Discitis and vertebral osteomyelitis are uncommon entities, and diagnosis often is confounded by their similar clinical presentation, because characteristic radiographic findings are not evident until late in the course of illness.
To compare the age distribution, clinical manifestations, and radiographic findings, especially magnetic resonance imaging (MRI), in children with discitis or vertebral osteomyelitis.
A retrospective review of 57 children with a discharge diagnosis of discitis or vertebral osteomyelitis hospitalized from January 1980 through December 1998.
Fifty patients met inclusion criteria: 36 with discitis and 14 with vertebral osteomyelitis. The mean age at presentation was younger for children with discitis than for those with vertebral osteomyelitis (2.8 vs 7.5 years of age) and the duration of symptoms longer for children with vertebral osteomyelitis than for those with discitis (33 vs 22 days). The initial symptom for both groups of children was refusal to walk, limp, or back pain, but children with osteomyelitis more often were febrile (79% vs 28%) and ill-appearing than those with discitis. Thirty-three patients with discitis had radiographs of the spine; 25 (76%) had abnormalities that were diagnostic. Ten discitis patients had MRI; 9 (90%) had abnormalities consistent with this diagnosis. Thirteen children with vertebral osteomyelitis had radiographs of the spine, but in only 7 (54%) were these abnormal. However, 11 had MRIs, and in each the diagnosis of vertebral osteomyelitis was established.
This comparative study suggests that age and clinical presentation distinguish most patients with discitis from those with vertebral osteomyelitis. Although radiographs of the spine usually are sufficient to establish the diagnosis of discitis, MRI is the diagnostic study of choice for pediatric patients with suspected vertebral osteomyelitis.