Injection Technique for Sesamoiditis of the Hand

Indications and Clinical Considerations

Sesamoiditis is a relatively uncommon pain syndrome that affects the hand. It is characterized by tenderness and pain over the flexor aspect of the thumb and, much less commonly, the index finger. The patient often feels that he or she has a stone or foreign body embedded in the affected digit when grasping things. The pain of sesamoiditis worsens with repeated flexion and extension of the affected digits. When the thumb is affected, the sesamoiditis usually occurs on the radial side, where the condyle of the adjacent metacarpal is less obtrusive. Patients with psoriatic arthritis may have a higher incidence of sesamoiditis of the hand ( Fig. 90.1 ).

On physical examination, pain can be reproduced by pressure on the sesamoid bone. In contradistinction to occult bony disease of the phalanges in which the tender area remains over the area of disease, with sesamoiditis the tender area moves with the flexor tendon when the patient actively flexes his or her thumb or finger. With acute trauma to the sesamoid, ecchymosis over the flexor surface of the affected digit may be present.

Plain radiographs are indicated for all patients with sesamoiditis to rule out fractures, tumors, and avascular necrosis and to identify sesamoid bones that may have become inflamed ( Fig. 90.2 ). On the basis of the patient’s clinical presentation, additional testing may be indicated, including complete blood cell count, sedimentation rate, and antinuclear antibody testing. Magnetic resonance imaging, computed tomography scanning, and/or ultrasound imaging of the fingers and bones of the wrist is indicated if joint instability, occult mass, occult fracture, infection, or tumor is suspected ( Figs. 90.3 and 90.4 ). Radionuclide bone scanning may be useful in identifying stress fractures of the thumb and fingers or sesamoid bones that may be missed on plain radiographs of the hand ( Fig. 90.5 ).