The effect of levodopa or levodopa-carbidopa (sinemet) on fracture healing

• Published in: Journal of orthopaedic trauma Vol. 20; no. 7; p. 470
• Main Authors: Costa, Elisabeth R, Weinhold, Paul, Tayrose, Gregory A, Hooker, Jennifer A, Dahners, Laurence E
• Format: Journal Article
• Language: English
• Published: United States 01.08.2006
• Subjects: Animals; Carbidopa - therapeutic use; Drug Combinations; Female; Fracture Healing - drug effects; Levodopa - therapeutic use; Rats; Rats, Sprague-Dawley
• ISSN: 0890-5339
• DOI: 10.1097/00005131-200608000-00004

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. 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. 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. 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.