Surgical Management of Scoliosis
Scoliosis is cinderella in the field of orthopedics. By assuming their posture is erect, mankind has paid the price. Hippocrates described scoliosis for the first time in 5 B.C. However, Galen (131-201 AD) is credited for coining the terms scoliosis, kyphosis and lordosis to describe the spinal deformities. Generally, we can define scoliosis as the apparent lateral curvature of the spine. In true sense, it is a tri-planar deformity with lateral, anteroposterior and rotational components.
The Scoliosis Research Society (SRS) defines scoliosis as “a lateral curvature of the spine greater than 10° as measured by Cobb’s method on a standing radiograph”. Scoliosis is present in approximately 2% to 4% of children aged between 10-16 years with a measurable but small curve. Also, the ratio of girls to boys is more than 5:1, in curves greater than 20°. In order to analyze the cosmetic and pathological implications of the deformity, it is necessary to compile certain essential information in each case.
Treatment of Scoliosis
To determine the correct treatment for scoliosis, a clinical and radiological examination has to be conducted. Following the examination, the below information has to be gathered.
- Type of scoliosis: The underlying cause whether idiopathic, congenital, neurogenic or miscellaneous has to be detected during the primary evaluation. The natural history of progression in congenital scoliosis or infantile idiopathic scoliosis is different from idiopathic adolescent scoliosis. Similarly, scoliosis following neurogenic conditions may behave differently.
- Severity and progression of the curve: Treatment of curves less than 40 degrees is non-operative. However, regular follow-up can determine its progression.
- The pattern of the curve: The deformity produced by various curve patterns is variable. However, right thoracic and right thoracolumbar curves progressing rapidly may need early surgical intervention.
- Curves more than 40 degrees in adolescents during growth spurt progressing rapidly may need surgical correction.
- The rigidity of the curve.
- Skeletal age of the patient.
- Associated anomalies especially in congenital scoliosis.
The most important factor in the management of scoliosis is the type of scoliosis.
Various methods have been used to treat adolescent idiopathic scoliosis over the years, including physical therapy, manipulation, and electrical stimulation, however there is no scientific evidence supporting their effectiveness. But, the two most widely accepted non-operative techniques for idiopathic scoliosis are observation and bracing.
Young patients with mild curves of less than 20 degrees will be examined every 6 to 12 months. While skeletally mature patients with curves of less than 20 degrees, do not require further evaluation. Furthermore, a curve of more than 20 degrees in a patient who has not reached skeletal maturity demands more frequent radiological examination, usually every 3 to 4 months. Consider orthotic treatment if there is an increase in the curve more than 25 degrees (with a rate of 5 degrees or more in 6 months).
Orthoses were initially intended to be worn 23 hours a day. However, concern about compliance has lead to part-time bracing regimens. Most part-time bracing protocols call for approximately 16 hours or less of brace wear each day. If the curve is less than 35 degrees and does not show significant vertebral wedging, part-time bracing for around 16 hours may be considered.
Full time bracing is advised, if significant progression of the curvature is noted. Consider orthotic treatment for adolescent idiopathic scoliosis with a flexible curve of 20 to 40 degrees in a growing child with a documented progression of 5 degrees or more. Although surgery is suggested, one can consider orthotic treatment for curves such as a cosmetically acceptable double major curve although surgery is usually suggested.
The indications for surgery in adolescent idiopathic scoliosis:
- Curves more than 50 degrees and curves more than 40 degrees in skeletally immature patients.
- Progression of the curve (5 degrees per year) in spite of bracing.
- Patients who do not accept bracing.
- Pain,increasing respiratory insufficiency, and neurological involvement, degenerative changes in the spine, spinal instability and cosmesis.
Other clinical and radiographic components of the deformity which may be considered as indication of surgery are:
- Sagittal alignment showing thoracic hyperkyphosis, thoracolumbar kyphosis, and lumbar kyphosis.
- Rib hump more than 3 cm.
- Decompensated curve, trunk shift.
The primary goals of surgery include:
- Arresting the deformity, pulmonary dysfunction and pain.
- Achieving the maximum correction of the deformity with minimum risk of surgical complications.
- Obtaining a balanced trunk.
- The achievement of the first three objectives should be as permanent as possible
Instrumentation that uses the pedicle as a source of purchase for bone screws from the posterior approach into the vertebral body has become an increasingly popular form of spinal fixation.
Congenital scoliosis refers to the presence of vertebral anomalies that produces a longitudinal growth imbalance of the spine. Among various types of scoliosis, congenital scoliosis poses unique problems that deserve special consideration. It requires different models of thinking about its natural history and treatment. The term “congenital scoliosis” is misleading as it suggests that the curvature is present at birth. Although, this may not be true in most cases. Even though, the vertebral anomaly that leads to the deformity is present at birth, the curve itself often presents much later.
The primary aim of treatment of congenital scoliosis is to achieve as straight a spine as possible by the end of growth, without compromising the neurologic status. However, if there is a marked imbalance, a perfectly straight spine may not be achieved.
The key factors in achieving optimum results are:
- Early diagnosis of the anomaly: If detected early enough before any gross deformity becomes evident, prophylactic surgery may prevent a major problem later.
- Anticipation: Knowing the natural history of the deformity will help in anticipating the progression of the curve and thereby instituting treatment earlier for the curves that have a tendency to progress faster.
- Prevention of deterioration: Deformities like a unilateral unsegmented bar with or without hemivertebrae, can be treated by surgery immediately on presentation irrespective of the age. However, others need to be observed at regular intervals of six months depending on the severity of the deformity at presentation. Compared to a complex multistage surgery later consider a simple operation now to balance the growth.
Prevention of severe scoliosis is a major commitment for spine surgeons. Beginning in 1984, the American Academy of Orthopaedic Surgeons (AAOS) and the Scoliosis Research Society (SRS) formally endorsed the concept of school screening for the early detection of scoliosis in children. But this is based on the assumption that early detection in children at risk would lead to the institution of non-operative treatment. Without treatment, many curves will worsen over time, and some of them eventually needing surgical intervention. Hence, children with significant scoliosis and no other symptoms, must be detected by clinical screening at a time when surgical treatment could be performed most effectively.