title: Injuries to appendage extremities and digit tips: A clinical and cellular update.
abstract: BACKGROUND
  The regrowth of amputated appendage extremities and the distal tips of digits represent models of tissue regeneration in multiple vertebrate taxa. In humans, digit tip injuries, including traumatic amputation and crush injuries, are among the most common type of injury to the human hand. Despite clinical reports demonstrating natural regeneration of appendages in lower vertebrates and human digits, current treatment options are suboptimal, and are complicated by the anatomical complexities and functions of the different tissues within the digits.
  
  
  RESULTS
  In light of these challenges, we focus on recent advancements in understanding appendage regeneration from model organisms. We pay special attention to the cellular programs underlying appendage regeneration, where cumulative data from salamanders, fish, frogs, and mice indicate that regeneration occurs by the actions of lineage-restricted precursors. We focus on pathologic states and the interdependency that exists, in both humans and animal models, between the nail organ and the peripheral nerves for successful regeneration.
  
  
  CONCLUSIONS
  The increased understanding of regeneration in animal models may open new opportunities for basic and translational research aimed at understanding the mechanisms that support limb regeneration, as well as amelioration of limb abnormalities and pathologies.
authors.affiliation: Institute for Stem Cell Biology and Regenerative Medicine, Departments of Pathology and Developmental Biology, Stanford University School of Medicine, Stanford, California.
authors.forename: Yuval
authors.initials: Y
authors.lastname: Rinkevich
authors.forename: Zeshaan N
authors.initials: ZN
authors.lastname: Maan
authors.forename: Graham G
authors.initials: GG
authors.lastname: Walmsley
authors.forename: Subhro K
authors.initials: SK
authors.lastname: Sen
mesh_terms: D000673:Amputation, Traumatic / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D000818:Animals; D005383:Finger Injuries / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D051379:Mice; D012038:Regeneration
keywords: digit; limb; nerve; regeneration; stem cells; wound healing