Anterior Cruciate Ligament (ACL)

The most common injury to the Anterior Cruciate Ligament (ACL) is a complete rupture of the ligament. This occurs most commonly following a pivoting movement, landing from a jump or during sudden deceleration.

ACL deficient patients tend to fall into one or two categories; those who are able to return to activity and those who have on going symptoms and instability.

Those who do manage to return to activity tend to need a course of rehabilitation to strengthen the muscles around the knee to compensate for the deficient ligament. This could take several months.

Those who have on going symptoms may require reconstructive surgery. The general time frame for people following ACL reconstruction is 4-6 months to return to running, 6-9 months to return to activities that involve changing direction and 9-12 months to return to competitive sport.

Signs and symptoms

Patients will often describe hearing a pop or crack followed by immediate pain when the ACL ruptures. More often than not the patient will not be able to continue with the activity. The knee will then normally swell very rapidly with the swelling being contained in and around the knee.

Patients will usually present to a minor injury unit or accident and emergency. Often the knee is difficult to assess in this acute stage but an X-ray may be taken and some indications of an ACL rupture may be present. For an accurate diagnosis the patient will need to be assessed by their GP, a physiotherapist or an orthopaedic consultant and may require a MRI scan.

The ACL deficient patient will often describe a feeling of instability, such as giving way, which usually occurs during changes of direction or pivoting, as well as during sporting activities if they have managed to return to sport following the injury. There is a possibility of other structures being injured alongside the ACL, most commonly the meniscus. This may add symptoms including catching, locking, painful clicking and recurrent swelling.

How physiotherapy can help

In all cases of ACL injury, physiotherapy is essential. In the non-surgical patients will require guided rehabilitation with a strong focus on strengthening, stability training and sport specific exercises. Patients who undergo ACL reconstruction they will require on average 6-9 months of regular physiotherapy to guide them through the stages of rehabilitation. Your physiotherapist will give advice on the protection and maximisation of the rebuilt ligament as well as guidance regarding  your return to sport.

If you suspect that you have sustained an ACL injury it is very important you follow the RICE principal immediately after the injury. That is you Rest the knee, Ice it, apply gentle Compression and Elevate it. It would also be extremely beneficial to attend our rapid assessment sports injury clinic in the Physiotherapy Department or a minor injuries unit in your local area.

For those not undergoing reconstructive surgery you will need to spend time focussing on strengthening your quadriceps, hamstrings and core stability muscles as well as improving your balance.

If you have sustained an ACL injury in the past and you continue to have symptoms and have not managed to return to your desired level of activity you should see your GP with the view to being referred to an orthopaedic consultant.