Anterior Cruciate ligament injury is one of the most prevalent injures in the knee. This is often seen during sports activities. However, this can happen during work or daily activity.
ACL injury accounts for up to 64% of knee injuries in cutting and pivoting sports. *2
Roles and features of ACL
ACL prevents the tibia from going forward and gives stability for rotation in both frontal and transverse planes. ACL consists of two bundles which are anteromedial and posterolateral bundle. Lateral intercondylar notch is the landmark to separate two bundles. They originate from intercondylar eminence of the tibia and inserts into lateral intercondylar ridge and lateral bifurcate ridge. Anteromedial and posterolateral bundles work together to stabilize knee joint from rotation load (posterolateral and anteromedial) and translational load (anteromedial). ACL is a band-like shape, trumpet-like shape at tibial insertion point and Crescent-like shape at the femur.
- Knee abduction with loads *3
- Direct trauma
- Indirect trauma (direct blow the thigh and translating femur posteriorly)
- Noncontact (falling from backwards after landing from high jump, sudden change of direction in sports)
- People who play soccer, basketball, ski, volleyball, netball, lacrosse, ice hockey and handball *1
- Valgus and rotation force (ex. knee goes in and feet turn out)
*Injuries are prone to occur with noncontact mechanisms (60-70% of ACL injuries)
Signs and symptoms
- Bone bruise *3
- Instability in the knee
- Popping sound
Secondary effect of ACL injury *1
- Joint effusion
- Instability in the joint
- Reduced functional performance
- Limited ROM
- Muscle weakness
- ACL reconstruction (Double bundles reconstruction, single bundle reconstruction, hamstrings tendon graft, quadriceps tendon graft, bone, )
- Knee brace if there are any other knee injuries such as MCL injury or meniscus tear
Rehabilitation or surgery?
There are some debated as to ACL injury treatment if the ACL reconstruction should be undergone or not. A research compared the outcome of ACL reconstruction with non-surgical treatment *9. 141 young, active adults with acute ACL injury were split into two groups which are ACL reconstruction followed by rehabilitation (62 participants) and just rehabilitation alone (59 participants). This study shows that there was no difference of symptom level measured by knee score between surgical treatment group and non-surgical group at two and five years. Although this was not strong evidence, 39% (23/59) of the participants in the non-surgical group underwent either ACL reconstruction or meniscus repair due to knee instability within 2 years while 51% of them determined to do in five years.
Stages of Rehabilitation* 8
- Acute recovery (recovery to light exercise)
·Ice to help heal wound and reduce swelling
·Walk without crutches and gain muscle control (mainly active exercise as pain allows)
*Resisted hamstrings exercise should be avoided for 10-12 weeks if it is hamstrings graft
* Resisted exercises should not be performed at least 4 weeks if it is patella-bone-patella graft
2. Strength and Coordination (single muscle exercise or weight bearing exercise)
·Develop muscle control and strength
·Gain the balance and stability
·Reduce recurrent knee swelling
*Knee swelling recurs due to overload
*Resisted open chain quadriceps exercise should be avoided as ACL graft strain can occur (machine leg extension or swimming kick)
3. Proprioceptive and Agility (this is the goal for non-athletes)
·Proper jumping and landing technique
·Progress muscle strength and stability
·Start to introduce compound exercise
4. Sports Specific Skills
·Complete running menu and sports specific drills
·Perfect jumping, hopping, landing and pivoting techniques
·Be ready for team training
5. Return to Competitive team ball sports (This is the goal for athletes)
·Complete sports specific rehabilitation and team training
·Confident enough to play and train sports
·Make sure to continue injury prevention program
*ACL graft and stiffness can last 8 months and remodelling continues after 12months
* For most people, it takes 12 months or so to return sports, especially for young athletes as they are at high risk for another knee injury within 12 months post-surgery. *10
- Kiapour AM, Murray MM. Basic science of anterior cruciate ligament injury and repair. Bone Joint Res. 2014;3:20–31.
- Benjamin Todd Raines, Emily Naclerio and Seth L Sherman Management of Anterior Cruciate Ligament Injury: What’s IN and What’s Out? Indian J Orthop 2017 51 (5): 563-575
- Levine JW, Kiapour AM, Quatman CE, Wordeman SC, Goel VK, Hewett TE, et al. Clinically relevant injury patterns after an anterior cruciate ligament injury provide insight into injury mechanisms. Am J Sports Med. 2013;41:385–95.
- Rahnemai-Azar AA, Sabzevari S, Irarrázaval S, Chao T, Fu FH. Anatomical individualized ACL reconstruction. Arch Bone Joint Surg. 2016;4:291–7
- Guenther D, Irarrázaval S, Nishizawa Y, Vernacchia C, Thorhauer E, Musahl V, et al. Variation in the shape of the tibial insertion site of the anterior cruciate ligament: Classification is required. Knee Surg Sports Traumatol Arthrosc. 2015;25:2428–2432.
- Hewett TE. An introduction to understanding and preventing ACL injury. In: Hewett TE, Schultz SJ, Griffin L, editors. Understanding and Preventing Non-Contact ACL Injury.Champaign, IL: Human Kinetics; 2007. pp. xxi–xxviii.
- North Sydney orthopaedic & sports medicine centre Justin roe Combined ACL and MCL injury https://www.justinroe.com.au/resources/infosheet-ACLMCLInfoSheetRoe2017.pdf
- Leo Pinczewski, justin Roe, Matthew Lyons, Benjamin Gooden, Phil Huang, Lucy Salmon and Emma Heath ACL rehabilitation protocol 2018 north Sydney orthopaedic research group
- Monk AP, Davies LJ, Hopewell S, Harris K, Beard DJ, Price AJ, et al. Surgical versus conservative interventions for treating anterior cruciate ligament injuries. Cochrane Database Syst Rev. 2016;4:CD011166.
- International Olympic Committee Pediatric ACL Injury Consensus Group, Clare L. Ardern, Guri Ekås, Hege Grindem, Håvard Moksnes, Allen F. Anderson, Franck Chotel, Moises Cohen, Magnus Forssblad, Theodore J. Ganley, Julian A. Feller, Jón Karlsson, Mininder S. Kocher, Robert F. LaPrade, Mike McNamee, Bert Mandelbaum, Lyle Micheli, Nicholas G.H. Mohtadi, Bruce Reider, Justin P. Roe, Romain Seil, Rainer Siebold, Holly J. Silvers-Granelli, Torbjørn Soligard, Erik Witvrouw, Lars Engebretsen International Olympic Committee Consensus Statement on Prevention, Diagnosis, and Management of Paediatric Anterior cruciate Ligament Injuries 2018 Orthop J Sports Med. 6 (3)