Anterior Cruciate Ligament (ACL) Injuries

Our ligaments are strong bands of tissue that connect one bone to another. The anterior cruciate ligament (ACL) is one of the two ligaments that cross in the middle of the knee to connect your thigh bone to your shin bone. The ACL plays an important role in stabilising your knee during activity.


An anterior cruciate ligament (ACL) injury is a tear or sprain of the ACL in the knee. ACL injuries seen by orthopaedic specialists in Singapore often occur during sports and fitness activities that can put stress on the knee.


Some of these activities include: 

  • Suddenly slowing down and changing direction 
  • Pivoting with your foot firmly planted
  • Sudden stop movements
  • Landing awkwardly from a jump 
  • Receiving a direct blow to the knee


Sports like soccer, basketball, combat sports, and downhill skiing are the common causes of ACL injuries for patients in Singapore. 


When your ligament is damaged, there is usually the presence of a partial or complete tear of the tissue. Sustaining a mild injury may end up stretching the ligament, but the ligament is left intact. While ACL sprains typically heal, ACL tears may result in knee instability that affects sporting activity, and in the long term may predispose to meniscal or cartilage damage in the knee.

Knee ACL Injury that Needs Surgery in Singapore
Signs and Symptoms

You may hear a popping sound in your knee and feel it give out from under you when you injure your ACL. 


Other accompanying symptoms include: 

  • Knee pain: varying from discomfort while walking to severe pain that does not allow weight bearing
  • Rapid swelling within 24 hours. 
  • The pain and swelling may resolve over time, however if you attempt to return to sport, your knee may feel unstable, commonly described as the “knee giving way”




When you visit an orthopaedic specialist or doctor in Singapore, they will find out more about your medical history, mechanism of injury and the symptoms that you’re experiencing. They will also perform a physical examination to check the structures of your injured knee and compare them with the non-injured one. These usually involve stress tests that check the integrity of the ACL. Your specialist will also check for signs of associated injuries such as meniscus tears and tears of the other ligaments of the knee.


While most ACL injuries can be diagnosed through a physical examination of the knee, your orthopaedic specialist may need to perform special imaging tests to rule out other causes and to determine the severity of your injury. These tests include X-rays, and MRI scans.




It is advisable to seek prompt medical treatment if you suspect that you’ve injured your ACL. A torn ACL will not be able to heal without surgery, and over time, may result in further damage to the meniscus and cartilage of the knee. 


The treatment options for an ACL tear are dependent on the patient’s individual needs, activity level and severity of injury. For instance, a young patient with a complete ACL tear, leading a very active lifestyle will likely require ACL surgery to safely return to sports. However, older and less active patients may choose to accept a more sedentary lifestyle without surgery.


Nonsurgical treatment options often involve wearing a knee brace and physical therapy to regain knee range of motion and strengthen surrounding muscles. However, as the ACL does not heal reliably, this is not an ideal treatment and patients usually have to accept a lower level of activity.


Your doctor may recommend ACL surgery as a treatment option if: 

  • You are an athlete and want to continue in your sport
  • More than one ligament in your knee is also injured
  • The injury is affecting your quality of life


Surgery involves ACL reconstruction with a tendon harvested from another part of your body (autograft) or from a specially processed cadaveric donor (allograft). This can be done through arthroscopic (keyhole) methods, allowing faster recovery with shorter length of hospitalisation.


Every case is different, hence it is best to consult an orthopaedic surgeon for an accurate diagnosis so that you can obtain the best treatment option that is most suitable for you. Reach out to us today if you suspect that you are suffering from an ACL injury, and let us help you enjoy a better quality of life.


Frequently Asked Question (FAQ)

1) Can ACL tears heal naturally?
Full ACL tears will not heal on their own as there is no blood supply to this ligament to help it recover. For partial or mild ACL tears, some level of healing is possible with rest and physical therapy, but it is important to consult with a trained medical professional for advice.
Partial ACL tears can worsen and result in a full rupture, especially if there’s continued stress to the knee. Follow up medical appointments and appropriate treatment plans are crucial in ensuring patients don’t exacerbate the condition.


2) Can ACL tears lead to further complications?
Leaving an ACL tear untreated runs the risk of developing chronic knee problems due to instability. Some common complications of ACL tears include meniscus tears, osteoarthritis, reduced range of motion, and chronic knee pain.

3) How long is recovery after an ACL reconstruction?
While you may be able to walk just weeks after an ACL reconstruction surgery, it may take a few months and up to a year for a full recovery and return to your previous level of physical activity. During this time, physical therapy and activity modification are important to improve the rate of success.