Anterior Cruciate Ligament (ACL) Tear
What Causes ACL Tear?
The ACL tears when excessive force is applied to the knee, usually in sports injury, fall or motor vehicle accidents. It occurs when the knee is twisted or jerked forward beyond a certain limit. ACL tear is common in certain sports such as football and skiing.
What Is an Anterior Cruciate Ligament (ACL)?
There are four ligaments that stabilises the knee joint. Two of them are located outside the knee joint and the other two are located inside the joint (intra articular). These intra articular ligaments cross each other in a cross-like formation and are therefore known as cruciate ligaments. The front intra articular ligament is known as the Anterior Cruciate Ligament (ACL).
What Are the Symptoms and Signs of an ACL Tear?
- Immediately after injury of the ACL, there will be significant pain and swelling at the knee
- Swelling normally occurs over a few hours
- Difficulty walking initially after injury
- The pain and swelling subsides after some time, but the knee remains unstable
- After the initial recovery, the patient usually experiences episodes of knee giving way specially when twisting or turning
Normal ACL Torn ACL
Can A Completely Torn ACL Heal Without Surgery?
A torn ACL cannot heal by itself. The knee joint is filled with synovial fluid, which prevents blood clot formation and torn ligaments to come into contact. Therefore, ACL cannot heal without surgery unlike the ligaments outside the joints, which have good healing potential.
If a torn ACL is left untreated, the patient may be predisposed to other knee injuries such as meniscus tear and may develop osteoarthritis.
What Is the Treatment for ACL Tear?
- Although ACL cannot heal by itself, many patients will cop well without surgery especially those with sedentary lifestyle with low physical demands.
- Following ice rest and analgesics immediately after ACL injury, physiotherapy treatment will improve the function of the knee over time.
- Without surgical treatment, those with torn ACL should not participate in high demand activities that requires jumping and pivoting.
- Surgery is recommended for young and physically active patients.
- ACL reconstruction is done by replacing the torn ligament with a tendon either from the patient (autograft) or from a donor (allograft).
- This surgery is normally conducted with arthroscopy (key hole surgery).
What Is an Arthroscopy?
Arthroscopy is the procedure of inserting a telescope into the knee and is connected to a monitor, so that the inside of the knee can be visualised. Through another small hole (portal), instruments are inserted into the knee to reconstruct the ligament.
What Should I Do After Surgery?
- After surgery, the patient will have to protect the operated ligament by using crutches or knee brace for about a month
- The patient can usually walk unaided after one month and can start jogging after four months.
- Depending on muscle strength, the patient may be able to resume sport activities after about nine months
What Is the Prognosis of ACL Injury?
Although there have been occasional cases of partially torn ACL healing on its own, ACL almost never heal by itself.
With accurate placement of graft and adequate rehabilitation, a patient undergoing ACL surgery can anticipate 85% to 90% recovery.
Is It Possible to Prevent ACL Tear?
Several studies have shown that muscle-strengthening and proprioception training can reduce the incidence of ACL tear in high physical demand athletes.
Adhering to strict rules of sports and with regular training, ACL injury can be reduced in professional sports.
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