Lauren M. Sadowsky, Ankur S. Narain, Fady Y. Hijji, Philip K. Louie, Daniel D. Bohl, and Kern Singh

12.1 Introduction

Spinal deformities such as scoliosis represent some of the most challenging cases for spinal surgeons. Scoliosis has a variety of potential etiologies, and progresses in severity from childhood to adulthood. Significant functional and cosmetic deficits can occur without proper screening, diagnosis, and treatment of this disorder. As such, it is important to understand the unique clinical history, radiographic techniques and measurement, and surgical strategies that present or are utilized in cases of scoliosis.

12.2 Background and Etiology

• Scoliosis is defined as a lateral curvature of the spine ≥10 degrees, typically accompanied with a variable degree of vertebral rotation.

• Etiologies include idiopathic (80–85%), congenital, neuromuscular, and syndromic:

– Idiopathic:

∘ Categorized based on age of presentation:

▪ Infantile: 0 to 3 years.

▪ Juvenile: 4 to 10 years.

▪ Adolescent: 11 to 17 years.

▪ Adult: ≥18 years (after skeletal maturity).

– Congenital:

∘ Present at birth.

∘ Can include failure of formation (e.g., hemivertebra) or failure of segmentation (e.g., congenital fusion):

▪ Often associated with genitourinary deformities.

– Neuromuscular:

∘ Due to muscular tone abnormalities (imbalance and lack of trunk control):

▪ Etiologies include cerebral palsy, myelomeningocele, myopathies, spinal cord trauma, and muscular dystrophies.

– Syndromic:

∘ Includes any syndrome presenting with scoliosis that is not neuromuscular or congenital:

▪ Associated syndromes include Marfan’s syndrome, osteogenesis imperfecta, skeletal dysplasias, Prader–Willi syndrome, Ehler–Danlos syndrome, and neurofibromatosis.

• Risk factors for acquired scoliosis:

– 2-4% of all adolescents have adolescent idiopathic scoliosis (AIS):

∘ Females and males affected equally.

▪ Larger Cobb’s angles in females than in males.

– Genetics: 97% of AIS patients have a family history of scoliosis.

– Age: up to 68% of adults older than 60 years have scoliosis due to progression of degenerative changes of the spine.

• Progression of deformity:

– Physiologic changes due to compressive forces on intervertebral disks and vertebrae on concave side → reduced growth and continued asymmetry.

12.3 History and Clinical Findings

• History:

– Age at onset:

∘ Peak growth occurs in males at 13.5 years and in females at 11.5 years.

∘ Scoliosis may progress during peak growth spurt.

– Presence of back pain and stiffness:

∘ 23% of AIS patients present with pain.

– Muscle fatigue from muscle strain and compensated posture.

– Shortness of breath/difficulty breathing due to severe thoracic scoliosis.

– Family history:

∘ Incidence increases seven times with a first-degree relative with scoliosis.

• Inspection:

– Any truncal imbalance in height/symmetry of shoulders, scapulae, spine, and waistline.

– Head misaligned over sacrum (trunk shift).

– Findings suggestive of other diagnoses: café au lait spots (neurofibromatosis type 1), axillary freckling (neurofibromatosis type 1), and hair tufts (spina bifida).

– Sexual maturity measured by Tanner’s grading stages.

• Height measurement:

– Monitor progression and skeletal growth.