Hyperextension injuries of the thoracolumbar spine in diffuse idiopathic skeletal hyperostosis.

Study Design: Retrospective study of a consecutive series of patients with thoracolumbar hyperextension injuries (TLHIs) complicated by diffuse idiopathic skeletal hyperostosis (DISH) presenting to a single institution during a 9-year period.

Objective: Assess epidemiological data, trauma mechanism, injury characteristics in hyperostotic spines, and short-term outcome.

Summary Of Background Data: An increase in TLHIs complicated by DISH was observed. In current literature, only case reports and small case series touch this topic.

Methods: All patients with TLHIs in the setting of DISH between January 2002 and December 2010 were reviewed retrospectively. Clinical and radiographical data during hospitalization including computed tomographic scans of all patients were analyzed as to epidemiological issues, trauma characteristics, neurological deficits, and short-term outcomes. Statistical analysis was performed to assess factors related to trauma characteristics.

Results: Twenty patients with 23 TLHIs were analyzed. Twelve injuries involved the thoracic region; 1, the lumbar region; and 10, the thoracolumbar junction. A total of 85.7% of injuries were due to high-energy impact. The distribution of transdiscal and transosseous injuries was almost equal (13/10). Patients with DISH with vertebral body fractures were significantly older than those with transdiscal injuries (78.3 yr vs. 69.8 yr, P < 0.026). Post-traumatic neurological deficit was present in 22.7% patients. Neurological complications did not occur in low-energy injuries. On average, spines were posteriorly stabilized over 2.1 segments. Twenty percent of the patients died within 3 months (average age, 80.7 ± 5.1 yr, range, 76-88 yr).

Conclusion: To our knowledge, this is the largest series of TLHIs in DISH-altered spines in literature. The study helps to understand controversial findings in literature about morphological properties of TLHIs in DISH-affected spines. Surgeons should be aware of preexisting alterations in traumatized spines and the impact on therapeutic decisions. Because of the "aging population" and implications of metabolic diseases on an "aging spine," the incidence of TLHIs in DISH will probably rise.