title: Mechanisms of proximal hamstring rupture in a non-athlete healthy middle-aged female.
abstract: OBJECTIVE
  To present an explicatory pathophysiological model for the rare clinical case of a total proximal hamstring rupture for the first time in the literature.
  
  
  METHODS
  A non-athletic healthy female (49 years) experienced a complete rupture of the right conjoint tendon of the biceps femoris (long head) and semitendinosus muscle while slipping down a lawn-covered slope (eccentric hip flexion and knee extension during stance phase of gait after heel-strike). A hamstring rupture was diagnosed by clinical examination and confirmed by magnet resonance imaging (MRI). Surgical reattachment of the conjoint tendon to the ischial tuberosity was performed. One year after surgery, she experienced no pain or functional impairment.
  
  
  RESULTS
  Histological analysis and immune-histochemical staining (vascular endothelial growth factor - receptor 2) of a biopsy taken intra-operatively revealed signs of fibroblast proliferation and vasculoneogenesis with absence of inflammatory changes indicating that repairing mechanisms and tissue remodeling had been taking place.
  
  
  CONCLUSIONS
  This case report provides evidence for the hypothesis that micro-injuries induce repairing mechanisms and thus tissue remodeling which leads to consecutive tissue weakening and mechanical failure during a non-adequate trauma. Micro-injuries can occur during leisure activities and remain clinically invisible until rupture.
authors.affiliation: Kreisklinik Altötting, Department of Traumasurgery, Altötting, Germany. sebastian.cotofana@pmu.ac.at
authors.forename: Sebastian
authors.initials: S
authors.lastname: Cotofana
authors.forename: Bernhard
authors.initials: B
authors.lastname: Tillman
authors.forename: Thomas
authors.initials: T
authors.lastname: Pufe
authors.forename: Selim
authors.initials: S
authors.lastname: Lehrer
authors.forename: Dorothee
authors.initials: D
authors.lastname: Watz
authors.forename: Monika
authors.initials: M
authors.lastname: Zangl
authors.forename: Harald
authors.initials: H
authors.lastname: Modlmayr
authors.forename: Ernest
authors.initials: E
authors.lastname: Knöckl
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Mahn
authors.forename: Werner
authors.initials: W
authors.lastname: Wambach
mesh_terms: D004438:Ecchymosis / Q000473:pathology; D005260:Female; D005347:Fibroblasts / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000293:injuries* / Q000473:pathology / Q000601:surgery; D018919:Neovascularization, Physiologic / Q000502:physiology; D012421:Rupture / Q000473:pathology / Q000601:surgery; D013708:Tendon Injuries / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome