AC Separation- Auston Matthews
Off to an insane start and on pace for a massive year, Auston Matthews is on the Injured reserve for ‘at least’ 4 weeks before he gets back into action. The hit was clean and looked like a typical hockey play, so we could just chalk it up to bad luck. But with a similar injury to the opposite shoulder last season and a history of shoulder problems dating back to his teenage years, Matthews’ shoulder issues may be more complicated than bad luck can explain.
The NHL has been historically vague with injuries compared to other sports, labelling them as “upper body”, “lower body”, or in this case “shoulder injury” leaving us in the dark to speculate what actually happened. We can’t say definitively what was injured but our best bet based on mechanism of injury, timeline of return, and how he was holding his arm it can either be 1 of 3 options: shoulder separation, shoulder dislocation, or brachial plexus injury. Shoulder dislocation is possible, but it was reported that this is the same injury that occurred last year on the opposite shoulder, which was a shoulder separation, so this article will focus on a shoulder separation injury. We at Spine and Sports will breakdown the injury and his recovery process over the next 4 weeks, but also as to why this may have happened for a second time in as many years.
What is a shoulder separation?
Shoulder separation, also known as AC joint separation, is not a true injury to the shoulder joint itself, but to the structures above the shoulder joint called the acromioclavicular (AC) joint. This is a connection point of the end of the collarbone (clavicle) to the top most part of the shoulder blade (acromion) that is held together by a ligamentous structure to improve stability of the shoulder complex, known as the acromioclavicular ligament. The AC ligament provides stability against forces applied across the body (horizontal plane), as well as forces applied to the front àback (anterior to posterior plane). Another ligament important to the stability of the AC joint are the coracoclavicular ligaments, which control stability of the shoulder in the vertical plane.
How does a AC joint separation happen?
AC joint injury is a very common injury among athletic populations as it is a vulnerable, unprotected structure and it accounts for 40-50% of shoulder injuries in contact sports. The most common mechanism of injury is a fall on an outstretched hand, or like in Matthews’ case, a direct trauma to the top of the shoulder with the arm positioned away (abducted) from the body. The picture below shows someone falling on their elbow and tearing their AC ligament.
Matthews’ did not have the same mechanism of injury but the force occurring at his shoulder was the same: a back to front (posterior to anterior) force on the shoulder and arm causing anterior and inferior displacement of the shoulder blade and acromion.
As you can see in the video, Trouba hits Matthews left shoulder in an unprotected position. His arm is positioned away (abducted) from his body and the force applied to his shoulder is down and forward (inferior and anterior). This overstretches and damages the AC joint by pushing the acromion process forward and down while the clavicle is in a stable position, causing a tear to occur.
What is Matthews doing to get back in the game?
Management of AC joint injuries vary upon grade and severity:
- Type 1- Sprain of the AC ligament, no tearing.
- Type 2- Tear of the AC ligament, no tearing of the coracoclavicular ligaments.
- Type 3- Tear of AC and coracoclavicular ligaments.
- Type 4- Tear of AC and coracoclavicular ligaments., with displacement of the clavicle.
We don’t know for sure what type of AC sprain Matthews may have suffered since the specifics were not released to the public, however, it was released to the public that he will need a minimum of 4 weeks recovery and does not need surgery, which narrows down which type it may be. Type 1 return to sport recovery time is 2-4 weeks, type 2 is 4-6 weeks and type 3 and 4 is 6-8 weeks. Types 1 and 2 are typically managed with conservative care (physiotherapy/chiropractic) and types 3 and 4 are more often treated with surgical care. Based on this, we can speculate that Matthews’ has a Type 2 AC injury, 4-6 week recovery treated conservatively.
There are 4 phases for the rehabilitation of AC ligament sprains, with variation based on the type of injury. We will focus on rehabilitation of a type 2 sprain.
Phase 1: 3-10 days post injury. The goal is to reduce pain/inflammation and protect the AC joint through sling immobilization and prevention of muscular atrophy. Active range of motion exercises as well as self-care activities such as icing are implemented. Immobilization via use of sling is discontinued when there is no pain at rest and with range of motion exercise.
Phase 2: Initial goal is to restore mobility by gradually progressing range of motion with home exercises and manual therapy techniques performed by the physiotherapist or chiropractor.
Phase 3: Goal is to strengthen the shoulder to enhance dynamic stability of the AC joint via immediate initiation of scapular exercises. This increase in stability of the scapula will help to improve strength while also helping with the repair process. Shoulder rehabilitation is aimed towards exercises that involve movements with the hand fixed on the wall to unload the weight of the arm.
Phase 4: Once the shoulder can be moved in multiple directions with no pain or limitations with significant strength gains in the scapular musculature and rotator cuff, sport specific training is incorporated to prepare for a full return to prior level of activity. In Matthews’ case, sport specific training would be tailored to hockey. Throughout his shoulder rehabilitation, cardiovascular training and leg strength would be maintained with progression of upper body exercises. Upper body strength/power training would include pushing and pulling exercises and dynamic exercises like med ball throws and prowler sled training.
Why is this the 2ndyear in a row that this has happened?
All we can do is use our knowledge of anatomy and biomechanics and speculate. Sure, it could be just dumb luck, like how Jack Eichel had a left high ankle sprain in 2016, and then on the right the following season. However, Matthews’ has reportedly suffered from shoulder injuries as far back as his teenage years. Due to the reported chronicity of shoulder issues, this leads us to believe that there may be some increased laxity in his shoulders from prior injuries, decreasing stability and increasing chance of injury. This laxity is created from repetitive injury to the ligaments of his shoulder, decreasing their ability to withstand load and tension and increasing injury risk. It’s not to say that this is the exact thing happening to Matthews’ but it is a possibility.
Take away: The more and more ligaments become injured, the greater susceptibility to injury they have. This goes for any region in the body.
What can be done to prevent laxity and instability in the shoulder?
Matthews’ has the best therapists on staff to ensure that he makes a full recovery, but so do you. The Physiotherapists and Chiropractors at South end spine and sports are well versed in sports injuries and are experts in the fields of manual therapy, rehabilitation, and injury prevention. Ligament injuries need to be tackled and dealt with as soon as possible by making sure they repair themselves fully and properly the first time. This is achieved through the use of active and passive care from your Physiotherapist or Chiropractor and continued progression of treatment until you are able to deal with the injury on your own. Treatment needs to be implemented immediately after an AC joint becomes sprained and South End Spine and Sports is here to help.
What kind of treatment would this look like at Spine and Sports?
The exercises explained above would be implemented, but manual therapy of the shoulder is just as important. Improving muscle and joint function of the surrounding structures of the injured shoulder is vital for fully recovery. This would include manual muscle techniques like Active Release Techniques (ART), Acupuncture, myofascial release, and cupping therapy. Joint mobilization/manipulation to the upper back may also be necessary to improve function of the shoulder girdle.
Thanks for reading, tune in next month for the most recent injury in the sport world. Email us with any questions or injuries you want to hear about next @ firstname.lastname@example.org.
Stay strong, stay heathy.
Doctor of Chiropractic, B.HKin.