Elsevier

The Lancet

Volume 371, Issue 9623, 3–9 May 2008, Pages 1527-1537
The Lancet

Seminar
Adolescent idiopathic scoliosis

https://doi.org/10.1016/S0140-6736(08)60658-3Get rights and content

Summary

Adolescent idiopathic scoliosis (AIS) affects 1–3% of children in the at-risk population of those aged 10–16 years. The aetiopathogensis of this disorder remains unknown, with misinformation about its natural history. Non-surgical treatments are aimed to reduce the number of operations by preventing curve progression. Although bracing and physiotherapy are common treatments in much of the world, their effectiveness has never been rigorously assessed. Technological advances have much improved the ability of surgeons to safely correct the deformity while maintaining sagittal and coronal balance. However, we do not have long-term results of these changing surgical treatments. Much has yet to be learned about the general health, quality of life, and self-image of both treated and untreated patients with AIS.

Introduction

Adolescent idiopathic scoliosis (AIS) is a structural, lateral, rotated curvature of the spine that arises in otherwise healthy children at or around puberty. The diagnosis is one of exclusion, and is made only when other causes of scoliosis, such as vertebral malformation, neuromuscular disorder, and syndromic disorders, have been ruled out. Patients are generally screened with Adams' forward bend test and a scoliometer, although a definitive diagnosis cannot be made without measuring the Cobb angle on a standing coronal radiograph (figure 1). When defined as a Cobb angle of at least 10°, epidemiological studies estimate that 1–3% of the at-risk population (children aged 10–16 years) will have some degree of spinal curvature, although most curves will need no intervention.1, 2 In this Seminar we discuss present notions about aetiopathogenesis, natural history, non-operative treatment, and surgery.

Section snippets

Aetiopathogenesis

Despite much clinical, epidemiological, and basic science research, the aetiopathogenesis of AIS remains unknown.3, 4 AIS is often seen in multiple members of one family, which strongly suggests that it has a genetic component. A meta-analysis of studies of twins showed concordance for AIS in 73% of monozygotic twins and 36% of dizygotic twins.2 Several studies that assessed large pedigrees showed different methods of inheritance, such as autosomal dominance, maternal factors, multiple gene

Natural history

The natural history of scoliosis varies with the aetiopathogenesis and curve pattern. Early long-term studies of so-called idiopathic scoliosis presented a grim prognosis, perpetuating the common misperception that all types of idiopathic scoliosis inevitably lead to disability from back pain and cardiopulmonary compromise.39, 40, 41, 42 Shortcomings of these earlier studies were (1) the inclusion of patients with other causes of scoliosis or of early onset idiopathic scoliosis; and (2) failure

Non-operative treatment

Although AIS is diagnosed and treated worldwide, treatment approaches vary internationally. In patients who still have growth remaining, watchful waiting (observation), followed by bracing if the curve progresses to greater than 25°, is the general course of care in North America.1, 2 Physical therapy (outpatient and inpatient rehabilitation) has been recommended as the first line of treatment for small curves and those with a low risk of progression by various, mostly European, clinicians.66,

Surgery

The primary objectives of surgical treatment with instrumentation are to (1) arrest progression, (2) achieve maximum permanent correction of the deformity in three dimensions, (3) improve appearance by balancing the trunk, and (4) keep short-term and long-term complications to a minimum. The generally agreed indication for surgery in adolescents is a primary curve greater than a Cobb angle of 45°. In adults, the surgical indications are pain related to the curvature that is unresponsive to

Conclusion

Although many controversies and unanswered questions surround AIS, the most difficult one is the absence of information about its aetiopathogenesis. We do not know if AIS is one entity or a manifestation of several causes. We are uncertain of all the factors that lead to progression and secondary manifestations of spinal deformity. The identification of aetiopathogenetic factors will enable improved prediction of progression and could aid in the development of more specific treatments.

Because

Search strategy and selection criteria

We searched the Cochrane Library and Medline from 1996 to 2006 for relevant literature and entered the following search terms: “adolescent idiopathic scoliosis”, “late onset scoliosis”, “scoliosis” AND “bracing” or “orthotic treatment”, “natural history”, “aetiology”, “pathogenesis”, “operative treatment”, “spinal fusion”, “surgical stapling”, “surgical stapler” or “thoracoscopy” or “video-assisted thoracic surgery” or “pedicle screw”. We mainly selected literature from the past 10 years,

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