Joseph W. Dryer, Emile Cheung, and Gordon Lee Engler

Goals of Surgical Treatment

To create lumbar lordosis when using hook and rod instrumentation of the lumbar spine, and to preserve motion segments in the lumbar spine by limiting the caudal extent of the fusion.

Diagnosis

Whenever fusion is required far the treatment of scoliosis, the surgeon must consider correction of the deformity in both the frontal and sagittal planes. Although the original Harrington instrumentation produced excellent correction in the frontal plane, the posterior distraction required to obtain such correction often distorted the sagittal plane. Thus, the term Harrington flat-back deformity described the loss of physiologic lumbar lordosis when Harrington instrumentation was used in the lumbar spine; long-term follow-up of these patients has shown extensive disc degeneration below the fusion, particularly in those patients fused to L3, L4, and L5.

A 36-inch standing lateral x-ray is required to properly assess the sagittal plane and plan the appropriate hook pattern so as to maximize lumbar lordosis. This is chiefly achieved by derotation of the lumbar spine as well as compression

Indications for Surgery

Idiopathic scoliosis with structural lumbar curves in excess of 40 degrees.

Contraindications