Conclusion
Osteoporosis is closely related to sarcopenia before and after fracture. Bone remodelling is influenced by muscle morphological and functional impairment and sarcopenia is considered one of the major factors for functional limitation and motor dependency in elderly osteoporotic individuals. Therefore, physical activity should be strongly recommended for OP patients at diagnosis.
Methods
Muscular performance status was evaluated using the Physical Activity Scale for the Elderly (PASE) test in 27 female patients with OP who underwent total hip arthroplasty for hip fracture, and in 27 age-matched female patients with OA who underwent total hip arthroplasty. Dual-energy X-ray absorptiometry (DEXA) was performed and the T-score values were used to discriminate between OP and OA patients. Body Mass Index (BMI) was calculated. As part of a multiparametric model of evaluation, biopsies of vastus lateralis muscle were analysed by immunohistochemical reaction to find a correlation with the above mentioned functional index.
Results
The PASE test showed that the OP patients had a low or moderate level of physical activity before fracture occurred, whereas the OA patients had more intensive pre-fracture physical performances. Histological analysis showed that osteoporosis is characterised by a preferential type II fibre atrophy; in particular, data correlation showed that lower PASE test scores were related to lower diameter of type II fibres. No correlation was found between bone mineral density (BMD) and PASE test results.