title: Immediate post-implantation skin immobilization decreases skin regression around percutaneous osseointegrated prosthetic implant systems.
abstract: A percutaneous, osseointegrated (OI) prosthetics are alternative docking systems for upper- and lower-extremity prostheses. Persistent inflammation and micro-motion are known to cause negative soft-tissue adaptation in wound healing and may also be detrimental to implant longevity. In this study, a unique single-stage sheep amputation and implantation model was developed to assess the efficacy of a porous coated sub-dermal fixation surface in the prevention of skin regression around a percutaneous osseointegrated prosthetic implant. Porous coated and smooth sub-dermal fixation surface prosthetics were implanted in the right forelimb of skeletally mature sheep for up to 12 months. Skin regression kinetics and sub-dermal fixation surface coverage were measured from histological samples. Quantitative measurements of porous coated surfaces yielded skin migration rates of 0.90 ± 0.23, 0.56 ± 0.15, 0.44 ± 0.22 mm/month for the 6, 9, and 12 month animals, respectively. In addition, three load dependent regions of skin adaptation were identified; an interface, a transition, and a stress absorbance region. Immediate post-implantation immobilization of the skin may foster improved load-bearing percutaneous device outcomes. The skin adaptations reported here will aid in informing the design and optimization of future percutaneous, OI devices intended for the treatment of upper- and lower-extremity amputees.
authors.affiliation: Bone and Joint Research Laboratory, DVA SLC HCS, Salt Lake City, Utah 84148; Department of Orthopaedics, University of Utah, Salt Lake City, Utah 84108, USA. brian.holt@hsc.utah.edu
authors.forename: Brian Mueller
authors.initials: BM
authors.lastname: Holt
authors.forename: Kent N
authors.initials: KN
authors.lastname: Bachus
authors.forename: James Peter
authors.initials: JP
authors.lastname: Beck
authors.forename: Roy Drake
authors.initials: RD
authors.lastname: Bloebaum
authors.forename: Sujee
authors.initials: S
authors.lastname: Jeyapalina
mesh_terms: D000497:Alloys; D000671:Amputation, Surgical; D000818:Animals; D004848:Epithelium / Q000254:growth & development; D005260:Female; D007103:Immobilization; D007368:Interferometry; D007700:Kinetics; D008297:Male; D016348:Osseointegration / Q000502:physiology*; D016062:Porosity; D019736:Prostheses and Implants; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D012756:Sheep; D012867:Skin / Q000254:growth & development* / Q000382:microbiology; D014025:Titanium; D014945:Wound Healing
chemical_list: D000497:Alloys; C031462:titanium alloy (TiAl6V4); D014025:Titanium