Affiliations: [a] Department of Orthopaedic Surgery, Hannover Medical School, Hannover, Germany | [b] ATOS Clinic Heidelberg, Heidelberg, Germany | [c] Hannover Medical School, Laboratory of Biomechanics, Hannover, Germany
Correspondence:
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Corresponding author: Thilo Floerkemeier, Department of Orthopedic Surgery, Hannover Medical School, Hannover 30625, Germany. Tel.: +49 511 5354527; Fax: +49 511 5354682; E-mail: Thilo.Floerkemeier@diakovere.de.
Abstract: BACKGROUND: A major problem associated with distraction osteogenesis is the long time required for consolidation. OBJECTIVE: The goal of this study was to determine whether a percutaneous injection of recombinant human bone morphogenetic protein-2 (rhBMP-2) in a Gelfoam carrier would enhance bone consolidation following distraction. METHODS:A unilateral tibial osteotomy combined with external stabilization was performed in 14 adult sheep. After a latency of four days, distraction was performed at 1.25 millimetres per day for 20 days. On days 23 and 30, the sheep received an injection of rhBMP-2/Gelfoam or buffer/Gelfoam. During the following 50 days, radiographs and in vivo torsional stiffness measurements were obtained weekly. The effect of rhBMP-2 treatment post-mortem was assessed using destructive biomechanical testing, quantitative CT and DXA analysis. RESULTS:The in vivo stiffness measurements of the sheep treated with rhBMP-2 were significantly higher than those of the carrier control group (p< 0.05). These in vivo data were verified by post-mortem biomechanical testing and quantitative CT analysis. The maximum torsional moment observed was 55% greater in the sheep treated with rhBMP-2. CONCLUSIONS:These data support the potential use of rhBMP-2 in an injectable carrier for enhancing consolidation, as it may ultimately lead to shorter treatment times for patients undergoing distraction procedures.
Keywords: BMP, bone consolidation, distraction osteogenesis, gelfoam, growth factor
