Anterior Cruciate Ligament (ACL) Injury

The Anterior Cruciate Ligament is one of four main ligaments in the knee which helps prevent excessive movement in the knee, making it stable. An ACL tear most commonly occurs during sport, and over 80% occur without any contact with another player. The ligament is typically injured during rapid changes in direction, sudden deceleration or when landing from a jump. Although less common the ACL can also be injured in day to day activities such as stepping off a ladder, slipping unexpectedly or twisting in high heels. Most commonly this type of injury occurs in sports that involve repeated stopping, starting and direction change such as netball, soccer, football and skiing.

Common Symptoms

  • Feeling or hearing a ‘pop’ in the knee at the time of injury
  • Sudden weakness, buckling or giving way of the knee
  • Pain in the knee, which is usually quite sharp at the time of injury
  • Significant knee swelling within the first few hours after the injury
  • Restricted movement, especially an inability to fully straighten the knee. This is particularly difficult once the knee has become swollen

Self Management

  • Immediately stop participation in the game or activity
  • Start the RICER ( Rest, Ice, Compression, Elevation, Referral) protocol immediately following the injury if possible
    • REST – Avoid any aggravating movement, to help prevent further injury
    • ICE – Apply an ice pack to the area for 20 minutes every 2 hours, for the first 48 to 72 hours
    • COMPRESSION – Apply gentle compression to the area by using a crepe bandage to wrap the knee.  Regularly check to ensure that it is not too tight.
    • ELEVATION – Elevate the leg on a pillow or stool if it is comfortable
    • REFERRAL – It is important to see either your physiotherapist or your general practitioner soon after the injury has occurred, to ascertain whether a referral to an orthopedic surgeon is necessary

Surgical Management

Not all ACL tears necessarily require surgery. There are many factors that must be considered when deciding whether or not surgery is the best option for the injured knee. Firstly, you must look at whether you participate in activities that require a fully functional ACL. Secondly, is the ligament completely torn and if so do you experience any functional instability in the knee. Finally is there risk of doing further damage to the knee if surgery is not performed. Often your GP or physiotherapist will suggest you see an orthopaedic surgeon to discuss all treatment options, and come to a decision that is the best option for you.

Physiotherapy Management

  • Help with the initial pain and swelling following the injury, and get you started on a basic exercise program as soon as possible after injury to help limit muscle wasting, knee stiffness and improve range of motion.
  • Help with pre-habilitation for surgery, that is educate you on what to expect from surgery, teach you the exercises to do following the procedure, get the knee moving as well as possible prior to surgery and teach you to use crutches if necessary.
  • Rehabilitation following surgery is a vital part of your recovery, and you will need regular physiotherapy sessions for approximately 3-6 months post surgery. Rehab following ACL surgery focuses on restoring range of motion, muscle strength and endurance, balance and proprioception, and eventually sport specific skills. The physiotherapist will set you up with a comprehensive home or gym based exercise program that will need to be reviewed regularly during the rehab process, with the aim of getting you back to your chosen sport or activity safely.
  • Some people will choose not to have surgery, and in these cases physiotherapy will help to strengthen the leg and core muscles, and to educate the patient about sensible sport and exercise choices in the future.