contraceptive usage, body mass index, history of malignancy, and smoking were evaluated. The incidence of DVT following AKS significantly increased in the patients older than 40 years who had a previous medical history of VTE, DM, and smoking. A variety of guidelines exist for VTE prophylaxis; however, one should focus on risk factors related to the patient's medical history and current medical conditions. In this study, smoking, DM, and previous history of DVT increased DVT risk significantly, and thromboprophylaxis should be kept in mind for these patients.