Diferencia entre revisiones de «Knee dislocation»

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==Background==
==Background==
*Popliteal artery injury occurs in ~25% of cases
[[File:Knee diagram2.png|thumb|Anatomy of anterolateral aspect of right knee.]]
**Neurologic injury/deficit may indicate vascular injury
*[[Vascular injury|Popliteal artery injury]] is common
*Spontaneous reduction occurs in up to 50% of dislocations; often occurs prior to ED arrival
**About 25% of cases
**Neurologic deficit may indicate vascular injury
*Spontaneous reduction common
**About 50% self-reduce, usually en route to ED


===Types===
===Types===
*Anterior (40%)
*Anterior (40%)
**hyperextension mechanism
**Hyperextension
**often involves PCL, ACL and either medial or lateral ligs are injured
**Associated injuries to PCL, ACL, and medial or lateral ligaments common
*Posterior (33%)
*Posterior (33%)
**popliteal artery often injured
**Usually due to impact with dashboard during motor vehicle collision
**dash board injury
**Popliteal artery often injured
*Lateral (18%)
*Lateral (18%)
*Medial (4%)
*Medial (4%)


==Clinical Features==
==Clinical Features==
*Suggested by severely injured knee that is unstable in multiple directions
[[File:PMC2850837 wjem-11-103f1.png|thumb|The lateral view of the left knee showed a posterior knee dislocation.]]
*Lateral collateral ligament injured with peroneal nerve palsy = knee dislocation
*Instability in multiple directions
*Evidence of collateral ligamentous injury combined with peroneal nerve palsy
*History of high-energy mechanism
**Patients with BMI > 40 commonly report low-energy mechanism
*Affected knee may hyperextend relative to unaffected knee when leg is lifted by the foot


===Associated Injuries===
===Associated Injuries===
*Nerve injury
*[[Vascular injury|Popliteal artery injury]]<ref>Tintinalli, J. E., Stapczynski, J. S., Ma, O. J., Yealy, D. M., Meckler, G. D., & Cline, D. (2016). Injuries to  Bones and Joints In Tintinalli's emergency medicine: A comprehensive study guide (Eighth edition.) (pp1863-1864). New York: McGraw-Hill Education.</ref>
**Cannot rule out based on normal distal pulses and Ankle Brachial Index (ABI) > 0.9
***Requires definitive vascular imaging or serial exams
*[[Peripheral nerve syndromes|Neurologic injuries]]
**Common peroneal nerve injury (25%)  
**Common peroneal nerve injury (25%)  
***Test for sensation in 1st dorsal web space, dorsiflexion of foot, extension of toes
***Test for:
**Tibial nerve injured less often
****Sensation in 1st dorsal web space
****Dorsiflexion of foot
****Toe extension
**Tibial nerve injured (less common)
*[[Fractures]]
*[[Fractures]]
**Femur and tibia most common
**Femur and tibia most common
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==Evaluation==
==Evaluation==
*Knee x-ray (to rule-out fracture); consider CT
[[File:PosteriorKneeDIsclocation.jpg|thumb|Plain lateral X-ray of the left knee showing a posterior knee dislocation]]
[[File:Lateral-knee-dislocation-1.jpg|thumb|A lateral dislocation of the knee]]
[[File:CTAngioOcclusionRtPop.jpg|thumb|CT angiogram 3D reconstruction, posterior view showing a normal artery on the left, and occlusion to right popliteal artery as a result of a knee dislocation]]
*Knee x-ray (to rule-out fracture)
*Vascular assessment
*Vascular assessment
**Assess popliteal and distal pulses
**Assess popliteal and distal pulses
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***ABI >0.9 - serial exams
***ABI >0.9 - serial exams
***ABI <0.9 - arterial duplexes or CT angio
***ABI <0.9 - arterial duplexes or CT angio
**Hard Signs
***Observed pulsatile bleeding
***Arterial thrill by manual palpation
***Bruit over or near the artery by auscultation
***Signs of distal ischemia
***Visible expanding hematoma
**Soft Signs
***Significant hemorrhage found on history
***Decreased pulse compared to the other extremity
***Bony injury or proximal penetrating wound
***Neurologic abnormality
*Consider CT Angiography:
**Asymmetric pulses
**ABI <0.9
**Clinical concern of vascular injury (ischemia, hemorrhage, or expanding hematoma)


==Management==
==Management==
*Reduce immediately
*Reduce immediately
**Posterior dislocation
**Avoid additional arterial injury by limiting excessive force during reduction
***Assistant holds distal femur and gently pulls counter-traction
 
***Provider pulls proximal tibia longitudinally then anteriorly
===Posterior dislocation<ref name="Procedures for orthopedic emergencies">Davenport M. Procedures for orthopedic emergencies. In: Bond M, ed. Orthopedic Emergencies: Expert Management for the Emergency Physician. Cambridge: Cambridge University Press; October 31, 2013.</ref>===
***Prevent additional arterial injury by limiting excessive force
#Grasp proximal tibia
**Anterior dislocation
#Have assistant grasp distal femur and provide gentle counter-traction
***As above, but reversed. Provider pulls gently counter traction on proximal tibia while assistant pulls distal femure proximally then anteriorly
#Apply longitudinal traction to proximal tibia
**Splint in 10-15 degrees of flexion <ref name="Procedures for orthopedic emergencies">Davenport M. Procedures for orthopedic emergencies. In: Bond M, ed. Orthopedic Emergencies: Expert Management for the Emergency Physician. Cambridge: Cambridge University Press; October 31, 2013.</ref>
#Move proximal tibia anteriorly
*Monitor for compartment syndrome
#Immobilize in 10-15 degrees of flexion
**no pulses: reduce immediately
#Assess neurovascular status
**no pulses post reduction: surgical exploration
#Obtain post-reduction imaging
***ischemic time >8 hours has amputation rates as high as 86%
 
*Neurological assessment
===Anterior dislocation<ref name="Procedures for orthopedic emergencies">Davenport M. Procedures for orthopedic emergencies. In: Bond M, ed. Orthopedic Emergencies: Expert Management for the Emergency Physician. Cambridge: Cambridge University Press; October 31, 2013.</ref>===
**Peroneal nerve most commonly injured
#Grasp distal femur
***Test for sensation in 1st dorsal web space, dorsiflexion of foot, extension of toes
#Have assistant grasp proximal tibia and provide gentle counter-traction
#Pull distal femur proximally
#Move distal femur anteriorly
#Immobilize in 10-15 degrees of flexion
#Assess neurovascular status
#Obtain post-reduction imaging
 
 
*Monitor for [[compartment syndrome]]
**No pulses: reduce immediately
**No pulses post reduction: surgical exploration
***Ischemic time >8 hours has amputation rates as high as 86%


==Disposition==
==Disposition==
*Institution will dictation admission process
*Institution will dictate admission process
**Suggested algorithm
**Suggested algorithm
***If: Strong pulses + ABI >0.9 + normal ultrasound, admit for obs and serial vascular exams
***If: Strong pulses + ABI >0.9 + normal doppler, admit for obs and serial vascular exams
***If: Good perfusion + asymmetric pulses or ABI <0.9 or abnormal ultrasound, consult vascular surgery + obtain CTA
***If: Good perfusion + asymmetric pulses or ABI <0.9 or abnormal doppler, consult vascular surgery + obtain CTA
***If: Weak pulses or signs of ischemia = emergent vascular surgery consult and OR
***If: Weak pulses or signs of ischemia = emergent vascular surgery consult and OR
*Consider trauma consult depending on mechanism and additional injuries
*Consider trauma consult depending on mechanism and additional injuries
==See Also==
*[[Knee (Main)]]
*[[Patella dislocation]]
== Calculators ==
{{Ottawa_Knee_Calculator}}
==External Links==
*Standard:  <https://emergencymedicinecases.com/occult-knee-injuries/>


==References==
==References==
<references/>
<references/>


*Review of Orthopaedics, 6th Edition, Mark D. Miller MD, Stephen R. Thompson MBBS MEd FRCSC, Jennifer Hart MPAS PA-C ATC, an imprint of Elsevier, Philadelphia, Copyright 2012
*Review of Orthopaedics, 6th Edition, Mark D. Miller MD, Stephen R. Thompson MBBS MEd FRCSC, Jennifer Hart MPAS PA-C ATC, an imprint of Elsevier, Philadelphia, Copyright 2012
*AAOS Comprehensive Orthopaedic Review, Jay R. Leiberman. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2009
*AAOS Comprehensive Orthopaedic Review, Jay R. Leiberman. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2009
*Levy BA, Fanelli GC, Whelan DB, Stannard JP, MacDonald PA, Boyd JL, Marx RG, Stuart MJ. Knee Dislocation Study Group. Controversies in the treatment of knee dislocations and multiligament reconstruction. J Am Acad Orthop Surg. 2009 Apr;17(4):197-206. http://www.ncbi.nlm.nih.gov/pubmed/19307669
*Levy BA, Fanelli GC, Whelan DB, Stannard JP, MacDonald PA, Boyd JL, Marx RG, Stuart MJ. Knee Dislocation Study Group. Controversies in the treatment of knee dislocations and multiligament reconstruction. J Am Acad Orthop Surg. 2009 Apr;17(4):197-206. http://www.ncbi.nlm.nih.gov/pubmed/19307669
==See Also==
*[[Knee (Main)]]
[[Category:Orthopedics]]
[[Category:Orthopedics]]

Revisión actual - 15:06 21 mar 2026

Background

Anatomy of anterolateral aspect of right knee.
  • Popliteal artery injury is common
    • About 25% of cases
    • Neurologic deficit may indicate vascular injury
  • Spontaneous reduction common
    • About 50% self-reduce, usually en route to ED

Types

  • Anterior (40%)
    • Hyperextension
    • Associated injuries to PCL, ACL, and medial or lateral ligaments common
  • Posterior (33%)
    • Usually due to impact with dashboard during motor vehicle collision
    • Popliteal artery often injured
  • Lateral (18%)
  • Medial (4%)

Clinical Features

The lateral view of the left knee showed a posterior knee dislocation.
  • Instability in multiple directions
  • Evidence of collateral ligamentous injury combined with peroneal nerve palsy
  • History of high-energy mechanism
    • Patients with BMI > 40 commonly report low-energy mechanism
  • Affected knee may hyperextend relative to unaffected knee when leg is lifted by the foot

Associated Injuries

  • Popliteal artery injury[1]
    • Cannot rule out based on normal distal pulses and Ankle Brachial Index (ABI) > 0.9
      • Requires definitive vascular imaging or serial exams
  • Neurologic injuries
    • Common peroneal nerve injury (25%)
      • Test for:
        • Sensation in 1st dorsal web space
        • Dorsiflexion of foot
        • Toe extension
    • Tibial nerve injured (less common)
  • Fractures
    • Femur and tibia most common
    • Check hip and ankle joints for associated fracture
    • Avulsion fractures common
  • Compartment syndrome risk high with vascular compromise

Differential Diagnosis

Knee diagnoses

Acute knee injury

Nontraumatic/Subacute

Evaluation

Plain lateral X-ray of the left knee showing a posterior knee dislocation
A lateral dislocation of the knee
CT angiogram 3D reconstruction, posterior view showing a normal artery on the left, and occlusion to right popliteal artery as a result of a knee dislocation
  • Knee x-ray (to rule-out fracture)
  • Vascular assessment
    • Assess popliteal and distal pulses
    • Measure ABIs
      • ABI >0.9 - serial exams
      • ABI <0.9 - arterial duplexes or CT angio
    • Hard Signs
      • Observed pulsatile bleeding
      • Arterial thrill by manual palpation
      • Bruit over or near the artery by auscultation
      • Signs of distal ischemia
      • Visible expanding hematoma
    • Soft Signs
      • Significant hemorrhage found on history
      • Decreased pulse compared to the other extremity
      • Bony injury or proximal penetrating wound
      • Neurologic abnormality
  • Consider CT Angiography:
    • Asymmetric pulses
    • ABI <0.9
    • Clinical concern of vascular injury (ischemia, hemorrhage, or expanding hematoma)

Management

  • Reduce immediately
    • Avoid additional arterial injury by limiting excessive force during reduction

Posterior dislocation[2]

  1. Grasp proximal tibia
  2. Have assistant grasp distal femur and provide gentle counter-traction
  3. Apply longitudinal traction to proximal tibia
  4. Move proximal tibia anteriorly
  5. Immobilize in 10-15 degrees of flexion
  6. Assess neurovascular status
  7. Obtain post-reduction imaging

Anterior dislocation[2]

  1. Grasp distal femur
  2. Have assistant grasp proximal tibia and provide gentle counter-traction
  3. Pull distal femur proximally
  4. Move distal femur anteriorly
  5. Immobilize in 10-15 degrees of flexion
  6. Assess neurovascular status
  7. Obtain post-reduction imaging


  • Monitor for compartment syndrome
    • No pulses: reduce immediately
    • No pulses post reduction: surgical exploration
      • Ischemic time >8 hours has amputation rates as high as 86%

Disposition

  • Institution will dictate admission process
    • Suggested algorithm
      • If: Strong pulses + ABI >0.9 + normal doppler, admit for obs and serial vascular exams
      • If: Good perfusion + asymmetric pulses or ABI <0.9 or abnormal doppler, consult vascular surgery + obtain CTA
      • If: Weak pulses or signs of ischemia = emergent vascular surgery consult and OR
  • Consider trauma consult depending on mechanism and additional injuries

See Also

Calculators

Ottawa Knee Rules

Ottawa Knee Rule
Criteria No (0) Yes (+1)
Age ≥55 years 1
Tenderness at head of fibula 1
Isolated tenderness of patella (no other knee bone tenderness) 1
Inability to flex to 90° 1
Inability to bear weight (4 steps both immediately and in ED) 1
Criteria Met / 5
Interpretation
0 X-ray NOT indicated — No Ottawa Knee Rule criteria met. Sensitivity 98.5% for fracture.
≥1 X-ray indicated — One or more criteria met; obtain knee radiographs to evaluate for fracture.
References
  • Stiell IG et al. Prospective validation of a decision rule for radiography in acute knee injuries. JAMA. 1996;275:611-615. PMID 8594242.
  • Stiell IG et al. Implementation of the Ottawa Knee Rule. JAMA. 1997;278:2075-2079. PMID 9403421.

External Links

References

  1. ↑ Tintinalli, J. E., Stapczynski, J. S., Ma, O. J., Yealy, D. M., Meckler, G. D., & Cline, D. (2016). Injuries to Bones and Joints In Tintinalli's emergency medicine: A comprehensive study guide (Eighth edition.) (pp1863-1864). New York: McGraw-Hill Education.
  2. ↑ 2.0 2.1 Davenport M. Procedures for orthopedic emergencies. In: Bond M, ed. Orthopedic Emergencies: Expert Management for the Emergency Physician. Cambridge: Cambridge University Press; October 31, 2013.
  • Review of Orthopaedics, 6th Edition, Mark D. Miller MD, Stephen R. Thompson MBBS MEd FRCSC, Jennifer Hart MPAS PA-C ATC, an imprint of Elsevier, Philadelphia, Copyright 2012
  • AAOS Comprehensive Orthopaedic Review, Jay R. Leiberman. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2009
  • Levy BA, Fanelli GC, Whelan DB, Stannard JP, MacDonald PA, Boyd JL, Marx RG, Stuart MJ. Knee Dislocation Study Group. Controversies in the treatment of knee dislocations and multiligament reconstruction. J Am Acad Orthop Surg. 2009 Apr;17(4):197-206. http://www.ncbi.nlm.nih.gov/pubmed/19307669
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