Reading pathology in bones for creating the biological profile: The case of diabetes

When creating a biological profile, the correct interpretation of bone lesions is fundamental since it may lead to the identification of diseases such as diabetes, cancer, gout or arthritis, which in turn can serve as crucial traits for identification. The present pilot study aims to verify the characteristic features of skeletal lesions on diabetics. Diabetes mellitus is one of the most widespread diseases, currently affecting more than 415 million people worldwide. Much is therefore known about the manifestation of this disease from a physiopathological, clinical and radiological point of view; however, from the forensic anthropological perspective, the macroscopic aspects of the consequences of diabetes on the skeleton are poorly described. This study aims to investigate the manifestation of diabetes mellitus on 19 skeletons of diabetic patients (and one negative control case), selected from the documented Milano Identified Skeletal Collection, according to their known pathological history. Aim of this investigation is to identify and describe the macroscopic signs left on dry bones by the diabetic condition, through an osteological analysis. Such skeletons were initially cleaned and studied from an anthropological point of view. After a clear revision of the main lesions described in the clinical practice, the same or corresponding manifestations (periostitis, lytic lesions, erosion, remodeled fractures, osteomyelitis and osteoarthritis) were sought, identified and described, as well as their localization on the skeleton and frequency of appearance. The results show that the lower limbs are the first areas involved in the diabetic condition, appearing as lytic lesions (50% of cases), erosion (40%) and, to a lesser extent, remodeling (30%), periostitis (25%) and deformation (5%). Such lesions can virtually affect any bone of the distal foot, but the most frequently affected areas are the head of the 1° and 5° metatarsal and the distal phalanx of the great toe; however, the severity of the extension of the pathology varies among the individuals considered, from cases without signs to cases of amputation at the femur. Only in 20% of cases the hand is also affected, in particular the 1° metacarpal, displaying alterations of the carpo-metacarpal joint. However, the most difficult aspect of the forensic anthropological practice is to differentiate similar manifestation caused by different pathologies. The present investigation therefore also attempted to provide initial and macroscopic guidelines for better performing a differential diagnosis between diabetes and other diseases, such as gout, leprosy, septic arthritis, osteomyelitis and periostitis, consequent to non-specific infections, and trauma.