European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society
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Previous studies have shown that zoledronic acid administration can increase mineral content and strength in distraction osteogenesis. Of the few studies that have examined the use of bisphosphonates in spinal arthrodesis, none have assessed the effect of single dose treatment. The objective of this study was to evaluate the feasibility of enhancing spinal fusion rate using single dose zoledronic acid (ZA) to increase fusion-mass size and mineral density. ⋯ This study has shown that zoledronic acid increased fusion-mass size and bone mineral content. Systemic ZA led to an increased fusion rate; however the fusion rate remained below 100%. We suggest that bisphosphonate treatment may require an anabolic conjunctive therapy to ensure enhanced successful fusion.
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With the advent of thoracoscopy, anterior release procedures in adolescent idiopathic scoliosis (AIS) have come into more frequent use, however, the indication criteria for an anterior release in thoracic AIS are still controversial in the literature. To date, few studies have assessed the influence on spinal flexibility and no study has so far been able to show a beneficial effect on the correction rate as compared to a single posterior procedure. The objective of this study was to evaluate the influence of thoracic disc excision on coronal spinal flexibility. ⋯ Disc excision in idiopathic thoracic scoliosis only slightly increased spinal flexibility as assessed by traction films. In our view a posterior release with osteotomy of the concave ribs (concave thoracoplasty, CTP) is more effective in increasing spinal flexibility. According to our clinical experience, an anterior release prior to posterior instrumentation in AIS should only be considered in hyperkyphosis, coronal imbalance or massive curves.
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Over the last century the neurocentral junction (NCJ) has been identified as a potential cause of adolescent idiopathic scoliosis (AIS). Disparate growth at this site has been thought to lead to pedicle asymmetry, which then causes vertebral rotation and ultimately, the development of scoliotic curves. The objectives of this study are (1) to incorporate pedicle growth and growth modulation into an existing finite element model of the thoracic and lumbar spine already integrating vertebral body growth and growth modulation; (2) to use the model to investigate whether pedicle asymmetry, either alone or combined with other deformations, could be involved in scoliosis pathomechanisms. ⋯ Simulations with asymmetry of pedicle growth rate did not cause scoliosis independently and did not amplify the scoliotic deformity caused by other deformations tested in the previous model. The results of this model do not support the hypothesis that asymmetrical NCJ growth is a cause of AIS. This concurs with recent animal experiments in which NCJ growth was unilaterally restricted and no scoliosis, vertebral wedging, or rotation was noted.