Common Conditions

Anterior Cruciate Ligament (ACL) Injury

ACL Injury Symptoms, Common Causes and Treatments

What is the function of anterior cruciate ligament (ACL)?

Anterior cruciate ligament is a strong band connective tissue, located inside our knee joints connecting the femur and tibia bone. It plays a critical role in stabilizing the knee, resisting anterior tibial translation and preventing excessive external rotation, as well as excessive valgus and varus stresses during pivoting sports. Besides, it also provides proprioceptive function due to the presence of mechanoreceptors in the ligaments.

Common Causes of Anterior Cruciate Ligament (ACL) Injury

ACL injuries are among the most commonly reported ligament injuries, with annual reported incidence approximately 1 in 3500 people in the United States alone. Most of the ACL injuries in athletes are non-contact injury, happening during pivoting and cutting during sports. Due to the complex role of ACL in knee functions, a comprehensive and individualized programme is required after injury.

Symptoms of Anterior Cruciate Ligament (ACL) Injury

Signs and symptoms of an ACL injury usually include:

Pop sound or a popping sensation in the knee during injury
Rapid swelling
Severe pain over knee and inability to weight bear
Reduced knee range of motion
Sense of ‘give way’ or instability

These symptoms can vary based on the severity of the injury and your tolerance for pain.

Risk factors

While anyone can injure their ACL, certain factors can put an individual at higher risk:

Poor conditioning: muscle strength not strong enough especially quadriceps and hamstrings
Fatigue: injuries happened during later phase of the games
Being female: higher risk of ACL injury with female-to-male ratio reported 4.5:1
Anatomical factors: larger body mass index, smaller ACL, hypermobility
Poorly fit shoes
Poor quality of the pitch
Previous ACL injury

Anterior Cuciate Ligament (ACL) Reconstruction Rehabilitation

Acute Stage (Week 1-5)

For those who undergo ACL reconstruction surgery, early and comprehensive rehabilitation is crucial to restoring full knee function and prevent muscle wasting. Different modalities including electrotherapy, ice and compress, soft tissue massage and joint mobilization technique can be used for pain and swelling control. Physiotherapists would educate patients to perform appropriate rehabilitation exercises which are safe and important for the following rehabilitation period.

Three factors are crucial:

Early weight bearing
Attain full terminal knee extension
Strengthening the whole trunk and lower limbs by closed and open kinetic chain exercise with symptoms allowed

Subacute Stage (Week 6-10)

During this stage, patients should have adequate knee range of motion and strength. Treatment plan would be focused on building up strength by both open and closed chain exercises such as lunges and squats. The intensity of the exercises would begin with light weight (less than 50% of maximum force) and progressively increased. Besides strengthening, proprioceptive training and coordination exercise would be added if the symptoms are well controlled.

Intermediate Stage (Week 11-16)

With adequate treatment and training, patients should have full range of motion and good lower limb strength at this stage. Treatment plan would then be focused on progressive loading as tolerated and implement dynamic jogging and hopping exercise. Different planes of movement should be added into the training programme to prepare patients for returning to on field training.

Later Stage (Week 17 onwards)

During this stage, the goal of treatment is to maximize strength and endurance of the knee, and begin different plyometric training. Deceleration, acceleration, pivoting and cutting are essential components in different sports and require loads of training to maneuver the technique and reflexes to improve efficiency and prevent another trauma.

Return to sport

Many studies showed that returning to sport earlier than 9 months after surgery would greatly increase the chance of re-rupture of the ACL. Therefore it is highly recommended that patients with ACL reconstruction should return to sport at least 9 months after surgery.

Criteria Of Returning To Sport

At least 90% quadriceps and hamstrings strength compared to uninjured side
At least 90% performance during different hop tests compared to uninjured side
No pain or swelling
Psychologically ready

Frequently Asked Questions

Does an ACL injury always require surgery?

No, not all ACL injuries require surgical treatment. For some mild, non-complete ACL tears, proper conservative treatment such as physical therapy and functional training can also help restore knee joint function. However, for severe injuries or unstable knees, surgical treatment is usually the better choice. Doctors will assess the best treatment plan for the patient based on the specific situation.

What should patients pay attention to during the post-operative rehabilitation period?

The rehabilitation process after surgery is a long and challenging one. Patients need to follow the physiotherapist’s advice and pay attention to the following:

Persist with daily functional and strength training exercises to gradually restore knee joint flexibility and muscle strength.
Undergo regular professional assessments and adjust the training plan accordingly based on the recovery progress.
Be patient during the recovery and do not return to intense physical activities too early to avoid re-injury.
Maintain a positive psychological state and follow the therapist’s guidance to complete the entire rehabilitation process.

What are the long-term impacts of an ACL injury?

If an ACL injury does not receive proper treatment and good rehabilitation, it may lead to some long-term consequences, such as:

Knee instability
Degenerative changes in the joint cartilage, increasing the risk of osteoarthritis
Decreased sports ability, making it difficult to return to the pre-injury level
Psychological impact, causing fear and anxiety towards future physical activities

Therefore, only through professional treatment and systematic rehabilitation training can these long-term consequences be minimized.

Testimonials & Reviews

After suffering years of chronic knee issues after ACL reconstructive surgery I was recommended to this clinic and the results were amazing. The centre does not only focus on pain relief but with an extremely holistic approach, assesses the root cause of pain and focuses on return to sports and performance once the pain diminishes. Most physiotherapy centres in Hong Kong do not even offer this level of attention to detail and service and would highly recommend to anyone having chronic pains or want to have proper post orthopaedic surgery rehabilitation!

Arnold Woo

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I had never been a believer in physio therapy in the past or that my experience with multiple chain medical physiotherapy center had brought me nothing but temporary improvements. Until I had came across mobilize physiotherapy where they take the extra mile to examine your situation and tailor a physiotherapy session. The physiotherapists at mobilize not only identifies the root cause and provide massages for pain relievers but also to provide take home excerises for improvements.

I was never rush out the door for the next session and they ensure that I had receive the right treatment before the session ends. I would highly recommend this physiotherapy center.

Edmond Chan

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I came to them with chronic neck and knee issues, and they didn't just provide massage therapy. They took the time to thoroughly evaluate the source of my problems and develop a comprehensive treatment plan. Through a combination of targeted hands-on therapy, customized strengthening exercises, and patient education, they helped me regain mobility and address the root causes of my pain. I learned the correct ways to strengthen the muscles and improve my posture to prevent future issues.

The staff is incredibly knowledgeable, taking the time to explain everything and ensure I understood how to continue my progress at home. Thanks to their expertise and dedication, I'm now pain-free and able to return to my regular activities without any limitations.

Arthur Liu

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I can't recommend my physio partner enough! They are always patient and provide valuable guidance to help me relieve chronic pain and improve my performance in jiu-jitsu. Their expertise has been invaluable to me. Highly recommended!

Felix Kung

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Mobilize Physiotherapy is definitely my long trusted go to for physiotherapy. I have been treated by Avery himself over the years and he have always provided the highest care, treatment and advice. I would highly recommend this clinic to anyone who suffer any sports-related or musculoskeletal conditions. All you need is to visit the right clinic and find the right person to help you!!!

Becks L

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Excellent services with professional suggestion for your rehabilitation. Ideal place, close to MTR station.

Phei Lau

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