What is the AC joint?
The Acromioclavicular joint (AC joint) is the joint formed between your collarbone (clavicle) and the bony outeredge of your shoulder blade called your acromion. It is the bony part you can feel on the top, outside of your shoulder. It is an important joint as it allows you to lift your arm overhead and allows us to have a lot of mobility around the shoulder complex.
How would I injure my AC joint?
The vast majority of AC joint injuries are from traumatic incidents during sports or accidents. The AC joint is often injured when you get a direct blow to the joint, such as landing on the ground with your arm by your side. This can happen during football tackles or bumps. The AC joint is also quite often injured when a large force is pushed upwards into the joint, such as falling on an outstretched arm when falling off your bike.
How will an AC joint injury be diagnosed?
More often than not after a traumatic injury you will get an X-ray of your shoulder. AC joint injuries will be shown on the X-ray and the degree of the injury will be interpreted by a radiologist or orthopedic surgeon. The grades of AC joint injury are:
Grade l: Slight stretching of the ligaments, all fibres intact and joint capsule intact
Grade ll: Rupture of one ligament, increased stretch of other ligament and capsule intact
Grade lll: Total rupture of both ligaments and joint capsule
Grade lV: End of collarbone is shoved backwards into upper trapezius muscle
Grade V: More severe level of a grade ll, with disruption to fascia also
Grade Vl: The collarbone is shoved downwards towards your ribs
How can physiotherapy help after AC joint injury?
Physiotherapy in the acute phase of an AC joint injury is highly dependent on what grade the injury is. If the injury is a low grade (grade l or ll), then the injury is typically managed conservatively with physiotherapy. If the injury is grade lll or higher, more often than not surgical intervention is warranted which changes the rehabilitation program your physiotherapist will take you through. However, there is still some debate whether a grade lll injury requires surgery, and the decision to operate or not is usually based on your current age, activity level and pre-injury function.
Grade l – ll injury physiotherapy management
After a grade l-ll injury, you can expect your physiotherapist to ask some questions to gain a deep understanding of what your pre-injury function was, and what your goals are so we can create an individualised plan to help you achieve them as soon as possible. They will also talk to you about the rehabilitation journey and expected milestones and rough timelines.
Initially the aim of physiotherapy in grade l-ll AC joint injuries is pain relief and to help let the initial injury and inflammation settle. You can expect your physiotherapist to use manual therapy techniques in the early stages to help minimise your pain, as well as helping support the joint using taping techniques or a sling if your pain is very intense. They may also recommend you speak to your GP or pharmacist about getting access to some pain relief or anti-inflammatory medication.
As your pain settles, your physiotherapist will give you a series or exercises to get your shoulder moving again. The first goal of the exercises is to start to regain full range of motion of the shoulder joint and to get your shoulder blade moving. Early stage exercises also focus on retaining as much strength as possible in the muscles of the shoulder and shoulder blade.
As you regain movement and function, your rehabilitation focus will turn to the movements/activities that you want to get back to. This will involve a graded return to activity program as prescribed by your physiotherapist, as well as making your exercises more specific to your goals.
*Please note these stages do not happen in isolation! Your physiotherapist may have you starting some exercise very early after your injury, this will be dependant on your symptoms*
Grade lll+ AC joint injury physiotherapy management
Most, but not all, grade lll or higher AC joint injuries will initially be surgically repaired. If you present to a physiotherapist with a grade lll or higher injury, they will refer you to be seen by an orthopedic specialist for their opinion. If the surgeon and yourself decide to manage the injury without surgery, then your rehabilitation will look much the same as for a grade l-ll injury, with the timelines being slightly slower due to the increased severity of the injury. You can expect to be in a sling for 4-6 weeks to allow the injury to heal, with you being allowed to come out of the sling 2-3 x per day to do some gentle range of motion exercises (*note: some surgeons are more conservative and will keep you in a sling full time for 6 weeks).
If you have a surgical stabilisation of the joint, your first 2-6 weeks will be spent in a sling to help the surgery site heal. You will usually review with your surgeon at 2 weeks post-surgery, at which point you will be given the go-ahead to start some more structured physiotherapy. Exercise during week 2-6 will focus on regaining passive movement of the shoulder within your tolerance limit, maintaining movement of the elbow, hand and wrist on the affected side, as well as some light resistance exercises to the muscles of the shoulder blade and shoulder joint.
From week 6 onwards, you will usually be cleared to come out of the sling and start more intensive exercises. Your physiotherapist will structure your rehabilitation to continue to improve your range of motion, as well as increasing the intensity and difficulty of the exercises. Typically at around week 10-12, your physiotherapist will start guiding you through some specific return to sport exercises. Full clearance to return to sport is possible when your surgeon is happy and you have met the following milestones with your physiotherapist:
- >95% range of motion of the non-injured side
- <5% strength difference vs non-injured side
- Full return to training with no pain/instability for at least 2 weeks
When can I return to sport after an AC joint injury?
Returning to sport after an AC joint injury is purely based on the severity of your injury and how well your rehabilitation is progressing. It is also highly dependent on what sport you play and what level of sport you had been playing. Most people are individual in their response after injury and best practice physiotherapy now operates on a ‘milestone based’ rehabilitation protocol rather than ‘time based’. This means that we focus on you hitting certain milestones along your rehabilitation journey, rather than waiting for time to elapse. This being said, if you stick to your plan, you can roughly expect to be close to the following timelines:
- Grade l: 2-4 weeks
- Grade ll: 4-8 weeks
- Grade lll+: 12-16 weeks
When can I return to work after an AC joint injury?
Timelines will be based on the grade of your injury, how you progress through your rehabilitation and the level of demand of your job. A rough timeline guide is as follows, and this is mainly based off higher grade injuries that require surgery:
- Desk-based work: 1-2 weeks
- Light manual labour (retail worker): 6-8 weeks
- Manual Labour: 12-14 weeks
- Overhead intensive manual labour: 4-6 months
Most lower grade injuries won’t need to miss much more than 2-4 weeks work, depending on the physical nature of your job.
Will I have long term issues after AC joint injury?
Sticking to your physiotherapists guidelines post injury or post surgery should minimise your risk of having any further issues in the future. Due to how close the AC joint is to the surface of the skin, it is not uncommon for the joint to look slightly higher or lower than the non-injured side even after surgery. This is purely an aesthetic issue and rarely has any impact on the function of the joint in the long term.
Will I be at higher risk of shoulder pain in the future?
If you follow your physiotherapists guidelines for rehabilitation, you will have a very low risk of any shoulder pain in the future. There is some debate about whether having a grade lll injury managed without surgery can slightly increase your risk of arthritis of the joint, but this should be discussed individually with your surgeon/physiotherapist. The good thing here is there is actually a low correlation between arthritic joint changes and pain levels.
How many times will I need to see a physiotherapist after an AC joint injury?
This will depend highly on how you are responding to treatment and recovering from your injury. After a grade l-ll injury, expect to see your physiotherapist 1-2 times per week in the first 4 weeks to help minimise your pain and get you moving as quickly as possible. As your injury settles and your rehab progresses, you can still expect to see your physiotherapist weekly as they manage your exercises and return to sport/activity plan. After you have returned to sport/activity, your physiotherapist will continue to work with you to make sure your return to activity/sport is sustainable. All up, it would not be unreasonable to see your physiotherapist 8-12 times over 10-12 weeks.
After surgery, how often you see your physiotherapist can change based on your surgeon’s guidelines. Some surgeons have different protocols and this can change your rehabilitation timelines slightly. After surgery, you will be in a sling for 2-6 weeks, and you can expect to see your physiotherapist 1-2 x per week in this time to help keep your shoulder moving and start your rehabilitation as early as the protocol allows. When out of the sling, you will be starting more intensive rehabilitation and this can be continued to be monitored 1-2 times per week. As with the grade l-ll injuries, your physiotherapist will continue to work with you even after you have returned to sport.
Should I get a cortisone injection in my AC joint after injury?
There is no evidence to show that cortisone will help the healing of your injury. It may have some short-term pain relief effects, but these effects are no better than just waiting and doing nothing at 6 weeks after your injury.