Not only bone density, but also quality of bone predicts fracture risk

(Press-News.org) In a study carried out at the University of Eastern Finland, bone histomorphometry and infrared spectroscopy revealed abnormal bone properties in children with vertebral fractures and in children after solid organ transplantation. Bone compositional changes in children with vertebral fractures and after different types of organ transplantation have not been reported previously.

Bone samples were investigated using bone histomorphometry, a microscopic method that provides information about bone metabolism and remodelling. In children with vertebral fractures, there were changes in bone composition, such as lower carbonate-to-phosphate-ratio and increased collagen maturity, which could explain the increased fracture risk. The results also suggest that in children who have undergone kidney, liver or heart transplantation, the various changes related to bone microarchitecture and turnover may be more important predictors of fracture risk than lowered bone mineral density alone. Early detection of such changes in bone quality could help prevent fractures.

Osteoporosis is the most common metabolic bone disease characterized by abnormal bone formation and resorption which lead to increased risk of bone fractures. However, the present diagnostics based on the measurement of bone mineral density predict fractures only moderately. In addition to decreased bone mineral density, changes in bone quality could explain increased fragility related to osteoporosis. The present study confirmed that bone histomorphometry is needed in clinical practice to study remodelling balance in bone in certain patient groups.

"Especially in clinically challenging scenarios where different treatment options are being considered, bone histomorphometry provides valuable information. An accurate diagnosis and choice of medication are especially important when treating paediatric patients," says Ms Inari Tamminen, MD, whose doctoral thesis on the topic was published in June.

The findings were originally published in Journal of Bone and Mineral Research and Journal of Bone and Mineral Metabolism.

The histomorphometry laboratory at the University of Eastern Finland in Kuopio is one of the few in the world analyzing clinical bone biopsies. More than 70 patient samples are analyzed annually. Over 30 years of expertise in quantitative histomorphometry have formed a solid basis for high quality research. Recent projects focus on paediatric patients with osteoporosis, genetic disorders and insufficiency fractures.



INFORMATION:



For further information, please contact:

Inari Tamminen, MD
tel. + 358 404 126052
inari.tamminen (at) uef.fi

Heikki Kröger, Professor
Head of Bone and Cartilage Research Unit
University of Eastern Finland
tel. +358 44 7172602
heikki.kroger (at) kuh.fi

Pioneering musculoskeletal research

The city of Kuopio in Eastern Finland is home to extensive and pioneering musculoskeletal research. The combined research facilities, infrastructure and multi-professional expertise of the University of Eastern Finland and Kuopio University Hospital form a Musculoskeletal Research Consortium, merging the efforts of orthopaedic surgeons, other medical specialists and physicists to create a continuum from basic science to clinical and epidemiological applications. Musculoskeletal problems are combated from various methodological perspectives by including aspects of tissue biology, epidemiology, orthopaedics, rehabilitation, medical physics and imaging.

Major research programmes focus on osteoporosis risk factors, bone quality, and novel improved diagnostics in orthopaedics.

Osteoporosis may be linked to sarcopenia, heart disease, depression and dementia

The globally recognized Kuopio Osteoporosis Risk Factor and Prevention Study (OSTPRE) is a population-based prospective cohort study which began in 1989. The OSTPRE study investigates genetic and acquired factors associated with fractures, falls, bone mineral density and bone loss in 14 220 peri- and postmenopausal women. The unique design of the study allows the researchers to examine whether osteoporosis, sarcopenia, coronary heart disease, depression and dementia share common risk factors and whether these cluster in the same individuals. The linking of OSTPRE data to National Health Register data will allow the validation of self-reports and increase the quality of OSTPRE secondary osteoporosis studies.

New insights into fracture resistance

In the bone quality research programme, bone material characteristics are assessed by established methods, such as quantitative bone histomorphometry, microCT and mechanical testing, as well as by newly developed methods, such as nanoCT, IR/Raman spectroscopy, nanoindentation and acoustic microscopy. The quantitative techniques provide information on factors affecting bone's fracture resistance, not hitherto possible.

Novel non-invasive diagnostics

To improve diagnostics in orthopaedics, the researchers develop and apply novel non-invasive or minimally invasive quantitative techniques for diagnosis of osteoarthrosis, osteoporosis and back pain syndrome. Novel contrast enhanced CT and intra-articular arthroscopic ultrasound and optical coherence techniques, and the pocket-size bone ultrasound device have been used in clinical patients for improved imaging of cartilage and subchondral bone and for better prediction of fracture risk.

At the University of Eastern Finland, musculoskeletal research is carried out at the Bone and Cartilage Research Unit (BCRU), headed by Professor Heikki Kröger. The special feature and the strength of BCRU's musculoskeletal research is the close research collaboration between orthopaedic surgeons and physicists. Heikki Kröger, Professor of Surgery, Orthopaedics and Traumatology, and Jukka Jurvelin, Professor of Medical Physics, are international leaders in their research fields, musculoskeletal diseases and bioengineering, respectively. In Finland, their activity in musculoskeletal research is not exceeded by others, as evidenced by their combined number of papers (551) and citations (13517). The Hirsch-indexes of Kröger and Jurvelin are 47 and 49, respectively. Both have been very active in doctoral training, summarizing 48 PhDs supervised by them.

BCRU website: http://www.uef.fi/crc/bcru