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A 22-year-old male asked:

If the acl has poor or no blood supply why does the knee swells up so rapidly when it is torn? if it has blood supply why doesn't a partial tear heal?

1 doctor answer2 doctors weighed in
Dr. David Trettin
Orthopedic Surgery 35 years experience
Acl tears bleed: Anterior cruciate ligaments tears generally cause a significant hemarthrosis( blood in joint) when acutely torn.This is from the tear itself and associated injuries.. Because the ligament is intraarticular it has poor helping potential when the blood supply is disrupted, unlike the medial collateral ligament ( mcl ). Partial ( one bundle) tears have poor healing potential for same reason
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Last updated Nov 27, 2017


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