Imaging of Musculoskeletal Tuberculosis

Abstract

Tuberculosis is one of the rare bone infections (RBI). This term refers to conditions where only a small percentage of cases have bone manifestations or where the infective organism is altogether rare (Abd El Bagi et al. 1999). Incidence of RBI can increase if predisposing factors prevail: for example, diabetes, immunocompromise, drug abuse, steroids therapy, immigration, undernourishment, and overcrowding. Osteoarticular tuberculosis is rare, occurring in 1–3% of all tuberculosis patients and is present in 30% of all extrapulmonary tuberculosis cases (Engin et al. 2000). Resurgence of tuberculosis is blamed on HIV infection and the development of multidrug resistance. Following the decline of tuberculosis in the second half of the last century in response to new efficient chemotherapeutic agents, osteoarticular tuberculosis was often overlooked, leading to a delay in diagnosis sometimes of many years (Yao and Sartoris 1995). Skeletal tuberculosis is almost invariably secondary. The original site is usually intrapulmonary or in the mesenteric glands. Occasionally the bone infection is by contiguity from a nearby joint or infected soft tissues. In some instances there is no apparent primary lesion. Skeletal involvement may follow the initial constitutional symptoms by 1–2 years. However, we have seen cases where the bone lesions preceded the chest disease. In one of our patients, miliary tuberculosis developed 6 months after the onset of knee infection. Concomitant pulmonary tuberculosis was reported in 12–50% of cases (Hugosson et al. 1996). This is more common in children.