Scoliosis is a common orthopaedic conditon affecting spinal aligment, growth and function.
A wide variety of conditions, many of which affect the neuromuscular system (eg, cerebral palsy, muscular dystrophy), are associated with the development of Scoliosis. However, the most common form of Scoliosis, which has an undefined etiology and affects otherwise normal adolescents, is the focus of this website.
Scoliosis can be diagnosed as:
Adolescent Idiopathic Scoliosis (hereby known as AIS) develops in approximately 1% to 3% of the population, primarily in minor forms that do not become progressive or problematic in later life. However, a small percentage of curves do progress to a range that warrants treatment with either an orthosis or surgical arthrodesis. Bracing to prevent and/or limit Scoliosis progression is an option only in the growing patient with a moderate curve (25º to 45º). Surgical treatment is considered for patients with curves greater than 40º to 50º.
Vertebral Disorders Scoliosis Kyphosis Lordosis
The natural history of AIS dictates the treatment algorithm. Rapid growth during adolescence (fastest for girls in the year before the onset of menses) is one of the greatest risk factors for Scoliosis progression, at times as much as 10º to 15º per year. Curves that have progressed to more than 25º to 30º during growth are likely to progress with further growth. Therefore, orthoses are suggested in the patients, with the goal of limiting curve progression as adolescent growth finishes.
Similarly, the treatment after completion of growth relates to the risk of progression compared to curves greater than 50º. Moreover, progression is much slower (0.5º to 2º per year) in adults than in adolescents. After the completion of growth, bracing is not practical to control the risk of progression, and surgical treatment is the only means of limiting progression and achieving deformity correction.
The orthopaedic evaluation of a patient with Scoliosis is critical to avoid a diagnosis of AIS when some other cause of the deformity exists. One of the more commonly missed causes of Scoliosis is intraspinal pathology, such as syringomyelia. Neurologic symptoms or signs (as subtle as asymmetric abdominal reflexes), as well as an unusual scoliotic curve pattern (left thoracic, hyperkyphotic), are associated frequently enough with intraspinal pathology to warrant MRI evaluation in such patients.
The variety of Scoliosis curves seems infinite but more common patterns of spinal deformity do exist, and treatment is based in part on curve morphology. Several systems of classifying Scoliosis have been devised.
The surgical treatment of AIS can be complex, both in the aspects of surgical technique, and more importanly, surgical decision making. These decisions include the approach-anterior, posterior or both; how much of the spine to fuse-one curve or two; which level to end distally; and the type and position of bone anchors to the spine (hooks, screws, wires). All these details cannot be presented completely in this text; however, the important principles are offered. For example, the advantages and disadvantages of each surgical technique and the appropriate surgical goals are presented on this website in the best way I can.
The outcomes of Scoliosis surgical correction are more reliable than in prior eras. Modern correction methods, both anteriorly and posteriorly, now provide more secure fixation with greater construct rigidity. The risk of excessive blood loss common in the past has been reduced with the use of electrocautery dissection and blood salvage/recirculation systems. In addition, the use of spinal cord neurologic monitoring allows reliable early intraoperative warning of the spinal cord injury/hypoperfusion. Thus, greater deformity correction is safely achievable with an early return to activity and reduced risk of pseudarthrosis.