Joint Dislocations

Background

Anterior shoulder dislocations represent 90-95% of shoulder dislocations. They present with the arm in a characteristic position of external rotation and slight abduction. The shoulder will have a flattened or ‘squared-off’ appearance with a prominent acromion. A palpable humeral head may be felt anteriorly. Comparison with the contralateral side should be examined for asymmetry looking for loss of convexity under the acromion on the affected side.

Posterior shoulder dislocations account for 5-10% of shoulder dislocations and tend to occur following seizures, electrocution injuries, or posteriorly directed blunt trauma to the shoulder. The deformity is usually less dramatic but may present with the arm held in abduction and internal rotation. Importantly the shoulder cannot be externally rotated on both passive and active movement.

Inferior shoulder dislocations are the least common type of shoulder dislocation (0.5%) and present with the arm full abducted and the elbow commonly flexed on or behind the head.

Neurovascular Assessment

It is essential to document function of the radial, ulnar, axillary and median nerves. An axillary nerve palsy results in numbness in the ‘regimental badge’ (outside of upper arm) area. The patency of the axillary artery must also be confirmed by the presence of symmetrical radial pulses.

Reduction Method

Anterior shoulder dislocations: traction-countertraction method.

• The patient should be in the supine position with an assistant close to the head of the bed.
• A sheet or towel is looped around the injured side axilla with one free end on the chest and the other underneath the back. The assistant uses these free ends to apply countertraction.
• The arm should be abducted and the elbow flexed to 90°.
• With the forearm, slow longitudinal traction is then applied to the affected limb.
• A distinct clunk will be felt as the shoulder reduces.

Posterior shoulder dislocations: supine, traction, internal rotation.

• The patient should be in the supine position.
• Traction is applied with careful internal rotation.
• The shoulder is then flexed and adducted while further internal rotation is added.
• Direct pressure to the humeral head from behind can help facilitate reduction.
• Once reduced the humerus is externally rotated gently but should never be forced.

Post Reduction Immobilisation

The arm should be immobilised in a sling for comfort. Movement of the elbow, wrist and hand should be encouraged.

Background

Elbow dislocations occur due to high energy trauma or sporting injuries. They typically present with a significantly swollen elbow held in flexion. The olecranon is prominent with disruption of the triangular relationship of the humeral epicondyles and olecranon.

In 50% of dislocations there is a disruption of the medial and lateral collateral ligaments.

In the other 50% there is an associated bony injury most commonly to the radial head or the coronoid process of the ulnar. Both of these structures restrain the anterior movement of the humerus.

Elbow dislocation + radial head fracture + coronoid process fracture is known as a ‘terrible triad’ injury: requires surgery due to inherent instability (evacuation timelines to surgery are the same as described above).

Neurovascular Assessment

It is essential to document function of the radial, ulnar, and median nerves. A neuropraxia of the ulnar nerve is relatively common. The patency of the brachial artery must also be confirmed by the presence of symmetrical radial pulses. It should be noted that a good capillary refill with absent pulse should still warrant suspicion of a vascular injury.

Reduction Method

• The patient should be in the supine position.
• With an assistant providing counter-traction grasp the patients wrist with one hand and cradle the underside of the dislocated elbow with the other.
• Apply in-line traction using both hands aiming to centre the olecranon between the humeral epicondyles.
• Successful reduction is given by a clunk.

Post Reduction Immobilisation

Above-elbow backslab (wrist to upper humerus) with the elbow at 90° of flexion. A SAM splint with bandaging can also be employed if plaster is unavailable

Background

Radiocarpal dislocations are rare high-energy injuries resulting from significant ligamentous disruption, often with associated fractures (fracture-dislocations). They typically occur following falls from height, motor vehicle collisions, or blast trauma. Clinically, there is gross deformity of the wrist with pain, swelling, and loss of function. 

Neurovascular Assessment 

It is essential to document function of the radial, ulnar, axillary and median nerves. Attention should be paid to the median nerve, as compression and an acute carpal tunnel syndrome is a recognised complication. The radial pulse and distal capillary refill should be documented. 

Reduction Method

• The patient should be in the supine position.
• With an assistant providing counter-traction to the forearm, longitudinal traction should be applied to the hand.
• Any deformity should be gradually corrected with gentle manipulation.
• A palpable or visible correction of deformity is indicative of a successful reduction.

Post Reduction Immobilisation

Below-elbow backslab (wrist and forearm) with the wrist neutral or in slight flexion. A SAM splint with bandaging can also be employed if plaster is unavailable. The limb should be elevated in a sling.

Background

Carpal dislocations most commonly occur as perilunate or lunate dislocations following high-energy hyperextension injuries of the wrist. They represent a spectrum of progressive ligamentous failure. Missed injuries are common. Clinically, there is wrist pain, swelling, and reduced range of motion; deformity may be subtle. Median nerve compression is a recognised complication.

Neurovascular Assessment 

It is essential to document function of the radial, ulnar, axillary and median nerves. Attention should be paid to the median nerve, as compression and an acute carpal tunnel syndrome is a recognised complication. The radial pulse and distal capillary refill should be documented. 

Reduction Method 

• Urgent reduction is required to relieve pressure on the neurovascular structures.
• The patient should be in the supine position.
• With an assistant providing counter-traction to the forearm, longitudinal traction should be applied to the hand for 10-15 minutes.

For dorsal (perilunate) injuries:

• The displaced carpus is reduced by distracting and slightly extending the wrist and then applying direct digital pressure over the carpus from dorsal to palmar while splinting the lunate with the opposing thumb.
• The wrist is then flexed slightly.
• The reduction is felt as the carpus relocates around the lunate. The distraction is then released.

For volar (lunate) dislocations:

• The dislocated lunate is reduced by distracting and slightly extending the wrist and then applying direct thumb pressure over the lunate from palmar to dorsal.
• The wrist is then flexed slightly.
• The reduction is felt as the lunate relocates. The distraction is then released.

Reduction may be incomplete or unstable; do not persist with repeated forceful attempts.

Post Reduction Immobilisation

Below-elbow backslab (wrist and forearm) with the wrist neutral or in slight flexion. A SAM splint with bandaging can also be employed if plaster is unavailable. The limb should be elevated in a sling.

Initial Surgical Management

Where resources allow (likely to be Role 3 and higher), regardless of whether a simple dislocation or a complex transcapral perilunate dislocation, the initial surgical management of these injures comprises two components:

1. Reduce the dislocation and place a single k-wire from dorsal radius into the lunate. This is effective in stopping re-dislocation, and does not interfere with subsequent procedures that are likely to be needed to repair and reconstruct damaged structures.
2. Perform a carpal tunnel decompression. These injuries swell considerably and risk injury to the median nerve. A full carpal tunnel decompression ensures that the nerve is protected.

NOTE: These injuries are often missed and can be challenging to diagnose and manage. If in doubt, seek urgent advice from deployed orthopaedic surgeon or use secure telemedicine communication for support from hand surgeons in the firm base. Once diagnosed, they require urgent transfer to an appropriate surgical facility for emergency care.

Background

Finger dislocations are very common and can often spontaneously reduce. They can present with varying degrees of swelling and bruising. They can occur at both the proximal and distal interphalangeal joint (PIPJ/DIPJ) and the metacarpophalangeal joint (MCPJ). The phalanx can dislocate in any direction but proximal dislocations tend to dislocate dorsally.

Neurovascular Assessment

Sensation of the ulnar and radial borders of the finger, and capillary refill should be assessed.

Reduction Method

• MCPJs can be reduced with gentle traction, flexion of the wrist and pressure over the metacarpal base.
• PIPJs can be reduced with gentle traction and pressure over the phalangeal base. If the are displaced volarly the base should be pushed dorsally.
• DIPJs can again be reduced with gentle tractions and pushing the base of the phalanx back into position.

Post Reduction Immobilisation

Fingers can be buddy strapped, or a splint can be applied to provide support.

Background

Dislocations of  the hip are usually posterior, and commonly occur following high energy trauma, such as a motor vehicle collision or a fall from height. Clinically the limb is shortened, flexed and internally rotated.

Anterior hip dislocations are less common but typically caused by an abduction force to the femur. Clinically the hip is held in external rotation with mild flexion and abduction.

It is important to note that the clinical appearance of a hip dislocation may be less evident if the femur is fractured.

Neurovascular Assessment

Posteriorly dislocated hips may result in sciatic nerve injury due to stretching of the nerve over the posteriorly dislocated femoral head. Fragments of bone can also injure the nerve.

Anterior dislocations can result in injury to the femoral artery, vein or nerve.

Lower limb pulses: Femoral, Popliteal, Dorsalis Pedis and Posterior Tibial should be assessed

Reduction Method

• Often requires sedation or brief anaesthesia, if available. Penthrox alone is unlikely to be sufficient. Addition of opioid analgesia is advised.
• The patient should be in the supine position with the pelvis stabilised by an assistant.
• The hip and knee are flexed to 90°. The clinician puts their forearm under the patient’s calf and applies upward traction.
• The femoral head is then lifted forwards into the acetabulum with gentle internal and external rotation movements.
• A obvious ‘clunk’ may occur to signal reduction, however, may be less obvious if there is a large posterior wall fracture.

Post Reduction Immobilisation

• The patient should be kept non-weight bearing through the affected leg pending assessment at a higher echelon of care.

Background

Knee dislocations are rare high energy traumatic injuries characterised by a high rate of neurovascular injury. Diagnosis is made clinically with careful assessment of limb neurovascular status. Ligamentous injury and concomitant fractures are common (60%).

Treatment is generally prompt reduction and temporary stabilisation, with assessment of limb perfusion, followed by delayed ligamentous surgical reconstruction.

Presence of the dimple sign - buttonholing of medial femoral condyle through the medial capsule is indicative of an irreducible posterolateral knee dislocation that requires open reduction – do not attempt closed reduction

Neurovascular Assessment

Tibial nerve: sensation to the sole/ lateral aspect of the foot; motor: plantar flexion, flexion of toes.

Peroneal nerves: sensation to second webspace/ dorsum of foot;  motor: foot eversion and big toe extension.

Lower limb pulses: Femoral, Popliteal, Dorsalis Pedis and Posterior Tibial should be assessed and compared to the contralateral side.

ABPI must be performed post reduction (and for suspected spontaneous reductions).

• if pulses present and ABPI >0.9: serial examination should be performed (100% negative predictive value) – recommended examination intervals of every two hours as a minimum.
• if pulses present and ABPI <0.9: urgent evacuation should occur for duplex ultrasound/ CT angiography if available +/- surgical exploration.
• if pulses absent and reduction has been confirmed: urgent evacuation for consideration of surgical exploration of the popliteal artery and prophylactic fasciotomies. Ischaemic time >6 hours is associated with amputation rates as high as 86%.

Reduction Method

• The patient should be positioned supine with the pelvis stabilised by an assistant.
• Apply longitudinal traction to the lower leg, with gentle medial, lateral, anterior, or posterior translation as needed to guide the tibia back into alignment with the femur.
• Be cautious and avoid applying pressure of the popliteal fossa (posterior knee) during reduction.
• Reassess neurovascular status of the limb.

Post Reduction Immobilisation

The knee should be immobilised in extension using a splint, or external fixation, as required. The patient should be non-weightbearing through the affected side. Monitoring for signs of compartment syndrome is essential.

Background

Irreduced patellar dislocations present with the knee held in flexion with an obvious lateral prominence. These commonly reduce spontaneously, before clinical assessment, leaving minimal definitive signs upon clinical examination. In these cases, patients may be unclear about what happened and may simply describe the knee ‘giving way’.

Neurovascular Assessment

Tibial nerve: sensation to the sole/ lateral aspect of the foot; motor: plantar flexion, flexion of toes.

Peroneal nerves: sensation to second webspace/ dorsum of foot;  motor: foot eversion and big toe extension.

Lower limb pulses: Femoral, Popliteal, Dorsalis Pedis and Posterior Tibial.

Reduction Method

• The patient should be in the supine position with the affected knee held in a comfortable position for the patient.
• A medial-directed force to the lateral aspect of the patella should be applied with the thumbs while slowly extending the leg.
• A palpable clunk should confirm the reduction of the patella.

Post Reduction Immobilisation

Splints that permit full knee flexion may be used for pain relief in the period immediately following injury. For first-time lateral patellar dislocations, unrestricted weightbearing should be encouraged with the assistance of mobility aides.

Background

An ankle dislocation occurs when there is an abnormal separation between the talo-tibial joint. A pure ankle dislocation without a concomitant fracture is exceedingly rare due to the strength of the stabilising ligaments around the ankle.

Most ankle dislocations are therefore fracture-dislocations. The patient will present with a dislocated foot relative to the tibia. It is important that rapid re-alignment of the ankle occurs, as failure to do so can cause significant morbidity.

Neurovascular Assessment

Sensation to the sole / lateral aspect of the foot and toe flexion (Tibial nerve).

Sensation to the first webspace and toe extension (Deep Peroneal nerve).

Sensation to the dorsum of the foot (Superficial Peroneal nerve).

The Dorsalis Pedis and Posterior Tibial pulses should be assessed, as should the capillary refill time of the foot.

Reduction Method

Anterior ankle dislocations

• Position the patient supine with the knee slightly flexed.
• While grasping the forefoot with one hand and the heel with the other, dorsiflex the foot to accentuate the deformity to disengage the talus.
• While an assistant provides counter-traction on the leg, apply direct traction to the foot and heel to extend the leg and allow the talus to drop back into position between the tibia and fibula.

Posterior ankle dislocations

• Position the patient supine with the knee flexed.
• While an assistant provides counter traction on the leg, grasp the heel with one hand and the dorsal metatarsals with the other.
• Slightly plantar-flex the foot to disengage the talus.
• Pull on the foot with both hands (elongating the leg) while sliding the talus anteriorly into position. A second assistant can be used to apply downward pressure on the tibia and fibula while the foot is pulled forward into position.

Lateral and medial translation can be corrected during either reduction manoeuvre.

Post Reduction Immobilisation

A below knee back-slab should ideally be applied. Where not available, a SAM splint can be bent and moulded to fit the shape of the lower leg, extending from just below the knee to the base of the toes, with the ankle in a neutral position.

The affected leg should be elevated to reduce swelling, and the patient should be non-weightbearing through the injured limb. VTE prophylaxis should be considered.