Characteristics and clinical outcome of bone and joint tuberculosis from 1994 to 2011: a retrospective register-based study in Denmark

BACKGROUND:  Information on bone-joint tuberculosis (BJ-TB) is mainly based on data from high incidence areas. We conducted a nationwide register-based analysis of BJ-TB in Denmark during 1994-2011.

METHODS:  We linked data from the national TB surveillance system on BJ-TB, hospital records, the Danish Hospital and Civil Registration Registry.

RESULTS:  We identified 282 patients with BJ-TB, 3.6% of all TB cases (n=7936). Spinal TB constituted 153/282 (54.3%); immigrants comprised 83.3% of all cases. Danes were older and had higher Charlson Comorbidity Index score than immigrants (p<.01). C-reactive protein and erythrocyte sedimentation rates were elevated in most cases. Median time to diagnosis after first hospital contact was 19.5 days for spinal TB and 28 days for other BJ-TB (p=.01). Of patients with spinal TB, 54/133 (40.6%) had neurologic deficits at admission and 23(17.3%) presented with cauda equina. Diagnosis was culture verified in 87%. Resistance to any drug was found in 10.2%. Median time on antituberculous treatment for patients with spinal and other BJ-TB was 9 months and 7 months, respectively (p <.01). Surgery was required in 68(44.4%) patients with spinal TB and in 42/129(32.6%) patients with other BJ-TB (p=.04). Sequelae was reported in 57.5% of patients with spinal TB and 29.1% of patient with other BJ-TB (p<.01). One-year mortality was 25.5% among Danes compared with 1.3% among immigrants (p<.01).

CONCLUSION:  BJ-TB was rare and seen mainly among younger immigrants in Denmark. Spinal TB comprised more than half of cases presenting with more severe symptoms and worse outcome than other forms of BJ-TB.