Translational Studies in Anterior Cruciate Ligament Repair

http://www.liebertonline.com/doi/abs/10.1089/ten.tea.2009.0147

• WHY NEED IT-"Recent years have shown a clearer
  definition of the clinical problem and established an underlying mechanistic cause of the incapacity of the
  anterior cruciate ligament to heal—the premature loss of provisional scaffold in the wound site. These clinical
  findings were then translated into a research objective, namely, to replace the missing scaffold with a biomaterial
  with appropriate structural and bio-stimulatory characteristics."
• WHY NEED IT- "Current estimates of
  the prevalence of reported ACL tears range at 4.8% of ambulatory
  individuals between 50 and 90 years of age, but it is
  very likely that the actual number, including asymptomatic
  tears in patients with low demand, is even higher.2,3 The risk
  of ACL tears is significantly increased by participating in
  particular sports, especially those involving pivoting, and for
  women.4–8 ACL tears are serious injuries causing immediate
  pain and loss of mobility."
• COLLAGEN AS BIOMATERIAL- "Among all biomaterials currently used in tissue
  engineering, collagen has a long-standing record as a biocompatible,
  biodegradable, and safe material for orthopedic
  applications and is the main constituent of the ACL"
• COLLAGEN IN COW ACL- "Murray et al. showed that cells from human torn ACL
  migrate into a scaffold made from bovine atelocollagen (Fig. 3) and secrete smooth muscle actin, which causes
  wound contraction44,45,62 (Fig. 2). ACL fibroblasts retain this
  ability also in the ruptured ACL, where they exhibit even
  higher outgrowth rates.62"
• WHY DOES ACL NOT HEAL- "A translational research approach helped to identify one
  potential reason why the torn ACL does not heal: the lack of a fibrin clot that stabilizes the defect and serves as a scaffold
  for cell migration and a source for stimulating factors."