Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), carries a significant clinical and financial burden for patients and the healthcare sector.1-3 In the United States, the total 1-year costs per patient with VTE can range up to $33,000.3 Patients who sustain a VTE event carry a risk of life-long sequelae and even death. Postthrombotic syndrome, affecting up to 30% of VTE patients, is detrimental to a patient's quality of life because of chronic hyperpigmentation, edema, pruritus, paresthesias, pain, and ulceration, with a 1-year cost burden up to $11,700.1-3 Additional long-term sequelae from the disease include recurrence of VTE, PE, chronic thrombotic pulmonary hypertension, and complications related to treatment including adverse or allergic drug reaction, bleeding events, and drug-induced thrombocytopenia.1,2
VTE has long been known as a major complication of orthopaedic surgery after lower extremity (LE) total joint arthroplasty and trauma. Although once considered an unlikely event after shoulder arthroscopy, VTE is now a known complication of elective upper extremity (UE) surgery albeit at lower rates than after LE surgery.4,5 Given the increasing incidence of shoulder arthroscopy and arthroplasty,6 an understanding of the disease process and incidence is essential when formulating a balanced prevention strategy as well as recognizing, diagnosing, and appropriately treating the disease.
For surgical patients sustaining a VTE event, Virchow triad, consisting of intimal injury as a result of the surgical procedure, a hypercoagulable state because of potential inherent patient risk factors combined with general anesthesia, and venous stasis because of altered/decreased mobility and surgical factors (eg, patient positioning, complete muscle relaxation, prolonged surgical times), offers a rationale for the increased risk of VTE after surgical intervention. The clotting cascade includes both intrinsic and extrinsic pathways (Figure 1). Several inherited disorders of the clotting cascade can result in a hypercoagulable state: antithrombin III deficiency, point mutation of factor V Leiden resulting in resistance to protein C, protein C/S deficiency, activated protein C resistance, prothrombin promoter mutation 20210 A, methylene tetrahydrofolate reductase mutations, plasminogen deficiency, and hyperhomocysteinemia.7 Secondary risk factors associated with all VTE events include advanced age, obesity, personal or family history of VTE, prolonged travel, prolonged or critical care hospitalization, trauma, elevated hormone conditions (eg, replacement therapy, estrogen contraceptives, pregnancy), significant medical comorbidities (eg, diabetes, heart/kidney/lung disease), cancer, and antiphospholipid antibody syndrome.7
Incidence and Risk Factors After Shoulder Surgery
The first case of DVT after elective shoulder arthroscopy was reported by Burkhart in 1990.8 Since that time, numerous studies have highlighted VTE as a complication after shoulder surgery. The reported VTE rates after shoulder surgery are wide in range. This finding is likely a reflection of the variability in study size and methodology (Tables 1–3). In general, available literature shows that symptomatic VTE rates are higher after shoulder arthroplasty (range, 0.24% to 2.6%4,5,9-12,14-16,18) than after arthroscopy (range, 0.01% to 0.38%9,14,16,20,21,23,24). Specifically, DVT rates are higher after shoulder arthroplasty (range, 0.09% to 1.69%4,9-12,14,16,19) than after arthroscopy (range, <0.01% to 0.38%9,14,16,20-25) as are PE rates (range, 0% to 3%4,9-14,16,19 versus 0% to 0.21%9,14,16,20-26). Although most VTE events occur within the first postoperative week, they can occur for 3 months after the surgery.6,11,13,14,16,23,26
Most studies show that VTE rates after shoulder surgery are less than 1% (Tables 1–3). Many of the studies are retrospective reviews of large national databases in the United States and Europe. Such studies of shoulder arthroplasty report maximal rates of VTE at 0.68%,4,5,15,16,18 DVT at 0.5%,4,16,17,19 and PE at 0.25%4,16,17,19 (Tables 1 and 2). Coding and clerical errors, short follow-up, limited data from limited sources, and patient death may all result in lost data capture and subsequently underestimate complication rates in these studies.17,18,21,22,25 In contrast, a review of prospectively gathered registry data between 1976 and 2008 by Singh et al11 analyzed the 90-day VTE rate after 4,019 primary shoulder arthroplasties at their institution. They found higher rates of symptomatic VTE at 1.2% and PE at 0.72% with a similar DVT rate at 0.45%.
Asymptomatic VTE events have been reported at even higher rates. Although the clinical significance of asymptomatic VTE is debatable, one cannot argue that symptomatic VTE and even fatal PE may begin as asymptomatic DVT.2 Thus, understanding the asymptomatic rate may assist in developing prevention and treatment strategies. In the only prospective study screening for VTE after elective shoulder arthroplasty, Willis et al13 examined 100 consecutive patients with a four-limb duplex ultrasonography at 2 days postoperative, and half of the patients were randomly selected to repeat the ultrasonography at 12 weeks. Patients symptomatic for PE underwent chest CT angiography on an as-needed basis. They reported rates of asymptomatic DVT at 13% and symptomatic PE at 3% with one death presumed secondary to PE. Most DVTs (10/13) were discovered at the 2-day ultrasonography. A limitation is the lack of preoperative ultrasonography screening which would have confirmed that these DVTs were new ones. They found that all UE DVTs (six) involved the surgical limb. No statistically significant risk factors were identified.
Similar to arthroplasty, VTE rates after shoulder arthroscopy tend to be lower in large database reviews which report maximum rates of VTE at 0.2%,16,21 DVT at 0.16%,16,21,22,25 and PE at 0.13%16,21,22,25 (Table 3). This finding is in contrast to the retrospective chart review by Kuremsky et al23 of 1,908 patients with a 90-day follow-up after shoulder arthroscopy showing higher rates of VTE at 0.31%, DVT at 0.26%, and PE at 0.21%. All VTE events were symptomatic and subsequently confirmed by ultrasonography or chest CT angiography per their standard protocol.23
Similar to shoulder arthroplasty, asymptomatic rates of VTE after arthroscopy are higher. In the only prospective study screening for VTE after shoulder arthroscopy, Takahashi et al26 examined 175 consecutive patients with a four-limb duplex ultrasonography 1 to 2 days postoperatively and 3 weeks to 3 months postoperatively. Exclusion criteria included a positive preoperative ultrasonography, active VTE preoperatively, and low volume surgeons. They found rates of VTE at 5.7%, DVT at 5.7%, and PE at 0.37%. No patient was symptomatic, including the one patient with an acute LE DVT followed by subacute UE DVT and nonfatal PE. They used only mechanical perioperative prevention strategies: foot pumps for 24 hours or until ambulation resumed and/or compression stockings. The authors did not find any difference between groups in regard to DVT risk factors.
Risk factors for VTE after shoulder surgery are presented in Table 4. In brief, they include prior VTE,5,11,12 advanced age,4,9,11,16,19 medical comorbidities,4,5,8,11,12,16,19,27-29 prolonged surgical times9 and hospital stays,19 more complex surgical procedures,9,12,16,18 traumatic surgical indications,4,11,18,19 and surgery at altitude greater than 4,000 feet.21 Conflicting evidence exists regarding some potential risk factors and is reviewed in the remainder of this section.
In a review of 422,372 Medicare claims for shoulder arthroplasty from 2002 to 2011, Young et al19 examined risk factors that increased the risk of postoperative PE: arthroplasty for fracture (odds ratio [OR], 2.43), total shoulder arthroplasty rather than hemiarthroplasty (OR, 1.33), advanced age (1.10), prolonged inpatient stay (OR, 1.12), chronic congestive heart failure (OR, 1.49), chronic lung disease (OR, 1.40), obesity (OR, 1.31), fluid and electrolyte disorders (OR, 1.33), and deficiency anemia (OR, 1.84). Contradicting the association between obesity and VTE found in many large reviews,5,11,12,19 Wagner et al30 specifically examined the correlation between increasing body mass index and outcomes of 4,567 shoulder arthroplasties in their prospective registry data from 1970 to 2013 and found no significant association with VTE.
The association between type of shoulder arthroplasty (ie, anatomic, reverse, hemi) and VTE has been examined although no definitive conclusions can be drawn.5,10,11,17,19 In a retrospective chart review of 2,574 primary shoulder arthroplasties with a 90-day follow-up between 2005 and 2009, Navarro et al10 found no association between reverse, anatomic, and hemiarthroplasty or humeral head resurfacing with VTE events. They suggested that any differences may be related to the underlying diagnosis (ie, arthroplasty for fracture) rather than the specific type of arthroplasty.10 Strengths of this study are the exclusion criteria (ie, infection, cancer, patient history of VTE, or on preoperative anticoagulation) and the methods of determining VTE rates (ie, diagnosis and procedure codes, ultrasonography results, anticoagulation prescriptions, death). In contrast, Jiang et al17 reviewed 19,497 patients in the National Inpatient Sample database from 2010 to 2011 and found that reverse shoulder arthroplasty carried a 2.24 relative risk of DVT over anatomic with no significant differences in PE rates. After adjusting for patient age and comorbidities (both higher in the reverse group), the risk remained. The authors suggested that the risk may have been because of longer surgical times, increased blood transfusions, and more surgical complications in the reverse group.17
Most available data include cancer,4,6,8,28 a history of prior VTE,4,11,12 and other medical comorbidities5,12,16,19 as risk factors for VTE after shoulder surgery. However, at least two authors contradict these findings. Imberti et al9 failed to show a notable association in a review of national registry data for 1,366 shoulder surgery patients (ie, arthroplasty, arthroscopy, trauma). Similarly, in a review of 533 shoulder arthroplasty patients, Tashjian et al12 did not find commonly cited risk factors as notable for VTE, including a longer period of altered mobility, family history of clotting disorder, hormone replacement therapy, or a history of cancer. Neither of these studies cite a power analysis and may be underpowered to determine risk factors.
After shoulder arthroscopy, risk factors for VTE have been established by two studies. Jameson et al16 reviewed 65,302 arthroscopy patients from 2005 to 2008 with 90-day follow-up, excluding only those with a history of VTE, in the Administrative Hospital Admissions Database, National Health Service, United Kingdom, finding a very low overall VTE rate of 0.01% from seven events. VTE was markedly associated with advanced age, diabetes, and an elevated Charlson Comorbidity Index. Cancienne et al21 examined the effect of altitude above 4,000 feet or below 100 feet on VTE rates after arthroscopic rotator cuff repair in 24,430 Medicare patients from 2005 to 2012 and found an increased rate of VTE (OR, 2.6), PE (OR, 4.3), and LE DVT (OR, 2.2) but not UE DVT in patients having surgery at high altitude. Altitude may be one reason why the review by Tashjian et al12 found a higher rate of VTE (2.6%) in their shoulder arthroplasty patients in Salt Lake City, UT, versus other retrospective and registry reviews (Table 1).
An additional risk factor for VTE in the setting of shoulder arthroscopy that has been suggested, but not confirmed, is lateral decubitus positioning with arm traction. In a review of studies comparing outcomes of lateral decubitus versus beach chair positioning for shoulder arthroscopy in 2015, Li et al28 noted a higher rate of VTE in patients undergoing surgery in the lateral decubitus position (15) versus in the beach chair position (6).28 However, Schick et al24 reported 23 VTE events in 15,033 patients undergoing shoulder arthroscopy, all in the beach chair position. Currently, no definitive correlation can be drawn between positioning and VTE risk.
Diagnosis of VTE is challenging as no physical examination findings are sensitive or specific. However, clinical suspicion should be high for patients with unilateral limb swelling, redness, pain, or a palpable cord. The judicious use of ultrasonography is appropriate when clinical concern exists. Contrast venography with radiograph, CT, or magnetic resonance imaging is an alternative diagnostic option.
Patients with PE may present with shortness of breath, cough, chest pain, tachycardia, tachypnea, hypoxia, hypocapnea, or electrocardiogram signs of right-sided cardiac stress. Chest CT angiography is the standard diagnostic test. Limitations include the need for intravenous contrast, radiation exposure, and nonportability. A negative D-dimer blood test may be helpful in excluding a diagnosis of VTE, but it cannot confirm the diagnosis postoperatively because surgical intervention leads to a transient elevation.
In addition to the aforementioned common clinical sequelae, VTE is one of the most common causes of unplanned readmission after shoulder surgery accounting for 4.4% to 23% of patients.5,6,22,31-33 Over 50% of patients presenting with VTE after shoulder surgery may require readmission: PE (OR, 268.93) and DVT (OR, 21.10).34 During admission immediately after shoulder arthroplasty, Young et al19 found that patients sustaining a PE event were more likely to suffer other medical complications such as myocardial infarction, pneumonia, cerebrovascular accident, acute renal failure, gastrointestinal complication, transfusion, need for mechanical ventilation, and nonroutine discharge. Death is also a potential consequence of VTE, occurring in zero to 0.28% of all patients after shoulder surgery or up to 33% of patients with a PE after shoulder surgery (Tables 1–3).10,12-14,19,23,26
Major guidelines directly applicable to shoulder surgery for VTE prevention are presented in Table 5.35,36 Early mobilization and use of perioperative mechanical prophylaxis such as sequential compression devices (SCDs) confer minimal risk when carefully applied, and it is reasonable to consider their use in all patients. The guidelines for chemoprophylaxis strategies recognize the significant risks associated with these drugs including major bleeding or adverse drug reactions (ie, heparin-induced thrombocytopenia). Therefore, the guidelines recommend carefully balancing the probability of VTE to bleeding risk in each patient. Providers and patients should communicate and develop individualized strategies.35,36
In 2009, the American Academy of Orthopaedic Surgeons (AAOS)35 gave a consensus (expert opinion) recommendation for the use of mechanical and/or chemoprevention for perioperative VTE prophylaxis in shoulder arthroplasty patients. The recommendation recognized that little evidence exists to support this statement but the consequences of VTE can be devastating. As discussed earlier, mechanical prophylaxis should be considered in all patients and chemoprevention should be tailored to individual needs and risk factors. No specific pharmacologic recommendations are given.35 As of the writing of this article, the AAOS does not offer guidelines nor recommendations for VTE prevention after other forms of shoulder surgery.
The National Institute for Health and Care Excellence (NICE) from the United Kingdom released their newest set of VTE prevention guidelines in 2010.36 Most shoulder arthroplasty patients will meet a recommendation for mechanical prophylaxis and chemoprevention based on the risk factors of (1) surgical intervention or trauma and (2) age 60 years or older36 (Table 5). The NICE only recommends the use of heparin or low-molecular-weight heparin for chemoprevention until patient mobility is restored at which point it can be stopped. The NICE recommends against the use of aspirin and antiplatelet agents. In 2011, Jameson et al16 reviewed a large national database over 4 years with 74,059 shoulder surgery patients. They compared a 6-month sample from before the original guidelines were released in 2007 with a 6-month sample well after release and found no significant decline in the VTE event rate for shoulder arthroscopy and fracture surgery. After the guidelines were released, a statistically significant decrease in mortality after total shoulder arthroplasty and a decrease in VTE rates after hemiarthroplasty were noted. The authors questioned the validity of their results, given the very low VTE event rate (Tables 2 and 3).
Guidelines for VTE prevention after shoulder surgery that include a standard algorithm are currently lacking, likely because of the overall low incidence of VTE and absence of evidence-based literature to support or negate the use of pharmacologic prophylaxis. As of the writing of this article, the authors are aware of no randomized, controlled trials directly comparing different forms of VTE prophylaxis. However, as previously mentioned, VTE confers significant long-term morbidity and mortality risk to the patient. Therefore, the use of efficacious, low-risk strategies such as early ambulation and mechanical devices (eg, perioperative LE SCDs) should be utilized in all patients when feasible. Although routine chemoprevention is likely unnecessary in young, otherwise healthy patients without a personal history of VTE undergoing short, elective procedures such as arthroscopy, consideration may be warranted for older patients with medical comorbidities, extended periods of altered mobility, trauma, and more complex surgical interventions (eg, arthroplasty). Pharmacologic options are presented in Table 6, and they most commonly include the use of enoxaparin, heparin, and/or aspirin.
The American College of Chest Physicians recommendations on management of VTE are in their 10th edition.37 Three months of pharmacologic anticoagulation is recommended as the treatment of surgical patients sustaining DVT, including distal leg DVT, to prevent clot propagation during the resorption process and decrease mortality. Pharmacologic options for anticoagulation are presented in Table 6, and Figure 1 displays their mechanism of action on the clotting cascade. Choice of anticoagulant is stratified based on the patient's cancer history.37 For patients without a cancer history, dabigatran, rivaroxaban, apixaban, or edoxaban is recommended. For patients with a cancer history, low-molecular-weight heparin is recommended. Anticoagulation is recommended over catheter-directed thrombolysis and/or inferior vena cava filter for acute DVT. The use of compression stockings to prevent postthrombotic syndrome of the affected leg is not recommended.
For patients with PE, treatment is based on patient symptomatology and embolism severity.37 For patients at low risk of recurrence and without a proximal leg DVT, subsegmental PE requires only surveillance of the proximal legs for new DVT using ultrasonography. However, high recurrent risk or proximal leg DVT in combination with subsegmental PE requires anticoagulation treatment. Low-risk patients may also be treated on an outpatient basis if stable. For patients displaying systemic symptoms, such as hypotension, admission and involvement of an internal medicine or vascular surgery specialist is warranted because the patient may require symptomatic support, antithrombotic therapy, catheter-based thrombus removal, or pulmonary thromboendarterectomy.37
Special Consideration: Upper Extremity DVT
Unique surgical risk factors predispose shoulder surgery patients to ipsilateral UE DVT. These risk factors include UE traction, retractor placement compressing or stretching venous structures, nonanatomic arm positioning, and vein manipulation.8 UE DVT then exposes a patient to unique sequelae such as superior vena cava syndrome.38 In a review of UE DVT, Grant et al39 found that recurrence after UE DVT is lower than that after LE DVT. Unfortunately, symptomatic PE (up to 12.4%), asymptomatic PE (up to 36%), and 1-year mortality (up to 40%) may all be higher after UE DVT compared with those after LE DVT.39 Mechanical prevention strategies used in the LE, such as compression stockings and SCDs, may not be recommended or feasible for use on the UE, although continued LE use may prevent UE DVT. Diagnosing UE DVT proceeds much the same way as for LE. Patients presenting with ipsilateral arm swelling after surgery should be evaluated for potential causes including appropriate postoperative edema, hematoma or seroma, infection, mass, and DVT/PE.40 Definitive diagnosis or exclusion of UE DVT can typically be confirmed with ultrasonography which has greater than 80% sensitivity and specificity compared with the benchmark, radiographic venography.40 Although MR or CT venography can also be used, they are not recommended for routine use because of the need for contrast, specialized equipment, expense, and lack of evidence proving superiority.40 In the case of UE DVT at or proximal to the axillary vein, the American College of Chest Physicians recommends anticoagulation with or without thrombolysis.37
Symptomatic VTE after shoulder surgery is an apparently rare but serious event; symptomatic VTE is higher after shoulder arthroplasty than after shoulder arthroscopy. Asymptomatic VTE is more common. Postthrombotic syndrome, recurrence, treatment complications, and death represent serious long-term economic and quality-of-life sequelae for patients. Prevention strategies should balance the risks of VTE with the risks of treatment. Therefore, the efficacious and low-risk strategies of mechanical prevention should be used in all patients when feasible. High-risk patients because of a history of prior VTE, medical comorbidities, age, surgical indication (eg, trauma), type and complexity of surgical intervention (eg, arthroplasty), and surgery at altitude may warrant pharmacological prophylaxis during their early postoperative period of reduced mobility. Once a VTE event is suspected, diagnosis and treatment proceeds with advanced imaging, consultation of medical and/or vascular specialists, and pharmacologic treatment. UE DVT warrants special consideration and increased awareness in this patient population.
Evidence-based Medicine: Levels of evidence are described in the table of contents. In this article, references 13 and 26 are level I studies. References 4, 10, 15, and 16 are level II studies. References 11, 12, 14, 17-19, 21, 22, 24, 27, 29, 31, and 33 are level III studies. References 1, 3, 5-9, 20, 23, 25, 28, 30, 32, 34, 38, 39, and 40 are level IV studies. References 2, and 35-37 are level V reports or expert opinions.
References printed in bold type are those published within the past 5 years.
1. Ruppert A, Lees M, Steinle T: Clinical burden of venous thromboembolism. Curr Med Res Opin 2010;26:2465–2473.
2. Rathbun S: The surgeon general's call to action to prevent deep vein thrombosis and pulmonary embolism. Circulation 2009;119:e480–e482.
3. Ruppert A, Steinle T, Lees M: Economic burden of venous thromboembolism: A systematic review. J Med Econ 2011;14:65–74.
4. Lyman S, Sherman S, Carter TI, et al: For symptomatic thromboembolic events after shoulder arthroplasty. Clin Orthop Relat Res 2006;448:152–156.
5. Day JS, Ramsey ML, Lau E, Williams GR: Risk of venous thromboembolism after shoulder arthroplasty in the Medicare population. J Shoulder Elbow Surg 2015;24:98–105.
6. Lovy AJ, Keswani A, Beck C, Dowdell JE, Parsons BO: Risk factors for and timing of adverse events after total shoulder arthroplasty. J Shoulder Elbow Surg 2017;26:1003–1010.
7. Esmon CT: Basic mechanisms and pathogenesis of venous thrombosis. Blood Rev 2009;23:225–229.
8. Burkhart SS: Deep venous thrombosis after shoulder arthroscopy. Arthroscopy 1990;6:61–63.
9. Imberti D, Ivaldo N, Murena L, et al: Venous thromboembolism in patients undergoing shoulder surgery: Findings from the RECOS registry. Thromb Res 2014;134:273–277.
10. Navarro RA, Inacio MCS, Burke MF, Costouros JG, Yian EH: Risk of thromboembolism in shoulder arthroplasty: Effect of implant type and traumatic indication. Clin Orthop Relat Res 2013;471:1576–1581.
11. Singh JA, Sperling JW, Cofield RH: Cardiopulmonary complications after primary shoulder arthroplasty: A cohort study. Semin Arthritis Rheum 2012;41:689–697.
12. Tashjian RZ, Lilly DT, Isaacson AM, et al. Incidence of and risk factors for symptomatic venous thromboembolism after shoulder arthroplasty. Am J Orthop 2016;45:E379–E385.
13. Willis AA, Warren RF, Craig EV, et al: Deep vein thrombosis after reconstructive shoulder arthroplasty: A prospective observational study. J Shoulder Elbow Surg 2009;18:100–106.
14. Wronka KS, Pritchard M, Sinha A: Incidence of symptomatic venous thrombo-embolism following shoulder surgery. Int Orthop 2014;38:1415–1418.
15. Farng E, Zingmond D, Krenek L, SooHoo NF: Factors predicting complication rates after primary shoulder arthroplasty. J Shoulder Elbow Surg 2011;20:557–563.
16. Jameson SS, James P, Howcroft DWJ, et al: Venous thromboembolic events are rare after shoulder surgery: Analysis of a national database. J Shoulder Elbow Surg 2011;20:764–770.
17. Jiang JJ, Toor AS, Shi LL, Koh JL: Analysis of perioperative complications in patients after total shoulder arthroplasty and reverse total shoulder arthroplasty. J Shoulder Elbow Surg 2014;23:1852–1859.
18. Shields E, Iannuzzi JC, Thorsness R, Noyes K, Voloshin I: Postoperative morbidity by procedure and patient factors influencing major complications within 30 days following shoulder surgery. Orthop J Sport Med 2014;2:1–7.
19. Young BL, Menendez ME, Baker DK, Ponce BA: Factors associated with in-hospital pulmonary embolism after shoulder arthroplasty. J Shoulder Elbow Surg 2015;24:e271–e278.
20. Brislin KJ, Field LD, Savoie FH III: Complications after arthroscopic rotator cuff repair. Arthroscopy 2007;23:124–128.
21. Cancienne JM, Burrus MT, Diduch DR, Werner BC: High altitude is an independent risk factor for venous thromboembolism following arthroscopic rotator cuff repair: A matched case-control study in Medicare patients. J Shoulder Elbow Surg 2017;26:7–13.
22. Hill JR, McKnight B, Pannell WC, et al: Risk factors for 30-day readmission following shoulder arthroscopy. Arthroscopy 2017;33:55–61.
23. Kuremsky MA, Cain EL, Fleischli JE: Thromboembolic phenomena after arthroscopic shoulder surgery. Arthroscopy 2011;27:1614–1619.
24. Schick CW, Westermann RW, Gao Y; ACESS Group, Wolf BR: Thromboembolism following shoulder arthroscopy: A retrospective review. Orthop J Sport Med 2014;2:1–5.
25. Shields E, Thirukumaran C, Thorsness R, Noyes K, Voloshin I: An analysis of adult patient risk factors and complications within 30 days after arthroscopic shoulder surgery. Arthroscopy 2015;31:807–815.
26. Takahashi H, Yamamoto N, Nagamoto H, Sano H, Tanaka M, Itoi E: Venous thromboembolism after elective shoulder surgery: A prospective cohort study of 175 patients. J Shoulder Elbow Surg 2014;23:605–612.
27. Ponce BA, Oladeji LO, Raley JA, Menendez ME: Analysis of perioperative morbidity and mortality in shoulder arthroplasty patients with preexisting alcohol use disorders. J Shoulder Elbow Surg 2015;24:167–173.
28. Li X, Eichinger JK, Hartshorn T, Zhou H, Matzkin EG, Warner JP: A comparison of the lateral decubitus and beach-chair positions for shoulder surgery: Advantages and complications. J Am Acad Orthop Surg 2015;23:18–28.
29. Murphy AB, Menendez ME, Watson SL, Ponce BA: Metabolic syndrome and shoulder arthroplasty: Epidemiology and peri-operative outcomes. Int Orthop 2016;40:1927–1933.
30. Wagner ER, Houdek MT, Schleck C, et al: Increasing body mass index is associated with worse outcomes after shoulder arthroplasty. J Bone Joint Surg 2017;99:929–937.
31. Westermann RW, Pugely AJ, Ries Z, et al: Causes and predictors of 30-day readmission after shoulder and knee arthroscopy: An analysis of 15,167 cases. Arthroscopy 2015;31:1035–1040.
32. Xu S, Baker DK, Woods JC, Brabston EW 3rd, Ponce BA: Risk factors for early readmission after anatomical or reverse total shoulder arthroplasty. Am J Orthop 2016;45:E386–E392.
33. Schairer WW, Zhang AL, Feeley BT: Hospital readmissions after primary shoulder arthroplasty. J Shoulder Elbow Surg 2014;23:1349–1355.
34. Belmont PJJ, Kusnezov NA, Dunn JC, Bader JO, Kilcoyne K, Waterman BR: Predictors of hospital readmission after total shoulder arthroplasty. Orthopedics 2017;40:e1–e10.
37. Kearon C, Akl EA, Ornelas J, et al: Antithrombotic therapy for VTE disease: CHEST guideline and expert panel report. Chest 2016;149:315–352.
38. Garofalo R, Notarnicola A, Moretti L, Moretti B, Marini S, Castagna A: Deep vein thromboembolism after arthroscopy of the shoulder: Two case reports and a review of the literature. BMC Musculoskelet Disord 2010;11:65.
39. Grant JD, Stevens SM, Woller SC, et al: Diagnosis and management of upper extremity deep-vein thrombosis in adults. Thromb Haemost 2012;108:1097–1108.
40. Desjardins B, Rybicki FJ, Kim HS, et al: ACR appropriateness criteria suspected upper extremity deep vein thrombosis. J Am Coll Radiol 2012;9:613–619.