Paul Randall Harrington (1911-1980)The 100th anniversary of Paul Harrington's birth, September 27, 2011, is a fitting time to reflect on his life and the inventive process. While he was not alone in the effort to develop scoliosis instrumentation, he alone succeeded. Why? Vernon Nickel, in a 1974 keynote address honoring Harrington, emphasized his “capacity to look at a problem in an entirely original way.”1
The problem that Harrington faced resulted from the North American poliomyelitis epidemics from 1947 to 1955. At the completion of three years of overseas service as chief of orthopaedics at the U.S. Army's 77th Field Evacuation Hospital, Harrington entered private practice in Houston. In early 1947, he was named head of the National Foundation for Infantile Paralysis Unit at the Jefferson Davis Hospital. With just nine patients, all in the rehabilitation phase, his time commitment was minimal. However, that summer, increasingly large numbers of patients, most of them children or adolescents, contracted poliomyelitis. Many were destined to develop progressive post-poliomyelitis scoliosis as they grew. Harrington's entirely original way of viewing scoliosis was his focus on asymmetrical loads and growth, which directed his attention toward younger patients with smaller curves and away from arthrodesis. He hypothesized that the scoliosis was due to asymmetrical facet loads that resulted in asymmetrical growth. He devised internal strutting of the spine to remove the asymmetrical loads and thus promote normal growth.
He proceeded cautiously, carefully documenting his work. Initially, he fashioned the implant anchors (hooks) himself. In 1954, the National Foundation for Infantile Paralysis (NFIP) awarded him two grants, one to develop an experimental model of scoliosis and the other to aid in the development of the implants. The NFIP also reassigned orthotist Tork Engen from Warm Springs, Georgia to Houston, Texas. One of his new assignments was to help Dr. Harrington with prototypes. Harrington's practice was well on the way to being totally devoted to the care of patients with scoliosis and related spine deformities.
In 1955, Harrington devised the now-familiar ratchet design and soon began a productive collaboration with Zimmer Manufacturing. After the introduction of the Salk vaccine in 1955, post-poliomyelitis scoliosis decreased. By the time that Harrington's experimental and clinical research proved that scoliosis was not due to asymmetrical facet growth and he accepted that arthrodesis was necessary for the success of the surgery, the worth of instrumentation correction and stabilization was undeniable. This was true not only for post-poliomyelitis scoliosis but also for other types of scoliosis2,3. Harrington had been sustained through these years of harsh criticism and rejection by his dogged persistence1.
The Harrington Instrumentation system became available in 1960. Zimmer had agreed that for two years the system would only be made available to surgeons who had had training with Harrington. Consequently, from 1960 to 1968, Harrington maintained a nearly impossible mentoring schedule. In 1963, John Moe presented the first independent clinical validation of Harrington Instrumentation, and John Cobb commented that “Dr. Harrington is a good man with a good idea. It would be too bad to have the poor results of people who shouldn't use this method be bad for a good man and his good idea.”4 Until 1970, all royalties ($0.50 per rod and $0.25 per hook) were donated to Harrington's research5. From 1970 until 1977, the royalties went to Harrington, who had become increasingly disabled by vascular disease since 19686,7. His last design (1966) was a pedicle screw8, which eventually became the precedent that the U.S. Food and Drug Administration accepted for screw labeling for the narrow indication of high-grade spondylolisthesis in January 19959.
Until 1985, with few modifications and additions, Harrington spinal instrumentation was the most widely used system in the world. The patient-based, health-related quality-of-life outcomes for patients with adolescent idiopathic scoliosis that were reported by Danielsson et al. at twenty years postoperatively leave very little room for improvement10.
To this day, many, if not most, spine implant dimensions relate back to those that Harrington worked out. Moreover, the predominant scoliosis surgical treatment paradigm in 2011 is the same as in 1960: instrumentation and arthrodesis.
In his later years, Harrington worked with his associate, Jesse Dickson, to document his clinical work, aided by one of the first computer databases11. Harrington was fascinated by the idiopathic scoliosis etiology and pathogenesis puzzle. Several of his observations suggest that structural scoliosis may have considerable capacity to resolve once the underlying cause is removed, provided that growth remains12-14. Harrington ended his last article on etiology with an acknowledgment: “To my friend and colleague, Dr. Moe, The Father of the Modern Treatment of Scoliosis, I would like to pass on this thought: Tomorrow, when we comprehend the molecular chemistry of the living process, can we then predict and perhaps prevent idiopathic scoliosis?”15
Ever the visionary, Harrington and his wife worked to establish the Mary Alice and Paul R. Harrington Distinguished Professorship in Molecular Orthopedics at his alma mater, the University of Kansas Medical Center. Soon after Harrington died, I (M.A.) first learned that he had willed his archives to the University of Kansas Medical Center, where I practiced. He chose this site because of his deep gratitude to the public school system of Kansas for his educational opportunities. In addition, he knew of the school of medicine's strong commitment to the history and philosophy of medicine. The Harrington Archives have served as a magnet for several other important archives, including those of the Scoliosis Research Society; Leonard F. Peltier, MD, PhD; Walter P. Blount, MD; and Rex L. Diveley, MD. These archives are preserved for academic study.
From July 28 to 30, 2005, the Harrington Spine Symposium was held at Harrington's alma mater to commemorate the twenty-fifth anniversary of his death. More than 115 registrants from seventeen countries attended. Harrington's archives reflect a person of immense natural ability, determination, and total commitment to a life of understanding. They provide lessons about the inventive process, the person, the increasingly singular focus, the problems and resolutions, and Harrington's relationships with his family, patients, peers, and industry. Only after spending hours in his archives could I fully appreciate a comment he made at the time of our last meeting, a few months before he died. He said that in the end he felt he had failed because successful arthrodesis was necessary to make the instrumentation work. This is a sobering testimonial to one of the risks accompanying the inventive process, a lingering sense of unfulfillment, no matter how successful the accomplishment. He would be pleased with the renewal of interest in growth modulation and even more pleased with the increasing efforts to understand, and eventually affect, the molecular basis or bases of idiopathic scoliosis.