An algorithmic approach to anterior shoulder dislocations

---

No patient is the ever same and this adage goes for anterior group shoulder dislocations (subcoracoid, subglenoid, and the rare subclavicular and intrathoracic). If you use the same technique every time there is going to be situations where you are simply using the wrong technique. That’s why I take an algorithmic approach to the patient in front of me. This includes addressing whether this patient needs an X-Ray, what type of injury they might have, whether this patient need sedating, and pre-planning what to do if Plan A fails. There are anatomical reasons why no technique works every time on every patient and it is important to be skilled in several methods so you can use the best method for each presentation. The techniques discussed rely upon the relative movements of the humeral head and the glenoid fossa of the scapula. Used correctly, these techniques require little or no force.

Here’s the generic algorithm, once you have mastered a few techniques you can adapt this to your particular skill set. For example, if your favourite zero position technique is FARES, then that fits into your own personal algorithm – my personal algorithmic approach appears below.

I'd also recommend declaring your plan to your patient and your team. 'Preparing to fail' is a great way to make good decisions in evolving situations especially when things aren't going to plan. Saying to your patient "I'm going to try a gentle technique using positioning and massage. Your shoulder may pop back in just with that, if not we are going to stop, get an X-ray, and get a bit more information before we try the next technique." This allows you to maintain the confidence of your patient (and yourself) if Plan A doesn't work, and stop you from spending too long on a technique that doesn't suit the patient or the injury.

For more detail on whether to X-Ray check out the FAQ section

There are currently no clear radiological guidelines to distinguish between these subtypes of anterior group dislocations. A retrospective case review (submitted for publication)  has shown that one measurement on an AP X-Ray will consistently separate subcoracoid and subglenoid subtypes. This is the IGIANV - take the distance between landmark points of the inferior glenoid (IG) and the inferior point of the anatomical neck (IAN) which appears as a notch on the Xray. Then take the vertical (V) measurement.

<44mm is subcoracoid

>44mm is subglenoid

Guideline developed by myself and Dr Andrew Long

Green line - IG to IAN

Yellow line - horizontal level of IAN

Blue line - IGIANV

IGIANV<44mm is subcoracoid

IGIANV>44mm is subglenoid