False-negative triple-phase bone scans in spinal cord injury to detect clinically suspect heterotopic ossification: a case series.

ABSTRACT

BACKGROUND/OBJECTIVE: Heterotopic ossification (HO) is a complication seen in patients after spinal cord injury (SCI). Triple-phase nuclear bone scanning is the most sensitive test for the detection of HO. This retrospective study assesses whether patients with clinically suspected HO but negative triple-phase nuclear bone scans develop delayed positive nuclear bone scans. CASE SERIES A cohort of patients with SCI and clinically suspected HO who underwent triple phase nuclear bone scans over a period of 2 years was identified from retrospective chart review of an acute inpatient SCI rehabilitation service. A subgroup of 7 patients with initially negative but subsequently positive triple-phase nuclear bone scans was identified, and the following data were collected date, mechanism, admission level, and admission completeness of injury as well as date, number, and results of bone scans. Laboratory studies were also collected during the time of imaging. RESULTS: Over a 2-year period, 343 patients were admitted to the SCI rehabilitation service; 60 patients were suspected of having HO and underwent a total of 85 triple-phase nuclear bone scans. Seven patients were identified with initially negative but subsequently positive bone scans. CONCLUSIONS: In patients with clinically suspicious HO but negative bone scans, follow-up scans are indicated to identify initial false-negative studies.