Internal fixation of the lumbar spine. The Hartshill rectangle.

The Hartshill rectangle fixation is a modification of the Luque system of segmental spinal instrumentation. The rectangle is formed from a 3/16-in stainless steel rod and incorporates a roof that allows it to fit snugly against the lamina and provides good rotational stability. The rectangle is secured to the spine by means of doubled 0.91-mm-diameter stainless steel wires. The technique of the Hartshill system in the lumbar spine is described in detail. The system has been used in 71 patients with good relief of pain and without major complication. In the first 45 cases, a simple, flat, unwelded rectangle was used, and in the last 26 the Hartshill rectangle was employed.