Passive mechanical features of single fibers from human muscle biopsies – effects of storage

Fredrik Einarsson^*¹ , Eva Runesson^*² and Jan Fridén³

¹Department of Orthopaedics, Sahlgrenska University Hospital, Göteborg, Sweden

²Lundberg Laboratory for Orthopaedic Research, Göteborg, Sweden

³Department of Hand Surgery, Sahlgrenska University Hospital, Göteborg, Sweden

author email corresponding author email* Contributed equally

Journal of Orthopaedic Surgery and Research 2008, 3:22doi:10.1186/1749-799X-3-22


Published:	7 June 2008

Abstract

Background

The purpose of this study was to investigate the effect of storage of human muscle biopsies on passive mechanical properties.

Methods

Stress-strain analysis accompanied by laser diffraction assisted sarcomere length measurement was performed on single muscle fibres from fresh samples and compared with single fibres from stored samples (-20°C, 4 weeks) with the same origin as the corresponding fresh sample. Basic morphological analysis, including cross sectional area (CSA) measurement, fibre diameter measurement, fibre occupancy calculation and overall morphology evaluation was done.

Results

Statistical analysis of tangent values in stress-strain curves, corresponding to the elastic modulus of single muscle fibres, did not differ when comparing fresh and stored samples from the same type of muscle. Regardless of the preparation procedure, no significant differences were found, neither in fibre diameter nor the relation between muscle fibres and extra-cellular matrix measured under light microscopy.

Conclusion

We conclude that muscle fibre structure and mechanics are relatively insensitive to the storage procedures used and that the different preparations are interchangeable without affecting passive mechanical properties. This provides a mobility of the method when harvesting muscle biopsies away from the laboratory.