What are the preoperative preparations and protocols for a patient undergoing total knee replacement?

Preoperative Management for Total Knee Arthroplasty

For patients undergoing total knee arthroplasty (TKA), antirheumatic medications should be managed according to medication class, with conventional DMARDs continued throughout the perioperative period while biologic agents should be withheld for one dosing cycle prior to surgery. 1

Medication Management

Antirheumatic Medications

Continue Through Surgery:

• Conventional DMARDs: Continue methotrexate, leflunomide, hydroxychloroquine, and sulfasalazine at current doses 1
  • These medications do not increase infection risk and may actually decrease risk of postoperative flares
  • Continuing these medications is associated with lower infection rates (RR 0.39,95% CI 0.17-0.91)

Withhold Before Surgery:

• Biologic agents: Withhold for one complete dosing cycle prior to surgery 1

  • Plan surgery at the end of the dosing cycle when active drug levels would be lowest
  • For example: for adalimumab (dosed every 2 weeks), plan surgery during week 3

• JAK inhibitors: Withhold for at least 3 days prior to surgery 1

  • Tofacitinib, baricitinib, and upadacitinib have short half-lives but can affect immune function

• For SLE patients:

  • Non-severe SLE: Withhold mycophenolate mofetil, azathioprine, cyclosporine, or tacrolimus 1 week prior to surgery 1, 2
  • Severe SLE: Continue immunosuppressive medications throughout the perioperative period 2

Anticoagulation Management

• Direct Oral Anticoagulants (DOACs): Discontinue based on renal function and specific agent 1

  • Timing varies by agent and creatinine clearance
  • For high bleeding risk procedures like TKA, longer interruption times are needed

• Warfarin: Consider maintaining therapeutic warfarin regimen throughout the perioperative period for high-risk patients 3

  • Evidence suggests this approach is not associated with increased risk of complications

Infection Prophylaxis

• Antibiotic prophylaxis: Administer cefazolin 1-2g IV 30-60 minutes before surgical incision 4
  • For prosthetic joint surgery, may continue prophylaxis for 3-5 days postoperatively
  • Adjust dosing for patients with reduced renal function

Thromboprophylaxis

• Venous thromboembolism (VTE) prophylaxis: Essential for all TKA patients as they are at high risk 1
  • Options include low molecular weight heparin, direct oral anticoagulants, or aspirin
  • Begin prophylaxis 6-12 hours after surgery once hemostasis is achieved

Postoperative Medication Resumption

• Biologic agents: Restart once the wound shows evidence of healing (typically ~14 days) 1

  • Ensure all sutures/staples are out
  • Confirm no significant swelling, erythema, or drainage
  • Verify no clinical evidence of surgical or non-surgical site infections

• DMARDs: Continue without interruption if maintained through surgery

• SLE medications: For patients who had medications withheld, restart 3-5 days after surgery if no wound healing complications or infection 2

Common Pitfalls to Avoid

1. Inadequate VTE prophylaxis: All TKA patients are at high risk for VTE and require appropriate prophylaxis 1

2. Inappropriate "stress dosing" of glucocorticoids: Continue patients on their usual glucocorticoid dose rather than increasing for "stress dosing" 1

3. Restarting biologics too early: Restarting before wound healing (typically 14 days) may increase infection risk 1

4. Discontinuing all antirheumatic medications: Conventional DMARDs should be continued to prevent disease flares 1

5. Inadequate timing of antibiotic prophylaxis: Ensure antibiotics are administered 30-60 minutes before incision for optimal tissue concentrations 4