title: The effect of levodopa or levodopa-carbidopa (sinemet) on fracture healing.
abstract: OBJECTIVE
  Levodopa (L-dopa) and L-dopa/carbidopa were evaluated to determine their effectiveness in the stimulation of bone healing of fractures at risk for nonunions.
  
  
  METHODS
  Forty-two retired breeder female Sprague-Dawley rats were divided into 2 experimental groups and 1 control. Thirty-six rats were evaluated for results. The right femur of each rat was fractured and an intramedullary omega pin was inserted to create a 2 mm bone gap. The rats were administered either 0.2 g/kg/d of L-dopa, 0.2/0.02 g/kg/d L-dopa/carbidopa in their feed, or plain powdered chow (Sham control group). The rats were killed at 5 weeks postsurgery. The femurs were excised, radiographed, and mechanically tested. Bone healing was assessed. Bone stiffness, ultimate load, and energy to failure were determined under 3 point bending using an Instron materials testing system.
  
  
  RESULTS
  The femurs of 30% of the Sham rats healed compared with 50% of the L-dopa/carbidopa and 84% of the L-dopa treated femurs. The healed L-dopa rat femurs had significantly greater ultimate load (P = 0.037) and energy to failure (P = 0.004) than the healed Sham rats. There were no significant differences between the L-dopa/carbidopa group and either the Sham or L-dopa group.
  
  
  CONCLUSIONS
  These results confirm that L-dopa administration increases the healing in nonunion fractures. The combination of L-dopa/carbidopa did not significantly increase fracture healing.
authors.affiliation: School of Medicine, University of North Carolina, 27599, USA.
authors.forename: Elisabeth R
authors.initials: ER
authors.lastname: Costa
authors.forename: Paul
authors.initials: P
authors.lastname: Weinhold
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Tayrose
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Hooker
authors.forename: Laurence E
authors.initials: LE
authors.lastname: Dahners
mesh_terms: D000818:Animals; D002230:Carbidopa / Q000627:therapeutic use*; D004338:Drug Combinations; D005260:Female; D017102:Fracture Healing / Q000187:drug effects*; D007980:Levodopa / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004338:Drug Combinations; C009265:carbidopa, levodopa drug combination; D007980:Levodopa; D002230:Carbidopa