Joint Dislocation Flashcards
Define dislocation and subluxation
Dislocation = Complete separation of 2 articulating bony surfaces, often caused by sudden impact to the joint
Subluxation = A partial or incomplete dislocation
Risk factors for dislocation
Loose ligaments (double jointed)
Ehlers-Danlos syndrome
General management for joint dislocation
A-E
Analgesia
Reduction: Each of the reduction methods works by abduction and external rotation to disengage the humeral head from the glenoid, with axial traction to reduce it.
Immobilisation
Consider surgical repair
X-ray to ensure relocation and no fracture
Neurovascular exam
Rehabilitation: early motion and physiotherapy
Aetiology of shoulder dislocation
95% anterior (anterioinferior): Trauma, 25% associated with humeral fractures
Posterior: seizures, electrocution
Appearance of a shoulder dislocation clinically and on imaging
Anterior: External rotation and abduction
- Humeral head visibly out of glenoid fossa
Posterior: internal rotation and adduction
- lightbulb sign
Inferior: arm fully abducted and elbow flexed or behind the head
Specific management for shoulder dislocation
Reduction
- Under local anaesthetic e.g. intra-articular lidocaine
- Procedural sedation e.g. IV morphine, midazolam, etomidate
Immobilisation: sling or sling + swathe (3 weeks)
Surgical referral: anatomic Bankart’s repair
Confirm reduction via AP lateral radiograph
Complications of shoulder dislocation
Hill-Sachs lesions: impaction injuries to the chondral surface of the posterior and superior portions of the humeral head
Bankart’s lesions: fractures of the anterior inferior glenoid bone
Rotator cuff tears
Axillary nerve damage
Aetiology of elbow dislocation and how does it rpesent
50% sports related - fall onto outstretched arm
Either simple (without fracture) or complex (with fracture of proximal radius/ulna/distal humerus)
Terrible triad:
1. Lateral collateral ligament injury → posterior dislocation
2. Radial head fracture
3. Coronoid fracture
Elbow held in flexion
Specific management for elbow dislocation
Reduction
- Under local anaesthetic e.g. intra-articular lidocaine
- Procedural sedation e.g. IV morphine, midazolam, etomidate
- Extend to 30 flexion → olecranon aligned to the centre of the medial and lateral condyle of the humerus → forearm flexed to 90 with longitudinal traction given to the arm → arm flexed further with direct downward prerssure to the olecranon
Immobilisation: posterior splint at 90 flexion with neutral rotation
Surgical referral: anatomic Bankart’s repair
Confirm reduction via AP lateral radiograph
Complications of elbow dislocation
Coracoid fracture
Stretching of the ulnar nerve
Recurrent instability
Aetiology of finger dislocation
Usually dorsal
Associated with axial loading, hyperextension, ball-catching sports
Either MCP, PIP or DIP
Either dorsal or volar (in respect of position of the distal part)
Specific management for finger dislocation
Reduction
- Under local anaesthetic e.g. intra-articular lidocaine
- Hyper-extend the PIP/DIP then light axial traction with pressure applied to the base of the dislocated digit
Immobilisation: buddy tape to an adjacent digit OR place splint in slight flexion
Surgical referral: anatomic Bankart’s repair
Confirm reduction via X-ray
Aetiology of hip dislocation
Axial loading of the femur towards the acetabulum
Bent knee with a dashboard in a motor vehicle crash
A hip that is abducted and externally rotated is more likely to sustain an anterior dislocation.
An adducted femur that is flexed at the hip will sustain a posterior hip dislocation
- The hip will then be fixed in this position and in flexion
Stewart-Milford classification describes if there is a concomitant fracture
Specific management for hip dislocation
Reduction
- Allis’s method
- Stimson’s gravity technique
Complications of hip dislocation
Sciatic nerve injury
Injury to femoral artery, vein, or nerve
Avascular necrosis
Osteoarthritis
Recurrent dislocation
