title: Model for muscle regeneration around fibrotic lesions in recurrent strain injuries.
abstract: OBJECTIVE
  The purpose of this study was to establish an in vivo model for muscle regeneration after strain injury in the presence of a fibrotic discontinuity.
  
  
  METHODS
  The musculus soleus of 5-wk-old male rats was exposed, completely lacerated, and sutured together with or without a collagen scaffold in between the muscle ends. The scaffold represents a fibrotic discontinuity in the muscle. Muscle healing was evaluated after 14 d by general histology and staining for myofibroblasts, satellite cells (activated), and inflammatory cells.
  
  
  RESULTS
  Around all wounds, satellite cells were activated. Inside the collagen scaffolds, satellite cells were absent, indicating that muscle regeneration was impaired. In the wounds without a collagen scaffold, the lacerated and the sutured myofibers contacted and had already started to regenerate, whereas this did not occur with an implanted scaffold.
  
  
  CONCLUSIONS
  A fibrotic discontinuity, such as an implanted collagen scaffold, delays muscle regeneration in skeletal muscle. This model is suitable to study skeletal muscle regeneration in the presence of a fibrotic lesion and to evaluate new treatment modalities for muscle strain injuries.
authors: Department of Orthodontics and Oral Biology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors: Sander
authors: S
authors: Grefte
authors: Anne Marie
authors: AM
authors: Kuijpers-Jagtman
authors: Ruurd
authors: R
authors: Torensma
authors: Johannes W
authors: JW
authors: Von den Hoff
mesh_terms: D000818:Animals; D003094:Collagen / Q000378:metabolism; D012090:Cumulative Trauma Disorders / Q000534:rehabilitation / Q000601:surgery; D004195:Disease Models, Animal; D005355:Fibrosis / Q000473:pathology; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000473:pathology*; D009426:Netherlands; D051381:Rats; D017207:Rats, Sprague-Dawley; D012008:Recurrence; D012038:Regeneration / Q000502:physiology*; D054457:Tissue Scaffolds
chemical_list: D003094:Collagen