ELBOW INSTABILITY

By:

Dr. Ahmed saleh

Ass.lect. Of orthopaedic surgery

HAND AND UPPER LIMB SURGERY UNIT

Mansoura University HospitalsDepartment Of Orthopedic Surgery

Hand & Upper Limb Surgery Unit

OBJECTIVES

• FUNCTIONAL ANATOMY

• STABILIZING FACTORS

• PATHOMECHANICS

• CLASSIFICATION

• DIAGNOSIS

• MANAGEMENT

OSSEUS ANATOMY

SOFT TISSUE ANATOMY

• Capsule:

Anteriorly: above coronoid and radial fossa to the coronoid and

annular ligament

Posteriorly: olecranon fossa to articular margins of the sigmoid notch

• Ligaments around the elbow:

Lateral collateral ligament complex

Medial collateral ligament

• Accessory structures.

SOFT TISSUE ANATOMY

• Lateral collateral ligament complex:

Lateral ulnar collateral ligament (

Radial collateral ligament

Annular ligament

Accessory lateral collateral ligament

SOFT TISSUE ANATOMY

• Medial collateral ligament complex:

▫ Anterior bundle (valgusstress)

▫ Posterior bundle.

▫ Transverse ligament

SOFT TISSUE ANATOMY

• Accessory structures:

The quadrate ligament: connecting the inferior margin of the annular

ligament to the ulna.

The accessory lateral collateral ligament: stabilizes the annular

ligament by connecting its inferior fibres to the supinator crest.

Oblique cord: from the lateral ulnar tubercle to the radius just below

the radial tuberosity.

STABILIZING FACTORS

STATIC STABILIZERS DYAMIC STABILIZERS

• PRIMARY:

▫ Ulnohumeral joint

▫ MCL

▫ LCL

• SECONDARY:

▫ RADIAL HEAD

▫ CFO&CEO

▫ CAPSULE

• ANCONEUS(VIP)

• TRICEPS

• BRACHIALIS

ELBOW FORTRESS

PATHOMECHANICS

• The most common mode of trauma is falling on outstreched hand

• Mechanism of injury:

Extension of the elbow till contact

Upon contact ; flexion will begin

External rotation of the UHJ (triceps effect)

Internal rotatio of humerus against forearm

Valgus moment (mechanical axis)

Combination of ER., valgus and axial compression……. Instability.

CLASSIFICATION

5 CRITERIA:

• ARTICULATION INVOLVED

• DIRECTION OF DISPLACEMENT

• DEGREE OF DISPLACEMENT

• TIMING

• SIMPLE OR COMPLEX

CLASSIFICATION

DEGREE OF DISPLACEMENT• HORRI CIRCLE OF DISRUPTION

• 3STAGES:

▫ 1: posterolateral rotatory subluxation

▫ 2: incomplete dislocation

▫ 3: a: AMCL intact

▫ 3:b: no ligaments intact

▫ 3:c :flexor pronator origin affected

DIAGNOSIS & MANAGEMENT

• Diagnosis of acute dislocation

• Diagnosis of posterolateral instability

• Diagnosis of complex instability

• Diagnosis of valgus instability

DIAGNOSIS

ACUTE DISLOCATIOAN• Radiological finding of AP and LAT views.

• Assesment of instability through ROM

• If unstable, test for varus and valgus stability:

Full pronation for the valgus stress test

Internal rotation of the shoulder for varus test.

Both should be examined in full extension and 30 deg. Flexion

• Stress x-ray views are important.

DIAGNOSIS

POSTEROLATERAL INSTABILITY• External rotation of radius and und ulna in relation to distal

humerus.

• They act as one unit (DD. Radial head dislocation)

DIAGNOSIS

POSTEROLATERAL INSTABILITY• Symptoms:

▫ Variable presentation

▫ Pain, clicking popping and snapping on certain positions.

▫ History of trauma or surgery.

• Signs:

▫ Lateral pivot shift.

▫ Drower test

▫ Table top relocation test

▫ Active floor push up sign

▫ Chair sign

DIAGNOSIS

POSTEROLATERAL INSTABILITY• Radiological evaluation:

▫ A)x-ray:

For associatedfractures( head radius and coronoid)

Impression fracture

Drop sign of the elbow(4mm wideness)

Imaging during pivot shift

▫ B) MRI:

Of little value

• Arthroscopic diagnosis: Shows widening of lateral edge of the joint, elongation of lateral ligament.

• IT IS A CLINICAL DIAGNOSIS.

DIAGNOSIS

POSTEROLATERAL INSTABILITY

MANAGEMENT

POSTEROLATERAL INSTABILITY• The key is to regain the function of LCL.

• It is done by:

• Correction of bony element if present.

Surgical repair : in acute cases. Not good results.

Reconstruction with tendon graft and fixation( different fixation tech.)

Recently, arthrscopic assisted reconstruction or electrothermalshrinkage.

DIAGNOSIS

COMPLEX INSTABILITY

• Elbow dislocation associated with bony element.

• Uncommon, poor prognosis.

• Most common: radial head and coronid fracture

• Others include: transolecranon , terrible triad & posterior

monteggia

ASSOCIATED

RADIAL HEAD FRACTURE• Responsible for 30% of valgus stability.

• Intact MCLl with excisioN of radial head…….. No instability.

• Reconstruction or replacement is mandatory in defecient mcl

• Silicon head vs titaneum mono block implant.

ASSOCIATED

CORONOID FRACTURE• Regan-Morrey classification

• O’driscoll:

LASSO REPAIR

TERRIBLE TRIAD

• Elbow dislocation , radial head fracture and coronoid fracture

• Management must be done by correction of the 3 elemnts.

• Radial head fixation or replacement alone ….. 50% failure.

• Ligament reconstruction and not reapir (avulsion not

midsubstance)

POSTERIOR MONTEGGIA LESION

• Posterior dislocation of the radial head and a proximal ulna fracture

with an anterior triangular fracture fragment at the level of the

coronoid process

• Fixation of the coronoid process is mandatory for acquiring

stability.

TRANSOLECRANON ELBOW DISLOCATION

HINGED EXTERNAL FIXATOR

• DYNAMIC OR STATIC

• STATIC FIXATOR : Easily applied , no elbow motion

• DYNAMIC FIXATOR: demanding frame , active and passive.

• Indiations:

▫ Temporary stabilization

▫ persistent elbow instability

▫ protection of comminuted radial head or capitellum

▫ Maintenance of elbow stability in the setting of comminuted coronoidfractures

▫ Hinged fixators also hava role in providing stability in chronic unreduced elbow

HINGED EXTERNAL FIXATOR

VALGUS INSTABILITY

• Mainly occurred in throwing athletes.1st discovered 1946.

• MCL injury is the cause.

• Diagnosis based on :

▫ History

▫ +ve valgus stress test( baseball player ….+ve)

▫ MRI . MR arthrography with gadolinium.

▫ Dynamic ultrasonography

• It is contraindicated to do surgery in:

▫ Asymptomatic athletes who will quit the game

▫ Patient associated with HU or RCJ arthritis.

VALGUS INSTABILITY

• Management is by reconstruction of the MCL either by JOBE technique or by docking technique.

TAKING HOME MESSAGE

• Stability of the elbow is gained by osseus and soft tissue.

• Ulnar lateral collateral and anterior band of medial collateral are the

passwords for elbow stability.

• Horri circle will define the degree of displacement.

• Homework of elbow dislocation does not end by reduction.test the

stability before going home.

• Pivot shift done in supination and valgus stress test done in pronation.

• X-ray is important to assess simplicity of dislocation.

• Instability of the elbow is mainly a clinical entity