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Health & Exercise Forum

ACL Injury May End Season But Not Career: Part 1 of 4 on ACL Injury

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Mar 19, 2012

Dr. Mackarey's Health & Exercise ForumPart 1 of 4

What do Matthew Knowles, Danielle Dalessandro and Matthew Langan have in common? These local basketball stars had their season cut short due to devastating knee injuries: torn anterior cruciate ligaments (ACL). However, while they may have ended their seasons, they did NOT end their careers! Knowles and Langan tore their ACL’s when they aggressively pivoted on one leg while shifting their body weight in another direction, causing them to hyperextend and rotate the knee. Typical of ACL tears in women, Danielle’s mechanism of injury was much more benign. She simply landed on one foot and her knee bent backward resulting in an ACL tear.

The tragedy for these athletes is the fact that they have trained tirelessly to achieve a starting position on their high school basketball teams. For the past 8 or more years they have missed many family meals and weekend activities to train, practice and play on school and travel teams in order to develop their skills to the highest level. Now, they will work tirelessly for the next 6 months to gain full recovery. They will be back…better than ever!

What is the ACL?

The ACL (i.e anterior cruciate ligament), is the major ligament that stabilizes the knee by preventing the anterior or forward motion of one knee bone on the other. It can be injured during hyperextension of the knee which forces the lower leg on the upper leg (i.e. the knee is straightened more than 10° beyond its normal fully straightened position) and pivoting injuries of the knee involving excessive inward turning of the lower leg.  Most ACL injuries occur during athletic activity and require either changing direction quickly (i.e. cutting around an obstacle or another player with one foot planted firmly on the ground) or landing after a jump with a sudden slowing down, especially if the leg is straight or slightly bent. A greater incidence of ACL injuries in women probably originates from several inter-related factors: hamstring-quadriceps muscle imbalance, joint laxity, and ankle braces.

How is the ACL injured?

Non-Contact Injuries:

Surprisingly, 80% of sports-related ACL injuries occur during non-contact activities involving:

  • Planting and cutting: the foot is positioned firmly on the ground followed by the leg turning in one direction or the other (ie. A football or baseball player making a fast cut or changing direction)
  • Straight-knee landing: the foot strikes the ground with the knee straight (ie. A basketball player coming down after a jump shot or a gymnast landing on dismount)
  • One-step-stop landing with knee hyper-extended: the leg abruptly stops while the knee is in an over-straightened position (ie. A baseball player sliding into base with the knee hyper-extended
  • Pivoting and sudden deceleration: a combination of rapid slowing down followed by a plant and twist of the foot that causes extreme rotation at the knee (ie. A football or soccer player quickly slowing down followed by a quick turn or change in direction)

Contact Injuries:

Sports-related, contact injuries to the ACL occur if the athlete gets hit very hard on the outside of the knee:

  • Clipping injury – in football
  • Slide tackle – in soccer

Non- athletic ACL injuries involving hyperextension and pivoting can occur with activities such as falling off a ladder, stepping off a curb, jumping from a moderate or extreme height, stepping into a hole, or missing a step when walking down a staircase.   Motor vehicle accidents in which the knee is forced under the dashboard may also rupture the ACL. “Wear and tear” to the ACL from repeated trauma can result in small tears, which, over time, can cause complete rupture of the ACL.

The severity of the ACL injury will depend on not only the position of the knee at the time of the injury, but also the direction and magnitude of the force.  Injury to the MCL (i.e. medial collateral ligament) as well as the lateral meniscus (i.e. shock-absorbing cartilage) may occur in more severe injuries.

Early symptoms of ACL injury

These may include a popping sound at the time of injury, profuse knee swelling within 6 hours of injury, and pain, especially when putting weight on the injured leg. If you think you injured your ACL, go to the nearest emergency room to receive instructions on how to care for your injured leg, including contacting a doctor that specializes in orthopaedic injuries.  Other helpful hints include:

  • Rest
    • Use crutches to rest the injured leg from weight bearing activities
    • Use a device to immobilize the knee
  • Ice
    • Place ice packs on your knee to control inflammation and reduce swelling
    • 15 to 20 minutes every hour
  • Compress
    • Wrap your knee with an ace wrap to control the swelling
  • Elevate
    • Elevate your injured leg above heart level to reduce swelling

Join us next week to discuss options after ACL injury.

Visit your doctor regularly and listen to your body.

CONTRIBUTING AUTHOR: Janet Caputo, PT, DPT, OCS is clinical director of physical therapy at Mackarey & Mackarey Physical Therapy Consultants, LLC in downtown Scranton where she practices orthopedic and neurological physical therapy.

NEXT MONDAY – Read Dr. Paul J. Mackarey “Health & Exercise Forum!” in the Scranton Times-Tribune. Next week read: Part 2 of 4 on ACL injuries.

This article is not intended as a substitute for medical treatment. If you have questions related to your medical condition, please contact your family physician. For further inquires related to this topic email:

Paul J. Mackarey PT, DHSc, OCS is a Doctor in Health Sciences specializing in orthopaedic and sports physical therapy. Dr. Mackarey is in private practice in Scranton, PA. He is an associate clinical professor of medicine at The Commonwealth Medical College.