Spinal infection poses a demanding diagnostic and treatment problem for which a multidisciplinary approach with spine surgeons, radiologists, and infectious disease specialists is required. Infections are usually caused by bacterial microorganisms, although fungal infections can also occur. The most common route for spinal infection is through hematogenous spread of the microorganism from a distant infected area. Most patients with spinal infections diagnosed in early stages can be successfully managed conservatively with antibiotics, bed rest, and spinal braces. In cases of gross or pending instability, progressive neurological deficits, failure of conservative treatment, spinal abscess formation, severe symptoms indicating sepsis, and failure of previous conservative treatment, surgical treatment is required. In either case, close monitoring of the patients with spinal infection with serial neurological examinations and imaging studies is necessary.

There has been a major resurgence of tuberculosis (TB) and drug-resistant tuberculosis in the last few decades. Although it has been brought under control in most Western countries, it is still a major cause of death in endemic regions like India. Osteoarticular tuberculosis (OA TB) forms a small proportion of the total cases of tuberculosis. Perceptions and practices of orthopedic surgeons are entirely different in endemic and non-endemic regions around the world, due to the vast difference in exposure. Literature from endemic areas puts stress on clinico-radiological diagnosis and empirical anti-tubercular treatment (ATT). Such practices, although non-invasive, simple to implement, and economical, carry a significant risk of missing TB mimics and developing drug resistance. However, OA TB is still perceived as a “diagnostic enigma” in non-endemic regions, leading to a delay in diagnosis. Hence, a high index of suspicion, especially in a high-risk population, is needed to improve the diagnosis. Evolving drug resistance continues to thwart efforts to control the disease globally. This review article discusses the perceptions and practices in different parts of the world, with India as an example of the endemic world, and lays down priorities for overcoming the challenges of diagnosing osteoarticular TB.

While implant-related infections continue to play a relevant role in failure of implantable biomaterials in orthopaedic and trauma there is a lack of standardised microbiological procedures to identify the pathogen(s). The microbiological diagnosis of implant-related infections is challenging due to the following factors: the presence of bacterial biofilm(s), often associated with slow-growing microorganisms, low bacterial loads, previous antibiotic treatments and, possible intra-operative contamination. Therefore, diagnosis requires a specific set of procedures. Based on the Guidelines of the Italian Association of the Clinical Microbiologists (AMCLI), the World Association against Infection in Orthopaedics and Trauma has drafted the present document. This document includes guidance on the basic principles for sampling and processing for implant-related infections based on the most relevant literature. These procedures outline the main microbiological approaches, including sampling and processing methodologies for diagnostic assessment and confirmation of implant-related infections. Biofilm dislodgement techniques, incubation time and the role of molecular approaches are addressed in specific sections. The aim of this paper is to ensure a standardised approach to the main microbiological methods for implant-related infections, as well as to promote multidisciplinary collaboration between clinicians and microbiologists.

The definition of peri-prosthetic joint infection (PJI) has a strong impact on the diagnostic pathway and on treatment decisions. In the last decade, at least five different definitions of peri-prosthetic joint infection (PJI) have been proposed, each one with intrinsic limitations. In order to move a step forward, the World Association against Infection in Orthopedics and Trauma (W.A.I.O.T.) has studied a possible alternative solution, based on three parameters: 1. the relative ability of each diagnostic test or procedure to Rule OUT and/or to Rule IN a PJI; 2. the clinical presentation; 3. the distinction between pre/intra-operative findings and post-operative confirmation. According to the WAIOT definition, any positive Rule IN test (a test with a specificity > 90%) scores +1, while a negative Rule OUT test (a test with a sensitivity > 90%) scores −1. When a minimum of two Rule IN and two Rule OUT tests are performed in a given patient, the balance between positive and negative tests, interpreted in the light of the clinical presentation and of the post-operative findings, allows to identify five different conditions: High-Grade PJI (score ≥ 1), Low-Grade PJI (≥0), Biofilm-related implant malfunction, Contamination and No infection (all scoring < 0). The proposed definition leaves the physician free to choose among different tests with similar sensitivity or specificity, on the basis of medical, logistical and economic considerations, while novel tests or diagnostic procedures can be implemented in the definition at any time, provided that they meet the required sensitivity and/or specificity thresholds. Key procedures to confirm or to exclude the diagnosis of PJI remain post-operative histological and microbiological analysis; in this regard, given the biofilm-related nature of PJI, microbiological investigations should be conducted with proper sampling, closed transport systems, antibiofilm processing of tissue samples and explanted biomaterials, and prolonged cultures. The proposed WAIOT definition is the result of an international, multidisciplinary effort. Next step will be a large scale, multicenter clinical validation trial.