Anterior Cruciate Ligament (ACL) injuries are common sporting injury, particularly for athletes playing sport that require a lot of sudden changes in direction eg. soccer, netball, rugby.
What is the ACL?
The ACL is one of the four stabilising ligaments within the knee. The picture below depicts a knee from the front angle, clearly showing the ACL, and surrounding ligaments.
As you can see, the ACL is like a rope running from the top of the shin bone (tibia) to the bottom of the thigh bone (femur).
The role of the ACL is to offer mechanical stability, prevent forward sheering of the shin against the thigh bone and to provide stability through rotational movements like twisting and pivoting.
(What’s the difference between a ligament and tendon? … refer to our website for the blog that explains the difference between tendons and ligaments)
Mechanism of injury:
The ACL is a high risk of rupture/complete tear during the following activities:
- Pivoting quickly on a foot that is planted on the ground
- Sudden changes of direction/stopping
- High impact to the knee when the foot is planted on the ground
Most people who have ruptured their ACL report hearing a “pop” followed by immediate pain and swelling within hours.
The ACL can rupture in isolation without damaging other ligaments and structures in the joint. Depending on the severity of the injury though, other ligaments or structures like the meniscus in the knee may be injured as well. This can then complicate your rehab and affect your options for treatment.
Treatment Options:
There has been increasing controversy about the best way to approach and treat a ruptured ACL. Obviously, surgeries do come with risks that may include the increased risk of developing osteoarthritis later down the track, and even a higher chance of re-rupture. On the other hand, if a ligament is left untreated, the remaining instability can put extra pressure on other structures in the knee also resulting in arthritis. Diligent physiotherapy is key to the success of you rehab either way.
Previously, most of these injuries were treated surgically, repairing the ruptured ligament. Recently however, specialists and physiotherapists are urging their patients to avoid surgery all together, and conservatively manage their injury. In this instance, the ligament is not repaired, rather the muscles around the knee are strengthened to stabilise the knee, avoiding the need for surgery. Researchers call this “functional instability.”
More and more research is showing that patients are able to return back to sport/function just as well without surgery then they are with, avoiding those possible risks of surgery.
Unfortunately, there is no specific assessment tool to identify those patients who would succeed in conservative management. More dynamic screening tools have been developed to identify these patients, but the decision is generally very individualised.
So, what is the best approach……the simple answer is it depends on your lifestyle and what your goals are. If you are an athlete, wanting to return to high-risk sports (like those mentioned above), ACL surgery may be recommended however for those people who have no desire to return to sport, and only need to perform day to day tasks, the conservative approach may be best. Additionally, injury to other ligaments/structures that may need surgical repair will also impact on the best treatment option for you.
Below will outline the difference between both conservative and surgical treatment options. It is important to discuss both options with your physiotherapy/specialist in order to choose the most appropriate option for you.
Initial Management:
Once the ACL rupture has been identified by your physiotherapist or through an MRI, rehabilitation starts immediately. The goals are to reduce pain, swelling, ensure your quads are activating and improve your balance and range of motion. Ice, anti-inflammatories and gentle exercise are all things your physiotherapist will get you started on. Your physiotherapist will then discuss with you, your options of surgical and conservative
Surgical ACL Reconstruction:
Surgical repair continues to be the most common treatment of ACL ruptures. The surgery involves making a new ACL ligament from either tendons in your own body (hamstring/patella/quadriceps) or a donor graft (e.g. from family member). Researchers are working on making a synthetic graft to lower the effect of injury to the grafted muscle however they are yet to be proven more beneficial.
The surgery is minimally invasive through arthroscopic approach and is often only day surgery (no overnight stay needed). Once the surgeon has removed the ruptured ligament and made a new one with the tendon chosen, the new ligament is secured in the place of the old ligament.
What happens after surgery?
Physio is started immediately after surgery. The initial goals of physiotherapy are to reduce swelling, ensure you have adequate quadricep activation and achieve full extension of your knee. You shouldn’t need to wear a brace post op however some specialists encourage you to do so, especially if other injuries were addressed during the surgery.
You generally follow up with the specialist a few times in the first 3 months.
How long will it be before I can run? The rule of thumb is 12 weeks before you can run in a straight line. Obviously, there is a lot of rehab and exercises that need to be done before this so ultimately it is up to how your rehab is going and whether your body can handle returning to running.
When can I get back to my sport? As mentioned above, it does depend on how you are recovering post op. Usually, most athletes are able to return to sport in 12 months post op. This will be following an extensive, sport specific rehab process.
Conservative Treatment:
There are several factors to take into consideration when considering conservative treatment of an ACL rupture:
- Other injuries to the knee that are affecting stability – eg. torn meniscus/MCL in addition to an ACL rupture which reduces the success of conservative treatment
- Level of sport you are wishing to return to – if returning to sports that require a high level of twisting/pivoting, research has shown that conservative management may not be as successful as surgical repair
In saying this, more and more specialists are encouraging appropriate patients (those with an isolated ACL rupture and those who are fairly sedentary/returning to sports requiring less pivoting/twisting) to consider conservative management. With the right rehab, surgery can be avoided and the risks of degenerative changes like arthritis can be reduced.
So, what if you want to return to a sport that requires high levels of pivoting but don’t want surgery? If you have an isolated ACL rupture and you have passed the screening post injury you could potentially manage well with conservative management however you will need to undergo a rigorous rehab protocol to ensure you knee is stable enough to avoid injuring other structures. You will be at risk of further, more serious damage to the knee if physio is not maintained.
For any questions, call mudgeephysio. (6372 4033) to book an appointment with one of our physiotherapists.