Extraspinal articular tuberculosis: An 11-year retrospective study of demographic features and clinical outcomes in East London

Abstract

The global incidence of tuberculosis (TB) infection was estimated by the WHO to be 10 million cases in 2018, 85% of whom had pulmonary TB (pTB) infection (WHO 2019). In Europe, the extrapulmonary TB (EPTB) incidence is increasing, accounting for 22.6% of new cases reported in 2017 (ECDC 2019). Furthermore, the incidence of articular TB infections has risen in Europe (Jutte 2004, Lesic 2010. This is reflected in UK surveillance data, where in 2017, 2.2% of new TB cases presented with non-spinal bone infections (Kruijshaar 2009, PHE 2018. Globally, this rise in EPTB infections has largely been ascribed to a growing population of immunosuppressed patients including those on long-term steroids and biologic therapies, as well as to an ageing population (Pigrau-Serrallach 2013, Byng-Maddick 2016). However, in low-incidence countries in Europe the rise in articular TB infections has also been attributed to increasing rates of migration (Jutte 2004, Krujishaar 2009. EPTB infection is thought to occur through haematogenous, contiguous or lymphatic spread in the primary infection stage, when mycobacteria can spread to any organ or tissue and remain dormant for years. Articular infection most commonly affects weight-bearing large joints such as the spine, knees and hips. Infection is often slowly progressing with joint effusions and pain, progressing to the formation of sinus tracts and eventually to complete joint destruction (Hogan 2017). Initial symptoms are vague and may mimic other conditions such as bacterial osteoarticular infection. This can result in significant diagnostic delay, especially in settings where TB is non-endemic and clinical suspicion is low (Erdem 2005, Broderick 2018). Most studies describing osteoarticular TB have focused on paediatric populations or on spinal TB with only a few published case series of extra-

Current concepts in the diagnosis and management of tuberculosis of the elbow joint

“…The elbow is the most frequently affected joint in the upper extremity; accounting for 1e5% of all cases of skeletal TB. 5,24 Fan et al reported an incidence of 10.3% from the retrospective data, whilst a recent study by McGuire et al suggested elbow as the second-largest site (19.4%) of extrapulmonary tuberculosis after knee joint (23.7%) in their large cohort of cases 21,26…”

“…17,22 Painful elbow due to early TB may also present as tennis elbow or a post-traumatic contusion leading to further delay in diagnosis. 21,28 Clinical manifestations can be constitutional and/or local. Constitutional features are present in about 20e30% of cases and may range from fatigue, evening rise of temperature, loss of appetite, loss of weight, and night sweats.…”

“…The culture-positive rate varies from 28 to 87%. 21 However, with enhanced culture methods such as BACTEC™ radiometric culture, it usually takes 2 weeks to grow mycobacteria with a culture-positive rate reaching up to 90%. 40 Multiple samples from skin, subcutaneous tissue, pus, and bone should be obtained and sent for culture sensitivity, ZN staining, histopathology, PCR, to increase the chances of correct diagnosis.…”

“…Out of 13 studies, 5 studies (102 elbows) have commented on relapse of the tubercular disease however, none of these studies reported features of relapse during their followup. 12,15,18,20,21 Radiological healing is commented on in three studies. Agarwal et al report complete healing at one year in 6 elbows and two other studies by Dix-Peek et al and Martini et al found radiological healing in all 37 cases that were followed up.…”