ACL Tear or Injury: Causes, Symptoms, Types & Treatment

What is ACL Tear ?

knee is undoubtedly one of the most complex ACL tearhinge joints in the human body. It helps in bending and straightening the leg. To perform these two principal actions, four ligaments are located in the knee that stabilizes the knee. They are anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL) and lateral collateral ligament (LCL).

Anterior cruciate ligament is one of the most important ligaments of knee that connects femur (thigh bone) and tibia (shinbone). ACL is made up of tough fibrous material that are critical for keeping knee stable and strengthened. It is located deep inside the knee joint, behind knee cap, above shin bone and below thigh bone.

ACL plays primary role in restraining the forward movement of tibia or shin bone. Its prevent the shin bone from excessively sliding forward and constrict the knee from rotation. It provides much-needed stability to the knee and even limits the stress across the knee joint. ACL also provides protection from valgus forces.

Anterior cruciate ligament receives tear due to over-stretching or over-extending of this ligament beyond its limit. If it is completely torn, then there is great probability that other ligaments such as MCL, PCL and LCL might also incur tear, damage or injury. Athletes and sporting individuals are most vulnerable to ACL tear because of lots of sporting movements requires sudden twisting, pivoting and sprinting.


What are the Causes of ACL Tear?

causes of ACL tear

ACL injury occurs when anterior cruciate ligament is torn inside the knee joint. According to research studies, women are more prone to ACL tear than men even the latter involvement in high intensity sports is much greater. Women are 5 times more likely to experience ACL tear. Some of the possible causes of ACL tear are:

  • Over-extension of knee: If knee is straightened or extended in excess of 10 degrees, which is beyond its normal limit, then most probably ACL will be torn.
  • Sudden Pivoting: If any individual sudden pivot, then the knee will go excessive inward movement that result in acl damage.
  • Awkward Landing: Improper landing techniques always result in ACl injury such as in sports like basketball, netball or gymnastics.
  • Sudden Acceleration & Deceleration: In sports like football, basketball, soccer, rugby, gymnastics and skiing, individuals requires sudden acceleration and deceleration, which makes them most vulnerable to ACL sprain.
  • Collision or Tackle: ACL will also gets damaged due to direct contact or collision like in case of tackle in soccer or football.
  • High Intensity Sports: Individuals involved in high intensity and power sports requires sudden stopping, twisting, pivoting, jumping, running, landing, sprinting or changing directions. If these actions are performed improperly, then they are most likely susceptible to ACL injury.
  • Awkward Twisting: If the foot is planted firmly on the ground and the player turns awkwardly, then ACL will gets torn.
  • Excessive Stress: When knee receives extreme stress because of valgus forces, ACL will get damaged.
  • Repetitive Stressful Activities: Due to continuance involvement in stressful activities, players are diagnosed with ACL tear. Always train under the guidance of experts and if ever any activity causes stress or pain in knee, it is wise and advisable to consult doctor or physiotherapist immediately.
  • Poor Physical Conditioning: Weak muscles and poor flexibility of body also results in torn ACL.

Diagnosis of MCL Tear :

ACL tear is generally diagnosed with clinical examination like pivot-shift test and anterior drawer test. In many cases, Lachman tests are also conducted because they are extremely reliable for diagnosing ACL injury much better. Doctors will also ask you about causes and symptoms of injury, and even conduct detailed physical test to analyze the injury.

MRI scan is most effect in providing visual images of ACL injury grades, location of the tear and even, if any other ligament is injured or damaged. In some cases, X-rays are also required to know whether any bone is broken or not.


Types of ACL injuries:

ACL grades types of injury

  • ACL Grade 1 Tear – Minor Sprain: A small number of fibres i.e. 10% are being torn or damaged. The micro-tear is incomplete and ligament is still connected keeping the knee stable. In addition, there is no loss of function. This type of tear do not require surgery.
  • ACL Grade 2 Tear – Partial Sprain: Significant numbers of fibres are torn and damaged resulting in moderate loss of function. However, the ligament is still connected but becomes loose. There is instability in the knee joint and it doesn’t require surgery.
  • ACL Grade 2 Tear – Severe Sprain: All the fibres are completely ruptured and the knee joint will become unstable. ACL will split into two, which results in total loss of function. Often, ACL is accompanied by tear in menisci or any other ligament. Surgery and comprehensive rehabilitation are required for complete recovery.

What are the Symptoms of ACL Tear?

Immediate after incurring ACL injury, patients will feel pain at the point of injury because the tissues will gets torn and inflamed. Some of the symptoms associated with ACL tear are:

  • Sharp pain at the point of injury i.e. deep inside the knee.
  • Audible tearing sound or pop can be heard at the time of injury.
  • Swelling and bruising will developed.
  • Knee will become unstable.
  • Loss of function and range of motion.
  • Tenderness in the knee joint.
  • Discomfort and uneasiness while walking.
  • Knee will become stiff as patient are unable to bend or straighten the leg.
  • Unable to bear weight of the body on knee joint.
  • Knee giving away sensation.

What are the Treatment of ACL Tear?

Treatment generally depends on the type and severity of injury. For athletes, it is important to get healed as quickly and safely as possible to return to sporting activities. Some of the common treatments that are extremely effective in healing the ACL tear are as follows:

  • R.I.C.E. Formula: The acronym stands for protect, rest, ice, compress and elevate. Immediately after surgery, patient should protect the knee from further injury, rest the knee, ice it 15-20 minutes several times a day, compress the knee with the help of elastic bandage and elevate the injured leg above the level of heart. This formula helps decrease pain and swelling.acl recovery
  • Bracing: Doctors often advise knee braces because they are extremely useful in providing protect and support to the knee. They even provide stability to the knee joint. Even after the ACL is healed, many athletes or sporting individuals are advised to use specific knee braces that will provide them strength and balance during playing sports.
  • Physical Therapy – Rehabilitation Program: Once the pain and swelling subsides, rehabilitation program should be started in the guidance of expert physical therapist. exercises are extremely important for recovering from ACL injury. Generally, torn ACL requires surgery. For example, if the patient is athlete or sportsperson, then surgery along with rehab program is conducted for speedy recovery and return to sports. However, if the patient is aged or have low activity level, then rehab along with bracing is sufficient for completely recovering from the injury. Some of the effective physical exercises are:

Phase 1 Exercises:  First Six Weeks after Injury

  1. Quadriceps Setting
  2. Heel Prop
  3. Heel Slides
  4. Straight Leg Lift
  5. Stationary Bicycle
  6. Standing Hamstring Curl
  7. Standing Toe Raise
  8. Hip Abduction
  9. Wall Slides
  10. Heel Slides
  11. Straight Leg Lift

Phase 2 Exercises:  6 Weeks after Injury Onward 

  1. Chair Squat
  2. Step-Ups
  3. One-Legged Toe Raises
  4. Hamstring Stretch
  5. Quadriceps Stretch
  6. Calf Stretch
  7. Leg Press
  8. Resisted Hamstring Curls

Additional Yoga & Physical Exercises:ACL yoga exercises

  1. Bridge
  2. Bridge with Leg Lift
  3. Moving Warrior 2
  4. Reclined Leg Raises
  5. Tree
  6. Leg Slides
  7. Child’s Pose
  8. Moving High Lunge
  9. Seated Staff Isometric Quad Engagement

  •  Medications: Analgesics are often prescribed by the doctors. However, it is advisable for consulting your doctor for effective medication and dose.
  • Compression Bandage: They are specially designed to provide comfort and support to the knee. Consult your doctor before wearing them. However, ensure you do not wrap tightly or wear at night.
  • Massage Therapy: Therapeutic massages are great in decreasing swelling and pain. It is considered safe by Mayo clinic as effective treatment for knee joint pain. Palpitation technique, cross-friction on the patella technique and roll massage are quite safe massages, which should be performed by expert and qualified physical therapist.
  • Crutches or Walker: They are quite useful while walking, because they hold off the patients from putting too much weight on the injured knee.
  • Surgery: ACL should be reconstructed with replacing torn ligament with healthy tissue graft. This surgery is called ACL reconstruction. ACL cannot be stitched back.

Recovery Period for ACL Tear: 

  • The First Days: PRICE formula is quite effective in initial days.
  • Weeks 1-2: Range of motion exercises are performed along with gait training and stationary bicycling.
  • Weeks 3-6: Balancing and pro-prioceptive exercises.
  • Weeks 7-12: Low impact activities like light jogging, cycling outdoors, & swimming pool workouts. Avoid high risk sports like basketball, soccer and football.
  • Months 4-7: Training drills like figure of 8, plyometrics, and sporting drills can be performed.
  • Month 8: Return to Sports: you may be able to return to playing sport after consulting your physical therapist or doctor.

Conclusion – ACL Tear:

The outlook is good. Many individuals and
return to sporting activities after a period 6 or 7 months. In order to avoid the recurrence of ACL tear, it is advisable to avoid aggravating activities. Always train under guidance of experts and learn proper sports techniques for successful career.