title: P2porous titanium implants improve tendon healing in an acute rat supraspinatus repair model.
abstract: BACKGROUND
  Current techniques in rotator cuff repair often lack structural integrity. P2porous titanium-coated constructs (DJO Surgical, Austin, TX, USA) promote osseointegration and soft tissue ingrowth. This study examined the ability of this material to improve the structural integrity of supraspinatus tendon repair in a rat model. We hypothesized that P2implants placed at the tendon-to-bone interface would improve mechanical and histologic measures of supraspinatus healing.
  
  
  METHODS
  Forty rats underwent supraspinatus repairs with P2implants in 1 shoulder and standard repair in the other. Rats were humanely killed at time 0 (n = 3), 2 weeks (n = 8), 4 weeks (n = 15), and 12 weeks (n = 14). Tendon-to-bone composite specimens were harvested and evaluated mechanically and histologically.
  
  
  RESULTS
  Tendon cross-sectional area was decreased in the P2implant group at 4 weeks, percentage of relaxation was increased at 2 weeks, elastic modulus was increased at 4 weeks, and maximum load and maximum stress were both increased at 2 and 4 weeks. Histologic analysis revealed no foreign body reactions within or around the P2implant, and healthy viable bone was visible within the P2implant.
  
  
  CONCLUSIONS
  The results support our hypothesis, specifically in early healing, in this randomized controlled animal study. These data support the use of P2porous titanium implants to improve tendon-to-bone healing.
authors.affiliation: McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Jennica J
authors.initials: JJ
authors.lastname: Tucker
authors.affiliation: McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Gordon
authors.affiliation: McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Zanes
authors.affiliation: McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Andrey
authors.initials: A
authors.lastname: Zuskov
authors.affiliation: DJO Surgical, Austin, TX, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Vinciguerra
authors.affiliation: Departments of Bioengeering, Biology, and Orthopaedics, University of Utah, Salt Lake City, UT, USA; Bone and Joint Research Laboratory, Department of Veterans Affairs, Salt Lake City, UT, USA.
authors.forename: Roy D
authors.initials: RD
authors.lastname: Bloebaum
authors.affiliation: McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA. Electronic address: soslowsk@upenn.edu.
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Soslowsky
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D020099:Coated Materials, Biocompatible; D008297:Male; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D016348:Osseointegration; D016062:Porosity; D019736:Prostheses and Implants; D011897:Random Allocation; D017207:Rats, Sprague-Dawley; D000070636:Rotator Cuff Injuries / Q000601:surgery*; D014025:Titanium; D014945:Wound Healing
chemical_list: D020099:Coated Materials, Biocompatible; D014025:Titanium
keywords: P(2) porous titanium; metal implants; rotator cuff repair; soft tissue fixation to bone; supraspinatus; tendon bone interface