Acta of Bioengineering and Biomechanics Vol. 9, No. 2, 2007 The application of the cell method in a clinical assessment of bone fracture risk F. COSMI 1 *, D. DREOSSI 2 1 Dipartimento di Energetia, University of Trieste, Italy 2 Facoltá di Medicina e Chirurgia University of Trieste, Italy The aim of this paper is to introduce a new technique for in vivo quantification of bone structure fracture risk. The elastic properties of the architecture obtained from bone digital radiographic images are determined using the cell method. Compression tests are simulated and the results of the numerical analysis are indexed. Such an index is considered to be indicative of the bone structure capabilities. The first clinical validation was carried on at CSMMO, Centro Studi Malattie Metaboliche dell’Osso (Gorizia, Italy), showing that this tech- nique can improve the diagnosis and help a physician in the identification of an actual fracture risk. The examination is not expensive, uses instrumentation that is widely available and therefore could be easily introduced in clinical use as a complement to the current os- teoporosis diagnosis methodologies. Key words: trabecular bone, fracture risk, cell method, osteoporosis, structural analysis 1. Introduction This paper describes a new technique for in vivo analysis of bone structure architecture, implemented in a software developed at the University of Trieste. The analysis starts with a conventional radiographic image and gives a result that can indicate possible pathological modifications of the bone and helps a physician in the early diagnosis of fracture risk. One of the goals of our research was to diagnose the fracture risk before the fracture occurs. Osteoporosis is bone disease, disease where the bones become thin, porous and brittle that predisposes a patient to a higher risk of fracture. Osteoporosis affects an estimated 75 million people in Europe, USA and Japan [1], being responsible for more than 1.5 million fractures annually; one out of two women and one out of four men over 50 will have an osteopo- rosis-related fracture in her/his remaining lifetime. The estimated US national direct care expenditures for osteoporotic fractures reached $18 billion in 2002, and these costs are rising [2]. Osteoporosis is often called a “silent disease” be- cause bone loss occurs without symptoms and people may not know that they suffer from osteoporosis until their bones become so weak that a sudden strain, bump or fall causes a fracture or a vertebra collapse. This disease is characterized by two factors: bone mass loss and micro-architectural deterioration of bone tissue [3]. At present there are no ways to measure accurately bone strength in clinical practice and osteoporosis is currently diagnosed by two methods: 1. Occurrence of an unexplained, non-traumatic fracture. 2. Measurement of bone density. DEXA (Dual Energy X-ray Absorptiometry) con- sidered to be the gold standard for measuring bone density is currently used both for the diagnosis and for ______________________________ * Corresponding author: Dipartimento di Energetia, University of Trieste, 34127 Trieste, Italy. E-mail: cosmi@univ.trieste.it Received: March 21, 2007, Accepted for publication: June 12, 2007