acl injury

What is the ACL?

The ACL is one of four major ligaments that stabilize the knee joint complex. The ACL attaches from the back of the thigh bone (femur) to the front of the main shin bone (tibia). The role of the ACL is to prevent the tibia translating forwards on the femur.

anterior view of the right knee - acl injury

Who injures their ACL?

ACL injury are relatively common among athletes who are involved in sports requiring frequent pivoting, twisting, and changes in direction. Common sports involve touch football, field hockey, basketball, netball, and skiing.

Females are also more likely to sustain an ACL injury compared to their male counterpart.

Types of Tears

ACL may occur in isolation, and can be classified into 3 grades. A grade I injury is a minor tear of the ligament, and can be very painful. Grade II is a significant tear to the ligament, and grade III is a complete rupture.

ACL injuries may also occur in combination with associated structures in the knee, including the medial meniscus and the medial collateral ligament (MCL). An injury involving all these structures is termed “O’Donohue’s triad”.

ACL Injury Symptoms

  • There may be an audible crack or pop may be heard at the time of injury
  • Extreme pain, especially at the immediate time of injury
  • Usually, athletes are unable to continue activity and there is immediate swelling of the joint. This swelling is occasionally minimal or delayed.
  • Knee movement is usually restricted, in particular the ability to fully straighten the knee.
  • Special tests are used to clinically guide diagnosis.
  • If clinically unsure, further investigative tests include MRI and X-ray.

ACL Injury Treatment

Treatment type is dependent on a number of factors including: age; lifestyle; degree of knee instability; occupation; other implicated structures; and patient preference.


  • Stop play
  • Rest, ice, compress, elevate
  • Reduce pain and swelling using modalities and local tissue techniques
  • Muscle strengthening
  • Increasing balance/stability
  • Gait (walking) retraining


Involves repairing or reconstructing the injured ACL


  • Hamstring graft
  • Patella tendon graft
  • LARS (Ligament Augmentation and Reconstruction System)

Length of physiotherapy rehabilitation following surgery

Generally rehabilitation takes 3-12 months depending on type of surgery and surgeon protocol.

How can a PPS Physio help?

Your PPS Physiotherapist can help diagnose the problem and establish its severity. From this information an appropriate treatment plan can be made to get you back to full recovery as soon as possible.

This may involve activity modification, massage and mobilizations and other therapeutic agents to make you feel better. They will also tell determine and correct any biomechanical or postural issues that predispose you to injury.

Most importantly, your PPS Physiotherapist in Kellyville and Carlingford clinics will provide you with specific stretches and an exercise program to prevent this issue from reoccurring when you return back sport. We are also offering our physio services on nearby suburb areas including Epping, Castle Hill, Hills District and Baulkham Hills.