title: Lubricin Distribution in the Menisci and Labra of Human Osteoarthritic Joints.
abstract: OBJECTIVE
  Lubricin is the principal boundary lubricant on articular cartilage. We aimed to describe the distribution of lubricin in the other articulating structures in the human knee and hip-menisci and labra-and to relate this distribution to the degree of tissue degeneration.
  
  
  METHODS
  Eighteen menisci and 6 labra were obtained from patients with osteoarthritis undergoing total knee and total hip replacements, respectively. Macroscopically intact specimens were fixed in formalin and processed for H&E staining and immunohistochemical evaluation with an antilubricin monoclonal antibody.
  
  
  RESULTS
  Lubricin was found in all tissues as a discrete layer on the tissue surface, within the extracellular matrix, and intracellularly, indicating that it plays a role in the tribology of these tissues in human subjects, and can be synthesized by cells within the tissues. While none of the samples displayed macroscopic tears, approximately 40% of the surface of the menisci and 80% of the surface of the labra displayed microscopic fibrillations and slight fraying. There was no effect of the degenerative changes on the distribution of lubricin.
  
  
  CONCLUSIONS
  Lubricin coats nearly the entirety of the surfaces of menisci and labra, including microfibrillations and tears, with possible implications towards the tribology of the tissues and healing of tissue damage.
authors.affiliation: Harvard Medical School, Boston, MA, USA ; Harvard-Massachusetts Institute of Technology (MIT) Division of Health Sciences and Technology, Cambridge, MA, USA ; Tissue Engineering, Veterans Affairs (VA) Boston Healthcare System, Boston, MA, USA ; Department of Orthopaedic Surgery, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Dafang
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Harvard Medical School, Boston, MA, USA ; Tissue Engineering, Veterans Affairs (VA) Boston Healthcare System, Boston, MA, USA ; Department of Orthopaedic Surgery, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Cheriyan
authors.affiliation: Harvard Medical School, Boston, MA, USA ; Department of Orthopaedic Surgery, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Martin
authors.affiliation: Department of Biochemistry, Rush University Medical Center, Chicago, IL, USA.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Schmid
authors.affiliation: Harvard Medical School, Boston, MA, USA ; Harvard-Massachusetts Institute of Technology (MIT) Division of Health Sciences and Technology, Cambridge, MA, USA ; Tissue Engineering, Veterans Affairs (VA) Boston Healthcare System, Boston, MA, USA ; Department of Orthopaedic Surgery, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Myron
authors.initials: M
authors.lastname: Spector
keywords: fibrocartilage; labrum; lubricin; meniscus