Acute knee injury: Difference between revisions

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==Management==
==Management==
*Knee brace, ice, elevation, ambulation as soon as comfortable
*If xrays are <u>positive</u> (when indicated)
**Full knee immobilization generally not indicated for single ligament injuries
**Treat underlying condition
*If xrays are <u>negative</u> or not indicated [[Ottawa knee rules]]
**Do full knee exam to check for ligamentous/meniscal instability:
***Negative exam --> RICE
***Positive exam or unable to evaluate secondary to pain/swelling --> knee brace + RICE


==Disposition==
==Disposition==

Revision as of 06:49, 9 November 2017

Background

Knee ligaments

Knee anatomy. Right knee shown from anterio-lateral view.
  • Anterior Cruciate Ligament
    • Limits anterior translation of tibia
    • 75% of all hemarthroses are caused by disruption of ACL
  • Posterior Cruciate Ligament
    • Limits posterior translation of tibia
    • Isolated injuries are rare
  • Medial Collateral Ligament
    • Provide restraint against valgus (outward) stress
  • Lateral Collateral Ligament
    • Provide restraint against varus (inward) stress

Clinical Features

  • Acute trauma and pain to knee

Differential Diagnosis

Knee diagnoses

Acute knee injury

Nontraumatic/Subacute

Evaluation

Ottawa knee rules

Ottawa knee rules points of tenderness (image of left knee).

X-ray is only required in patients who have an acute injury and one or more of the following:

  • Age >55
  • Isolated tenderness of the patella
  • Tenderness at the fibular head
  • Inability flex to 90 degrees
  • Inability to walk 4 steps BOTH immediately after the injury and in the ED

Knee x-rays

  • Anteroposterior and lateral views
    • Consider sunrise if pain over patella

Management

  • If xrays are positive (when indicated)
    • Treat underlying condition
  • If xrays are negative or not indicated Ottawa knee rules
    • Do full knee exam to check for ligamentous/meniscal instability:
      • Negative exam --> RICE
      • Positive exam or unable to evaluate secondary to pain/swelling --> knee brace + RICE

Disposition

  • Depends on diagnosis; most often results in outpatient ortho referral

See Also

External Links

References