Elbow - Lateral View
How to perform the examination
Patient Positioning
Primary position (recommended): the patient is seated with the upper limb resting on a table, the elbow flexed at 90 degrees, and the forearm in pronation to fully expose the lateral compartment. The arm should be abducted approximately 45 degrees from the trunk to optimize access to the lateral epicondylar structures.
Alternative position: the patient can be positioned supine with the upper limb adducted to the trunk and the elbow flexed. The forearm should be rotated to allow optimal access to the radiocapitellar compartment. This position facilitates dynamic examination with pronation–supination movements.
Anatomy to Identify
- Lateral epicondyle (tendinopathies, calcifications, bone erosions)
- Humeral capitellum (cartilage alterations, osteochondritis dissecans)
- Radial head (fractures, subluxations, structural changes)
- Radial collateral ligament (lesions, laxity, thickening)
- Lateral epicondylar tendons (epicondylitis, partial tears)
- Annular ligament of the radius (alterations, calcifications)
Probe
High-frequency linear transducer (10–15 MHz) essential for imaging the superficial structures of the lateral compartment. Beam steering techniques are crucial to overcome anisotropy of the epicondylar tendons. Doppler is fundamental for assessing neovascularization in epicondylitis and synovial inflammatory processes. Frequency modulation allows optimization of imaging from superficial tendinous structures to deeper joint components.
Anatomical Zones
Lateral epicondyle
The lateral epicondyle of the humerus represents the origin site of the extensor muscles of the forearm and hand. In hemophilic arthropathy, this region may develop chronic inflammatory changes due to biomechanical alterations and functional compensations that arise secondary to joint disease.
Characteristic: Lateral bony prominence, insertion site of the common extensor tendons
Findings:
- Reactive enthesopathy: Thickening of the extensor tendons with altered echotexture at their epicondylar origin.
- Tendinous calcifications: Intratendinous calcific deposits due to chronic degenerative processes.
- Bone erosions: Irregularity of the epicondylar profile due to chronic inflammatory processes.
- Secondary epicondylitis: Compensatory inflammation resulting from biomechanical alterations of the elbow.
Probe Positioning
Place the probe longitudinally over the lateral epicondyle of the humerus, following the course of the extensor tendons. The probe marker should be oriented proximally toward the arm. Apply minimal pressure to avoid compressing the superficial tendinous structures.
Humeral capitellum
The humeral capitellum is the lateral articular surface of the distal humerus that articulates with the radial head. In hemophilic arthropathy, this structure is frequently involved in intra-articular erosive processes and represents a critical site for assessing disease progression.
Characteristic: Spherical surface covered by hyaline cartilage, articulating with the radial head
Findings:
- Cartilage erosions: Focal loss of articular cartilage with surface irregularity.
- Osteochondritis dissecans: Osteochondral lesions with possible formation of loose bodies.
- Subchondral sclerosis: Increased echogenicity of the subchondral bone due to chronic remodeling.
- Articular deformities: Morphological alterations of the capitellum due to progressive erosive processes.
Probe Positioning
Perform longitudinal and transverse scans at the radiocapitellar joint. The probe should be placed posterior to the lateral epicondyle to visualize the articulation between the humeral capitellum and the radial head.
Clinical Cases by Severity grade
The clinical cases are organized according to the HEAD-US protocol (Head-to-Head Assessment of Ultrasound Score), which classifies the severity of hemophilic arthropathy into four levels. Click on each level to explore the available cases for that specific joint–projection combination.