ACL Injuries – Everything You Need to Know

Dr. Todd Swenson, Blount Orthopaedic Associates

It is estimated that there are 200,000 ACL injuries per year in the United States. Due to the prevalence of this injury, there are often many questions about how ACL tears occur, treatment options, and the healing process.  Dr. Todd Swenson, an Orthopaedic Surgeon from the Orthopaedic Hospital of Wisconsin, provides you with everything you need to know about ACL injuries.


How do ACL Injuries Occur?

The anterior cruciate ligament (ACL) is one of the four major ligaments found in the knee joint. These ligaments connect the femur (thigh bone) to the tibia (shin bone) and permit for coordinated function and stability of the knee joint. 

The ACL is most often torn in a non-contact injury when an individual is performing the following actions:

  • Twisting
  • Pivoting
  • Stopping suddenly
  • Landing from a jump

An individual of any age or fitness level can injure their ACL. These injuries are most common in sports such as soccer, basketball, football, and skiing. The ACL can be torn as an isolated injury or may occur in conjunction with other torn structures (ligament, cartilage).

With the increased sports participation by female athletes, the prevalence of ACL injuries in women has rapidly increased. Many factors beyond athletic participation alone contribute to this increased risk of ACL injury in the female athlete; these include differences in anatomy, muscle mass/function as well as training. Preventative training programs addressing lower extremity muscle imbalances in addition to jumping and landing techniques have evolved in an attempt to assist the female athlete in avoiding an ACL injury.

How is a Torn ACL Treated?

Strategies for the treatment of a torn ACL depend upon many variables. Patient age, an individual’s lifestyle as it pertains to his/her level of activity, in addition to any associated injuries are all considered in formulating a recommended treatment. Isolated ACL tears, particularly in those whose physical demands and activity level are limited, can be managed non-surgically through the use of physical therapy, possibly in conjunction with functional bracing.  Most young and athletically active patients as well those with combined injuries will most often be best managed with surgery.

What does ACL Surgery Entail?

Once surgery has been recommended, a patient is frequently first treated with a period of pre-surgical rehabilitation (“prehab”). The goal of prehab is to assist in resolving acute inflammation, restore knee range of motion and improve impaired muscle function. This approach has been shown to improve the outcome of surgery and minimize potential post-operative complications.

In simplistic terms, ACL surgery involves removing the torn ligament fibers and then introducing a substitute piece of tissue (graft) into the knee. The graft is placed through bone tunnels created in the tibia and femur. Once the graft tissue heals and incorporates within these bone tunnels, that portion which is within the knee joint spanning between the two tunnels becomes the patient’s “new” ACL. Options for graft material include using a piece of tissue from the patient’s own body (autograft) or cadaveric tissue (allograft). Preferred graft material in most cases is autograft and options include hamstring tendon, patellar tendon, and quadriceps tendon.

What Happens After Surgery?

Following surgery, a prolonged period of healing and rehabilitation is necessary in order for an optimal outcome to occur. Therapy is carried out under the supervision of a physical therapist and/or athletic trainer. Rehabilitation protocols focus on restoring range of motion, muscle strengthening, balance exercises, movement exercises and ultimately sport-specific training. The time from surgery until release to unrestricted athletic participation varies from patient to patient. A normal physical examination of the knee, a return of normal muscle strength and the ability to perform a variety of functional tests with minimal asymmetry to the opposite extremity are all objective criteria used to make this determination. Dr. Swenson states, “Depending upon the level of commitment put forth by the patient to their rehabilitation regimen, this time frame is typically 8 to 12 months. Returning to sports and other ACL-dependent activities without being adequately rehabilitated places a patient at significant risk for re-injury, irrespective of the time frame from their surgical procedure.”  

At the Orthopaedic Hospital of Wisconsin, we care about helping the members of our community maintain their active lifestyles. When orthopaedic care is required, we are here to help. Visit our website to learn more about different kinds of knee conditions we treat and the procedures we perform. If you have an ACL injury that needs to be treated contact us here or call us at 414-961-6880.