Chapter 138 Venous Thromboembolism Prophylaxis After Knee Surgery

The European Approach

EFFECT OF PROPHYLAXIS AFTER KNEE ARTHROSCOPY

In Europe, an ever-increasing number of total knee replacements, and countless arthroscopic procedures and other periarticular knee procedures, are performed each year. The risk of thromboembolism must be considered (Table 138-1)^1,⁵ and appropriate prophylaxis applied.

Table 138-1 Risk of Venous Thromboembolism in Knee Surgery

There is no universal approach across Europe. Every country, every hospital, and indeed every individual surgeon will have their own strategy based on their philosophy, their experience, and their resources. There are guidelines in some countries that may or may not be followed (Box 138-1). Some countries have universally accepted practices (e.g., low-molecular-weight heparin [LMWH] use in France) whereas in other countries there is a wide range of practice and much controversy (e.g., United Kingdom). However, it is generally believed that warfarin is obsolete and aspirin is inadequate (Box 138-2).

Box 138-1

Dutch recommendations adapted from www.cbo.nl; German recommendations adapted from Prophylaxis of venous thromboembolism. Eur J Vasc Endovasc Surg Vasc Med 38:1–132, 2009; French recommendations adapted from Samama CM, Albaladejo P, Benhamou D, et al; Committee for Good Practice Standards of the French Society for Anaesthesiology and Intensive Care (SFAR): venous thromboembolism prevention in surgery and obstetrics: clinical practice guidelines. 23:95–116, 2006; Italian recommendations adapted from Laziosanità-Agenzia Di Sanità Pubblica: 20__ (http://www.asplazio.it/); Swedish recommendations adapted from the Swedish Health Department: 2004.

European Guidelines

British Recommendations ¹³

Elective knee replacement: TED stockings, foot pumps or calf compressors on admission, continued until tolerated. Start chemical prophylaxis (LMWH, dabigatran, rivaroxaban or fondaparinux) postoperatively and continue 10 to 14 days.

Knee arthroscopy and other procedures: Consider offering combined VTE prophylaxis with mechanical and pharmacologic methods to patients having orthopedic surgery (other than hip fracture, hip replacement, or knee replacement), based on assessment of risks and after discussion with the patient. Start mechanical VTE prophylaxis at admission. Choose any one of the following based on individual patient factors:

• Antiembolism (compression) stockings (thigh or knee length): Use with caution; foot impulse devices, intermittent pneumatic compression devices (thigh or knee length).

• Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility; start pharmacologic VTE prophylaxis 6-12 hr after surgery.

• Choose LMWH or unfractionated heparin (UFH; for patients with renal failure).

• Continue pharmacologic VTE prophylaxis until the patient no longer has significantly reduced mobility.

Dutch Recommendations

Elective knee replacement: For thromboprophylaxis during hospitalization for knee arthroplasty, fondaparinux, LMWH, or a vitamin K antagonist (VKA) is recommended (grade 1A, American College of Chest Physicians [ACCP]). Acetylsalicylic acid is not recommended as monotherapy (grade 1A, ACCP). Graded compression stockings or foot pumps are not recommended as monotherapy for thromboprophylaxis in elective knee arthroplasty (grade 1B, ACCP). Intermittent pneumatic compression is an alternative to fondaparinux, LWMH, or VKA for thromboprophylaxis in knee arthroplasty during hospitalization (grade 1A ACCP).

German Recommendations

Total knee replacement: LMWH or fondaparinux (in case of former adverse effects of LMWH). In case of contraindication for LMWH or fondaparinux, intermittent pneumatic compression is recommended. For elective cases, VTE prophylaxis can be started preoperatively with LMWH; duration, 11-14 days.

Arthroscopically assisted surgery of longer operation time in knee: VTE prophylaxis should be given until normal active range of motion and weight-bearing (WB) of 20 kg is reached, at least for 7 days.

Pharmacologic VTE prophylaxis with LMWH or fondaparinux: begin in select patients preoperatively when time to surgery is sufficient (no definitive time given).

French Recommendations

Elective Knee Replacement: LMWHs are the standard preventive treatment after (grade A).

UFH (even activated partial thromboplastin time [aPTT]–adjusted) and VKAs should not be used as first-line prophylaxis after major orthopedic surgery of the lower limbs (grade A).

Aspirin should not be considered as a prophylactic measure for VTE (grade B).

Mechanical methods should not be prescribed alone as first-line treatment in the absence of comparisons providing level 1 evidence (grade A), but they are a preferred choice when antithrombotics are contraindicated because of the risk of bleeding (grade A).

Properly fitted elastic compression stockings are an effective adjuvant therapy to pharmacologic prophylaxis because they have no interactions (grade B).

Knee arthroscopy: In view of the low risk associated with this type of surgery, LMWH prescription should not be routine but should be considered only if the patients have one or more additional risk factors (grade B).

Italian Recommendations

Knee replacement: LMWH 12 hr preoperatively or 12-24 hr postoperatively, or fondaparinux or warfarin (dose-adjusted; target international normalized ratio [INR] = 2.0-3.0. Aspirin and mechanical methods not recommended.

Knee arthroscopy: No prophylaxis routinely. If risk factors present, then consider LMWH.

Norwegian Recommendations

No guidelines.

Sweden Recommendations

The Swedish Health Department has published a priority document on VTE prophylaxis, which recommends 7-10 days of VTE prophylaxis for knee arthroplasty. There is no preference regarding LMWH, fondaparinux, oral factor Xa inhibitors, or oral direct thrombin inhibitors in this document.

Effect of Prophylaxis After Knee Arthroscopy

The effect of prophylaxis after knee arthroscopy has not been clearly established.¹⁵ Meta-analyses have suggested that LMWH reduces the incidence of distal deep vein thrombosis (DVT) diagnosed by sonography after knee arthroscopy (Table 138-2). However, the clinical benefit of this is uncertain; the number needed to harm is only 20. There is a mixed effect and no clear stratification for individual risk or complexity of procedure There is insufficient evidence to conclude that thromboprophylaxis is effective in preventing thromboembolic events safely in people with unknown risk factors for thrombosis who are undergoing knee arthroscopy.