The Harrington rod is an obsolete instrument once used as a corrective device for scoliosis and other spinal abnormalities that resulted in a curvature of the spine. This steel rod was surgically attached to the spine to straighten it. An extremely successful treatment for scoliosis, it was eventually replaced with more stable and flexible spinal corrective devices. In some cases, individuals treated with the Harrington rod developed a condition known as Flatback Syndrome, requiring corrective surgery.
Made of stainless steel, the Harrington rod was outfitted with hooks on either end that were essentially anchored at both ends of the patient's spine. After implantation, the rod would be adjusted via a ratcheting system to straighten the spine. Initially implanted without the aid of spinal fusion, the device was found to weaken over time and would eventually break. Post-operative bracings, or casts, were eventually required to establish spinal immobilization and allow the vertebral fusions time to heal.
The first of its kind, the Harrington rod, also referred to as a Harrington implant, was developed in 1953 by Dr. Paul Harrington, an orthopedic surgeon. Designed to correct the spinal instability and deformity caused by scoliosis, the instrument was also used to treat spinal abnormalities caused by conditions such as fractures, multiple sclerosis, and Marfan syndrome. Instability in the spine occurs when movement results in the loss of normal spinal shape. The spine's inability to maintain its shape can result in nerve damage, deformity, and severe, incapacitating pain.
Rod implantation would often cause the ribcage to spread, sometimes resulting in the creation of a hump. For some individuals, when the rod was implanted it extended beyond the natural curvature of the lower back, known as the lordosis. The loss of this curvature resulted in Flatback Syndrome, in which the patient is unable to stand upright and, in some cases, walks with a forward stoop. Though many individuals did not experience such an adverse effect from the low-placed rod, those who did experience a loss of curvature required corrective surgery to realign the spine.
The Harrington rod became obsolete in the late 1990s, after nearly one million individuals had had the correctional device implanted. It was replaced by more versatile instruments that functioned on the same principle but eliminated some of the adverse affects. The Cotrel-Dubousset procedure was introduced in the mid-1980s, and offered curve and rotation correction without the risk of Flatback Syndrome. A versatile system known as the Isola System stabilized and aligned the spine using translation procedures and segmental anchoring.