Changes of biochemical and biomechanical properties in dupuytren disease

Background.-The major biochemical characteristic of Dupuytren disease is th e progressive and irreversible deposition of excess fibrous collagen charac terized by an enhanced type III collagen proportion. Objective.-To investigate the influence of changes of the collagen spectrum on the biophysical properties of the palmar aponeurosis. Design.-Variably affected palmar regions from 30 individuals with Dupuytren disease were classified according to histologic test results and clinical stage. Biochemical, biomechanical, and thermal contracture studies were per formed. Results.-The relative type III collagen content increased with increasing t issue involvement and was found to correlate with calorimetric and biomecha nical properties with the exception of the Young modulus. In experiments on the thermal isometric contracture, the collagen denaturation temperature d ecreased with increasing type III collagen content, ie, increasing involvem ent. To study the dependence of biophysical properties from the collagen ty pe distribution independent of structural changes, as seen in Dupuytren dis ease, we investigated rat skins from animals of an age range characterized by dramatic changes in type III collagen content (0-18 months). Biomechanic al data also correlated significantly with type III collagen content in rat skin with the exception of the time constant of stress relaxation. Conclusion.-In light of these results, we suggest that structural changes, such as reduced collagen fibril diameters, associated with alterations in t he type III collagen proportion may influence biophysical properties of con nective tissues in the involved palmar aponeurosis in addition to alteratio ns of the cross-linking pattern.