title: Preliminary investigation of a biological augmentation of rotator cuff repairs using a collagen implant: a 2-year MRI follow-up.
abstract: BACKGROUND
  the inability to restore the normal tendon footprint and limit strains on the repair site are thought to contribute to re-tearing following rotator cuff repair. The purpose of this study was to use a collagen implant to augment rotator cuff repairs through the restoration of the native tendon footprint and the induction of new tissue to decrease overall tendon strain.
  
  
  METHODS
  repairs of full-thickness rotator cuff lesions in 9 adult patients were augmented with a novel collagen implant placed over the bursal surface of the repair. Tendon thickness and footprint anatomy were evaluated using MRI at 3, 6, 12, and 24 months. Clinical results were assessed using standard outcome metrics. Mean follow-up for all patients was 25.8 months.
  
  
  RESULTS
  the implant induced significant new tissue formation in all patients by 3 months. This tissue matured over time and became indistinguishable from the underlying tendon. At 24 months all repairs remained intact and normal footprint anatomy of the tendon was restored in all patients. All clinical scores improved significantly over time.
  
  
  CONCLUSIONS
  the ability of a collagen implant to induce new host tissue formation and restore the normal footprint anatomy may represent a significant advancement in the biological augmentation and ultimate durability of rotator cuff repairs.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia.
authors.forename: Desmond John
authors.initials: DJ
authors.lastname: Bokor
authors.affiliation: Department of Orthopaedic Surgery, Royal North Shore Hospital, St. Leonards, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Sonnabend
authors.affiliation: Alfred Imaging & Alfred Advanced Sports Imaging Centre, Drummoyne, Australia.
authors.forename: Luke
authors.initials: L
authors.lastname: Deady
authors.affiliation: Sydney Shoulder Specialists, St. Leonards, Australia.
authors.forename: Ben
authors.initials: B
authors.lastname: Cass
authors.affiliation: Sydney Shoulder Specialists, St. Leonards, Australia.
authors.forename: Allan
authors.initials: A
authors.lastname: Young
authors.affiliation: Rotation Medical, Inc., Plymouth, MN, USA.
authors.forename: Craig
authors.initials: C
authors.lastname: Van Kampen
authors.affiliation: College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Arnoczky
keywords: collagen implant; cuff repair; footprint; tendon