Internal disc disruption and axial back pain in the athlete.

Axial back pain is commonly encountered by the sports medicine physician and has a variety of potential pain generators. Internal disc disruption is an important diagnosis to consider, particularly if there is a history of spinal trauma. The pathogenesis of IDD is not definitively known, although related theories exist. The process may begin with a vertebral endplate fracture followed by an inflammatory degradation of the disc matrix. Annular tears extend from the nucleus pulposus to the periphery and nociceptive nerve endings grow into the inner annulus and become sensitized by the biochemical degradative products. This lowers the pain threshold for mechanical stimulation during normal loading of the lumbar disc. Athletes are at high risk for IDD because of the repetitive axial compressive and torsional forces required in many sports. Diagnostic evaluation includes a thorough history and physical examination, whereas MR imaging is the modality of greatest use. Acute IDD is a symptomatic annular tear that commonly responds to aggressive conservative care delineated in the five-stage rehabilitation program. Chronic IDD may be episodic or constant. Pressure-controlled, provocative discography should be considered for athletes with chronic constant lumbar discogenic pain. Minimally invasive treatment options, such as IDET, may prove useful for a subset of patients with discographically proven IDD. Further clinical and basic science research is needed. Spinal fusion rarely is indicated for the athlete with internal disc disruption and no evidence of instability. Technological advances should continue to contribute to the arsenal of future treatments for internal disc disruption.