Valgus Instability and Elbow Rehabilitation Quiz

Elbow Instability

• Elbow instability is the second most common large joint dislocation.
• The annual incidence is 5.21 per 100,000.
• About a quarter of these dislocations are associated with elbow fractures.
• The prevalence of elbow dislocations is higher in individuals aged 47% compared to 53% in the elderly.

Elbow Stabilizers

• Elbow dynamic stabilizers are composed of muscles that cross the elbow joint.
• These include the triceps, anconeus, and brachialis.
• The UCL and LUCL along with the supporting common flexor/pronator and extensor tendons also act as primary static stabilizers.
• These tissues contribute to the stability of the elbow joint in various movements.

Ulnar Collateral Ligament (UCL)

• The medial ulnar collateral ligament (MUCL) acts as a primary restraint against valgus stress.
• The anterior and posterior bands of the MUCL are crucial for resisting valgus stresses, especially during extension and flexion, respectively.
• The transverse ligament provides additional support for the medial side.

Lateral Collateral Ligament Complex (LUCL)

• The LUCL, radial collateral ligament, and annular ligament act as restraints to varus and posterolateral rotatory instability.
• The complex is essential for stabilizing the elbow against varus stress.
• Various ancillary collateral ligaments also support the joint's stability.

Classification of Elbow Dislocations

• Elbow dislocations categorized by timing (acute, chronic, recurrent).
• Classified by direction (anterior, posterior, posterolateral, posteromedial, medial, or lateral).
• Classified by the associated injury grade (subluxation or perched, simple, or complex).
• Classified by articulations involved (Ulno-humeral or Radio-humeral joint).

Etiology of Elbow Instability

• Traumatic causes, such as falling on an outstretched hand, and axial loading through the forearm.
• overuse injuries, especially in sports like baseball and tennis

Mechanism of Injury

• Common injuries occur when falling on an outstretched hand with an axial load transmitted through the forearm.
• This force creates a rotational component that can result in the damaging of the elbow soft tissue.
• This can be a complex event that affects several structures in a complex way.

Posterolateral Rotatory Instability (PLRI)

• PLRI involves a combination of axial load, elbow flexion, external rotation, and valgus force.
• The Horii Circle further demonstrates these events in the disruption of the elbow joint structures.

Evaluation of Elbow Instability

• History-taking includes age, sports/work history, details of trauma mechanism, and symptoms description.
• Observation includes evaluation for bony and soft tissue anomalies, ecchymosis, and swelling, protective postures and ROM (range of motion).
• Palpation- assessing bony landmarks and painful areas.
• Instability and special tests include stress tests (valgus, varus, lateral pivot shift), chair and prone push-up, and table-top relocation tests.
• Imaging includes radiographs (AP, lateral of oblique), CT scans, and MRI.

Treatment

• Conservative treatments include immobilization (i.e., casts or splints) and manual therapy in simple or low functional demand cases.
• Recommendations in case of complex or high functional demand, and/or failure of conservative treatment include surgery.
• Job/sport-specific activity and targeted muscle strengthening exercises.

Imaging for Instability

• Plain anteroposterior, lateral, and oblique X-rays are used to assess the joint for fractures and dislocations
• Computed tomography (CT) is ideal in checking for hidden fracture fragments and soft tissue disruption
• MRI also aids in the visibility of fracture fragments and soft tissue injuries
• Dynamic fluoroscopy and ultrasound are used to evaluate the dynamic motions of the bony and soft tissue structures and are helpful in determining if instability persists.

Complications

• Recurrent instability, heterotopic ossification, chronic regional pain syndrome (CRPS), nerve injury, and infections.
• Elbow stiffness can also be a consequence of improper treatment/management.

Outcome Measures

• Disability of Arm, Shoulder, and Hand (DASH) scores
• Mayo Elbow Performance Score (MEPS)
• Oxford Elbow Score (OES)

Bibliography

• Numerous cited references, each pertaining to a specific aspect of elbow instability, providing supportive research to each point.