Evaluation of Femoral Bone Fracture Healing in Rats by the Modal Damping Factor and Its Correlation With Peripheral Quantitative Computed Tomography.

Introduction Monitoring the progress of fracture healing is essential in order to establish the appropriate timing that ensures adequate bone strength for weight-bearing. In the present experimental study on a rat model of femoral fracture healing, the measurement of bone density and strength by peripheral quantitative computerized tomography (pQCT) was correlated with the modal damping factor (MDF) method. Methods Four groups of 12 male six-month-old Wistar rats each were anesthetized and submitted to baseline femoral pQCT and MDF scanning, followed by aseptic midshaft osteotomy of the right femur which was fixed by a locking intramedullary nail technique.

A new, low cost, locking plate for the long-term fixation of a critical size bone defect in the ratfemur: in vivo performance, biomechanical and finite element analysis.

Background: The optimum fixation device for the critical size bone defect is not established yet.

Objective: A reliable, feasible and low-cost fixation device for the long-term maintenance of a critical bone defect.

Methods: A custom-made plate made of poly-methyl-methacrylate was used for the fixation of a critical defect of rats' femurs.

Development of a new optical device and its feasibility in prostate cancer detection.

Aim: To develop a new optical device (prostate optical device, POD) for assessment of prostate tissue stiffness and evaluate its sensitivity and specificity in prostate cancer detection.

Patients And Methods: POD was tested in prostate phantoms and in patients with indications for prostate biopsy. Its sensitivity and specificity were compared to digital rectal examination (DRE) and transrectal ultrasonography (TRUS).

Alteration in serum leptin correlates with alterations in serum N-telopeptide of collagen type I and serum osteocalcin during the progression of osteoporosis in ovariectomized rats.

The role of leptin during the progression of osteoporosis was investigated in ovariectomized rats by correlation of serum leptin levels with N-telopeptide of collagen type I (NTx) and osteocalcin levels before ovariectomy and 20, 40 and 60 days after the operation. Furthermore, peripheral quantitative computed tomography was used to confirm the development of severe osteoporosis in rats on day 60. The levels of NTx and osteocalcin were significantly increased on day 20 [61.

Modal damping for monitoring bone integrity and osteoporosis.

We applied a noninvasive method to assess bone structural integrity. The method is based on the measurement of the dynamic characteristics of the bone (quality factor and modal damping factor) by applying vibration excitation in the range of acoustic frequencies, in the form of an acoustic sweep signal. Excised sheep femora were tested to detect changes in modal damping, density (kg/m3), bone mineral density (kg/m2) and bone mineral (hydroxyapatite) percentage.