The effect of levodopa or levodopa-carbidopa (sinemet) on fracture healing.
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.
Costa
Elisabeth R
ER
School of Medicine, University of North Carolina, 27599, USA.
Weinhold
Paul
P
Tayrose
Gregory A
GA
Hooker
Jennifer A
JA
Dahners
Laurence E
LE
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
D004338:Drug Combinations; C009265:carbidopa, levodopa drug combination; D007980:Levodopa; D002230:Carbidopa