Xiphisternal Joint Injection

Indications and Clinical Considerations

The xiphisternal joint can serve as a source of pain that may often mimic pain of cardiac and upper abdominal origin. It is susceptible to the development of arthritis, including osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, Reiter syndrome, and psoriatic arthritis. The joint is often traumatized during acceleration–deceleration injuries and blunt trauma to the chest. With severe trauma the joint may fracture, sublux, or dislocate ( Figs. 112.1 and 112.2 ). The joint also is subject to invasion by tumor either from primary malignancies, including thymoma, or from metastatic disease. This joint appears to serve as the nidus of pain for xiphodynia syndrome. This is a constellation of symptoms, including severe intermittent anterior chest wall pain in the region of the xiphoid process, made worse with overeating, stooping, and bending ( Fig. 112.3 ). The patient may report a nauseated feeling associated with the pain of xiphodynia syndrome.

Physical examination reveals that the pain of xiphodynia syndrome is reproduced with palpation or traction on the xiphoid. The xiphisternal joint may feel swollen, and physical deformity of the anterior chest wall may be noted in patients with an abnormal xiphisternal angle ( Figs. 112.3 and 112.4 ). Stooping or bending may reproduce the pain. Coughing may be difficult, which may lead to inadequate pulmonary toilet in patients who have sustained trauma to the anterior chest wall. The xiphisternal joint and adjacent intercostal muscle also may be tender to palpation. The patient also may note a clicking sensation with movement of the joint.

Plain radiographs are indicated for all patients with pain thought to be emanating from the xiphisternal joint to rule out occult bony disease, including tumor (see Fig. 112.1 ; Fig. 112.5 ). On the basis of the patient’s clinical presentation, additional testing may be indicated, including complete blood cell count, prostate-specific antigen, sedimentation rate, and antinuclear antibody testing. Magnetic resonance imaging, computed tomography, and ultrasound imaging of the joint are indicated if joint instability, fracture, or an occult mass or other abnormality is suspected. ( Figs. 112.6 and 112.7 ). The injection technique described later serves as both a diagnostic and a therapeutic maneuver.

Clinically Relevant Anatomy

The xiphoid process articulates with the sternum via the xiphisternal joint ( Fig. 112.8 ). The xiphoid process is a plate of cartilaginous bone that becomes calcified in early adulthood. The xiphisternal joint is strengthened by ligaments but can be subluxed or dislocated by blunt trauma to the anterior chest. The xiphisternal joint is innervated by the T4-T7 intercostal nerves and by the phrenic nerve. It is thought that this innervation by the phrenic nerve is responsible for the referred pain associated with xiphodynia syndrome. Posterior to the xiphisternal joint are the structures of the mediastinum. These structures are susceptible to needle-induced trauma if the needle is placed too deeply. The pleural space may be entered if the needle is placed too deeply and laterally, and pneumothorax may result.