Ananterior cruciate ligament (ACL) tearis a knee injury that can cause symptoms like pain, swelling, and a popping sound. The tear can be partial or complete, and symptoms are generally more severe with more extensive injuries. Trouble standing is just one sign that you need immediate medical attention.
With partial tears, it’s also possible to experience little to no ACL tear symptoms at first. This sounds like a good thing, but it can result in you continuing your activity, further compromising your ligament and potentially worsening the tear.
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This article explains the signs and symptoms of an ACL tear. It will also discuss when you need emergency attention and what medical tests your healthcare provider may use to diagnose this condition.
What Is the ACL?TheACLis theband of tissuesthat connects the bottom of the thighbone to the top of the shinbone. It helps stabilize the knee.
What Is the ACL?
TheACLis theband of tissuesthat connects the bottom of the thighbone to the top of the shinbone. It helps stabilize the knee.
Signs and Symptoms of an ACL Tear
The signs and symptoms of an ACL injury can vary.
Hearing a “Pop”
Individuals who have an ACL tear may hear a loud “pop” at the time of the injury. Even if you don’t hear the pop, you may feel a sudden shift in the joint.
Knee Swelling and Pain
Swelling of the knee jointoccurs in almost all individuals with an ACL tear. Swelling may show up within hours after the injury.
This may be due to the injury to the ligament itself or a condition known ashemarthrosis, which is bleeding in a joint. Symptoms of hemarthrosis include swelling, pain,warmth, and difficulty with movement.
Pain associated with an ACL tear is common. Keep in mind, the level of pain may vary depending on the severity of the injury.
Knee Instability
Because the ACL is critical to the stability of the knee joint, thejoint may give outif the ligament tears.
This may happen during cutting or pivoting movements common in many sports. However, in some individuals with this injury, instability can occur while walking or getting into a car.
When to Seek Emergency Care
See a healthcare provider right away if you have:
Diagnosing an ACL Tear
Physical Exam
To check for an ACL tear, your healthcare provider may use specific tests including:
In addition to performing these specific tests, your healthcare provider will check your knee for swelling and overall strength. The other major knee ligaments may also be assessed.
Imaging
Your healthcare provider may order imaging tests to check the severity of the injury. Imaging tests may include:
Summary
To check for a torn ACL your healthcare provider may perform certain tests and/or order imaging tests like an X-ray or MRI.
Frequently Asked QuestionsAn ACL tear can feel painful and your knee may feel unstable.Learn MoreKnee Pain: Causes, Diagnosis, and TreatmentYes. Swelling tends to occur within a few hours after the injury.Learn MoreSymptoms and Diagnosis of a Swollen KneeAn ACL tear cannot heal on its own. If not treated properly, the tear can get larger.Learn MoreHow Knee Pain Is TreatedDepending on how severe the tear is, treatment may include surgery and/or a knee stabilizing device like abrace.Physical therapymay also be recommended.Learn MoreSurgical ACL Treatment
Frequently Asked Questions
An ACL tear can feel painful and your knee may feel unstable.Learn MoreKnee Pain: Causes, Diagnosis, and Treatment
An ACL tear can feel painful and your knee may feel unstable.
Learn MoreKnee Pain: Causes, Diagnosis, and Treatment
Yes. Swelling tends to occur within a few hours after the injury.Learn MoreSymptoms and Diagnosis of a Swollen Knee
Yes. Swelling tends to occur within a few hours after the injury.
Learn MoreSymptoms and Diagnosis of a Swollen Knee
An ACL tear cannot heal on its own. If not treated properly, the tear can get larger.Learn MoreHow Knee Pain Is Treated
An ACL tear cannot heal on its own. If not treated properly, the tear can get larger.
Learn MoreHow Knee Pain Is Treated
Depending on how severe the tear is, treatment may include surgery and/or a knee stabilizing device like abrace.Physical therapymay also be recommended.Learn MoreSurgical ACL Treatment
Depending on how severe the tear is, treatment may include surgery and/or a knee stabilizing device like abrace.Physical therapymay also be recommended.
Learn MoreSurgical ACL Treatment
6 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.University of Michigan Health. Michigan Medicine.Anterior cruciate ligament (acl) injuries.American Academy of Orthopaedic Surgeons.Anterior cruciate ligament (acl) injuries.MedlinePlus.Anterior cruciate ligament (acl) injury-aftercare.Potpally N, Rodeo S, So P, Mautner K, Baria M, Malanga GA.A review of current management of knee hemarthrosis in the non-hemophilic population.CARTILAGE. 2021;13(1_suppl):116S-121S. doi:10.1177/1947603520942937Cimino FM, Volk BS, Setter D.Anterior cruciate ligament injury: diagnosis, management, and prevention.AFP. 2010;82(8):917-922.Nemours Teenshealth.Anterior cruciae ligament (acl) tears.
6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.University of Michigan Health. Michigan Medicine.Anterior cruciate ligament (acl) injuries.American Academy of Orthopaedic Surgeons.Anterior cruciate ligament (acl) injuries.MedlinePlus.Anterior cruciate ligament (acl) injury-aftercare.Potpally N, Rodeo S, So P, Mautner K, Baria M, Malanga GA.A review of current management of knee hemarthrosis in the non-hemophilic population.CARTILAGE. 2021;13(1_suppl):116S-121S. doi:10.1177/1947603520942937Cimino FM, Volk BS, Setter D.Anterior cruciate ligament injury: diagnosis, management, and prevention.AFP. 2010;82(8):917-922.Nemours Teenshealth.Anterior cruciae ligament (acl) tears.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
University of Michigan Health. Michigan Medicine.Anterior cruciate ligament (acl) injuries.American Academy of Orthopaedic Surgeons.Anterior cruciate ligament (acl) injuries.MedlinePlus.Anterior cruciate ligament (acl) injury-aftercare.Potpally N, Rodeo S, So P, Mautner K, Baria M, Malanga GA.A review of current management of knee hemarthrosis in the non-hemophilic population.CARTILAGE. 2021;13(1_suppl):116S-121S. doi:10.1177/1947603520942937Cimino FM, Volk BS, Setter D.Anterior cruciate ligament injury: diagnosis, management, and prevention.AFP. 2010;82(8):917-922.Nemours Teenshealth.Anterior cruciae ligament (acl) tears.
University of Michigan Health. Michigan Medicine.Anterior cruciate ligament (acl) injuries.
American Academy of Orthopaedic Surgeons.Anterior cruciate ligament (acl) injuries.
MedlinePlus.Anterior cruciate ligament (acl) injury-aftercare.
Potpally N, Rodeo S, So P, Mautner K, Baria M, Malanga GA.A review of current management of knee hemarthrosis in the non-hemophilic population.CARTILAGE. 2021;13(1_suppl):116S-121S. doi:10.1177/1947603520942937
Cimino FM, Volk BS, Setter D.Anterior cruciate ligament injury: diagnosis, management, and prevention.AFP. 2010;82(8):917-922.
Nemours Teenshealth.Anterior cruciae ligament (acl) tears.
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