An algorithmic approach to the shoulder dislocation

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No patient is the ever same and this adage goes for shoulder dislocations. 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 algorithm appears below the generic one.

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

And if you happen to be working on a football or ski field, here’s my field algorithm. 

 The short answer is that whatever your dislocation technique skill set is at baseline, if you can use the available data to improve your decision making at each step, you will increase the probability of success.

The long answer is below!

For every shoulder dislocation scenario there will be a decision to make at each point. These decisions will be based upon information that may range from being fully available and requiring analysis, to unavailable or partially available. There will need to be a risk analysis for your decision once the availability of data has been assessed. Most of the decision points have not been settled by rigorous scientific experiments so expertise needs to be used alongside experience, so the process below will use estimates that will vary based upon your own skill level with each technique. Due to the various factors involved in each dislocation, the ‘what do I do next?’ questions are all complex and prone to cognitive bias with regards to risk assessment. Going with gut instinct or using the same technique you always use is not going to helpful when to encounter a different pattern of patient/injury factors that renders your go-to approach unsuitable. I’ve used a case example below to illustrate the various factors to consider for each scenario, using the algorithm to create an individualised plan for your patient. All prediction numbers are estimates based on expertise rather than hard science, and as you will also see from the footnotes, there are many unanswered questions that, once properly researched, could allow us to improve our predictions and therefore our individualised patient plans.

“I always use Kocher’s technique and have a great success rate of 90%”

Operator’s self-assessment of likelihood of success with Kocher’s technique using intuition – 90%

After assessment of all data available in this scenario:

Likelihood of success with Kocher’s technique – 30%

Likelihood of success with Zero position technique – 55%

Likelihood of success with seated scapular manipulation technique – 60%

Likelihood of success with prone scapular manipulation technique – 90%

Data required

Patient factors - 58 year old male, overweight but otherwise well, cooperative, pain controlled (3/10) after IV morphine

Injury factors - mechanism of fall onto shoulder, X-ray shows greater tuberosity avulsion fracture (GTa#) and sub-glenoid dislocation[1]

Operator factors – Previously worked in Ski-fields and experience of over 50 successful reductions. First line is Kocher’s, uses morphine if needed and if unsuccessful moves to sedation and traction. 

[1] Research question – This patient already has an XRay. How accurate are emergency personnel at predicting anterior (sub-coracoid) or antero-inferior (sub-glenoid) shoulder dislocations based on mechanism of force and clinical assessment?

If your usual approach is ‘Kocher’s for 90%, and sedation and traction for the remaining 10%' then you are not using all the available information and risk unnecessary pain during reduction techniques, or an avoidable sedation. 

Note that the information available for the estimated data points is not absolute as there has not been research into specific sub-type injuries and the operator proficiency and patient factors vary from case to case. The footnotes collect some questions that have yet to be answered which could provide more accurate estimates to these predictions.

Kocher’s can sometimes work in sub-glenoid injuries, this can sub-divided further depending upon the injury type and the manoeuvre used. Assuming that the patient is cooperative and comfortable (pain/spasm), they are able to fully adduct the humerus, and the humeral head is not wedged beneath the rim, then Kocher’s can be attempted. All 3 manoeuvres can be used if the humeral head is intact; only the first manoeuvre (external rotation) can be used if the humeral head is damaged (GTa# or GTi#); an old Hill-Sach’s lesion without significant impaction could theoretically provide the fixed point to move between manoeuvre 2 and 3 but there really are other techniques that are more likely to succeed in this scenario.

Based on all the available data, this operator’s individualised approach for this scenario now looks more like this:

Plan A - first manoeuvre Kocher’s (30% likelihood of success), 

Plan B - prone scapular manipulation (90%),

Plan C - sedation plus scapular manipulation (patient fully seated or angle based on airway management during procedure), 100%.