Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee Arthroplasty Case Study

Introduction
Venous thromboembolic disease (VTED) is a well-known complication that can occur following total hip and knee arthroplasty. Forms of VTED include asymptomatic deep vein thrombosis (DVT), symptomatic DVT, and pulmonary embolism, the latter possibly being fatal. Although the incidences of symptomatic DVT and pulmonary embolism are low, the incidence of asymptomatic DVT has been estimated to be 20% in patients undergoing primary hip and knee arthroplasty.1  VTED is the most common reason for emergency readmissions after total knee or hip arthroplasties.1 Further, the incidence of VTED has remained static over the past 20 years.1 Thus, the number of these complications will likely rise commensurate with the predicted increase in volume of these procedures.

In addition, prophylaxis against VTED is required by healthcare agencies and payers,2 and the federal government has become involved. For example, the Surgical Care Improvement Project has been mandated by the United States Centers for Medicare and Medicaid Services and offers guidelines. However, controversy remains regarding the most appropriate agents as well as the timing and duration of their administration. 3-5
The American Academy of Orthopaedic Surgeons (AAOS) published guidelines on this topic in 2007;6 that guideline had differences regarding prophylaxis compared with the American College of Chest Physicians guideline, last updated in 2008.7 This has led to many questions concerning the most appropriate prophylactic regimen.8 The AAOS work group was convened to reevaluate the available evidence concerning this topic and to update this clinical practice guideline.
 

History and Preoperative Evaluation
A 72-year-old man is considering a total hip arthroplasty for disabling pain from hip arthritis. He has failed various nonsurgical treatment modalities during the past year, including analgesics, decreased activity levels, and the use of a cane. He undergoes an orthopaedic evaluation in which a further history, physical examination, and radiographs are taken. His history reveals mild hypertension, and he has not had prior VTED, bleeding disorder, or history of liver disease. He takes an anti-hypertensive medication and aspirin regularly “to prevent a heart attack.” He questions his orthopaedic surgeon about the use of these medications before his surgery.

The AAOS clinical practice guideline recommends discontinuance of antiplatelet agents (eg, aspirin, clopidogrel) before undergoing elective hip or knee arthroplasty (Grade of Recommendation: Moderate).

Because his neighbor has had “blood clots and extra bleeding after every operation he gets,” the patient then asks questions about his risk of these complications. The AAOS guideline asserts that patients undergoing elective hip or knee arthroplasty are already at high risk for venous thromboembolism. The practitioner might further assess the risk of venous thromboembolism by determining whether this patient had a previous venous thromboembolism (Grade of Recommendation: Weak). The AAOS guideline notes that patients undergoing elective hip or knee arthroplasty are at risk for bleeding and bleeding-associated complications. This patient should be assessed for known bleeding disorders (eg, hemophilia) and for the presence of active liver disease (Grade of Recommendation: Consensus).


Total Hip Arthroplasty Procedure
The patient stops taking aspirin 1 week before his scheduled surgery and undergoes an uncomplicated total hip arthroplasty under spinal anesthesia.

The AAOS guideline suggests the use of neuraxial (eg, intrathecal, epidural, spinal) anesthesia for patients undergoing elective hip or knee arthroplasty to help limit blood loss, even though evidence suggests that neuraxial anesthesia does not affect the occurrence of VTED (Grade of Recommendation: Moderate).

Postoperative Care
Postoperatively, the patient is placed on aspirin and a bilateral lower extremity pneumatic compression device. The AAOS guideline recommends the use of pharmacologic agents and/or mechanical compressive devices for the prevention of VTED in patients undergoing elective hip or knee arthroplasty who are not at elevated risk beyond that of the surgery itself for venous thromboembolism or bleeding (Grade of Recommendation: Moderate).

The patient ambulates on the day of surgery with assistance from the nursing staff, as well as later in the day during a physical therapy session. The AAOS guideline recommends that patients undergo early mobilization following elective hip and knee arthroplasty. Early mobilization is of low cost, minimal risk to the patient, and consistent with current practice (Grade of Recommendation:Consensus).

By postoperative day 2, the patient is ready for discharge. Although the patient was completely asymptomatic, his wife asked about his getting an ultrasound evaluation before going home because that is what her best friend, who received a total hip arthroplasty last year, got. She was assured that her husband did not need this evaluation, and the patient was sent home on aspirin and compression stockings. He made an uneventful full recovery from the surgery. The AAOS guideline recommends against routine postoperative duplex ultrasonography screening of patients who undergo elective hip or knee arthroplasty (Grade of Recommendation: Strong).

References
1. Johanson NA, Lachiewicz PF, Lieberman JR, et al: Prevention of symptomatic pulmonary embolism in patients undergoing total hip or knee arthroplasty.
J Am Acad Orthop Surg 2009;17(3):183-196.

2. Markel DC: Venous thromboembolism (VTE) screening, prophylaxis, evaluation and management in adult hip and knee arthroplasty. Presented at the18th Annual Meeting of the American Association of Hip and Knee Surgeons, Dallas, TX, November 7-9, 2008.

3. Pellegrini VD Jr, Sharrock NE, Paiement GD, Morris R, Warwick DJ: Venous thromboembolic disease after total hip and knee arthroplasty: Current
perspectives in a regulated environment. Instr Course Lect 2008;57:637-661.

4. Parvizi J, Azzam K, Rothman RH: Deep venous thrombosis prophylaxis for total joint arthroplasty: American Academy of Orthopaedic Surgeons guidelines.
J Arthroplasty 2008;23(7 suppl):2-5.

5. Callaghan JJ, Warth LC, Hoballah JJ, Liu SS, Wells CW: Evaluation of deep venous thrombosis prophylaxis in lowrisk patients undergoing total knee arthroplasty.
J Arthroplasty 2008;23(6 suppl 1):20-24.

6. Barrack RL, Burnett RS: Deep vein thrombosis prophylaxis: Protecting the patient or the surgeon? Semin Arthroplasty 2008;19:109-111.

7. Geerts WH, Bergqvist D, Pineo GF, et al; American College of Chest Physicians: Prevention of venous thromboembolism. American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest 2008; 133(6 suppl):381S-453S.

8. Burnett RS, Clohisy JC, Wright RW, et al: Failure of the American College of Chest Physicians-1A protocol for lovenox in clinical outcomes for thromboembolic prophylaxis.
J Arthroplasty 2007;22(3):317-324.