Transcript Acute knee trauma after total knee arthroplasty

Acute Knee Trauma
June 2013
Farhan Quader
Eliona Corrigan, MD
H&P
• 55 y/o female with hx of total knee arthroplasty
presented to ED after fall
– height of 3-5’ onto concrete
– point of impact = left knee
• Could not ambulate after fall
• Endorsed tingling around the site which later
resolved
– +Pain around site, 10/10
• PMH:
– HTN, obesity, sickle cell trait
• PSH:
– Total Knee Arthroplasty
• Physical exam: Left knee deformed, tibia
anteriorly translocated. No ankle nor hip pain.
Brisk cap refill, however, palpable dp/pt on
right side with weakly palpable dp on left and
non-palpable pt
DDx and Screening
Ddx:
– Knee dislocation
– Contusion
– Ligament sprain/tear
– Things to consider: arterial/venous insufficiency
Screening:
- Knee radiograph
- Ultrasound
- CT
- MRI
Screening Modality
• Patient falls under variant 2:
inability to bear weight
• Procedure of choice is X-ray
knee
• Ottawa Knee Rule: patients with
acute knee pain with 1 or more
should have X-ray:
– Are 55 years of age or older
– Have palpable tenderness over the
head of the fibula
– Have isolated patellar tenderness
– Cannot flex the knee to 90
degrees
– Cannot bear weight immediately
following the injury,
– Cannot walk in the emergency
room (after taking four steps).
AP view unremarkable
Lateral view remarkable
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Left Knee Radiograph AP and Lateral Knee
Left Knee
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Left Knee Radiograph AP and Lateral (previous)
Knee
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Knee Radiograph, Lateral view s/p reduction
Left Knee Xray
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Left Knee Radiograph AP and lateral s/p reduction
Left Knee
Popliteal Ultrasound ultrasound
Left Popliteal artery
Ultrasound longitudinal
Left Popliteal artery
Popliteal arteriogram
Conclusion
- Anterior dislocations are most common after knee trauma
- Dislocations characterized in terms of tibial displacement with
respect to femur (anterior, posterior, medial, lateral, and rotary)
- Further characterized into high velocity and low velocity
- High: violent force such as car accident; result in damage to
the structures of the knee complex
- Low-velocity: occur in sports settings and seen in athletic
trainers; lower rates of neurovascular and associated softtissue damage
- Predisposing factor = injury to ACL or MCL
- Damage to neurovascular system is one of the greatest concerns
- Popliteal artery is injured in approximately 20-40% of all knee
dislocations
- Peroneal nerve can still be injured due to it’s anatomical location
as it passes around the fibular neck; 33% of knee dislocations