Shoulder Trauma Part 3- Ligaments
My name is Gavin Jennings and I am an Orthopaedic Surgeon specialising in shoulder problems
This presentation is the third of three parts giving an over view of trauma of the shoulder girdle
Parts 1 and 2 dealt respectively with trauma to the bones and tendons of the shoulder.This part focusses on injuries of the ligaments.
The important ligaments around the shoulder include those which stabilise the ball and socket or gleno-humeral joint and those which stabilise the acromio-clavicular joint or ACJ
The ligamentous stabilisers of the gleno-humeral joint include the labrum and its attached capsular thickenings known as the glenohumeral ligaments (GHL). The inferior GHL’s are the most important for stability. The stabilisers of the AC joint are the acromio-clavicular ligaments and, more importantly the coraco-clavicular ligaments (found between the coracoid process and the undersurface of the clavicle (or collar bone).
The inner (medial) end of the clavicle also attaches to the sternum at the sterno-clavicular joint.
I will first consider the most common ligament injuries ie those that relate to glenohumeral dislocations.
The most common type of glenohumeral dislocation by far is anterior i.e. the humeral head comes out of the front of the socket. These constitute almost 95% of shoulder dislocations. In about 5% of cases, the shoulder dislocates backwards (posteriorly). Unfortunately, posterior dislocations are, on occasions, missed in the Accident and Emergency environment. With shoulder dislocations it is very important to check for axillary nerve function by testing for sensory loss in the mid-deltoid (“Regimental Badge Patch”) area and testing for contraction of the three heads of the deltoid.
Posterior dislocations occur in trauma , not surprisingly, with a posteriorly directed force, often in a forward flexed and adducted arm. However, they should always be considered when a patient presents with shoulder pain following a fit. Examination of a patient with a posterior dislocation will reveal very limited external rotation and the so called “lightbulb sign” on an AP x-ray.
Traumatic anterior dislocations, once reduced, are often managed non-operatively. However surgery is often considered if they have become recurrent or in the first time dislocation in a young contact sportsman.
If surgery is considered, almost invariably this would be preceded by an MRI Arthrogram (where dye is placed into the joint prior to scanning) This is primarily to confirm the presence of a labral separation or a Bankart lesion (or one of it’s variants as shown here). If there is no significant damage to the bones, an arthroscopic Bankart repair is usually the procedure of choice.
AC joint dislocations (or separations as they are known elsewhere such as in the USA) are usually classified according to the progressively worsening damage first to the acromio-clavicular ligaments, then the coraco-clavicular ligaments. Traditionally we have tended to treat types four to six (where the coraco-clavicular ligaments are torn) operatively. More recently there is a trend to consider even the higher grades for a trial of non-operative management, with those patients who fail to recover reasonably rapidly undergoing delayed surgery to stabilise the joint.
Many types of operation have been described, but most of these are a variation of the so called Weaver-Dunn procedure. This involves a repair of the coraco-clavicular ligaments and the use of the coraco-acromial ligament to reinforce the repair. More recently we have tended to use an artificial ligament to take the place of the damaged coraco-clavicular ligaments rather than attempt a repair. If the patient presents early, it is possible to perform an all-arthroscopic repair using an artificial ligament alone.
Finally I’d like to mention sterno-clavicular joint dislocations. These again can be anterior, or much more rarely posterior.
Posterior dislocations can sometimes represent a medical emergency, if there is pressure on the midline structures (such as the trachea) lying behind it. Emergent reduction is indicated in such cases. Treatment of anterior dislocations will depend on factors such as the age of both the patient and the injury.
Many thanks for listening to Part 3 of an overview of shoulder girdle trauma. Please don’t hesitate to contact me for further information.