Hill Sachs Lesion Impaction fracture of humeral head against glenoid rim Anterior dislocations, Occurs against anterolateral surface Incidence rate 40-90% As high as 100% in recurrent dislocations (Provence 2012) Posterior dislocations Occurs against anterolateral surface (“reverse Hill Sachs lesion”) Incidence 86%.
Be vigilant for concomitant neurovascular injuries and always perform a full neurovascular assessment before and after reduction Carefully review radiographs for posterior dislocations as they may appear “normal” at first glance Be comfortable with multiple reduction techniques. Joint injections and systemic analgesia will facilitate reduction.
Depending on patient response to initial attempts, procedural sedation may be necessary. Mat sen FA et al. Principles for the evaluation and management of shoulder instability.
Incident of associated injury in posterior shoulder dislocation : Systematic review of the literature. Patel DN et al. Lunatic erect: Case series with review of diagnostic and management principles.
Results of treatment of lunatic erect (inferior shoulder dislocation). Sex distribution is bimodal and relative incidence is dependent on patient age.
Younger patients tend to be male and injury is often related to sporting trauma: Etiology The shoulder is exceptionally maneuverable and sacrifices stability to enable an increase in function.
Its shallow glenoid fossa, relatively weak glenohumeral ligaments, and redundant capsule render it particularly susceptible to dislocation. The process of dislocation is massively disruptive to the labrum, joint capsule, supporting ligaments, and muscles.
Plain radiograph Anterior and inferior dislocations are usually simple diagnoses, with the humeral head and outline of the glenoid being incongruent. It is also important to remember to scrutinize the ribs and portion of the lungs and mediastinum included in the film for unexpected findings (e.g. pneumothorax).
Think about the soft tissue structures that might be injured, particularly the neurovascular bundle with inferior dislocations. As a general rule, the shorter the duration of dislocation the fewer complications (size of Hill-Sachs lesion, neurovascular compromise, etc.
Early arthroscopy, labial repair and debridement may be of use, especially in young patients with anterior dislocation in which there is a high (up to 85%) rate of recurrence 3. Shoulder dislocations can also be associated with large rotator cuff tears in the older ages groups.
The major morbidity associated with untreated massive rotator cuff tears in this age group requires a clinician to ensure actively that these injuries are not missed. This can be done by clinical examination, looking for weakness in the rotator cuff muscles or radiologically with ultrasound or MRI.
Shoulder pseudodislocation : apparent inferior displacement of the humeral head from capsular distension secondary to a large arthrosis/effusion. While the hip has a deep pocket, the shoulder also has a socket, but it is much shallower.
The makeup of the shoulder consists of a socket joint and a ball. Because of the way this sets up, the shoulder enjoys a broader range of movement than the hip.
If you feel like your shoulder has become dislocated, you should seek medical attention right away. Don’t try to put it back into the socket, you may end up creating more problems than you already have by damaging the surrounding muscles as well as the blood vessels and nerves.
If you can put ice on your shoulder, you may be able to bring down the swelling and eliminate some pain. The first thing the doctor will do is feel around your shoulder and the socket area to check the swelling, deformity and tenderness.
Used to diagnose conditions, this test utilizes an electromagnetic energy beams that are invisible. They produce images of the bones, organs, and internal tissues on film.
External radiation is used to create the images of the body, internal structures, and organs in order to provide a more definitive diagnosis. The X -rays go through the structures of the body and provide a “negative” with solid areas showing up in white.
The shoulder should only be reduced, or put back into the socket by a trained professional in the medical field. You will want to strengthen the muscles in your rotator cuff, so they are better able to support the shoulder and help to prevent another dislocation.
Most surgical procedures are performed right after the dislocation if it has been determined there has been any damage to nerves, muscles, tendons or blood vessels. This will help to improve your range of motion as well as the stability and strength to your shoulder.
In most clinical scenarios this refers to a radiograph of the glenohumeral joint. Ideally, a shoulder radiograph series will provide adequate views of the clavicle, acromioclavicular joint (ACJ), glenohumeral joint (GHz) and the scapula.
However, it is worth being aware that if you are unable to get an adequate view of the clavicle or the scapula, more specific dedicated radiographs can be requested (e.g. an AP cephalic view of the clavicle). Whether these views are required will largely be dictated by the patient’s history and the findings on clinical examination.
Scapular Y/lateral view The humeral head lies on top of the glenoid fossa, with the coracoid process anterior to it (the side of the rib cage represents anterior in this view). AP view : the humeral head will lie medial and inferior to the glenoid fossa.
Lateral view : the humeral head will lie anterior and inferior to the glenoid fossa. The humeral head will also lie inferior to the coracoid process and this is typically most obvious in the lateral view.
In this view, you should see the inferior borders of the acromion and the clavicle line up in a healthy individual. Widening of the gap between the acromion and clavicle may indicate pathology affecting the acromioclavicular ligament (e.g. a tear).
<7 mm = possible supraspinatus tendon tear (a common rotator cuff injury) >12 mm = joint widening (e.g. due to effusion) AP view of a normal acromioclavicular joint with yellow lines to illustrate the alignment of the inferior aspect of the acromion process and distal clavicle, and green lines to indicate acromioclavicular (1), coracoclavicular (2) and acromiohumeral (3) distances 8.
The projection of this image is suboptimal and makes the acromiohumeral distance slightly harder to see. Figure 1 of the normal AP shoulder demonstrates this distance more clearly 7 In all views, follow the outline of the cortex (outer white edge) of each bone, not forgetting to look at the ribs as well.
This is doubly true in the context of trauma, as rib fractures and the subsequent complications may be missed by a distracting injury like a fractured humerus or dislocated shoulder. As with all radiographs, make sure you don’t stop looking once you have found a fracture or the specific abnormality you requested the investigation for (the presence of an obvious shoulder dislocation doesn’t rule out the possibility of other bony injuries).
This can sometimes be difficult and is an easy heuristic trap that can be prevented by being thorough and having a framework or system to follow. Look around the bones and joints for any signs of darkening/fluid levels that may represent blood or fat (lipohaemarthrosis), which suggests a fracture even if one cannot be seen.
Special care should be taken to review the rest of the radiograph, especially the lungs and the ribs, as well as any other areas included in the image. In the context of trauma, rib fractures and pneumothoraces are common and may not be noticed if the patient’s main complaint is shoulder pain.
Dr Jonny Hacking Show references Geeky Medics. Adapted from an original image by Georg Mattiassich, Lucian Lion Markovic, Rolf Michael Drifter, Reinhold Premiere, Peter Wagerer, Albert Propel.