P seudarthrosis following posterolateral lumbar spinal fusion remains a significant clinical problem, despite the frequent use of instrumentation. 4, 5, 9, 12 The quest to eliminate pseudarthrosis continues and at present is focused on biological enhancement of the fusion process. Studies investigating the biological sequences of posterolateral spinal fusion have shown that events in the center of the fusion mass lag behind those adjacent to the transverse processes and this may be related to decreased oxygen tension at the center of the fusion mass. 2, 3
Ashley R. Poynton, Fengyu Zheng, Emre Tomin, Joseph M. Lane and G. Bryan Cornwall
Tord D. Alden, Debra D. Pittman, Elisa J. Beres, Gerald R. Hankins, David F. Kallmes, Benjamin M. Wisotsky, Kelvin M. Kerns and Gregory A. Helm
T he use of osteoinductive proteins to promote or enhance spinal fusion is attracting great interest in the basic science and clinical communities. 4, 5, 7, 9, 15, 18, 19, 21, 22, 24, 25 Although internal fixation devices have been developed that can successfully achieve short-term stabilization at virtually all levels of the spine, long-term stability requires bone fusion, typically using autologous bone grafts as the osteoinductive material. Although autografts are currently the “gold standard” for initiating bone fusion in the clinical setting, the
Julie G. Pilitsis, David R. Lucas and Setti R. Rengachary
Bone is a tissue that constantly undergoes deposition, resorption of stromal matrix, and remodeling. These processes may be altered by a variety of chemical, mechanical, cellular, and pathological mechanisms. Understanding the physiology of bone healing and the mechanisms affecting this process is important not only when evaluating normal skeletal development but also when initiating fracture repair. Because the ultimate success of spinal fusions involves creation of an osseous union, we focus this review on the anatomy and physiology of bone under physiological conditions, normal bone healing and mechanisms that alter it, and available adjuvant therapies that may enhance healing potential in a clinical setting.
Amir Hasharoni, Yoram Zilberman, Gadi Turgeman, Gregory A. Helm, Meir Liebergall and Dan Gazit
S pinal fusion has become a popular surgical technique. Instrumentation systems designed to provide segmental fixation and maintain stability and deformity correction have become increasingly refined and available. As more spinal fusions have been performed, problems such as fusion failure, pseudarthrosis, and infections at the bone-graft donor site have become more common. 1, 11 Autologous bone grafts continue to be gold-standard material for achieving successful spinal fusions. Nevertheless, attempts at arthrodesis of the lumbar spine, even when performed
Jeffrey J. Laurent, K. Michael Webb, Elisa J. Beres, Kevin McGee, Jinzhong Li, Bert van Rietbergen and Gregory A. Helm
T he use of spine fusion to increase spinal stability has been reported in the US since 1911. 19 Since that time the number and variety of indications for spine fusion have increased. In the lumbar spine, the procedure most often performed to achieve fusion is posterolateral intertransverse process arthrodesis in which autologous bone grafts are used. Despite the success achieved with this procedure, nonunion has been reported to be as high as 35% in humans and is a common cause of failed-back syndrome. 12, 33 In addition, current methods of spinal fusion
Amitabha Chanda, Donald R. Smith and Anil Nanda
successfully adapted mainly in cardiovascular and orthopedic surgery. 1, 2, 30–32, 35 In patients undergoing neurosurgical procedures, however, the use is not widely reported. 4 The usefulness of the cell saver technique in autotransfusion was examined in this study, and we assessed its related complications and cost effectiveness in patients undergoing spinal fusion. Clinical Material and Methods We included 50 patients who underwent instrumentation-assisted lumbar and thoracic spinal fusions between January 1998 and June 2000. There were 32 male and 18 female
Jianxiong Shen, Jinqian Liang, Haiquan Yu, Guixing Qiu, Xuhong Xue and Zheng Li
not modifiable. Recent literature has focused on identifying modifiable risk factors and prevention strategies that may decrease the rates of wound infections after spinal fusion. Perioperative factors such as cognitive impairment, use of an allograft in patients with neuromuscular scoliosis, use of preoperative skeletal traction, age greater than 20 years, and higher intraoperative blood loss have been reported as risk factors for infection. 6 , 16 , 25 However, there are limited published data about the risk factors for the development of delayed infections after
David H. Walker and Neill M. Wright
Bone morphogenetic proteins (BMPs) have increasingly become a focus of research in the laboratory, with animal models, and in human clinical trials for the treatment of spinal disorders. Basic science research has elucidated the putative mechanism of action of BMPs, and the efficacy of BMPs in inducing bone formation has been evaluated in multiple animal models of anterior and posterior spinal fusion. Not only has BMP been shown to improve the quality and amount of bone formation when used as a supplement to autograft, it has also been shown to promote superior fusion in the absence of autograft, even in high-risk fusion models involving the use of nicotine or nonsteroidal antiinflam-matory agents. Both completed and ongoing clinical trials have demonstrated the efficacy of recombinant BMP, leading to the first BMP product being approved for clinical use earlier this year.
Animal models and clinical trials have also been used to evaluate the safety of BMPs. Although few complications have been reported, BMPs can induce heterotopic bone formation, especially when placed adjacent to exposed neural elements. Potentially more serious, antibody formation has been seen in up to 38% of patients in some clinical trials. No clinical sequelae have been reported despite the development of antibodies against BMP, a naturally occurring human protein implicated in processes other than osteoinduction.
The future directions of biological manipulation of the osteoinduction process include further understanding of the interactions of the BMP subtypes, the interactions of BMP with its receptors, and exploring other molecules capable of osteoinduction.
Christopher M. Holland, Meysam A. Kebriaei and David M. Wrubel
consistent with an ASIA C classification at the C-6 level. FIG. 4. Postoperative MR images obtained 16 months after surgery. T2-weighted sagittal image (A) and axial images obtained at C-5 (B) and C5–6 (C) demonstrating the severe spinal cord injury with nearcomplete transection. Note the bilateral meningeal diverticula present in Panel C, which are likely indicative of traumatic avulsion of the C-6 nerve roots. Discussion Spinal fusion procedures in neonatal patients pose specific technical and mechanical challenges related to the distinct anatomical
Anthony M. T. Chau, Lileane L. Xu, Rhys van der Rijt, Johnny H. Y. Wong, Cristian Gragnaniello, Ralph E. Stanford and Ralph J. Mobbs
(87), MEDLINE (512), and EMBASE (494) ( Fig. 1 ). From these, 5 articles were found to be appropriate for the clinical question, of which 3 were RCTs 5 , 25 , 33 and 2 were NRCTs ( Table 3 ). 4 , 12 The indications for iliac crest harvesting in these studies were all related to spinal fusion. No studies from other disciplines such as oral maxillofacial surgery were located. The study by Yang et al. 33 was translated into English and evaluated. F ig . 1. Preferred reporting items for systematic review and meta-analyses (PRISMA) flow diagram of study