Narrow Results

Purpose: To investigate whether magnetic resonance relaxation-time measurements have a role in monitoring fracture healing.

Methods: Magnetic resonance relaxation-time measurements were used to assess callus formation in chicks' tibiae and were correlated to the histopathologic and biomechanical changes that occur throughout the process of fracture repair.

Results: The effective transverse relaxation time (T₂) values recorded during fracture healing process were significantly longer (p = 0.0151) at day 14 (65.5575 ms.), compared with those recorded at days 3 (52.68 ms.) and 7 (55.4313 ms.). The T₂ values distributions (a) at day 14 (0.2304) were significantly lower (p = 0.0313) compared with those recorded at days 7 (0.2721) and 10 (0.2742). Using a semiquantitative histologic evaluation, a significant increase in the amount of endosteal new bone (p = 0.048), and periosteal new bone (p = 0.008), associated with a significant decrease in the amount of old bone (p = 0.007) and cartilaginous tissue (p = 0.001) was observed. Analysis of the torque-angle curves demonstrated a low torque and a large angular deformation associated with low stiffness at 3–7 days post-fracture, and a high torque and a small angular deformation associated with high stiffness at 10–14 days post-fracture.

Interpretation: Magnetic resonance relaxation-time follows the histopathologic and biomechanical changes occurring during the process of fracture repair and it may have a role as a potential method for objective estimation of fracture repair.

Design: Study on the union pattern of femoral shaft fractures after interlocked intramedullary fixation. Objective: To assess the fracture healing pattern — the so-called callus types — and its formation speed, and age influence. Setting: Orthopedic and traumatic services. Material and methods: Among all the healed femoral shaft fractures, 10 patients at least in each decade from late teens to eighth decade who were regularly followed radiographically with a certain interval upto complete fracture union were chosen. Results: All the fractures healed primarily with external periosteal callus which was followed sometimes later by intercortical uniting callus with disappearance of fracture line. Conclusion: All the nailed femoral shaft fractures healed primarily by periosteal bridging callus irrespective of age, fracture type, and use of interlocking screws, though some less external callus formation after sixth decade was observed.

Corrective osteotomy with callus filling at fracture site for malunion after distal radius fracture is a rare technique, but it achieved a favorable postoperative outcome. The patient, 66-year-old female, visited our hospital 4 months after distal radius fracture. Corrective osteotomy of the distal radius was planned aiming at improving the wrist joint function, and was performed using a volar locking plate, then the bone defect was filled with callus as autogenous bone grafting. At 12 months after surgery, left wrist joint pain and the range of motion have improved, and the Mayo wrist score was excellent. To our knowledge, there has been no study on the treatment of bone defects by filling with callus. Since favorable bone fusion was achieved with callus, this treatment method may overcome the disadvantages of autogenous bone graft, such as pain at the donor region.

In order to understand the mechanisms of fracture healing, especially the neovascularization of the callus, we have established a closed femoral fracture model in rats. This chapter describes a microangiography technique that has been adopted to investigate temporal changes in the three-dimensional (3D) vasculature of the healing callus. Quantitative evaluation protocols for vessel size distribution, total vessel volume, and volume fraction have also been established for comparative studies.