ACL tear

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An ACL tear or an anterior cruciate ligament tear is a type of tear in a ligament which is one of the four main ligaments present in the knee joint. These ligaments are necessary and highly important for the stabilization of the joint in the knee and thus a tear in such an important ligament is quite fatal (compromises stability and function of knee). But with medical science doing so much advancement nothing is beyond repair including a tear in the ACL. But with technological advances in medical science, it is repairable and in a minimally invasive manner. Butas far as accidents go, a torn ACL is nothing uncommon. It mostly occurs whenever a person undergoes a sudden change of movement. However, you will have to take adequate amount of rest to return back to your day to day activities after an ACL tear.

What is the ACL?

The anterior cruciate ligament (ACL) is one of the main stabilising ligaments in the knee. It runs diagonally through the centre of the knee joint and attaches to the back of the femur (thigh bone) and to the front of the tibia (shin bone). It passes in front of the posterior cruciate ligament (PCL), a similar structure that runs in the opposite direction. These two ligaments cross near the centre of the knee; it is this crossing of the ligaments that gives them their name (cruciate). 

What does the ACL do?

The main function of the ACL is to stabilise the knee, especially during rotation, sidestepping, and pivoting movements. It also provides significant feedback information to the muscles surrounding the knee to help control balance (proprioception), thereby allowing coordinated activities. Your ACL cannot repair itself, so this means that when the ACL is injured (ruptured or torn), the tibia can move abnormally on the femur and the knee can often buckle. The main feeling is often a sense of the knee giving way during twisting or pivoting movements (instability) and a sense of not trusting the knee when turning. Sometimes patients may experience pain or an ongoing lack of confidence (proprioception) in their knee.

What is an ACL Tear?

For those who are still unsure regarding what an ACL tear actually is, you must know it falls under the category of second or third degree sprain that occurs in the ACL. The ACL is not a big structure. It is quite small and it is responsible for supporting the thigh bone and prevents it from sliding backwards or even stops the forward movement of the tibia. If there is a tear in your ACL, you won’t be able to perform your normal movements.

What are the Causes of an ACL Tear?

• When you try to change your direction of motion suddenly or slow down your fast paced motion
• When you land on a hard surface after jumping from a considerable height and you happen to land incorrectly
• When you stop suddenly
• When you try to pivot but your foot is firmly placed on ground. e.g. football, netball, basketball or skiing and other sports activity
• When you receive a great impact or blow on your knee from a hard object like a football or anything else.  In contact sports the ACL can be injured when a direct blow is applied to the outside of the knee. Sometimes, the ligament is damaged in isolation and sometimes in combination with other structures inside the knee e.g. other ligaments, menisci (shock absorbing cartilages), or joint surface articular cartilage. 

How do you diagnose an ACL injury?

Typically patients experience knee pain and early swelling after a twisting injury to the knee. Sometimes they feel (or even hear) a ‘pop’ or a click inside the knee. Often they are unable to continue with the game and have to stop the activity. This typical history would alert your doctor to an ACL injury. Examining a knee acutely injured is sometimes difficult due to pain and swelling and examination findings often become easier to elicit a few weeks after the initial injury. Sometimes your consultant will investigate the knee injury with an MRI scan which shows the structures inside the knee which are damaged and can aid treatment decisions. If scans are equivocal sometimes an examination under anaesthetic and a diagnostic arthroscopy (keyhole operation) is used to get more information about the injury before making a definitive treatment plan.

What are the Symptoms of ACL Tear?

The main symptoms associated with an ACL tear are listed below:

• A loud pop is heard by many patients when they undergo an ACL tear. Though this varies from patient to patient as some of them don’t notice the sound.
• An excruciating pain in the knee is something that is common to all patients who suffer from an ACL tear. This pain makes it next to impossible to walk or even carry weight.
• The portion of the knee which is affected soon becomes to swell starts swelling. The swelling occurs within a few hours after you have hurt yourself. This swelling occurs because of internal bleeding.
• The patient fails to straighten the knee.
• The patients also complain about a feeling of instability.
• If there is associated meniscus injury, knee gets locked in flexion attitude.

How is an ACL injury treated?

All patients need to recover from the acute knee injury with common sense measures to reduce swelling and pain. These would include

RICE Therapy- Rest, Ice, Compression, Elevation

• Rest (+/- crutches)  
• Regular ice packs  
• Compression
• elevation
• Anti-inflammatory medication .

Treatment options are very much tailored to the individual patient and are dependent on lots of factors including severity and frequency of ongoing symptoms, response to physiotherapy, age, sporting aspirations and damage to other structures. It is important that you are fully informed of all the options available and the advantages and disadvantages of the different treatments so that together with your consultant you can select the best treatment path for you.

Not everyone who has an ACL rupture ends up with a problem. The older and less sporty you are, the less likely it is to go on causing trouble. Nevertheless, the majority of people with a rupture of their ligament will notice looseness but for a proportion of people this can be overcome with conservative management via physiotherapy including strengthening and proprioceptive exercises.

Treatment options

Non-operative (conservative) treatment

Physiotherapy Initially, conservative treatment by physiotherapy is aimed at reducing swelling, restoring the range of movement at the knee and restoring full muscle power. It can also help to improve confidence in walking and regaining trust in your knee. Once your knee is more settled, a large part of physiotherapy management is aimed at addressing any muscle weakness present around the knee, hip, spine and pelvis and any deficits in proprioception. Proprioception can be re-trained using exercises designed to test your balance and coordination. Stability of the knee can be improved with intensive physiotherapy exercises - not just for strengthening the muscles at the front (quadriceps) and the back (hamstrings) of the knee but more importantly for improving balance (proprioception) and the ability to “hold on to your knee”. Good muscle performance and enhanced proprioception are both key factors in a successful conservative management approach to ACL injury. Adjustments may be required to daily activities and sports whilst having physiotherapy. A gradual return to daily activities and carefully graded progression back to competitive sport will be planned, if this is your goal. Some people seem to gain benefit from and respond well to this physiotherapy and can manage very well without their ACL. Additionally, some patients choose to give up certain sports that require more pivoting movements (e.g. football) and prefer to continue with sports which involve moving in straight lines, e.g. running and cycling.

Operative treatments

Operative treatments are based around a procedure called an ACL reconstruction. This surgery involves replacing the damaged ligament with a new ‘graft’. Usually the hamstring tendons (from the same leg) are used to make a new graft and via a special technique the graft is placed across the knee and secured in the femur and tibia by screws and buttons. This stabilises the knee. Postoperatively there is a big commitment to rehabilitation and further physiotherapy for up to 9-12 months to see the maximum benefit from the surgery.

Summary

ACL injury is fairly common and needs to be managed carefully by a consultant orthopaedic surgeon with an interest in knee surgery

What are the Treatment Measures for an ACL Tear?

• An ACL reconstruction surgery is recommended by the doctors in many cases. This is mostly when you are an athlete or you have wounded your ligament in more than one place.
• Enough rest is needed for you to commence day to day activities.
• You must ice your knee at least twice a day.

An ACL tear may not always be grave and a surgery is not always needed. As soon as you suspect an ACL tear, you must go to the doctor and the doctor will perform an X-ray to see how much grave the condition is and then prescribe you the necessary steps.