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Torn human rotator cuff tendons have reduced collagen thermal properties on differential scanning calorimetry
Author(s) -
Chaudhury Salma,
Holland Christopher,
Porter David,
Tirlapur Uday K.,
Vollrath Fritz,
Carr Andrew J
Publication year - 2011
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.21450
Subject(s) - rotator cuff , tendon , tears , differential scanning calorimetry , structural integrity , medicine , denaturation (fissile materials) , anatomy , chemistry , surgery , physics , structural engineering , nuclear chemistry , engineering , thermodynamics
The cause of the high failure rates often observed following rotator cuff tendon repairs, particularly massive tears, is not fully understood. Collagen structural changes have been shown to alter tendon thermal and mechanical properties. This study aimed to form a quantitative rather than qualitative assessment, of whether differences in collagen structure and integrity existed between small biopsies of normal, small, and massive rotator cuff tears using differential scanning calorimetry. Thermal properties were measured for 28 human biopsies taken intra‐operatively from normal, small, and massive rotator cuff tendon tears in this powered study. Denaturation temperatures are represented by T onset (°C) and T peak (°C). The T onset is proposed to represent water‐amide hydrogen bond breakage and resulting protein backbone mobility. T peak reportedly corresponds to the temperature at which the majority of proteins fall out of solution. Denaturation enthalpy (ΔH) should correlate with the amount of triple helical structure that is denatured. Fluorescence and confocal microscopy allowed quantitative validation. Small and massive rotator cuff tears had significantly higher T onset , T peak , and ΔH compared to controls. Polarized light microscopy of torn tendons confirmed greater collagen structural disruption compared to controls. These novel findings suggest greater quantifiable collagen structural disruption in rotator cuff tears, compared to controls. This study offers insight into possible mechanisms for the reduced strength of torn tendons and may explain why repaired tendons fail to heal. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:1938–1943, 2011