Anterior cruciate ligament (ACL) injuries

What causes an ACL injury?

The classic injury scenario is a change in direction, or jump/landing that goes wrong, twisting the knee, and causing damage to the ACL. This often happens during sporting activities when the body rotates but the foot remains firmly on the ground (typically during football, rugby or skiing), or a bad landing (during netball or basketball).

What are the symptoms?

  •  A significant number of patients hear a ‘pop’ or ‘snap’, and/or the knee gives way, followed by swelling within a few hours
  • You may find that you are unable to put all your weight on the affected leg and that you cannot fully straighten or bend it
  • In the longer term the knee may feel unstable and may even give way, particularly with a change of direction or rotation. Over time this leads to repetitive damage to the joint surface and meniscus (cartilage), potentially leading to the early onset of osteoarthritis

How is it diagnosed?

A diagnosis made during a medical consultation is backed up by X-rays and an MRI scan to show the extent of the damage.

How is it treated?

Not all ACL ruptures require surgery and if surgery is required, it’s not usually considered urgent; this is because having surgery too early, particularly when a patient can’t fully straighten their knee by themselves, can lead to considerable problems later on. Rather than having surgery within a day or two of the injury, it’s often better to try non-operative treatment first.

Non-operative treatment: after an ACL injury, you will be offered physiotherapy to restore your joint movement, muscle strength and coordination. Some people find that this is all they need to return to their normal level of activity.

Surgery: if, after trying non-operative treatment, the knee still feels unstable, you may need to have a procedure known as ACL reconstruction. Some patients may opt for earlier surgery, especially if they wish to return to high levels of activity involving changing direction, jumping and landing such as skiing, football, rugby, tennis, netball, basketball; this can save a second period of physiotherapy, help to retain fitness levels for these sports, and protecting against future meniscal tears.

Recovery goals after ACL surgery:

Phase 1 – Early (approximately 6-8 weeks)
Goals (which should ideally be achieved by the end of this phase):
•    Minimal pain
•    Minimal swelling in the knee
•    Full movement of the knee, especially straightening out the knee
•    A normal walking pattern without a limp both on flat ground and on the stairs
•    Starting to regain good strength in the operated leg and good ‘core control’
•    Equal balance when standing on one leg with eyes open/eyes closed

Phase 2 – Middle (approximately 3-4 months)
Goals (which should ideally be achieved by the end of this phase):
•    No pain
•    No swelling
•    80% strength in the muscles of the operated leg when compared with the other leg
•    Good ‘core control’
•    Good single leg squat strength and control
•    Good basic hopping and landing skills
•    Being able to start jogging with an even running style and without a limp (only to be attempted when strength is good and under the guidance of a physiotherapist)

Phase 3 – Late (approximately 6-9 months or more)
Goals (which should ideally be achieved by the end of this phase):
•    No pain
•    No swelling
•    At least 90% strength in the muscles of the operated leg when compared with the other leg
•    A good level of general fitness
•    Good agility and coordination in preparation for a return to sport
•    Being confident and mentally prepared for a return to sport
 

Important: This information is only a guideline to help you understand your treatment and what to expect. Everyone is different and your rehabilitation may be quicker or slower than other people’s. Please contact us for advice if you’re worried about any aspect of your health or recovery.