title: Histologic Evaluation of Biopsy Specimens Obtained After Rotator Cuff Repair Augmented With a Highly Porous Collagen Implant.
abstract: OBJECTIVE
  To histologically evaluate biopsy specimens from patients who previously underwent rotator cuff repair augmented with a highly porous collagen implant.
  
  
  METHODS
  Biopsies of collagen implant/host-tissue constructs were obtained from 7 patients undergoing a second arthroscopic procedure at various time periods (5 weeks to 6 months) after arthroscopic rotator cuff repair augmented with a collagen implant overlay. The biopsy specimens were examined histologically for host-tissue ingrowth, host-tissue maturation, and host-implant biocompatibility.
  
  
  RESULTS
  At the earliest time period (5 weeks), the biopsy revealed the presence of host cells (fibroblasts) within the interstices of the porous collagen implant. Cells were aligned along the linear orientation of the collagen implant structure, and there was evidence of early collagen formation. The 3-month biopsies showed increased collagen formation, maturation, and organization over the surface of the implant and evidence of the collagen implant. At 6 months, the newly generated tissue had the histologic appearance of a tendon, suggesting functional loading of the new generated host tissue. There was no evidence of any remnants of the collagen implant in the 6-month biopsy. There was no evidence of any inflammatory or foreign body reaction within any of the tissue samples.
  
  
  CONCLUSIONS
  Biopsies of collagen implants retrieved from human rotator cuff repair subjects revealed cellular incorporation, tissue formation and maturation, implant resorption, and biocompatibility.
  
  
  CONCLUSIONS
  The histologic observations from these clinical biopsies support the biocompatibility of this implant and its ability to promote new connective tissue with the histological appearance of tendon over the surface of the native cuff tendon.
authors.affiliation: Laboratory for Comparative Orthopaedic Research, Michigan State University, East Lansing, Michigan, U.S.A.. Electronic address: arnoczky@cvm.msu.edu.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Arnoczky
authors.affiliation: College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, U.S.A.
authors.forename: Shariff K
authors.initials: SK
authors.lastname: Bishai
authors.affiliation: Schofield, Hand, Bright Orthopaedics, Sarasota, Florida, U.S.A.
authors.forename: Brian
authors.initials: B
authors.lastname: Schofield
authors.affiliation: Lowell General Hospital, North Chelmsford, Massachusetts, U.S.A.
authors.forename: Scott
authors.initials: S
authors.lastname: Sigman
authors.affiliation: Harbin Clinic Orthopaedics and Sports Medicine, Rome, Georgia, U.S.A.
authors.forename: Brad D
authors.initials: BD
authors.lastname: Bushnell
authors.affiliation: Hommen Orthopaedic Institute, Miami, Florida, U.S.A.
authors.forename: Jan Pieter
authors.initials: JP
authors.lastname: Hommen
authors.affiliation: Rotation Medical, Inc., Plymouth, Minnesota, U.S.A.
authors.forename: Craig
authors.initials: C
authors.lastname: Van Kampen
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D001706:Biopsy; D003094:Collagen / Q000737:chemistry*; D005260:Female; D005347:Fibroblasts / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D012189:Retrospective Studies; D017006:Rotator Cuff / Q000473:pathology*; D000070636:Rotator Cuff Injuries / Q000601:surgery*; D055815:Young Adult
chemical_list: D003094:Collagen