The anterior cruciate ligament or ‘ACL’ is a ligament inside the knee joint that provides stability to the knee by stopping forward movement of the tibia or shin bone.
The most common method of injuring the ACL is a bending and twisting movement of the knee with the foot planted on the ground. This movements can occur when changing direction sharply in a sprint or due to an awkward landing from a jump. The ACL can also be injured by a direct blow to the knee resulting in an inward rotation movement. Injuries to the ACL can be categorised from a Grade 1 where less than 50% of the ACL is torn, grade 2 where more than 50% of the ACL is torn and a full rupture of the ALC is known as a grade 3 tear.
When the ACL is completely torn there is an audible ‘popping’ noise and a feeling of something within the knee joint moving out of and then back in. Pain is usually experienced for the first few minutes after the injury and can subside quickly. The injured knee may feel unstable when walking and running or perform a twisting motion. Significant swelling normally occurs within the first couple of hours and lasts for up to 10 days. It is common to experience muscle tightness and weakness around the knee immediately after your injury.
You should see your physiotherapist as ACL tears are initially diagnosed using physical tests where a physiotherapist or doctor assesses the integrity of the ligament. They consider how much movement the knee joint has relative to the other side. This test should be done at the time of injury or after the swelling has gone away as it can be difficult to assess movement within the knee joint when the knee is significantly swollen. Your physio may refer you to a specialist for an MRI to assess the degree of the ligament tear and to check if the meniscus or medial collateral ligament (MCL) is also injured.
Grade 1 & 2 ACL tears are managed conservatively with physiotherapy. Your physiotherapist will initially focused on reducing pain and swelling, restoring range of motion and a normal walking pattern in the first 0-2 weeks. From week 3 on-wards, your physio will focus on restoring strength, balance and motor control using a progressive exercise program. Your physiotherapist will use the limb symmetry index to benchmark your progress. You should aim for a minimum of 90% symmetry with the uninjured side on strength testing. For individuals who require a high level of function such as those who play ball sports, runners or dancers, return to sport testing will need to be completed to ensure that you have the ability to return safely without concern of re-injury. An estimated time frame for a grade 1 tear is around 8 weeks while a grade 2 ACL tear can vary between 12 to 26 weeks.
Grade 3 ACL tears can either be managed surgically or conservatively with physiotherapy but you should always have a review with an ACL surgeon whichever treatment pathway you decide to choose. An estimated time frame for rehabilitation is 9 to 12 months from the date of injury with conservative management or from the date of surgery. Given the significant length of rehabilitation you may be eligible for ACC programs to help provide extra supports in your care.
Rehabilitation plans differ depending if you choose to go down the surgical or non-surgical route, but the below rehabilitation phases are to give you a guide on what you can expect during your rehabilitation. Which ever pathway you choose you can expect your rehabilitation to be between 9 to 12 months.
The beginning phase is focused on managing the swelling and bring down your pain. Rest, ice, compression, and elevation are all good ways to help bring the swelling in your knee. Once your pain and swelling has reduced you will need to focus being able to full straighten your knee again.
Squatting, single leg balance, walking and cycling are all common exercises in the early phases of an ACL rehabilitation. At this stage your swelling in your knee should have subsided and you should feel like you are back to walking normally again.
The majority of ACL rehabilitation will consist of a gym component. This is because your knees have to absorb a lot of force, so they need to have the sufficient strength to cope. Using weights in the gym allows you to utilise the overload principal to stimulate extra strength around your knee. Using the limb symmetry index is a great to benchmark how strong your knee needs to be. Ensuring your knee strength is within 10% of the other side is a great way to know how much more you need to keeping pushing yourself.
Hopping, jumping and running are all important movements to get back to doing the things you love. These are known as plyometric movements. Ensuring you have the sufficient strength, balance and co-ordination to stop yourself on landing are some the biggest factors will influence your risk of re-injury. See our sports injury rehab page for some of the common return to sport testing we like to use at Link Health and Fitness.
We have experienced senior clinicians with one of the best equipped facilities on Auckland’s North Shore. Our patients have access to a full gym and Pilates studio to allow us to develop an exercise program specific to your needs. Independent gym exercise is an important part of most ACL rehabilitation. At Link Health and Fitness a physiotherapist is always available during staffed hours to offer you additional support.
We are part of several ACC programs, and you may be eligible to receive fully subsidised healthcare for your injury. To find out more don’t hesitate to book online or contact us on 095536565.