A new device to quantify regenerate torsional stiffness in distraction osteogenesis

We present a newly developed torsional stiffness measurement device with th e potential to quantitatively assess the in vivo torsional stiffness of bon e regenerate during distraction osteogenesis. We describe the form and func tion of this device and its application in a model of regenerate consolidat ion. The device was able to produce data to assess stiffness of the regener ate with an accuracy between a a +/- 3 and +/- 9% for material stiffness ra nging between 0.1 and 2.4 Nm/degrees and with a precision of +/- 3.6%. This method provides advantages over similar methods of bone fracture healing a ssessment with guaranteed maintenance of bone axis; minimized risk of bone misalignment during the bone healing process and a close relation to the fu nctional loading pattern in torsion of bones such as tibia and femora. (C) 1999 Elsevier Science Ltd. All rights reserved.