Adolescent Idiopathic Scoliosis

AIS is a progressive deformity of the spine which arises in teenagers with no apparent cause. Scoliosis can cause cosmetic deformity, including uneven shoulders and a rib hump, pain in the thorax and reduced chest and lung volume.

Though the causes of AIS are unknown, one theory posits that the vertebral bodies and anterior spine grow too fast in relation to the posterior elements. The posterior elements act in tension, and the spine begins to buckle. This buckling only makes things worse, as the anterior spine continues to grow and adapt to the applied loads, resulting in wedge shaped vertebral bodies, unusual discs, and a three dimensional deformity.

First line treatment usually involves bracing, which has been shown to slow the progression of scoliosis, but rarely reverses curve progression [1]. Bracing is non-invasive, but bracing is uncomfortable, intrusive and compliance in teenagers is mixed.

Arthrodesis, or fusion is a surgical procedure in which the vertebral bodies are fused together after correction of deformity. Normally, screws or hooks and rods are placed into the vertebral bodies with rods connecting them. Fusion can be done through a posterior approach, or through an anterior approach after a thoracotomy. This is a surgical approach, which frequently leaves a major scar, and can leave the patient open to infection, hardware problems and pseudarthrosis. Furthermore after a fusion, the patient's axial skeleton cannot grow further, so the surgeon must time the operation early enough that the curve can be corrected fully while still allowing the patient to grow as much as possible. [2]

Adolescent Idiopathic Scoliosis

AIS refers to a curvature of the spine which arises in teenage years with no apparent cause

Arthrodesis

Fusion, or arthrodesis is a surgical procedure where a joint is fused. In the spine this refers to any surgery where the goal is to join multiple vertebrae into one bone.

Pseudarthrosis

Pseudarthrosis is a false joint arising from failed fusion surgery. This is usually bad.

Intravertebral Disc

Between the vertebrae of a spine is a structure called the disc. This structure is made of fibrous and gellatinous tissue which connects and gives flexibility to the spine.