What is the initial treatment for a swollen knee with interior pain and difficulty bearing weight?

Initial Treatment for a Swollen Knee with Interior Pain and Difficulty Bearing Weight

The initial treatment for a swollen knee with interior pain and difficulty bearing weight should include radiographic imaging of the knee, followed by PRICE therapy (Protection, Rest, Ice, Compression, Elevation), and appropriate pain management with oral NSAIDs such as ibuprofen.

Initial Assessment and Imaging

When a patient presents with a swollen knee, interior pain, and difficulty bearing weight, radiographic imaging should be the first diagnostic step:

• Radiographs (X-rays) are the recommended initial imaging modality according to the ACR Appropriateness Criteria 1
• A minimum of two views should be obtained:
  • Anteroposterior (AP) view
  • Lateral view (with knee at 25-30 degrees of flexion)
• Additional views may include patellofemoral, internal oblique, and external oblique views if indicated

Radiographic imaging is particularly important when the patient meets Ottawa rule criteria, including:

• Focal tenderness
• Inability to bear weight (defined as inability to take four weight-bearing steps) 1

Initial Non-Pharmacological Management (PRICE Protocol)

After imaging to rule out fracture, implement the PRICE protocol:

1. Protection: Avoid activities that cause pain and protect the knee from further injury
2. Rest: Limit weight-bearing activities; use crutches or a walking stick if needed
3. Ice: Apply cold packs to the knee for 15-20 minutes every 2-3 hours during the first 48-72 hours
   • Cold therapy reduces pain and swelling by decreasing blood flow to the area 2, 3
4. Compression: Use an elastic bandage or compression sleeve to reduce swelling
   • Intermittent pneumatic compression has been shown to be more effective than cold packs alone for reducing knee swelling 2
5. Elevation: Keep the affected knee elevated above the level of the heart when possible to reduce swelling

Pharmacological Management

For pain control, NSAIDs are recommended as first-line therapy:

• Ibuprofen: 400-800 mg every 6-8 hours as needed for pain relief (not to exceed 3200 mg daily) 4
• Acetaminophen (up to 3g daily) can be used as an alternative for patients with contraindications to NSAIDs 5

Follow-up Management

If symptoms persist beyond the initial treatment:

1. For suspected osteoarthritis:

   • Exercise therapy (both land-based and aquatic exercises) 1, 5
   • Weight loss if the patient is overweight 1, 5
   • Consider referral for physical therapy

2. For suspected internal derangement (if no fracture is seen on initial radiographs):

   • Consider advanced imaging:
     • MRI for suspected meniscal or ligamentous injury
     • CT for suspected occult fracture 1

3. For suspected joint infection:

   • If fever, severe pain, erythema, or marked warmth is present, urgent evaluation is needed
   • Joint aspiration may be required for diagnosis 1

Common Pitfalls and Caveats

• Do not immediately order MRI or other advanced imaging before radiographs 1
• Do not encourage full weight-bearing activities before adequate pain control and reduction of swelling
• Do not delay appropriate imaging in patients who cannot bear weight, as this may indicate fracture
• Do not miss signs of joint infection, which requires urgent intervention
• Do not exceed recommended NSAID dosages, especially in elderly patients or those with comorbidities

By following this approach, you can effectively manage the acute phase of a swollen knee with interior pain and difficulty bearing weight while setting the stage for appropriate follow-up care based on the underlying cause.