Most common type of anterior shoulder dislocation?
High-Yield Explanation
Ans. b (Subcoracoid) (Ref. Bailey & Love surgery, 24th/pg. 499)SHOULDER DISLOCATIONTypes:# About 95%-- anterior dislocation.# In < 5% -- posterior dislocation.- Posterior dislocations are unusual, and seen after injuries such as electrocution or after a seizure.- Recurrent traumatic instability. This is predominately in one direction, most commonly anteroinferiorly.- Atraumatic instability. Although there may be an initiating event, this is often less traumatic, for example a fall climbing stairs rather than a sporting injury.Causes of Recurrent shoulder dislocation:- Hill-Sachs lesion (injury to the posterolateral aspect of the humeral head)- Lax joint capsule- Bankart's lesion (detachment of the anteroinferior segment of glenoid labrum)Test for recurrent shoulder dislocation- "Apprehension test". Q- Sulcus testQ:# The shoulder can often be subluxed inferiorly to produce a sulcus sign, with a lateral sulcus appearing beneath the acromion as the arm is pulled down.X-ray- A sign of posterior shoulder dislocation =>"Light-bulb" sign.Comparison of Posterior and Anterior shoulder dislocationsClassified According to Displacement of the Humeral HeadType of DislocationFeaturesOther Clinical cluesRadiographsPosterior# 95% subacromial# 5% subglenoid and subspinous# Humeral head posterior to the glenoid# Arm held in the sling position with adduction and internal rotation# Attempts at abduction and external rotation cause extreme pain# Coracoid process prominent, glenoid fossa empty anteriorly, and humeral head bulging posteriorly# On AP view; vacant glenoid sign, 6-mm sign, light bulb sign# On lateral view or Y view: humeral head appears posterior to the glenoid fossaAnterior# 99% subcoracoid and subglenoid# Humeral head anterior to the glenoid# Arm held in abduction and slight external rotation (abduction more prominent with subglenoid dislocation)# The patient cannot adduct or internally rotate the shoulder# Seen from the front, the shoulder appears "squared off"# Distal acromion prominent on a side view# On AP view: obvious dislocation On lateral view: humeral head appears anterior to the glenoid fossaReprinted with permission. Roberts JR, Hedges JR. Clinical Procedures in EmergencyMedicine, 6th edition, Philadelphia: Saunders/ Elsevier, 2014, 0. 958Rx# Physiotherapy should be tried first in these patients.# As well as muscle strengthening, re-education of the patient and shoulder is necessary, and specific muscle groups may need to be targeted.# Approximately half of the patients will require surgery and a capsular tightening procedure is carried out through an anterior approach.- This is a successful procedure but there is a higher failure rate than with patients found to have a Bankart defect.- Arthroscopic shrinkage of the capsule may have a place in these patients, and this is currently being evaluated.DISLOCATION OF THE GLENOHUMERAL JOINT# Approximately 45 per cent of all joint dislocations in adults occur at the glenohumeral joint.# Rx:- The dislocation should be reduced as early as possible and this can usually be accomplished under sedation.- There are three common methods of reduction dislocations:# Hippocratic method.# Hanging-arm method.# Kocher's method.