Injection Technique for Os Supratrochleare-Related Elbow Pain

Indications and Clinical Considerations

Elbow pain secondary to os supratrochleare is seen with increasing frequency in clinical practice because of the increased interest in physical fitness and the use of exercise machines. Os supratrochleare is the name given to an accessory ossicle occasionally found in the posterior elbow, which is often found adjacent to the proximal aspect of the olecranon process. It is thought that accessory ossicles, such as os supratrochleare bones, serve to decrease friction and pressure of tendons as they pass in proximity to a joint. Similar accessory ossicles are found in the feet, hands, and wrists ( Fig. 60.1 ).

Elbow pain secondary to os supratrochleare is characterized by tenderness and pain over the posterior elbow. The patient often feels that he or she has gravel in the elbow and may report a severe grating sensation with flexion and extension of the elbow (see Fig. 55.2 ). The pain of os supratrochleare worsens with activities that require repeated flexion and extension of the elbow or with forceful overhead throwing. Os supratrochleare is often associated with loose bodies in the elbow joint and may coexist with olecranon bursitis.

On physical examination, pain can be reproduced by pressure on the os supratrochleare. In contradistinction to olecranon bursitis, in which the tender area remains over the olecranon bursa, in os supratrochleare the area of maximum tenderness will be just above the olecranon process. A creaking or grating sensation may be appreciated by the examiner, and locking or catching on extension and flexion of the elbow may occasionally be present.

Plain radiographs are indicated for all patients with os supratrochleare to rule out fractures and to identify accessory ossicles that may have become inflamed ( Fig. 60.2 ). Plain radiographs will also often identify loose bodies or joint mice, which are frequently present in patients with elbow pain secondary to os supratrochleare. On the basis of the patient’s clinical presentation, additional testing, including complete blood cell count, sedimentation rate, and antinuclear antibody testing, may be indicated. Magnetic resonance imaging (MRI) of the elbow joint is indicated if joint instability, occult mass, or tumor is suspected and to further clarify the diagnosis. Radionuclide bone scanning may be useful in identifying stress fractures or tumors of the elbow and distal humerus that may be missed on plain radiographs. Screening laboratory testing consisting of complete blood cell count, erythrocyte sedimentation rate, and automated blood chemistry should be performed if the diagnosis is in question. Arthrocentesis of the elbow joint may be indicated if septic arthritis or crystal arthropathy is suspected.

Os supratrochleare pain syndrome is a clinical diagnosis supported by a combination of clinical history, physical examination, radiography, and MRI. Pain syndromes that may mimic os supratrochleare pain syndrome include primary disease of the elbow, including gout and occult fractures, as well as bursitis and tendonitis and epicondylitis of the elbow, both of which may coexist with os supratrochleare. Osteochondritis dissecans, Panner disease, and synovial chondromatosis may also mimic the pain associated with os supratrochleare. Primary and metastatic tumors of the elbow may also manifest in a manner analogous to elbow pain secondary to os supratrochleare.