Anterior Cruciate Ligament (ACL) Tear

What is an Anterior Cruciate Ligament (ACL) Tear?

Cruciate ligaments are found inside the knee joint. The anterior cruciate ligament (ACL) is in the front of the kneecap, and the posterior (PCL) is in the back. These ligaments form an “X” because they run diagonally of each other. They control back and forth movements of the knee, stabilize rotational movement, and create alignment for the tibia and the femur bone.

ACL tears are common in physical activity or sports that require sudden changes in direction or stopping, such as in gymnastics, football, skiing, and tennis.   Patients often describe a popping sensation, rapid onset of pain, swelling, and instability during these injuries.

Knee Ligaments 

  1. Collateral Ligaments

Collateral ligaments control sideways movements of the knee. These two ligaments are located on the inside and outside of the knee. The medial is on the inside, and the lateral is outside the knee joint.

  1. Cruciate Ligaments

Cruciate ligaments control the knee’s back and forth motions and prevent rotational movements. These ligaments are located on the inside of the knee joint and as mentioned previously, form an “X” with the anterior ligament in the front of the knee and the posterior behind.

What Types of ACL Injuries Are There? 

ACL injuries are sprains or full tears, and there are three phases of these injuries classified in grades 1, 2, and 3. ACL injuries are often accompanied by other knee injuries that are attributed to the same abrupt stopping, rapidly switching direction, or injury. Grade 3 ACL injuries are the most common, and they are the most severe, causing a complete tear of the ligament.

The Three Grades of ACL Injury Are as Follows:

  1. Grade 1 sprain—The ligament fibers are stretched but not torn. This may cause some pain, but it’s not unbearable, and the knee joint is still stabilized.
  2. Grade 2 sprain—Some of the fibers are torn, but others remain intact. This is a partial tear and will cause pain and instability of the knee joint, but it’s not a complete tear.
  3. Grade 3 sprain—This is the most common ACL injury, and with it, all the ligament fibers are torn, resulting in a complete tear and break between the ligaments. The knee will not be supported, the knee joint is unstable, and it’s, of course, painful.

At Sforzo | Dillingham | Stewart Orthopedics + Sports Medicine, we take our time with each patient to listen and present options that are customized to their specific needs. Dr. Charles E. Stewart specializes in ACL reconstruction and repair.

Anterior Cruciate Ligament (ACL) Tear Symptoms: 

ACL tear symptoms are generally the same for most individuals, but the additional injury to the knee such as a meniscus tear, articular cartilage damage, and other ligaments or tendon tears are common and can amplify the symptoms through a range of levels.

  • Limited range of motion—At the onset of the injury, the pain and instability due to the ligament tear will cause the knee to give out, and limited, if any, pressure can be applied.
  • Popping sensation in the knee—It’s common to feel a popping sensation and to audibly hear it as well with an ACL injury.
  • Swelling and pain—With the injury, it’s not uncommon for the knee to swell, due to the inflammatory response of the body, by sending white blood cells to the area. Fluid may soon begin to accumulate in and around the knee, and it is a painful injury.
  • Instability—Due to the instability of the knee joint, it will be extremely difficult to walk and may require assistance. When this happens to professional basketball or football players, we often see their teammates helping them off the court or field.
  • Continual knee instability—After the ACL is healed or healing, it may still prevent the quality of support and stability that the knee once had. They may notice that this is the case when trying to run or pivot the knee. Many patients have persistent knee instability and are susceptible to reinjury. 

Anterior Cruciate Ligament (ACL) Tear Causes

There are numerous causes of ACL tears, but it’s common in athletes and those that are physically active.

  • Sudden change in direction—In basketball, when the player dribbles the ball and tries to trick the opponents, they will use a technique known as cutting. This is when they change direction abruptly. This and similar movements are often the cause of many ACL tears. 
  • Pivoting—When individuals pivot direction, especially in sports, these movements often torque the knee and tear the ACL.
  • Jumping to an awkward landing—In gymnastics, we often see athletes try to stick the landing but land awkwardly and tear their ACL. This can happen in any haphazard jumping and tripping incident.
  • Stopping suddenly—If a runner is going along at a certain pace and then slows down or quickly stops, it can cause an ACL tear due to the jarring motion and buckling of the knee.
  • Direct blow to the knee—When an accident or trauma takes place, and the knee is directly hit, often, an ACL tear will happen. In football, we often see this happen when a player is tackled. Receiving a direct blow to the knee or having a collision, such as a football tackle

Risk Factors for Anterior Cruciate Ligament (ACL) Tear Condition?

ACL tears are common, and the onset of the tear is usually the cause of injuries from sudden movements, especially those of pivoting motions or changing direction. Basketball and volleyball players often experience torn ACLs, as do athletes that make quick movements.

Risk factors include:

  • Suddenly and abruptly shifting direction
  • Abruptly stopping running
  • Repeated stress to the knee
  • Hit to the knee
  • Falling or jumping up (if the knee is torqued, it can cause the ACL to tear)
  • Being Female (thought to be associated with anatomy, muscle strength, and control)
  • Participating in certain sports and activities, such as soccer, football, basketball, dance, etc.
  • Poor-fitting footwear can cause falls and instability to the knee

How is Anterior Cruciate Ligament (ACL) Tear diagnosed? 

The onset of pain, swelling, and instability will be a clear sign that something is wrong with the knee. Seeking medical care is crucial. The earlier ACL tears are diagnosed and treated, the better the outcome for the patient.  

Along with a physical examination, orthopedic surgeons will also utilize diagnostic testing, which may include X-rays, magnetic resonance imaging (MRI), and ultrasound.

ACL Treatment

Depending on any other coexisting knee injury, the health of the patients, and the age of the patient, treatment may vary. ACL full thickness tears will not heal on their own and require surgery to rebuild it with grafted tissue; however, for the elderly and patients that live inactive lifestyles, conservative treatment may be sufficient. This includes bracing, physical therapy, pain medications, limiting function, and weight-bearing.

Surgical intervention is typically recommended for ACL tears. Grafts are often taken from the patient’s own tendons. These will help to rebuild the ACL, and new tissue will naturally grow over time and cause it to become more stable.

With decades of experience, at Sforzo | Dillingham | Stewart Orthopedics + Sports Medicine all of our surgeons are board certified, and fellowship trained. We offer you the best treatment options and care.


How long does it take to recover from anterior cruciate ligament?

After surgery, the patient will regain some range of motion within a few weeks. A full recovery takes between eight months to one year.  Again, the ligament may not be as strong as it once was at first, so taking precautions to alleviate reinjury are highly recommended.

Can a torn cruciate ligament heal itself?

Torn ligaments require surgery to rebuild the ligament and regain strength.

What happens if a torn ACL is not repaired?

In the case of no surgery to repair the ACL, the patient will be very limited in means of function, weight bearing and range of motion.  Physical therapy may help to readjust to life without being able to utilize the knee the way they once did.

Focusing On You

As healthcare is ever changing, Sforzo | Dillingham | Stewart Orthopedics + Sports Medicine, is doing things differently…

  • Christopher R. Sforzo, M.D. is a board certified orthopedic surgeon and fellowship trained in hand and upper extremity surgery. He provides expert care in the treatment of problems involving the shoulder, arm, elbow, forearm, wrist and hand. He performs many procedures using minimally invasive techniques includi
  • Christopher L. Dillingham, M.D. is a board certified orthopedic surgeon and fellowship trained in hand, shoulder, and arm surgery. He specializes in the treatment of problems with rotator cuff disorders, carpal tunnel syndrome and nerve injury, joint replacement, arthritis surgery, fracture repair, foot and ankle
  • Charles E. Stewart M.D. is a board certified, Johns Hopkins fellowship-trained orthopedic surgeon specializing in adult complex reconstruction of the lower extremity. His specialties include, lower extremity sports injuries, meniscal injuries, partial knee replacement, total hip and knee arthroplasty (replacement), as
  • Philip A. Meinhardt, M.D. is a board certified orthopedic surgeon and fellowship trained spine surgeon. He specializes in adult spinal surgeries including reconstruction of spinal deformities, minimally invasive/microscopic spinal procedures, decompression, spinal instrumentation, fusion procedures and microscopic cer



After tearing my rotator cuff, not only was I experiencing pain but my quality of life was diminished. Playing golf and working out were painful rather than enjoyable. Graci and I sought out Fellowship trained Dr. Christopher Sforzo and the team at Sforzo | Dillingham | Stewart Orthopedics + Sports Medicine. I was treated non-surgically and am now pain free, mobile and enjoying everything I did before.

- Dennis and Graci McGillicuddy

As avid golfers and tennis enthusiasts, our rotator cuff injuries left us in pain, and unable to enjoy our sport. In researching for the most qualified surgeons, we found that Sforzo | Dillingham | Stewart Orthopedics + Sports Medicine not only had the highest level of training and experience, but they were also highly recommended by friends and associates who had excellent results. We, too, had outstanding…

- Mike Wilton, Bud Polley and Arnie Vance

I was visiting the area looking at property and considering a full time re-location from Minnesota when I was in a traffic accident. The result was a very painful shoulder injury that would ultimately require bilateral RTC repairs. I was unable to undertake regular day-to-day activities or participate in my favorite sport – tennis. It was essential that I choose a shoulder specialist that could quickly set…

- Pat Cooper

Over the years we had seen several orthopedists in town but were never impressed. They seemed to lack knowledge or compassion or both. Then when Liza was in high school, she went to Sforzo | Dillingham | Stewart Orthopedics + Sports Medicine for a minor sports injury. They not only diagnosed her somewhat obscure problem, but explained things in a way that she understood without being patronizing…

- Liza, John and Betsy Kane-Hartnett

As a very busy business owner in Sarasota, having not one, but two, massive rotator cuff tears had a debilitating effect on both my personal and professional life. From my first consultation with Sforzo | Dillingham | Stewart Orthopedics + Sports Medicine, I knew I was in good hands. The surgeons are board-certified and fellowship-trained, which gave me the confidence in achieving a successful outcome. More importantly,…

- Bob Kirschner

Latest Blog Posts