Typical Findings in Bone Biopsies in “Male Idiopathic Osteoporosis”

Introduction Male idiopathic osteoporosis (MIO) is a chronic condition leading to low-traumatic fractures and requires transiliac bone biopsy for further clarification. In the present study we evaluated transiliac bone biopsy specimens retrospectively to identify the most common reasons for MIO.

Methods Bone biopsy specimens of 30 male adults aged 44.6±13 (mean±SD) were analyzed histomorphometrically by microscopy and quantitative backscattered electron imaging and were compared to a reference database. Furthermore, demographic data, laboratory results including bone turnover markers, bone mineral density (BMD) and trabecular bone score by DXA were assessed.

Results BMD measurements at lumbar spine and total hip revealed osteoporotic (46.4%;44.4%), osteopenic (39.3%;40.7%) and normal (14.3%;14.8) values (mean -2.3±1.8;-2.0±1.4), respectively. TBS was 1.3±0.1. Laboratory results including bone turnover markers and testosterone were generally in normal range. The static histomorphometry parameters were decreased in MIO patients: bone volume (46.6%), trabecular number (23.3%) and trabecular thickness (46.7%) compared to reference values (Z-score<-1SD). Dynamic histomorphometry parameters were available in 8 subjects. An increase in osteoid volume and mineralizing surface was found in 28.6% of patients (Z-score>1SD). Mineralizing surface was decreased in 42.9% (Z-score<-2SD). Bone formation rate was elevated (28.6%, Z-score>1SD), decreased (28.6%, Z-score<-1SD) or normal (42.9%, Z-score 0±1SD). An increase in osteoid surface (Z-score>2SD) or decrease (Z-score<-2SD) in osteoblast surface was found in 50% of subjects.

Discussion MIO is a heterogenous group of bone diseases. The most common biopsy findings were low-turnover osteoporosis/osteopenia (40%), defects in bone microstructure (37%) and defects in mineralization/osteomalacia (40%). Bone biopsies are mandatory to differ the various causes of MIO and to initiate specific treatment.

Keywords Male Idiopathic Osteoporosis, Bone Biopsy, Histomorphometry, Osteomalacia, fragility Fracture

Korrespondenzadresse Daniel Arian Kraus, Ludwig Boltzmann Institut für Osteologie, Heinrich-Collin-Straße 30, 1140 Wien, Österreich, E-Mail: [e-mail]

Publication History

Article published online:
08 September 2022