Muscle biopsies from the supraspinatus in retracted rotator cuff tears respond normally to passive mechanical testing: a pilot study
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Fredrik Einarsson • Eva Runesson • Jo´n Karlsson • Jan Fride´n
- چاپ و سال / کشور: 2010
Description
Purpose The aim of the present study was to assess the function of the isolated muscle component in retracted rotator cuff tears. Methods Muscle biopsies were harvested from the supraspinatus and the ipsilateral deltoid in seven patients undergoing surgery for a large, retracted rotator cuff tear. Single fibres and fibre bundles were subjected to passive stretching in vitro with subsequent recordings of tension and sarcomere lengths using the laser diffraction technique. Stress–strain curves were plotted, and the elastic modulus was calculated for all preparations. Morphology was evaluated with regard to collagen fraction, ratio between fast and slow fibres, fibre size and fibre size variability using standard staining techniques. Results Intra-individual comparisons of the stress–strain curves showed a high degree of conformity in terms of both shape and tangent values, and there were no statistically significant differences in the elastic modulus for single fibres and bundles in the deltoid and supraspinatus muscles, respectively, supported by the analysis of the observed confidence interval of the differences between the paired values of the elastic modulus. There were no differences in collagen content, fibre size and ratio between fast and slow fibres in the deltoid and supraspinatus muscles, respectively. Conclusion We conclude that muscle biopsies from the supraspinatus in retracted rotator cuff tears respond normally to mechanical testing in vitro.
Knee Surg Sports Traumatol Arthrosc (2011) 19:503–507 DOI 10.1007/s00167-010-1284-0 Received: 10 May 2010 / Accepted: 16 September 2010 / Published online: 28 October 2010
