Authors
Abstract
Background: One of the most important challenges after vertebroplasty (VP) and kyphoplasty (KP) is the stress concentration at the junction of bone and cement which would cause not only pain, but also new microfractures or osteonecrosis. We would like to present a new concept of using hexagonal porous structure. This model is tested biomechanically in comparison with vertebrae treated with VP and KP.
Methods: Ten Ovine vertebrae were divided into 5 groups - 2 in each group: the groups included normal vertebrae, VP, KP and vertebrae treated by hexagonal porous structure as metal pearls (steel or brass). These vertebrae were all put under mechanical static pressure. The displacement and yield points were compared in the 5 groups.
Results: The hexagonal metal treated vertebrae showed a displacement of 5.5-6 mm before reaching the ultimate strength of 3.5-4.5 KN. This displacement for VP and KP was 2.5-3 mm. The improvement of mechanical behavior was observed in vertebrae treated by hexsgonal metal pearls compared to those treated by the VP and KP.
Conclusions: The toughness vertebrae by hexsgonal metal pearl treatment increases and this will reduce the stress in vertebral end plates and interdiscal pressure. This would reduce the chance of fracture in the adjacent vertebrae.
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