Normal Elbow

Introduction

Routine radiography, ultrasound, CT, and MR imaging (conventional and arthrography) are the main diagnostic modalities used for diagnosis of abnormalities around the elbow joint.

Conventional Radiography

Radiography ( Fig. 10-1 ) is used for primary evaluation of any osseous elbow pathology by assessment of the bony contours, joints, and fat pads. Limited soft tissue evaluation and ionizing radiation are major limitations. Generally, plain film series for evaluation of the elbow includes anteroposterior, lateral, internal, and external oblique views. Radiocapitellar projection can be useful for fractures of the radial head, capitellum, or coronoid process and the humeroradial and humeroulnar articulation.

Computed Tomography

Complex osseous anatomy and pathology that is poorly visualized on conventional radiography can be evaluated better with CT ( Fig. 10-2 ; see also Video 10-1 ) using multiplanar reconstructions and surface rendering of the osseous anatomy and by rotation of the reconstructed model in infinite projections. Complex fractures, dislocations, degree of healing, and calcifications such as matrix calcification (osteoid, cartilage) in some bone tumors or in soft tissues can be assessed better.

Computed Tomographic Arthrography

Articular cartilage abnormalities such as chondral and osteochondral fractures and osteochondritis dissecans as well as synovial and capsular abnormalities are well depicted by CT arthrography ( Fig. 10-3 ). The soft tissues are poorly visualized compared to MRI. Ionizing radiation, invasive technique, metal artifacts in postoperative patients, and high costs are other disadvantages.

Magnetic Resonance Imaging

Soft tissue anatomy and pathology can be better visualized by MRI ( Figs. 10-4 to 10-6 ). MRI does not involve any ionizing radiation, but higher costs, longer examination time, and patient claustrophobia can pose problems.

MR Arthrography

MR arthrography ( Fig. 10-7 ) has an added advantage over plain MR imaging in better evaluation of articular cartilage, intraarticular bodies, and collateral ligaments. Indirect MR arthrography performed by intravenous injection of gadolinium-based contrast is noninvasive and less expensive. Direct MR arthrography involves intraarticular injection of gadolinium-based contrast using a lateral approach over the radial head or a posterolateral approach between the olecranon, humerus, and radial head. It is invasive and expensive, but distention of the joint capsule allows for excellent evaluation of the intracapsular structures.