title: Parecoxib impairs early tendon repair but improves later remodeling.
abstract: BACKGROUND
  Cyclooxygenase-2 inhibitors inhibit bone repair.
  
  
  OBJECTIVE
  Cyclooxygenase inhibitors might also have a negative effect on early tendon repair, although a positive effect on late tendon repair previously has been shown.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Achilles tendon transection was performed on 80 rats. Sixty rats were given daily intramuscular injections of either parecoxib (6.4 mg/kg body weight) or saline for the first 5 days after surgery and sacrificed either at 8 or 14 days. The remaining 20 rats were given intramuscular parecoxib or saline injections from day 6 until sacrifice at 14 days.
  
  
  RESULTS
  At 8 days, early parecoxib treatment caused a 27% decrease in force at failure (P = .007), a 25% decrease in maximum stress (P = .01), and a 31% decrease in energy uptake (P = .05). Stiffness and transverse area were not significantly affected. At 14 days, early parecoxib treatment caused a decrease in stiffness (P = .004). In contrast to early treatment, late parecoxib treatment caused a 16% decrease in cross-sectional area (P = .03) and a 29% increase in maximum stress (P = .04).
  
  
  CONCLUSIONS
  During early tendon repair, a cyclooxygenase-2 inhibitor had a detrimental effect. During remodelling, however, inflammation appears to have a negative influence, and cyclooxygenase-2 inhibitors might be of value.
  
  
  CONCLUSIONS
  The results suggest that cyclooxygenase-2 inhibitors should be used with care in the early period after tendon injury.
authors.affiliation: Section for Orthopaedics and Sports Medicine, Department of Neuroscience and Locomotion, Faculty of Health Sciences, Linköping, Sweden.
authors.forename: Olena
authors.initials: O
authors.lastname: Virchenko
authors.forename: Björn
authors.initials: B
authors.lastname: Skoglund
authors.forename: Per
authors.initials: P
authors.lastname: Aspenberg
mesh_terms: D000125:Achilles Tendon / Q000187:drug effects / Q000254:growth & development* / Q000293:injuries*; D000818:Animals; D001696:Biomechanical Phenomena; D016861:Cyclooxygenase Inhibitors / Q000009:adverse effects* / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D007273:Injections, Intramuscular; D007555:Isoxazoles / Q000009:adverse effects* / Q000494:pharmacology* / Q000627:therapeutic use; D019637:Orthopedic Procedures; D051381:Rats; D017207:Rats, Sprague-Dawley; D013708:Tendon Injuries / Q000534:rehabilitation / Q000601:surgery*; D016474:Weight-Bearing
chemical_list: D016861:Cyclooxygenase Inhibitors; D007555:Isoxazoles; C409945:parecoxib