The metaphyseal bone defect in distal radius fractures and its implication on trabecular remodeling-a histomorphometric study (case series)

Biomechanical properties and clinical significance of cancellous bone in proximal femur: A review

Trabecular bone plays an important role in the load-bearing capacity of the femur. Understanding the structural characteristics, biomechanics, and mechanical conduction of the trabecular bone is of great value in studying the mechanism of fractures and formulating surgical plans. The past decade has witnessed unprecedented progress in imaging, biomechanics and finite element analysis techniques, translating into a better understanding of trabecular bone. This article reviews the research progress achieved over the years regarding femoral trabecular bone, especially on factors influencing the strength of the proximal femoral cancellous bone and cancellous bone microfractures and provides a comprehensive overview of the latest findings on proximal femoral trabecular bone and their clinical significance.

What happens to the posterior comminution in extra-articular fractures of the distal radius treated with volar locking plates?

Extra-articular fractures of the distal radius with posterior displacement are typically treated with volar locking plates. However, this fixation method does not address the posterior comminution, which seems to have no impact on the final result. The purpose of this study was to determine the fate of the posterior comminution. This was a retrospective study of 22 patients over 50 years old with a distal radius fracture. A preoperative computed tomography (CT) scan was performed to evaluate the comminution. All fractures were fixed with a volar locking plate. All patients underwent a bone density scan. Patients were reviewed at 6 months post-operative to determine their clinical, radiological and functional outcomes. The CT scan was performed again to determine the fate of the comminution. At 6 months post-operative, 82% of patients had an oval metaphyseal defect. The mean volume of this defect was 1.86 mL. The contents of this defect most closely resembled fat. There was no statistical link between the defect's volume and the various parameters studied. On the other hand, the defect's density was positively related to the functional outcome and negatively related to the patients' body mass index. Because of the compression experienced by the cancellous bone, a distal metaphyseal defect often persists after consolidation in dorsally displaced distal radius fractures. The posterior comminution is ultimately of little consequence.

Inter-trabecular bone formation: a specific mechanism for healing of cancellous bone

Background and purpose - Studies of fracture healing have mainly dealt with shaft fractures, both experimentally and clinically. In contrast, most patients have metaphyseal fractures. There is an increasing awareness that metaphyseal fractures heal partly through mechanisms specific to cancellous bone. Several new models for the study of cancellous bone healing have recently been presented. This review summarizes our current knowledge of cancellous fracture healing. Methods - We performed a review of the literature after doing a systematic literature search. Results - Cancellous bone appears to heal mainly via direct, membranous bone formation that occurs freely in the marrow, probably mostly arising from local stem cells. This mechanism appears to be specific for cancellous bone, and could be named inter-trabecular bone formation. This kind of bone formation is spatially restricted and does not extend more than a few mm outside the injured region. Usually no cartilage is seen, although external callus and cartilage formation can be induced in meta-physeal fractures by mechanical instability. Inter-trabecular bone formation seems to be less sensitive to anti-inflammatory treatment than shaft fractures. Interpretation - The unique characteristics of inter-trabecular bone formation in metaphyseal fractures can lead to differences from shaft healing regarding the effects of age, loading, or drug treatment. This casts doubt on generalizations about fracture healing based solely on shaft fracture models.