Injection Technique for Slipping Rib Syndrome

Indications and Clinical Considerations

Slipping rib syndrome is a constellation of symptoms, including severe knifelike pain emanating from the lower costal cartilages associated with hypermobility of the anterior end of the lower costal cartilages. Other names for slipping rib syndrome are listed in Box 114.1 . The tenth rib is most commonly involved, but the eighth and ninth ribs also can be affected. Slipping rib syndrome is almost always associated with trauma to the costal cartilage of the lower ribs. These cartilages often are traumatized during acceleration–deceleration injuries and blunt trauma to the chest. With severe trauma, the cartilage may sublux or dislocate from the ribs. Patients with slipping rib syndrome also may report a clicking sensation with movement of the affected ribs and associated cartilage.

Physical examination reveals that the patient will vigorously attempt to splint the affected costal cartilage joints by keeping the thoracolumbar spine slightly flexed. Pain is reproduced with pressure on the affected costal cartilage. Patients with slipping rib syndrome exhibit a positive hooking maneuver test. The hooking maneuver test is performed by having the patient lie in the supine position with the abdominal muscles relaxed while the clinician hooks his or her fingers under the lower rib cage and pulls gently outward ( Fig. 114.1 ). Pain and a clicking or snapping sensation of the affected ribs and cartilage indicate a positive test.

Plain radiographs are indicated for all patients with pain thought to be emanating from the lower costal cartilage and ribs to rule out occult bony disease, including rib fracture and tumor. 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 of the affected ribs and cartilage is indicated if joint instability or occult mass is suspected ( Fig. 114.2 ). The injection technique described later serves as both a diagnostic and a therapeutic maneuver.

Clinically Relevant Anatomy

The cartilage of the true ribs articulates with the sternum via the costosternal joints ( Fig. 114.3 ). The cartilage of the first rib articulates directly with the manubrium of the sternum and is a synarthrodial joint that allows a limited gliding movement. The cartilage of the second through sixth ribs articulates with the body of the sternum via true arthrodial joints. These joints are surrounded by a thin articular capsule. The costosternal joints are strengthened by ligaments. The eighth, ninth, and tenth ribs attach to the costal cartilage of the rib directly above. The cartilage of the eleventh and twelfth ribs are called floating ribs because they end in the abdominal musculature (see Fig. 114.3 ). The pleural space and peritoneal cavity may be entered when performing the following injection technique if the needle is placed too deeply and laterally, and pneumothorax or damage to the abdominal viscera may result.