What is the recommended post-operative course for a patient after total knee arthroplasty (TKA)?

Recommended Post-Operative Course for Total Knee Arthroplasty

The optimal post-operative course for total knee arthroplasty (TKA) should include a multimodal pain management approach with femoral nerve block or spinal anesthesia with morphine as the primary technique, supplemented with paracetamol, NSAIDs/COX-2 inhibitors, and opioids as needed, along with cooling compression techniques and early rehabilitation. 1

Pain Management

Primary Analgesic Techniques

• Femoral Nerve Block (FNB)
  • Single injection FNB is recommended as first-line for postoperative analgesia
  • Alternative: Spinal anesthesia with local anesthetic plus spinal morphine
  • Both techniques provide superior pain control compared to conventional systemic analgesia alone 1

Multimodal Systemic Analgesia

1. Basic regimen (for all patients):

   • Paracetamol/acetaminophen (1000 mg every 6 hours)
   • NSAIDs (conventional) or COX-2 selective inhibitors
   • Cooling and compression techniques (e.g., Cryo/Cuff)

2. For breakthrough pain:

   • Strong IV opioids for high-intensity pain
   • Weak opioids for moderate to low-intensity pain

3. IV acetaminophen consideration:

   • Two doses of IV acetaminophen (intraoperative and 6 hours postoperatively) can significantly reduce opioid consumption and improve immediate postoperative pain scores 2
   • Particularly beneficial during the first 8 hours post-surgery (reduced pain scores from 4.0 to 2.0) 2

Not Recommended Based on Evidence

• Gabapentin does not improve outcomes when added to multimodal analgesia (no effect on morphine consumption, pain scores, or length of stay) 3
• Combined femoral and sciatic nerve blocks (insufficient evidence) 1
• Intra-articular local anesthetic and/or morphine (inconsistent efficacy) 1
• Epidural local anesthetic ± opioid (increased risk of adverse events with no better benefits) 1

Rehabilitation Protocol

Day of Surgery (POD 0)

• Begin physical therapy within 24 hours of surgery
• Focus on transfers and basic mobility
• Initiate ankle pumps and quadriceps sets
• Apply cooling compression device

Early Postoperative Period (POD 1-3)

• Progressive ambulation with appropriate assistive devices
• Range of motion exercises targeting 90° knee flexion by discharge
• Quadriceps and hamstring strengthening exercises
• Continue cooling compression between therapy sessions

Discharge Planning (typically POD 2-3)

• Ensure patient can safely transfer and ambulate
• Confirm adequate pain control on oral medications
• Provide clear instructions for home exercise program

Special Considerations

Pain Management Challenges

• TKA patients often experience significant pain, particularly with movement
• Pain is typically more severe after TKA than total hip arthroplasty
• 52% of TKA patients report moderate pain and 16% report severe pain when walking 1 month after surgery 4
• Consider extending multimodal analgesia beyond the immediate postoperative period

Opioid-Sparing Approaches

For patients with contraindications to opioids:

• Enhanced peripheral nerve block techniques (consider tunneled femoral nerve catheter)
• Maximize non-opioid medications (acetaminophen, NSAIDs, muscle relaxants)
• Periarticular injections during surgery
• This approach has been successful even in challenging cases like opioid-induced hyperalgesia 5

Common Pitfalls and How to Avoid Them

1. Inadequate pain control limiting rehabilitation

   • Ensure pain medications are administered before physical therapy sessions
   • Use multimodal approach rather than relying solely on opioids

2. Overreliance on opioids

   • Maximize non-opioid analgesics first
   • Use opioids primarily for breakthrough pain

3. Neglecting posterior knee pain

   • While FNB provides excellent anterior knee coverage, it may not adequately control posterior knee pain
   • Supplement with appropriate systemic analgesics

4. Insufficient post-discharge pain management

   • Provide clear analgesic plan extending beyond hospitalization
   • Schedule follow-up to assess pain control and functional recovery

5. Delayed mobilization

   • Ensure pain control is adequate to allow early mobilization
   • Balance pain management with the need to avoid motor blockade that prevents mobilization

The evidence strongly supports that proper pain management in the post-operative course of TKA is critical for successful outcomes, with regional anesthesia techniques (particularly FNB) showing the most consistent benefits for pain control and functional recovery 1.