Injury to the anterior cruciate ligaments - why timely intervention is important

How is it that in the UK in particular this injury is treated so terribly?

The problem is that when people fall over and they twist their knee and they go first to their GPs (family doctor) or more commonly to the A&E (Accident Department), rather than seeing a knee specialist, As long as there is no actual broken bone on the X-ray nine times out of ten they are told “No broken bones – you have just sprained your knee – don’t worry about it” - the anterior cruciate ligament (ACL) rupture is just missed!

It's not rocket science

An ACL rupture is actually a very easy thing to diagnose. Classically it occurs during twisting and turning in sports – so in my country (the UK) it is for men football and for the ladies netball, and during the skiing season obviously both sexes commonly injure their cruciate ligaments skiing.

The history they give is classical – usually the scenario is during a non-contact, twisting movement when the knee buckles and gives way. Often the patient will hear a loud noise and also describe the sensation of the two bones feeling as if they are no longer opposing one another. They often say that they felt the knee twist out of position and then twist back into position and describe this with their with their two fists (representing the femur and tibia), rotating them apart of then putting them back together again, and say that this is what happened to their knee. They feel immediate pain and have immediate swelling, and fall to the ground. Sometimes, if it is not too painful immediately they may try and take a step or two but the knee just gives way. Invariably they are unable to play on and they have to come off whatever they were doing as they cannot take any weight through the knee.

“I was running, I changed direction, the knee gave way, I heard a noise, the knee swelled up and I could not continue what I was doing and had to be helped home.” When you hear that history in someone playing sport you almost do not need to examine them because the history is so descriptive of that specific injury - maybe they have injured more than one ligament, but with that story they have almost certainly at least injured their anterior cruciate ligament.

They then present to their GPs or to A&E, and for some unbelievably strange reason no-one acts on their story because they invariably do not get to quite the right person early. They are sent off after their X-rays to do endless amounts of rehabilitation.

The interesting this is that it will settle down. Classically, the patient will be hobbling for two or three weeks, and then the knee won’t feel too bad and usually people get back to a reasonable level of activity and when the knee feels strong again they try and play sport and they say – “Well, I tried to get back to football but when I got back onto the football pitch the very first time I tried to change direction my knee let me down.” And then they are back to square one again.

Of course, every time the knee gives way you are potentially damaging the joint surface and the meniscal cartilages inside the knee. That is why we have become much more more aggressive in the way we treat this injury and recommend reconstruction in active individuals with symptoms of instability. In a fit active person, particularly in someone under the age of 30 and more especially if they are under 20, there is no question that you should have your ACL reconstructed to prevent this secondary damage.

The ideal time to operate

The ideal time to operate is six to eight weeks after the injury when the knee has settled down, swelling is minimal and the range of movement is good. When we reconstruct the ligament we carry out any necessary repairs to the meniscal shock absorbers and tidy up any joint surface damage. At this early stage the secondary damage to these structures is usually minimal as opposed to the situation with a delayed reconstruction when this secondary damage to the joint surface and menisci is usually extensive. In the ACL deficient knee that has been neglected for a long period of time, the shock absorbers are often too badly damaged to repair and all that be offered is meniscectomy or removal of damaged tissue. Similarily, the joint surface is often badly damaged and requires extensive debridement or microfracture (a procedure carried out to make new cartilage in the damaged area).

The average time to ACL reconstruction in most of Europe, the USA - in fact most of the western world - is approximately six to twelve weeks. The average time in the UK within the National Health Service is twelve to eighteen months and to be honest the private sector is not much better!! By the time we knee surgeons in the UK get to the patients, the knee has usually undergone severe injury through recurrent instability. Once the knee has had that secondary damage, then you are really on a bit of a slippery slope.

I recently carried out a live surgical demonstration of an ACL reconstruction at the German Arthroscopic Knee Society meeting in Garmisch, Germany (February 2011). The patient was seven weeks post injury and had been placed in a brace and given crutches. She was told to be careful to protect the knee to minimise the risk of secondary damage. Because she underwent the surgery so soon after the injury and had taken the above precautions there was no additional damage to the joint surfaces or meniscal shock absorbers.

UK patients with the classical history we discussed above must not let themselves be fobbed off. They must somehow get themselves urgently to a knee surgeon and have an MRI scan. It would not be a bad idea for them to get the knee into a low profile brace, but they are expensive - a decent low profile brace could cost as much as £400.

Does age matter?

It is actually very rare to injure the ACL if one is less than ten, and it is still rare if one is less than fifteen. It then becomes relatively common between the ages of fifteen and thirty.

There is no longer an age limit to ACL reconstruction. There used to be an age cut-off to ACL surgery at the lower and upper end (over 40), but that has completely changed. If an eight year old presents to me with a cruciate deficient knee I would reconstruct the ligament as soon as I could. Every now and then you see the other extreme, that is an ACL injury in an active more elderly patient, for example if a fit 65 year old who enjoys playing tennis ruptures their ACL ligament. If there is little other damage to the knee, I would also offer this person a reconstruction and in my experience they do very well.

There has been a lot of work done on paediatric ACL surgery, and David Hunt(1) (Consultant Knee surgeon from St Mary's Hospital, Paddington) recently (2010) reviewed his series in the British Journal of Bone and Joint Surgery. There was a significant number of patients. This series, as well as many others in the literature, suggest that an ACL reconstruction in children is a safe and effective treatment. The main concern is an injury to the growing area of the bones around the knee when the new ligament is inserted. The literature indicates that this is incredibly rare in this young group of patients. There were no growth plate injuries in David Hunt's series.

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