ACL Tear

What an ACL tear is

The anterior cruciate ligament runs diagonally through the center of the knee, from the back of the thigh bone to the front of the shin bone. Its job is to stop the shin bone sliding forward under the thigh bone and to help control rotation when the knee twists. It sits inside the joint, and unlike ligaments on the outside of the knee it has a limited capacity to heal itself once torn through.

Most ACL injuries happen without anyone touching the knee. Pivoting on a planted foot, decelerating suddenly, changing direction, or landing awkwardly from a jump can load the ligament beyond what it can take, which is why the injury is common in soccer, basketball, football and skiing. A direct blow can also do it. Tears may be partial or complete, and the ACL is frequently injured along with other structures, such as the meniscus, the articular cartilage or the collateral ligaments.

Symptoms that often bring people in

• A pop felt or heard in the knee at the moment of injury
• Rapid swelling of the joint after the injury
• A sense that the knee gave way, or is no longer trustworthy on turns and uneven ground
• Pain and difficulty putting full weight through the leg
• Reduced ability to fully straighten or bend the knee
• Later episodes of buckling during pivoting activity

How it is evaluated

Evaluation starts with the story of the injury, which is often quite characteristic. Examination compares the injured knee with the other side and includes tests in which the surgeon gently draws the shin bone forward or rotates the knee to assess how the ligament is holding, along with swelling, motion and the other ligaments. X-rays are typically taken to rule out a fracture, since in some injuries the ligament pulls away a small piece of bone. MRI is commonly used to confirm the tear and to look for accompanying meniscus and cartilage injury that may influence what is recommended.

Treatment options in general terms

Not every ACL tear is treated the same way, and non-surgical management is a legitimate path for some people. It may involve:

• Early management of swelling and motion. Settling the acutely swollen knee and restoring the ability to straighten it.
• Structured rehabilitation. Restoring quadriceps and hamstring strength, balance and neuromuscular control.
• Bracing and activity modification. Support and a shift away from cutting and pivoting sports, which some people accept willingly.

Surgery may be discussed when the knee remains unstable or when the demands placed on it require a functioning ligament. Options include:

• ACL reconstruction. Replacing the torn ligament with a graft of tendon tissue, usually done arthroscopically.
• Treatment of associated injuries. Repairing or trimming a torn meniscus, or addressing cartilage damage, at the same time.

What to expect when you consult Dr. Wolfson

Dr. Wolfson has treated sports injuries and orthopedic trauma throughout his career and is board certified in the United States and Canada. A consultation covers how the injury happened, an examination of both knees, review of imaging, and a discussion of what you need the knee to do, since the decision about surgery depends on your goals rather than on the MRI alone. Complimentary phone consultations are available for patients outside the Bay Area.

This page provides general information about ACL tears and is not medical advice. It is not a substitute for examination, imaging and diagnosis by a qualified physician. Every case is different and requires individual evaluation. If you have severe pain, an obvious deformity, loss of function, fever, or an injury from a significant accident, seek medical care promptly.

Contact Dr. Wolfson if you would like to setup an appointment. If you are a new patient, please book all in-person appointments with Dr. Wolfson via telephone.

If you live outside of the San Francisco Bay Area, you can request a complimentary phone consultation with Dr. Wolfson to assess your case. Please call or e-mail us to set up your complimentary consultation.

Call: (415) 221-4400

E-mail: [email protected]