Added Value of Impact Microindentation in the Evaluation of Bone Fragility: A Systematic Review of the Literature

• Published in: Frontiers in endocrinology (Lausanne) Vol. 11; p. 15
• Main Authors: Schoeb, Manuela, Hamdy, Neveen A. T., Malgo, Frank, Winter, Elizabeth M., Appelman-Dijkstra, Natasha M.
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 07.02.2020
• Subjects: Absorptiometry, Photon; Biopsy, Needle - instrumentation; Biopsy, Needle - methods; Bone and Bones - pathology; Bone Density; Bone Diseases, Metabolic - diagnosis; Bone Diseases, Metabolic - pathology; bone material strength index (BMSi); bone quality; Endocrinology; Equipment and Supplies; fracture risk; Fractures, Bone - diagnosis; Fractures, Bone - pathology; Humans; Microtechnology - instrumentation; Microtechnology - methods; Osteoporosis - diagnosis; Osteoporosis - pathology; osteoporosis primary and secondary; Osteoporotic Fractures - diagnosis; Osteoporotic Fractures - pathology; osteoprobe; Predictive Value of Tests; rare bone diseases; Risk Factors; Specimen Handling - instrumentation; Specimen Handling - methods; bone mineral density; osteoporosis primary and secondary; dual energy x-ray absorptiometry (DXA); rare bone diseases; osteoprobe; bone quality; bone material strength index (BMSi); fracture risk
• ISSN: 1664-2392; 1664-2392
• DOI: 10.3389/fendo.2020.00015

The current gold standard for the diagnosis of osteoporosis and the prediction of fracture risk is the measurement of bone mineral density (BMD) using dual energy x-ray absorptiometry (DXA). A low BMD is clearly associated with increased fracture risk, but BMD is not the only determinant of bone strength, particularly in secondary osteoporosis and metabolic bone disorders in which components other than BMD are affected and DXA often underestimates true fracture risk. Material properties of bone which significantly contribute to bone strength have become evaluable with the impact microindentation (IMI) technique using the OsteoProbe® device. The question arises whether this new tool is of added value in the evaluation of bone fragility. To this effect, we conducted a systematic review of all clinical studies using IMI in humans also addressing practical aspects of the technique and differences in study design, which may impact outcome. Search data generated 38 studies showing that IMI can identify patients with primary osteoporosis and fractures, patients with secondary osteoporosis due to various underlying systemic disorders, and scarce longitudinal data also show that this tool can detect changes in bone material strength index (BMSi), following bone-modifying therapy including use of corticosteroids. However, this main outcome parameter was not always concordant between studies. This systematic review also identified a number of factors that impact on BMSi outcome. These include subject- and disease-related factors such as the relationship between BMSi and age, geographical region and the presence of fractures, and technique- and operator-related factors. Taken together, findings from this systematic review confirm the added value of IMI for the evaluation and follow-up of elements of bone fragility, particularly in secondary osteoporosis. Notwithstanding, the high variability of BMSi outcome between studies calls for age-dependent reference values, and for the harmonization of study protocols. Prospective multicenter trials using standard operating procedures are required to establish the value of IMI in the prediction of future fracture risk, before this technique is introduced in routine clinical practice.