Common Dislocations Flashcards
General principles of assessment and treatment of common dislocations?
Prompt reduction (usually closed); if presentation is late, closed reduction may not be possible and the risk of a poor outcome is higher
Assess neurovascular status BEFORE AND AFTER reduction
A short period of splintage is normally enough but some may benefit from surgery, e.g:
• Stabilisation procedures
• Joint excision or replacement
Occurrence of shoulder dislocations?
Vast majority of GH joint dislocations are ANTERIOR
Types of shoulder dislocations?
Traumatic, e.g:
• Severe external rotation
• Fall onto an elbow
Atraumatic, e.g:
• Ligamentous laxity (youngsters)
• CTDs, like Ehler-Danlos syndrome
Clinical signs of a shoulder dislocation?
Loss of symmetry and contour
Patient supports arm due to apprehension and pain
Nerve and arterial injuries assoc. with anterior shoulder dislocation?
AXILLARY NERVE PALSY is the commonest assoc. nerve injury, causing:
• Numbness in the “badge patch” area (where soldiers where stripes)
• Unable to assess deltoid function acutely
Effect on any part of the brachial plexus or on axillary artery
Lesions assoc. with anterior shoulder dislocation?
Bankart lesion - anterior dislocation usually causes detachment of the anterior labrum and capsule from the glenoid
Hill-Sachs lesion - may also have an impaction fracture on the posterior humeral head
Can also have an assoc. :
• Rotator cuff tear
• Fracture of the great tuberosity
Ix for shoulder dislocations?
X-ray - appears obvious
Reduction techniques?
- Traction (most common)
- Hippocratic
- Holding weight
- Kocher manoeuvre
Re-dislocation rates for anterior shoulder dislocations?
If <20 years, 80% chance of re-dislocation:
• Offer surgical stabilisation
If >30 years, 20% chance of redislocation:
• Offer physiotherapy
General treatment principles for anterior shoudler dislocation?
Reduction
Most are then in a broad-arm sling for 3 weeks, followed by physio
Surgical stabilisation offered for recurrent dislocation or for those <20 years:
• Reattachment of Bankart lesion
• Can be done arthroscopically
Signs of axillary nerve injury?
Usually, neurapraxia and this tends to resolve
Axonotmesis may/may not resolve
Persistent loss of deltoid power is very difficult to treat
Ix and treatment options for a rotator cuff tear assoc. with anterior shoulder dislocation?
If, despite physio, pain is not resolving and there is evidence of impingement:
• US or MRI
Consider subacromial decompression and cuff repair
Treatment of a greater tuberosity fracture assoc. with anterior shoulder dislocation?
Tends to reduce after reduction of GH joint
It may need to be fixed if it remains substantially displaced
Treatment of generalised ligamentous laxity and instability assoc. with a shoulder dislocation?
If there is evidence of hypermobility, a Bankart repair is insufficient
Specialised physio can help avoid surgery but sometimes it cannot be avoided
Occurrence of posterior shoulder dislocations?
Uncommon
Cause of posterior shoulder dislocations?
Posterior force on adducted and internally rotated shoulder
May occur during a seixure
Ix for posterior shoulder dislocations?
X-ray - light bulb sign indicates a severely internally rotated humeral head
Treatment of posterior shoulder dislocations?
Closed reduction and sling
Physiotherapy
Describe an AC joint dislocation?
From a fall onto the shoulder that is usually sports-related
Treatment of AC joint dislocation?
If there is mild displacement and the coracoclavicular ligaments are intact:
• Conservative Mx
If ≥100 displacement and persistent pain, even with conservative Mx:
• Coracoclavicular ligament reconstruction
Types of SC joint dislocations? Treatment?
Anterior - bony lump that can be left alone
Posterior - can compress trachea, oesophagus or brachiocephalic vein and cause: • Dyspnoea • Dysphagia • Venous congestion These must be reduced
Occurrence of elbow dislocations?
2nd most common dislocation in the body
Treatment of a pure elbow dislocation?
THERE IS NO FRACTURE
Reduction and then casting for 1 week, followed by physio
Good prognosis
Potential fracture sits in an elbow fracture-dislocation?
- Radial head
- Ulna
- Coronoid process
Treatment of elbow fracture-dislocations?
Fix large fractures
May need to replace the radial head
May need to repair ligaments
Complications of elbow-fracture dislocations?
High risk of stiff elbow
Types of forearm fracture-dislocations?
- Monteggia
* Galeazzi
Treatment of forearm fracture-dislocations?
Fix fracture
Reduce dislocation
What are perilunate dislocations?
Rare but often missed on initial imaging, leading to rapidly progressive wrist OA
Inv. dislocation of the carpus relative to the lunate, which remains in normal alignment with the distal radius
Ix for perilunate dislocations?
X-ray:
• AP views tends to be normal (may see a slightly flexed scaphoid forming the O-sign OR the lunate will have a triangular appearance, forming the piece-of-pie sign)
• Lateral view is required
Treatment of perilunate dislocations?
URGENT REDUCTION and stabilisation (wires)
If late presentation, open reduction
Problems assoc. with a perilunate dislocations?
May have a concurrent scaphoid fracture
Types of finger dislocations?
- Dorsal PIPJ dislocations (most common)
* Volar PIPJ and dorsal DIPJ dislocations
Occurrence of finger dislocations?
Common in cricketers
Treatment of finger dislocations?
Can reduce on the pitch or under ring-block with local anaesthetic
Splint for 3 weeks and can tape to the neighbouring finger and encourage early ROM
DO NOT USE ADRENALINE IN FINGERS
Complications of finger dislocations?
Can lead to swan-neck deformity, with disruption of the volar plate
OR
Boutonniere deformity with disruption of the central slip of extensor tendon
Describe hip fracture
Native hip only dislocates with high-energy injury, e.g: road-traffic accidents
There is a high incidence of other injuries so ABCD
Injuries assoc. with hip fracture?
Fracture of the posterior wall acetabulum
Femoral head avulsion fracture, from ligamentum teres
Treatment of hip dislocation?
Emergency reduction
May require internal fixation if there is a:
• Large acetabular wall fracture
• Femoral head fracture
Complications of hip dislocations?
Risk of AVN and heterotopic ossification
Describe dislocations of hip replacement
Anteriorly/posteriorly and may injure the sciatic nerve
Abductors usually tear
Treatment of dislocations of hip replacement?
1st time:
• Closed reduction and knee splint
Recurrent dislocation may need revision surgery:
• Can implant a “restrained” cup, preventing dislocation but reducing ROM and may not last as long
Occurrence of patellar dislocation?
Fairly common, esp. in adolescents
Describe a patellar dislocation
Dislocates LATERALLY from sudden quads contraction +/- direct blow (e.g: clash of knees)
There is an obvious deformity, with the patella sitting on the side of the knee
Assoc. injuries with patellar dislocation?
May have an osteochondral fracture that causes lipohaemarthrosis (fluid level on X-ray) +/- a loose body in the knee
Factors that predispose to patellar dislocation?
- Female
- <20 years of age
- Ligamentous laxity, e.g: in Ehlers-Danlos syndrome
- Genu valgum
- Shallow trochlea
- Femoral neck anteversion
Treatment of patellar dislocation?
Reduction and splint for 3 weeks, followed by physio
Recurrence risk of patellar dislocation?
10-30% recurrence with 1st time dislocation
50% recurrence with 2nd time:
• May offer surgical stabilisation and medial patello-femoral ligament (MPFL) reconstruction
Describe knee dislocations
Serious injuries with a high incidence of:
• Popliteal artery injury
• Common fibular nerve injury
• Compartment syndrome (due to vascular and re-perfusion injury)
Treatment of knee dislocations?
Emergency reductions, external fixation +/- revascularisation
Usually requires multiligament reconstruction
Treatment of ankle fracture-dislocations (ankle tends to have a fracture with dislocation)?
Fixation stabilises the joint
Describe subtalar joint dislocation
High-energy injuries, usually with medial dislocation
Treatment of subtalar dislocation?
Reduction and a cast for 3 weeks
If soft tissues are interposed, may require open reduction
Assoc. problems with subtalar dislocation?
Can be assoc. with a talar neck fracture, AKA “Aviator’s Astragalus”
High risk of AVN
Pressure on skin can produce white skin; this is a bad sign of oncoming skin necrosis and wound breakdown
Describe tarso-metatarsal dislocations
AKA Lisfranc fracture-dislocation - rotation of a hyperplantarflexed foot
Ix for Lisfranc fracture-dislocation?
X-ray - subtle signs:
• Look for flake fractures at the base of the 2nd metatarsal
• Too much space between the 1st and 2nd metatarsals
• Cuneiforms and metatarsals may not align
May need CT scans +/- stress X-rays to diagnose
Complications of untreated Lisfranc fractures?
Chronic forefoot pain and requirement for internal fixation
