title: An animal model to evaluate skin-implant-bone integration and gait with a prosthesis directly attached to the residual limb.
abstract: BACKGROUND
  Despite the number of advantages of bone-anchored prostheses, their use in patients is limited due to the lack of complete skin-implant integration. The objective of the present study was to develop an animal model that would permit both detailed investigations of gait with a bone-anchored limb prosthesis and histological analysis of the skin-implant-bone interface after physiological loading of the implant during standing and walking.
  
  
  METHODS
  Full-body mechanics of walking in two cats were recorded and analyzed before and after implantation of a percutaneous porous titanium pylon into the right tibia and attachment of a prosthesis. The rehabilitation procedures included initial limb casting, progressively increasing loading on the implant, and standing and locomotor training. Detailed histological analysis of bone and skin ingrowth into implant was performed at the end of the study.
  
  
  RESULTS
  The two animals adopted the bone-anchored prosthesis for standing and locomotion, although loads on the prosthetic limb during walking decreased by 22% and 62%, respectively, 4months after implantation. The animals shifted body weight to the contralateral side and increased propulsion forces by the contralateral hindlimb. Histological analysis of the limb implants demonstrated bone and skin ingrowth.
  
  
  CONCLUSIONS
  The developed animal model to study prosthetic gait and tissue integration with the implant demonstrated that porous titanium implants may permit bone and skin integration and prosthetic gait with a bone-anchored prosthesis. Future studies with this model will help optimize the implant and prosthesis properties.
authors.affiliation: School of Applied Physiology, Center for Human Movement Science, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Brad J
authors.initials: BJ
authors.lastname: Farrell
authors.affiliation: School of Applied Physiology, Center for Human Movement Science, Georgia Institute of Technology, Atlanta, GA, USA. Electronic address: boris.prilutsky@ap.gatech.edu.
authors.forename: Boris I
authors.initials: BI
authors.lastname: Prilutsky
authors.affiliation: School of Applied Physiology, Center for Human Movement Science, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Kistenberg
authors.affiliation: Georgia Hand, Shoulder & Elbow, Atlanta, GA, USA.
authors.forename: John F
authors.initials: JF
authors.lastname: Dalton
authors.affiliation: Tufts University School of Medicine, Boston, MA, USA; Poly-Orth International, Sharon, MA, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Pitkin
mesh_terms: D000818:Animals; D001186:Artificial Limbs; D002415:Cats; D005684:Gait / Q000502:physiology*; D006614:Hindlimb; D006801:Humans; D008297:Male; D023421:Models, Animal; D016348:Osseointegration; D011187:Posture / Q000502:physiology*; D019919:Prosthesis Implantation; D012879:Skin Physiological Phenomena; D053441:Suture Anchors; D014025:Titanium
chemical_list: D014025:Titanium
keywords: Bone-anchored prostheses; Histology; Osseointegration; Porous percutaneous titanium implant; Prosthetic gait; Skin–implant–bone interface