ACJ (Hook Plate, Surgilig)

I am going to talk about the various ways of treating an ACJ dislocation – surgery for an arthritic ACJ is discussed in the ‘surgery for tendonitis’ section.

So, you are one of the unfortunate ones who has an ACJ dislocation that requires surgical stabilization – either because it is an acute grade 5 or a lower grade that is causing problems a few months down the line.

Remember what we are trying to do is get those torn ligaments next to each other so that they can scar up and heal with the ACJ lined up as it should be.

The operation I do depends on whether your’s is an acute injury (operation possible within 2-3 weeks) or chronic (anytime longer than that). In the acute case I just use the Hook Plate and in the chorionic cases that is augmented with an artificial ligament.


Acute Cases using Hook Plate

What does that entail?

The surgery is done as a day-case, under a general anaesthetic and through an 8 cm (or so) scar running lengthways along the end of the clavicle and across the damaged ACJ. I clear away any tissue that may have got caught in the joint and which would prevent the two bones lining up properly and make sure they do line up in the right place. Then I insert a Hook Plate. This is a metal plate with a hook on the end. The hook goes under the acromion and when I push down on the plate end this reduces the ACJ back into alignment and I can attach the plate to the clavicle with screws. By reducing the ACJ back to its original alignment, the torn ends of those ligaments come together and can heal up.

Hook Plate used to ‘hook’ under the acromion and stabilse the ACJ

That sounds a bit barbaric – isn’t there a keyhole way to do this?

There are lots of ways to do this – including a keyhole method – but, in my experience, they don’t work as well as the Hook Plate because they simply aren’t strong enough to hold the weight of the arm in place while those ligaments heal. So that is what I use.

A model shoulder showing the Hook Plate with the plate screwed to the clavicle and the hook under the acromion.


Does that plate stay in?

No. It has to come out. That is very important. Usually it comes out after about 4 months.

A Hook Plate stabilising an ACJ dislocation


What is the recovery like after this operation? Can I use my arm? Can I play sports?

You have to be in a sling for 2 weeks (it’s the same with any operation to stabilise the ACJ) so you can’t drive or do physical work. You can move the elbow and use your hand so you aren’t rigidly tied down. The purpose of the sling is to stop you trying to use the arm up in front of you.

Once you come out of the sling then you start therapy to get the shoulder moving again and build up your activities week by week.

Will I get full movement back?

Yes you will but probably not until I take the plate out. Most people find that they don’t get full movement before the second operation but that last bit returns very quickly afterwards.

So you will be able to do some sports and activities between the surgeries but not all.

And will it be a normal shoulder after that?

It should be as good as new so you can get back to full activity and do everything you want to do with it.

The aim is to get movement back first and then build up your strength. Physiotherapy is very important and swimming (or exercises in the water) is a great way to rehabilitate. Usually the recovery is very quick after the plate comes out – maybe 6 weeks – but remember the plate stays in for about 3 – 4 months after the first operation. So overall it will be 4 – 5 months before you are really back to normal.


Chronic Cases using the Hook Plate + Infinity Loop

You said after 3 weeks I’d missed the Hook Plate option? I damaged my ACJ 6 months ago, was told it would heal but it is still mobile and painful. So how do you deal with that?

Thankfully there is an excellent option in the chronic case. So we haven’t blown your chances of a great shoulder if we made the wrong decision early on believing that it was going to go on getting better.

At this stage the ends of the torn ligaments won’t heal together because they have scarred up while they were separated. So even if they are brought together with a Hook Plate they won’t bond up. In this situation I have to add an artificial ligament that will hold the clavicle back onto the scapula with the ACJ lined up permanently and I use something called the Infinity Loop. This ligament provides the long-term, permanent fixation of the ACJ in its proper alignment but I also put in a Hook Plate to keep everything stable for the first few months while the ligament bonds to the bone and the bodys natural tissues start to incorporate into the articial ligament. The Hook Plate not only limits the up and down movement but also the forward and backward movement at the ACJ while everything beds in.

Click on the link below to see a video of the Infinity Loop being inserted.


The plate does need to be taken out after 4 months so a second procedure is required but that is a quick job and doesn’t really slow things up.

You will be in a sling for 2 weeks after the surgery and then you start to mobilise guided by the physios.

I don’t expect you to have regainied full movement before the plate comes out – although a few do – but any residual stiffness does come back very quickly after the plate has been removed.