title: Mechanical characteristics of articular cartilage bonds.
abstract: BACKGROUND
  Sutures for adaptation of articular cartilage are used in arthritis therapy techniques. However, little is known about the mechanical functionality of these sutures. The objective of the present work was to compare the mechanical properties of articular cartilage bonds either generated by suture, or, alternatively, by chemical cross-linking of the opposing surfaces or in vitro integrative repair of cartilage blocks.
  
  
  METHODS
  Bonding was achieved by suture in varying numbers, positions and orientations, by surface cross-linking using carbodiimide in combination with pepsin or guanidine (immediate bonding), or by cultivation for 14 days, either with or without testosterone. The mechanical properties of the cartilage bonds were measured under tensile loading.
  
  
  RESULTS
  Suture led to the highest maximal load at failure and by far to the highest strain and lowest stiffness of the bonded samples. Immediate bonding by chemical cross-linking in combination with pepsin led to a low force at failure, but the highest stiffness, as compared to all other groups. Cultivation in the presence of testosterone led to a higher force at failure and a higher strain than chemical cross-linking.
  
  
  CONCLUSIONS
  Suture technique for bonding of cartilage surfaces leads to a very elastic adaptation which allows synovial fluid flow in between the interface of cartilage wounds. Long-term bonding of cartilage wounds would be counteracted by a fluid flow through the interface during motion of the joint. Immediate bonding of cartilage wounds by chemical cross-linking reagents might be a useful alternative tool. Even more promising, with regard to the mechanical properties, appears to be integrative repair of cartilage blocks stimulated by testosterone.
authors.affiliation: Department of Trauma Surgery, Regensburg University Medical Center, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany. Carsten.Englert@klinik.uni-regensburg.de
authors.forename: Carsten
authors.initials: C
authors.lastname: Englert
authors.forename: Johann
authors.initials: J
authors.lastname: Fierlbeck
authors.forename: Sabine Schulz
authors.initials: SS
authors.lastname: von Glasser
authors.forename: Michael
authors.initials: M
authors.lastname: Nerlich
authors.forename: Joachim
authors.initials: J
authors.lastname: Hammer
mesh_terms: D000268:Adhesiveness; D000818:Animals; D001696:Biomechanical Phenomena / Q000295:instrumentation / Q000379:methods; D002358:Cartilage, Articular / Q000737:chemistry* / Q000502:physiology* / Q000601:surgery; D002417:Cattle; D004548:Elasticity; D019544:Equipment Failure Analysis; D066298:In Vitro Techniques; D008422:Materials Testing; D013314:Stress, Mechanical; D013536:Suture Techniques / Q000295:instrumentation*; D013537:Sutures; D013718:Tensile Strength; D014014:Tissue Adhesives / Q000737:chemistry*
chemical_list: D014014:Tissue Adhesives