Benzel's Spine Surgery

Scheuermann Disease

Summary of Key Points Other names include Scheuermann kyphosis (Scheuermann thoracic kyphosis), Calve disease, idiopathic juvenile kyphosis of the spine, and juvenile discogenic disease. Scheuermann kyphosis is the most common cause of hyperkyphosis in adolescents aged 12 to 17 years.…

Late-Onset Idiopathic Scoliosis

Summary of Key Points Late-onset scoliosis, or adolescent idiopathic scoliosis (AIS), as it has previously been described, is a coronal and rotational deformity that usually presents near puberty. AIS curves with greater Cobb angles are at higher risk of progression…

Early-Onset Scoliosis

Summary of Key Points Management of early-onset scoliosis (EOS) requires an understanding of not only spinal deformity but also of the natural history and growth of the spine, thorax, and lungs. Idiopathic EOS is a diagnosis of exclusion and should…

Congenital Spinal Deformity

Summary of Key Points Congenital spine deformity originates in early gestation, with multiple combinations of failure of formation, segmentation, and other anomalies possible. Associated vertebral, intraspinal, and visceral anomalies are common and may be clinically hidden. Screening for renal, cardiac,…

Spinal Cord Dysraphism and Myelodysplasia

Summary of Key Points Spinal dysraphisms result from errors in neural tube development; the types and severities of spinal dysraphism can be traced back to specific events in embryogenesis. Open neural tube defects, or spina bifida aperta, include myeloschisis, meningocele,…

Biomechanics of Motion Preservation Techniques

Summary of Key Points Motion-preserving surgery has been developed in an attempt to reduce the likelihood of intervertebral disc degeneration at segments adjacent to a fusion. The functional spinal unit (FSU) is defined as the smallest motion segment of the…

Biomechanics and Implant Materials: The Anterior Column

Summary of Key Points Interbody cages are commonly used to supplement fusion procedures and function to stabilize the anterior spine, increase the area for fusion, provide indirect decompression of nerve roots, and restore lumbar lordosis. Cages may be inserted via…

Implant Attributes: Cantilever Beam Fixation

Summary of Key Points Cantilever beam fixation, widely used in spinal instrumentation, is described as a beam that is rigidly fixed at one end and supports a load. Each screw and rod in a segmental/nonsegmental construct is a potential cantilever.…

Spine Fusion: Biology and Biomechanics

Summary of Key Points Successful integration and mechanical performance of a bone graft in spinal fusion is a function of graft properties and the graft–host interface. The principles of osteoinduction, osteoconduction, and osteogenesis dictate bone graft incorporation, the process of…