The Hartshill rectangle, a metal frame fixed to the laminae by sublaminar wires, has been used in 50 cases. Twenty idiopathic adolescent scolioses have been corrected from 49.3 degrees to 24.7 degrees with excellent stability of the curve at six and twelve months follow-up. Twelve paralytic scolioses were corrected from 71 degrees to 34.7 degrees but, in nine cases, the associated pelvic obliquity was not appreciably altered. Eleven adult scolioses, with an age range between 20 and 68 years, were corrected from 66.3 degrees to 38.7 degrees by a two-stage procedure of anterior release followed by posterior fixation with a Hartshill frame. In six patients with spinal metastases the Hartshill frame was used to provide spinal stability. The segmental fixation gave immediate post-operative comfort and allowed the patient to mobilise early without bracing. There were transient neurological complications--three cases of cutaneous hyperaesthesiae and one of monoparesis of a lower limb. Failure of the apparatus was encountered in cases of severe deformity with bending of the metal of the rectangle in two cases, breakage of distal wires in three cases and slipping of wires on the frame in two cases. The Hartshill frame provides stable fixation of the spine. It produces a three-dimensional correction of the scoliosis with preservation of reformation of the normal physiological kyphosis and lordosis. It is indicated for the correction of sagittal deformities, particularly in older patients and adults with thoracolumbar or lumbar curves and for spinal instability, especially in cases of destruction of posterior bony and ligamentous elements of the spine.