Elbow Dislocations, Instability and Contracture-Elbow Instability: Anatomy, Biomechanics,Diagnostic Maneuvers, and Testing

Elbow Instability: Anatomy, Biomechanics,Diagnostic Maneuvers, and Testing

Pdf Summary

Elbow instability can result from trauma or chronic overuse, causing loss of important stabilizers. Diagnosis of elbow instability can be made using specific examination maneuvers and testing. The anatomy and biomechanical characteristics of the elbow play a role in the diagnosis. The bony and ligamentous stabilizers of the elbow provide primary and secondary constraints to elbow instability. The ulnohumeral articulation, anterior bundle of the medial collateral ligament (MCL), and lateral collateral ligament (LCL) complex are important stabilizers. The AMCL of the MCL provides the majority of the restraint to valgus and posteromedial rotatory instability, while the LCL complex is the primary restraint to posterolateral rotatory instability (PRLI). Muscles crossing the elbow also play a role in stabilizing the joint. Various diagnostic maneuvers can be used to evaluate each type of instability. These may include the valgus stress test, milking maneuver, moving valgus stress test, lateral pivot-shift test, posterolateral rotatory drawer test, chair push-up test, prone push-up test, gravity-assisted varus stress test, and table-top relocation test. Radiographs, computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography (US) can be used to evaluate osseous abnormalities, ligamentous injuries, and other soft tissue damage. MRI is particularly effective in evaluating soft tissue structures. Overall, a comprehensive understanding of elbow anatomy, biomechanics, and diagnostic testing is crucial in accurately diagnosing and managing elbow instability.

Keywords

elbow instability

trauma

chronic overuse

diagnosis

examination maneuvers

bony stabilizers

ligamentous stabilizers

ulnohumeral articulation

medial collateral ligament

lateral collateral ligament