This document discusses elbow instability, including anatomy, stabilizing factors, classification, diagnosis, and management. It covers the soft tissue and bony anatomy of the elbow. Elbow stability relies primarily on the ulnohumeral joint, medial and lateral collateral ligaments. Injuries can range from subluxation to complete dislocation. Diagnosis involves clinical examination and imaging. Management depends on the injury, and may include repair, reconstruction, or fixation of bony and ligamentous injuries.

1. ELBOW INSTABILITY
By:
Dr. Ahmed saleh
Ass.lect. Of orthopaedic surgery
HAND AND UPPER LIMB SURGERY UNIT
Mansoura University Hospitals
Department Of Orthopedic Surgery
Hand & Upper Limb Surgery Unit

2. OBJECTIVES
• FUNCTIONAL ANATOMY
• STABILIZING FACTORS
• PATHOMECHANICS
• CLASSIFICATION
• DIAGNOSIS
• MANAGEMENT

3. OSSEUS ANATOMY

4. 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.

5. SOFT TISSUE ANATOMY
• Lateral collateral ligament complex:
 Lateral ulnar collateral ligament (
 Radial collateral ligament
 Annular ligament
 Accessory lateral collateral ligament

6. SOFT TISSUE ANATOMY
• Medial collateral ligament
complex:
▫ Anterior bundle (valgus
stress)
▫ Posterior bundle.
▫ Transverse ligament

7. 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.

8. STABILIZING FACTORS
STATIC STABILIZERS DYAMIC STABILIZERS
• PRIMARY:
▫ Ulnohumeral joint
▫ MCL
▫ LCL
• SECONDARY:
▫ RADIAL HEAD
▫ CFO&CEO
▫ CAPSULE
• ANCONEUS(VIP)
• TRICEPS
• BRACHIALIS

9. ELBOW FORTRESS

10. 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.

11. CLASSIFICATION
5 CRITERIA:
• ARTICULATION INVOLVED
• DIRECTION OF DISPLACEMENT
• DEGREE OF DISPLACEMENT
• TIMING
• SIMPLE OR COMPLEX

12. 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

13. DIAGNOSIS & MANAGEMENT
• Diagnosis of acute dislocation
• Diagnosis of posterolateral instability
• Diagnosis of complex instability
• Diagnosis of valgus instability

14. 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.

15. DIAGNOSIS
POSTEROLATERAL INSTABILITY
• External rotation of radius and und ulna in relation to distal
humerus.
• They act as one unit (DD. Radial head dislocation)

16. 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

17. 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.

18. DIAGNOSIS
POSTEROLATERAL INSTABILITY

19. 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 electrothermal
shrinkage.

20. 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

21. 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.

22. ASSOCIATED
CORONOID FRACTURE
• Regan-Morrey classification
• O’driscoll:

23. LASSO REPAIR

24. 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)

25. 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.

26. TRANSOLECRANON ELBOW DISLOCATION

27. 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 coronoid
fractures
▫ Hinged fixators also hava role in providing stability in chronic unreduced
elbow

28. HINGED EXTERNAL FIXATOR

29. 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.

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

31. 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