Acute Joint DislocationsSubluxation there is still joint contactDislocation complete loss of joint contact

Definition: An acute complete separation of the articular surface: Joint surfaces are no longer in contact

Described according to position of distal fragment to proximal fragment: Anterior, Posterior, Inferior, Superior

Usually results from significant trauma – high energy trauma:Sport injuries, RTA

Clinical Features: Pain Inability to move the limb Abnormal shape of the joint The limb is often held in a characteristic position Careful neurovascular exam before and after reduction is attempted

Imaging:X-rays:

Adequate views–AP and lateral (may be painful) Try your best to take another view though it is very diffecult.

Confirm the diagnosis Rule-out fractures

I.e. fracture-dislocation Reduce before X-rays in knee, ankle, why?

Very small vessels dislocation will immediately occlude the neurovascular cause injury (ischemia)

CT Scan: Needed in some cases to exclude fractures (e.g. hip)

Principle of Treatment:Dislocation confirm diagnosis

Urgent reduction closed, if failed Open surgical under GA Adequate pain relief; muscle relaxant; or GA Imaging before and after reduction: Post-reduction films Immobilization allow the soft tissue to heal Physiotherapy (after 2 – 3 weeks)

Complications: Neurovascular injury: Knee, Ankle Avascular necrosis of bone: Hip (head of hip) Recurrent dislocation: Shoulder Heterotopic ossification (bone in soft tissue) Joint stiffness Secondary osteoarthritis

A) Acromio-Clavicular Dislocation.B) Acute Shoulder Dislocation.

I. Anterior Shoulder Dislocation.II. Posterior Shoulder Dislocation.

C) Hip Dislocation.I. Posterior Hip Dislocation.

II. Anterior Hip Dislocation.III. Central Hip Dislocation.

D) Patella Dislocation.E) Knee Dislocation.

A) Acromio-Clavicular Dislocation: More seen in cyclist direct fall on shoulder tip.

Relates to the ligaments injured

Type1: Partial tear of the AC ligament Pain, Normal XrayType2: Complete tear of the AC ligamentType3: Complete tear of the AC and CC (coracoid) ligaments

Treatment:- Conservative sling + physiotherapy

Not active patient.- Surgery in unstable complete tears

Athletic (reconstruct the ligament)

B)B)B)

Acute Shoulder Dislocation:- Most common dislocated joint- Factors:

1. Shallow glenoid socket2. Wide range of motion

- Types:1. Anterior dislocation most common.2. Posterior

- We classify according to the distal part (the humeral head)

I. Anterior Shoulder Dislocation:- The humeral head lies anterior to the glenoid - Mechanism of Injury:

1. Forced abduction and external rotationThrowing / catching a ball (American football, baseball, basket ball)Hitting a ball with a racketForced on weight lifting

2. Fall on the backwards stretching handAbduction and external rotationIn old patients (rotator cuff muscles tear)

3. Direct force on upper humerus- Clinical Picture:

Patient holding the affected arm Shoulder in adduction The lateral outline of the houlder may be flattened Bulge may be seen and felt just below the clavicle Tenderness Inability to move Must examine for NV injury

(Axillary nerve injury most common)

- X – Ray: Antero-posterior & lateral

(axillary) views Overlapping shadows of humeral

head and glenoid Humeral head lies below and

medial to glenoid - X – Ray shows three subtypes (no need

to know):

Sub – Coracoid (Anterior)

Luxatio- Erecta(True Inferior)

Rare(Like statue of

Liberty)

- Rule-out greater tuberosity fracture

- Associated Lesions and Injuries:1. Avulsion of the antero-inferior glenoid labrum (Bankart

lesion)2. Indentation of the posterior-lateral part of the humeral head

(Hill-sachs lesion)- Reduction Techniques:

1. Kocher’s Method:Flex elbow at 900

Externally rotateAbductionRise slowlyInternally rotate

2. Stimson’s Method:Arm hanged + weightAnalgesiaWeight 10 lbs

Spontaneous reduction

3. Milch’s Method:Traction in abductionCounter-tractionRotation

4. Hippocratic Method:TractionFoot in patient axillaAdduction

- Complications:1. Recurrence dislocation (most common)

Specially if < 20 years2. Rotator cuff muscle tear (Elderly)3. Axillary nerve injury; neuropraxia (Temporary)

Numbness of loss of sensation on the lateral upper limbCan’t abduct the shoulder

4. Axillary artery injury5. Shoulder stiffness immobilization > 3 weeks6. Under-reduced dislocation (undiagnosed)

Femoral head eaten up

II. Posterior Shoulder Dislocation:- Humeral head lies behind the glenoid - Mechanism of Injury:

1. Indirect force internal rotation + adductionConvulsion or with an electric shock.

2. Direct fall on the elbow + shoulder internally rotated.- The diagnosis is frequently missed > 50%- Clinical Picture:

The arm is held in internal rotation and in locked position The front of the shoulder looks flat with a prominent coracoid.

- X-Ray: May be missed in on AP view

The humerHumeral head is medially rotated electrical light bulb

Empty glenoid sign Axillary or scapular

view is essential Rule-out fractures:

Neck, glenoid, lesser tuberosity- CT- Associated Lesions and Injuries:

1. Revere Bankart (posterior-inferior)2. Rotator cuff muscles tears 3. Lesser tuberosity fracture

Recurrent Shoulder Dislocation- Usually anterior:

Occurs when abducting and externally rotating:(Swimming, dressing, reaching backwards and up, combing hair ..)

- Clinical Picture:HistoryPositive apprehension test.

- Factors predisposing to recurrent dislocation:1- Age at first dislocation < 20 years2- Associated injuries:

Bankart: avulsion of the glenoid labrum Hill-Sachs: posterior-lateral depressed fracture humeral head.

3- Shoulder instability- Treatment: Surgical Arthroscopic repair of Bankart’s lesion.

Habitual Shoulder Dislocation- Patients with ligament laxity and muscle flaccidity are more

prone

-

C) Hip Dislocation:- Results of a large force (high energy force) – RTA- Hip usually very stable

Shape of head and acetabulum Acetabular Labrum

Strong fibrous ring Increases femoral head coverage Contributes to hip joint stability

Very strong ligaments and muscles.- Types:

1. Posterior most common2. Anterior

I.

Posterior Hip Dislocation:- Mechanism of Injury:

Road Traffic Accident Knee striking against the dashboard (unrestrained in the car)

- Clinical Picture: Short limb, adducted,

internally rotated and slightly flexed.

Pain Inability to move the hip

- Role-out: Associated fractures femur or acetabulum Sciatic nerve injury

- Reduction: Under GA Allis

Assistant: Stabilizes pelvisPosterior-directed force on both ASIS’s

Surgeon: Stands on stretcher Gently flexes hip to 90o Applies progressively increasing traction to the

extremity Applies adduction with internal/external rotation Reduction can often be seen and felt

Prone Position: Sleeping on his tummy, on the bed side Traction internal rotation external rotation

Check stability and NV- CT Scan Best to demonstrate an acetabular fracture (or any

boney fragment)To confirm there are no intra-articular fragments

- Complications: Sciatic nerve injury 10% Avascular necrosis of the femoral head

> 40% if reduction is delayed by > 12 hours Heterotropic ossification

II. Anterior Hip Dislocation:- Rare - Leg is externally

rotated, abducted and slightly flexed

- Palpable head in the groin area

III. Central Hip Dislocation:- A fracture / dislocation

Acetabular fracture

Position at impact determines the type of hip dislocation:1. Dash board posterior 2. Both legs abducted, externally rotated and knee flexed Anterior 3. Central

D) Patella Dislocation:- 1st time often in sports more in

adolescent females- Sudden quadriceps pull normal genu valgus pulls patella

laterally

- Clinical Picture: History of sudden injury May have spontaneously reduced

- X – Ray Clear

- Treatment:

Reduction easy Push from lateral to medial and extend the knee

Surgery if recurrence - Factors of Recurrence:

Ligament laxity Increased genu valgus High patella

E) Knee Dislocation:- High energy usually RTA- Torn cruciate ligaments and one or both of the collateral

ligaments - Vascular injury- Nerve injury- Dislocated joint may reduce spontaneously - Present with swelling and gross instability- If still dislocated gross deformity - Repeated vascular examination is necessary

Popliteal artery injury risk of compartment syndrome Common peroneal nerve injury

- X-Ray: Dislocation Fractured tibial spine (cruciate ligament avulsion) Avulsion of fibular stolid (collateral ligament avulsion)

- Angiography- Urgent reduction reduce without x-ray- Immediate vascular intervention if needed - Acute or delayed reconstruction of ligaments - Complications:

Instability Stiffness

F) Other Dislocations:- Fingers:

Sports, ball games, falls Reduction very easy – by traction