Costochondritis / Sternocostal Dysfunction post-MVA

Once cardiac and pulmonary causes are cleared, anterior chest wall pain after an MVA is most likely costochondritis or sternocostal dysfunction — injury to the cartilaginous joints where the ribs meet the sternum. The seatbelt and airbag concentrate enormous force directly over those joints during a frontal collision. The distinguishing clinical sign is that the pain is reproducible when you press on the rib-sternum junctions — that's your clinician recreating it with finger pressure, which cardiac pain simply doesn't do. This palpable tenderness is both diagnostic and reassuring.

Costochondritis from an MVA typically resolves over four to twelve weeks, with pain peaking in the first two to five days as inflammation reaches its height. Gentle movement is better than immobility — avoiding deep breathing to "guard" the pain actually slows healing and can contribute to shallow breathing patterns that cause their own problems. Diaphragmatic breathing retraining is part of our treatment protocol for exactly this reason. Class IV laser, gentle sternocostal joint mobilization, and soft-tissue therapy to the intercostals and pectorals accelerate the process considerably.

Yes — airbag deployment itself is a force event. Airbags deploy at speeds of 100–220 mph and make contact with the chest within milliseconds. That impact compresses the costochondral and sternocostal joints just as it prevents the more severe injury of striking the steering wheel directly. It's a trade, and generally a favorable one, but the anterior chest wall absorbs real force in the process. The seatbelt adds a diagonal restraint force simultaneously. This dual mechanism — airbag impact plus seatbelt compression — is why anterior chest wall injuries are so common in frontal crashes, even when overall injury severity is low.

Those movements create rotational force through the rib cage, which directly stresses the sternocostal and costochondral junctions. Rolling in bed twists the thorax against a relatively fixed sternum; reaching across the body draws the pectoral muscles across the injured cartilage. These are predictable aggravating movements for any anterior chest wall injury, and they don't indicate anything structurally dangerous. As the inflammation decreases with treatment, those functional limitations improve — most patients notice meaningful improvement in these specific movements within two to three weeks of care.

Imaging is used to rule things out, not to confirm costochondritis. Standard X-rays and CT scans show the bone and can identify rib fractures, sternal fractures, or pneumothorax — all of which require different management. Cartilaginous joint injuries don't show on standard imaging. If the ER has cleared you of fracture and internal injury, that clearance is what we need to begin treatment. We may request imaging if clinical findings suggest a fracture was missed, but for uncomplicated anterior chest wall pain with ER clearance, a thorough physical exam is the appropriate next step.