What is the ACL?
The knee joint is formed by three bones, namely, the thighbone (femur), the shin bone (tibia) and the kneecap (patella). The knee joint is held together by four ligaments – the ACL (Anterior cruciate ligament), the PCL (Posterior Cruciate Ligament), the MCL (Medial Collateral Ligament), the LCL (Lateral Collateral Ligament), the 4 ligaments wok together to keep the knee stable during movements. Out of the 4 ligaments, the anterior cruciate ligament (ACL) is the most important because it allows the knee to perform high speed pivoting movements, which is especially important in sports such as soccer, basketball, tennis and skiing. The ACL forms a cross with the PCL, and hence the name “cruciate ligament”.
What is an ACL Tear?
ACL tear usually occurs as a result of a twisting injury during sports. It is a very common injury among athletes who partake in high impact sports such as soccer, basketball or combat sports. This may be due to a rapid change in direction, sudden stops, wrong landing from a jump or fall incorrectly and direct collisions/ tackle resulting in a partial or full tear of the ACL.
Commonly, a popping sound is heard at the moment of injury, accompanied by an excruciating pain, and usually the following signs and symptoms:
- Pain and swelling of the knee that lasts more than 48 hours
- Loss of full range of motion
- Tenderness and swelling along the joint line
- Discomfort while walking
- Instablity – the feeling of the knee giving way/ buckling
What is an ACL Tear?
Besides physical examinations that assess knee stability and mobility, MRI will be the most accurate method to diagnose an ACL tear. It is important to assess whether there are any concomitant injuries to the cartilage/ meniscus.
The injury is then graded accordingly:
- Grade 1: No tear. Minimal stretching of the ligament. The knee is fairly stable.
- Grade 2: Partial tear. The ligament is overstretched such that it is damaged and loose.
- Grade 3: Complete tear. The knee joint is unstable. Surgery is required for correction.
Frequently Asked Questions
Without this ligament, the knee tends to give way. When the body turns, the leg doesn’t follow, and your knee will buckle. Each time the knee buckles, you will likely damage the knee structures further. In other words, you will likely develop earlier post-traumatic arthritis (arthritis that develops as a result of injury) each time you injure your knee.
The honest truth is that the ACL will never heal on its own.
You will find that your knee is weak and tend to buckle, especially when you exercise and ultimately, you’ll likely develop post-traumatic arthritis prematurely. Think of your knee as a car, If you don’t fix a problem, it will eventuallybreak down.
The good news is that not every patient with an ACL injury requires surgery. Conservative non-surgical treatment aim to rehabilitate the ACL through a combination of strengthening, lifestyle modifications, and bracing.
A knee brace stabilize the knee externally, taking over the work of your ligament. However, your ligament will never heal on its own, and the brace can only compensate to a certain extent. for the time being.
ACL and the hamstrings work as a pair, hence stretching/ strengthening the hamstrings will be able to compensate some of the ACL function and provide some stability to the knee.
The plain truth is that if you’re very active and keen to return to sports, you will be better off considering the surgical treatment, or else you risk injuring your knee repeatedly But if you enjoy a more sedentary lifestyle, conservative treatment may also be the right choice. With conservative treatment, you can expect to regain 50-to-60 percent of your previous knee function. Back to the car analogy, if you are travelling on a highway and your car’s maximum speed is only 50-60km/hr, will that work for you?
We make those decisions based on patient’s age and lifestyle. Active patients under the age of 40-45 are generally ideal surgical candidates – their surgical risk is extremely small with very high functional recovery and restoration of the knee function.
Athletes often have difficulty returning to pre-injury performance as their sport heavily relies on full functioning ACL to perform manoeuvres such as cutting, pivoting and sudden turns. And hence most athletes would opt for ACL reconstruction surgery.
The estimated timeline for post ACL reconstruction surgery recovery is as follows.
2 weeks before the surgery: Physical therapy may be recommended to reduce pain and swelling, restore full range of motion and strengthen muscles. This increases the chances of a full recovery after the surgery.
0-2 weeks after the surgery: Crutches must be used to reduce weight being put on the knee. Dressing of the wounds need to be kept dry. Frequent icing and elevation will help to reduce swelling. And pain killers/ anti-inflammatory medications/ antibiotics will be prescribed to help manage the post operative pain and reduce the risk of infection.
2-4 weeks after the surgery: A knee brace will be recommended to be fitted and worn for 6 weeks after the4 surgery. Physiotherapy would commence and should be done consistently to ensure a speedy recovery.
2-9 months after the surgery: Progressive physiotherapy will help to strengthen muscles around the knee and improve flexibility. Depending on the specific type of sports that the patient is returning to, Dr Chan may also recommend a tailor made therapy programme together with the physiotherapists. It is paramount for recovery that patients work closely with their doctor and the physiotherapist to ensure a full recovery after the ACL reconstruction surgery.