191 – Is routine VTE prophylaxis required for patients with fragility fracture of the pelvis or lower extremity?

Taylor D’Amore, Guillermo Araujo, Ivan Salce, Nigel Rossiter.

Response/Recommendation: Chemoprophylaxis against venous thromboembolism (VTE) is recommended for patients with a fragility fracture of the pelvis or lower extremity as long as the risk of VTE outweighs the risk of bleeding given other medical comorbidities. The use of intermittent pneumatic compression (IPC) devices should be considered for those who cannot receive chemoprophylaxis.

Strength of Recommendation: Low.

Rationale: Fragility fractures are those fractures that result from low-level trauma, such as a fall from standing height, where mechanical forces would not ordinarily cause a fracture1.  Patients frequently present with pain and limited mobility but may not be able to recall the inciting event2.  The treatment spectrum varies from open reduction internal fixation to percutaneous fixation to non-operative treatment2.

Only one retrospective study was found with a dedicated focus on VTE in low-energy isolated fractures.  In this retrospective review of 1,701 patients by Prensky et al., 71.8% (1,222) of the patients sustained lower extremity fractures.  Up to 85.6% of patients with a lower extremity fracture received chemoprophylaxis in the form of low-molecular-weight heparin (LMWH), heparin, or vitamin K antagonists.  The number receiving chemoprophylaxis rose to 94% when looking at only patients who sustained a hip or pelvis fracture.  There were 19 clinically symptomatic VTE in patients with lower extremity fractures within 90 days of discharge.  Seventeen of the 19 VTE occurred in patients with hip or pelvis fractures for an overall VTE rate of 2.6% in patients with hip and pelvis fractures and 0.7% for all other fractures.  Female sex and high body mass index (BMI) were found to be statistically significant predictors of VTE3.  It should be noted that 30.5% of the fractures in this study were classified as hip fractures.  Hip fractures are specifically excluded from our recommendation as this question is addressed separately.

There remains a paucity of literature on this topic and the rest of the recommendation is based on studies that did not differentiate between high and low energy trauma.  In a survey of 103 Orthopaedic Trauma Association (OTA) members, there was no consensus for the modality or duration of VTE prophylactic agent following pelvis or acetabular (P&A) fractures regardless of weight-bearing status, need for surgery or type of surgical intervention.  In this survey, LMWH and aspirin (ASA) were the two most frequently prescribed chemoprophylaxis for patients receiving VTE prophylaxis4.  For nonsurgical P&A fractures, 64.7% prescribed LMWH while 19.6% prescribed ASA.  For surgically treated P&A fractures, 75.7% prescribed LMWH, and 7.8% prescribed ASA4.  Contrary to practices of American surgeons, surveys of trauma centers in the United Kingdom found that 45% of P&A trauma units do not routinely prescribe chemoprophylaxis post-operatively and 56% do not prescribe chemoprophylaxis for conservatively managed patients5; 62% do not use chemoprophylaxis following cast immobilization after lower limb injuries6.

In a retrospective review of 901 patients who underwent surgical treatment of a fracture below the hip, thromboprophylaxis decreased the risk of post-operative VTE from 6.8% to 2.3%.  While the exact mechanism of injury for these is not known, over 50% of the patients sustained an injury from a slip or fall6,7.  An industry-funded prospectively randomized controlled trial (RCT) evaluating IPC devices found that when coupled with LMWH, these devices decreased the rate of VTE from 1.7% (LMWH only) to 0.4% (LMWH combined with IPC) in 1,803 patients undergoing a variety of orthopaedic procedures8.

A recent systematic review of 15 studies of individual risk of VTE due to lower limb immobilization after injury describes advancing age as the most consistent individual risk following injury type and BMI.  However, physicians should take into consideration the limited evidence supporting thromboprophylaxis in these cases9.  Also, early fixation, before 48 hours, of pelvic and lower extremity fractures should be noted as an independent predictor of VTE10.  Another systematic review of 5 level I studies for surgical management of tibia fractures suggested no routine prophylaxis due to doubtful clinical benefit11.

With foot and ankle surgery, there is no consensus; some studies do not recommend prophylaxis in outpatient surgery patients without individual risks for VTE or those not requiring immobilization12–16.  Furthermore, others advise using VTE prophylaxis in long cast immobilization, independent of the previous procedure, until weight-bearing or removal17–19.  However, there is a bias in these studies: VTE events following Achilles tendon ruptures are greater than ankle fractures treated surgically or conservatory20.  American College of Chest Physicians (ACCP) guidelines do not support routine prophylaxis, but IPC is recommended in this field21.

Further research is needed in the form of high-quality prospective RCT to determine the need for VTE prophylaxis in patients who sustain a fragility fracture of the lower extremity.  Although there have been some attempts to create VTE risk assessment tools22,23, to this day none have been validated or standardized24.  Until then, risk stratification based on other medical comorbidities should play a role in shared decision-making between the surgeon and the patient in determining the need for VTE prophylaxis in these patients.  Specifically, patients treated surgically should be separately evaluated from those treated non-operatively, and the ability of a patient to frequently mobilize factored into the outcomes25.  It is important to consider that while chemoprophylaxis has been shown to decrease the incidence of VTE, its impact on all-cause mortality and mortality from PE is up for debate26–28.  Studies designed to answer this question should delineate symptomatic from asymptomatic VTE events.  Additionally, broad use of VTE prophylaxis is not without risks with at least one study demonstrating that the risk of death from major bleeding on LMWH was greater than the mortality from PE avoided by its use29.

References:

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2.         Rommens PM, Wagner D, Hofmann A. Fragility Fractures of the Pelvis. JBJS Rev. 2017;5(3):e3. doi:10.2106/JBJS.RVW.16.00057

3.         Prensky C, Urruela A, Guss MS, Karia R, Lenzo TJ, Egol KA. Symptomatic venous thrombo-embolism in low-energy isolated fractures in hospitalised patients. Injury. 2013;44(8):1135-1139. doi:10.1016/j.injury.2013.04.018

4.         Lim PK, Ahn J, Scolaro JA. Venous Thromboembolism Prophylaxis After Pelvic and Acetabular Fractures: A Survey of Orthopaedic Surgeons’ Current Practices. J Am Acad Orthop Surg. 2020;28(18):750-755. doi:10.5435/JAAOS-D-19-00409

5.         Guryel E, Pearce R, Rickman M, Bircher M. Thrombo-prophylaxis in pelvic and acetabular trauma patients: a UK consensus? Int Orthop. 2012;36(1):165-169. doi:10.1007/s00264-011-1276-9

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7.         Park S-J, Kim C-K, Park Y-S, Moon Y-W, Lim S-J, Kim S-M. Incidence and Factors Predicting Venous Thromboembolism After Surgical Treatment of Fractures Below the Hip. J Orthop Trauma. 2015;29(10):e349-354. doi:10.1097/BOT.0000000000000336

8.         Eisele R, Kinzl L, Koelsch T. Rapid-inflation intermittent pneumatic compression for prevention of deep venous thrombosis. J Bone Joint Surg Am. 2007;89(5):1050-1056. doi:10.2106/JBJS.E.00434

9.         Horner D, Pandor A, Goodacre S, Clowes M, Hunt BJ. Individual risk factors predictive of venous thromboembolism in patients with temporary lower limb immobilization due to injury: a systematic review. J Thromb Haemost. 2019;17(2):329-344. doi:10.1111/jth.14367

10.       Forsythe RM, Peitzman AB, DeCato T, et al. Early lower extremity fracture fixation and the risk of early pulmonary embolus: filter before fixation? J Trauma. 2011;70(6):1381-1388. doi:10.1097/TA.0b013e318215b928

11.       Patterson JT, Morshed S. Chemoprophylaxis for Venous Thromboembolism in Operative Treatment of Fractures of the Tibia and Distal Bones: A Systematic Review and Meta-analysis. J Orthop Trauma. 2017;31(9):453-460. doi:10.1097/BOT.0000000000000873

12.       Mangwani J, Sheikh N, Cichero M, Williamson D. What is the evidence for chemical thromboprophylaxis in foot and ankle surgery? Systematic review of the English literature. Foot (Edinb). 2015;25(3):173-178. doi:10.1016/j.foot.2014.07.007

13.       Fleischer AE, Abicht BP, Baker JR, Boffeli TJ, Jupiter DC, Schade VL. American College of Foot and Ankle Surgeons’ clinical consensus statement: risk, prevention, and diagnosis of venous thromboembolism disease in foot and ankle surgery and injuries requiring immobilization. J Foot Ankle Surg. 2015;54(3):497-507. doi:10.1053/j.jfas.2015.02.022

14.       Metz R, Verleisdonk E-JMM, van der Heijden GJMG. Insufficient Evidence for Routine Use of Thromboprophylaxis in Ambulatory Patients with an Isolated Lower Leg Injury Requiring Immobilization: Results of a Meta-Analysis. Eur J Trauma Emerg Surg. 2009;35(2):169-175. doi:10.1007/s00068-008-8015-y

15.       Richey JM, Ritterman Weintraub ML, Schuberth JM. Incidence and Risk Factors of Symptomatic Venous Thromboembolism Following Foot and Ankle Surgery. Foot Ankle Int. 2019;40(1):98-104. doi:10.1177/1071100718794851

16.       Zheng X, Li D-Y, Wangyang Y, et al. Effect of Chemical Thromboprophylaxis on the Rate of Venous Thromboembolism After Treatment of Foot and Ankle Fractures. Foot Ankle Int. 2016;37(11):1218-1224. doi:10.1177/1071100716658953

17.       Saragas NP, Ferrao PNF, Saragas E, Jacobson BF. The impact of risk assessment on the implementation of venous thromboembolism prophylaxis in foot and ankle surgery. Foot Ankle Surg. 2014;20(2):85-89. doi:10.1016/j.fas.2013.11.002

18.       Lassen MR, Borris LC, Nakov RL. Use of the low-molecular-weight heparin reviparin to prevent deep-vein thrombosis after leg injury requiring immobilization. N Engl J Med. 2002;347(10):726-730. doi:10.1056/NEJMoa011327

19.       Braithwaite I, De Ruyter B, Semprini A, et al. Cohort feasibility study of an intermittent pneumatic compression device within a below-knee cast for the prevention of venous thromboembolism. BMJ Open. 2016;6(10):e012764. doi:10.1136/bmjopen-2016-012764

20.       Blanco JA, Slater G, Mangwani J. A Prospective Cohort Study of Symptomatic Venous Thromboembolic Events in Foot and Ankle Trauma: The Need for Stratification in Thromboprophylaxis? J Foot Ankle Surg. 2018;57(3):484-488. doi:10.1053/j.jfas.2017.10.036

21.       Falck-Ytter Y, Francis CW, Johanson NA, et al. Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2 Suppl):e278S-e325S. doi:10.1378/chest.11-2404

22.       Watson U, Hickey BA, Jones HM, Perera A. A critical evaluation of venous thromboembolism risk assessment models used in patients with lower limb cast immobilisation. Foot Ankle Surg. 2016;22(3):191-195. doi:10.1016/j.fas.2015.08.003

23.       Douillet D, Nemeth B, Penaloza A, et al. Venous thromboembolism risk stratification for patients with lower limb trauma and cast or brace immobilization. PLoS One. 2019;14(6):e0217748. doi:10.1371/journal.pone.0217748

24.       Carr P, Ehredt DJ, Dawoodian A. Prevention of Deep Venous Thromboembolism in Foot and Ankle Surgery. Clin Podiatr Med Surg. 2019;36(1):21-35. doi:10.1016/j.cpm.2018.08.002

25.       Warren JA, Sundaram K, Hampton R, Billow D, Patterson B, Piuzzi NS. Venous thromboembolism rates remained unchanged in operative lower extremity orthopaedic trauma patients from 2008 to 2016. Injury. 2019;50(10):1620-1626. doi:10.1016/j.injury.2019.09.003

26.       Kakkar AK, Cimminiello C, Goldhaber SZ, et al. Low-molecular-weight heparin and mortality in acutely ill medical patients. N Engl J Med. 2011;365(26):2463-2472. doi:10.1056/NEJMoa1111288

27.       Samama MM, Cohen AT, Darmon JY, et al. A comparison of enoxaparin with placebo for the prevention of venous thromboembolism in acutely ill medical patients. Prophylaxis in Medical Patients with Enoxaparin Study Group. N Engl J Med. 1999;341(11):793-800. doi:10.1056/NEJM199909093411103

28.       Prevention of fatal postoperative pulmonary embolism by low doses of heparin. An international multicentre trial. Lancet. 1975;2(7924):45-51.

29.       Millar JA. Effect of medical thromboprophylaxis on mortality from pulmonary embolus and major bleedingy. Australas Med J. 2015;8(9):286-291. doi:10.4066/AMJ.2015.2447