Acute Joint Dislocation

Dr. Abdulrahman Algarni, MD, SSC (Ortho), ABOSAssist. Professor, King Saud University

Consultant Orthopedic and Arthroplasty Surgeon

objectivesTo know mechanisms of the most common

joint dislocations

Be able to make the diagnosis

To know and interpret the appropriate x-rays

To know the common complications and how to avoid them

Acute Joint DislocationComplete separation of the

articular surface: Joint surfaces are no longer in contact

Position of distal to proximal fragment: Anterior, Posterior, Inferior, Superior

Acute Joint DislocationUsually results from

high-energy trauma

They occur most frequently in young patients

Clinical FeaturesPainful; inability to move the limb

Abnormal shape of the joint

The limb is often held in a characteristic position

Careful NV exam before reduction is attempted.

ImagingX-rays

adequate views

Confirm the diagnosis

Rule out fractures i.e. a fracture-dislocation

Reduce before X-rays: knee, ankle

CT scan

Treatment

Urgent reduction: Closed; surgical if failed

Adequate pain relief; muscle relaxant; GA

Imaging after reduction: Post-reduction films

Immobilization

physiotherapy

Complications

• Neurovascular injury: Knee, ankle

• Avascular necrosis of bone

• Recurrent dislocation: shoulder

• Heterotopic ossification

• Joint stiffness

• Secondary osteoarthritis

ACUTE SHOULDER DISLOCATION

• The most commonly dislocating joint

• shallowness of the glenoid socket and wide extraordinary range of motion

ACUTE SHOULDER DISLOCATION

• Anterior dislocation is the most common

• Posterior dislocation is rare; less than 2%

ANTERIOR SHOULDER DISLOCATION

Fall on the outstretched hand (abduction & external rotation)

ANTERIOR SHOULDER DISLOCATION

• The lateral outline of the shoulder may be flattened

• Bulge may be felt just below the clavicle

ANTERIOR SHOULDER DISLOCATION

• X-rays: antero-posterior and lateral (axillary) views:

• Overlapping shadows of the humeral head and glenoid fossa

ANTERIOR SHOULDER DISLOCATION

The head usually lying below and medial to the socket

Rule out greater tubrosity fracture

ANTERIOR SHOULDER DISLOCATION

Avulsion of the antero-inferior glenoid labrum (Bankart lesion).

Indentation of the postero-lateral part of the humeral head (Hill–Sachs lesion)

ANTERIOR SHOULDER DISLOCATION

Reduction

Different techniques: Kocher’s, Stimson’s, Milch’s, Hippocratic

ANTERIOR SHOULDER DISLOCATION

Reduction

Kocher’s method

ANTERIOR SHOULDER DISLOCATION

Complications Recurrent dislocation: age at first dislocation

Rotator cuff tear: elderly

Axillary nerve injury; neuropraxia

Axillary artery injury

Shoulder stiffness: prolonged immobilization

Unreduced (undiagnosed) dislocation

POSTERIOR SHOULDER DISLOCATION

Indirect force producing marked internal rotation and adduction

Convulsion, or with an electric shock

POSTERIOR SHOULDER DISLOCATION

The diagnosis is frequently missed; more than 50%

The arm is held in internal rotation and is locked in that position

The front of the shoulder looks flat with a prominent coracoid

POSTERIOR SHOULDER DISLOCATIONImagingThe humeral head is medially

rotated (electric light bulb)

(The empty glenoid sign)

Axillary or Scapular view is essential

Rule out fractures; neck, glenoid or lesser tuberosity

CT

HIP DISLOCATION

High energy trauma

posterior (the commonest)

anterior

POSTERIOR HIP DISLOCATION

Road Traffic accident; knee striking against the dashboard

Limb is short, adducted, internally rotated and slightly flexed.

POSTERIOR HIP DISLOCATION

Rule out associated fractures;

femur or acetabulum

Rule out sciatic nerve injury

POSTERIOR HIP DISLOCATIONReduction

POSTERIOR HIP DISLOCATIONReduction

POSTERIOR HIP DISLOCATIONReduction; stable

CT scan: the best to demonstrate an acetabular fracture (or any bony fragment)

POSTERIOR HIP DISLOCATION

Sciatic nerve injury; 10%

Avascular necrosis of the femoral head ;10%

If reduction is delayed by more than 12 hours, it rises to over 40%

Hetrotopic ossification

ANTERIOR HIP DISLOCATION

Rare compared with posterior

The leg lies externally rotated, abducted and slightly flexed

Palpable head in the groin

KNEE DISLOCATION

High energy mechanism; RTA

The cruciate ligaments and one or both lateral ligaments are torn

KNEE DISLOCATIONIf dislocated joint has reduced spontaneously; swelling and

gross instability

KNEE DISLOCATION

If still dislocated; gross deformity

KNEE DISLOCATION

Repeated vascular examination is necessary; popliteal artery injury; risk compartment syndrome

Common peroneal nerve injury: 20 % of cases

KNEE DISLOCATION

X-ray: dislocation, fracture of the tibial spine (cruciate ligament avulsion), avulsion of the fibular styloid (collateral ligament avulsion)

KNEE DISLOCATION

Angiograpy

KNEE DISLOCATION

Urgent reduction

Immediate vascular intervention if needed

Acute or delayed reconstruction of the ligaments

KNEE DISLOCATION

Complications

Instability

Stiffness

SummaryDislocation is an orthopedic emergency and

need urgent reduction

Anterior shoulder dislocation is the commonest

Obtain adequate imaging to rule out posterior shoulder dislocation

Acute unstable knee is a knee dislocation until proven otherwise

Always suspect vascular injuries with dislocated knee