Clinical Study Hip Osteoarthritis and Osteoporosis: Clinical and Histomorphometric Considerations Umberto Tarantino, 1 Monica Celi, 1 Cecilia Rao, 1 Maurizio Feola, 1 Irene Cerocchi, 1 Elena Gasbarra, 1 Amedeo Ferlosio, 2 and Augusto Orlandi 2 1 Department of Orthopaedics and Traumatology, University of Rome “Tor Vergata”, Viale Oxford 81, 00133 Rome, Italy 2 Department of Anatomic Pathology, University of Rome “Tor Vergata”, Viale Oxford 81, 00133 Rome, Italy Correspondence should be addressed to Monica Celi; monica.celi@uniroma2.it Received 24 November 2013; Revised 24 January 2014; Accepted 15 March 2014; Published 14 April 2014 Academic Editor: Nicola Napoli Copyright © 2014 Umberto Tarantino et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Although an inverse relationship between osteoarthritis (OA) and osteoporosis (OP) has been shown by some studies, other reports supported their coexistence. To clarify this relationship, we analyzed the interplay between clinical and histomorphometric features. Bone mineral density (BMD) and histomorphometric structure were assessed in 80 patients of four diferent age-matched groups undergoing hip arthroplasty for severe OA or OP-related femoral fracture. Harris Hip Score was also performed. Surgical double osteotomy of the femoral head was performed and microscopic bone slice samples analysis was performed by using a BioQuant Osteo sotware. Bone volume fraction (BV/TV) was lower ( < 0.01) in subjects with femoral neck fracture (20.77 ± 4.34%) than in subjects with nonosteopenic OA (36.49 ± 7.73%) or osteopenic OA (32.93 ± 6.83%), whereas no diference was detected between subjects with femoral neck fractures and those with combined OA and OP (20.71 ± 5.23%). Worse Harris Hip Score was found in those patients with the lowest BMD and BV/TV values. Our data support recent evidences indicating the possibility of impaired bone volume fraction in OA patients, with a high risk of developing OP, likely for their decreased mobility. Further studies are needed in order to investigate biomolecular pathway and/or growth factors involved in bone volume impairment in OA patients. 1. Introduction he improvement of living conditions and advances in medicine in the last 50 years increased life expectancy, allowing ageing-related diseases to become a common cause of death and disability. Osteoarthritis (OA) and osteoporosis (OP) are extremely frequent among elderly people and their impact on life quality makes them of high sociohealth relevance [1–3]. Several observations reported an inverse association between OA and OP and large longitudinal studies suggested a protective efect of one disease on the other one [4–7]. his belief was partly supported from the evidence of opposite mechanisms driving the development of bone changes associated with OA and OP. Reduction of the bone mass and quality are key features of OP and determine a high risk of fractures [8, 9]. Instead, OA is characterized by increased bone density [10–14] and cartilage remodelling opposite to those of OP [10, 14–16]. However, other studies failed to show an inverse relationship between OA and OP and reported impaired bone quality and increased risk of fracture in patients with OA [17–20]. Histomorphometry is a recently developed method aimed at evaluating microscopic structure of bone that relects changes and turnover activities of absorption and formation [21]. Histomorphometric assess- ment allows for a comprehensive semiquantitative analysis of microscopic organization and structure of bone by using speciic grids and sotware. his allows a computer-assisted analysis of images and obtaining detailed information on volumes and surfaces occupied by diferent bone component, with particular reference to the distribution of the bone volume compared to the total area. In order to better clarify the relationship between OA and OP, we compared clinical and microscopic bone features in patients with OA or fracture undergoing hip arthroplasty. Dual energy X-ray Hindawi Publishing Corporation International Journal of Endocrinology Volume 2014, Article ID 372021, 5 pages http://dx.doi.org/10.1155/2014/372021