Share this page
Legacy Spinal Technologies
Harrington Rods
A historical overview of the first widely used spinal instrumentation for scoliosis, its lasting influence, and the long-term problems — such as flatback deformity — that led to its replacement. This is a technique of the past; I do not use it, and this page is written for patients who have, or once had, Harrington instrumentation.
The Harrington rod, introduced in the early 1960s, was the first spinal instrumentation to be used widely for scoliosis, and it transformed the surgical treatment of spinal deformity. It is now a technique of the past — I do not use Harrington rods, and they have long been superseded by modern segmental systems — but a great many people, now adults, were treated with them, and they occupy an important place in the history of spinal surgery. This page explains what the Harrington rod was, why it mattered, and, importantly for those who have one, what is understood about its long-term effects and the problems, such as flatback deformity, that eventually led surgeons to move on from it.
For information only — not medical advice. The content on this page is patient education to help you understand a condition or treatment. It is not a substitute for personalised assessment by a qualified clinician. Always consult your doctor or specialist about your own symptoms, diagnosis, and treatment decisions.
What the Harrington rod was and why it mattered
Before the Harrington rod, scoliosis was treated largely with plaster casts and fusion without internal metalwork, and correction was limited and unreliable. Paul Harrington's system used a metal rod anchored with hooks at the top and bottom of the curve, with a ratchet mechanism that allowed the surgeon to distract — to lengthen and straighten — the concave side of the curve, holding the correction while the spine fused. For its time this was a revolutionary advance, giving far more reliable correction than anything before it, and it became the standard treatment for scoliosis for roughly two decades. Its influence on every instrumentation system that followed is hard to overstate.
The flatback problem
The Harrington rod's great limitation became clear only with long-term follow-up. Because it worked mainly by distraction — straightening the spine by pulling it long — it tended to flatten the natural inward curve of the lower back, the lumbar lordosis, especially when the instrumentation extended low into the lumbar spine. The result, in some patients, was flatback deformity: a loss of the normal lumbar curve that leaves a person stooped forward, unable to stand fully upright, and often in pain and easily fatigued. This recognition — that straightening the spine in one plane could create a problem in another — was one of the key lessons that drove the development of the segmental systems that replaced it, which aim to restore the spine's natural front-to-back curves as well as correcting the sideways curve.
What long-term follow-up shows
People treated with Harrington instrumentation are now decades out from their surgery, and there is a reasonable body of long-term follow-up. Overall, many patients treated in the Harrington era have done well and maintained their correction over 20 to 30 years, with quality of life often comparable to the general population; some studies of long-term outcomes are broadly reassuring. But a minority developed problems related to flatback, adjacent-level degeneration below the fused segment, or back pain, and some have needed revision surgery in adult life to restore their spinal balance. Interestingly, studies of patients who had a Harrington rod removed years later have generally found that the deformity did not progress significantly afterwards, which is reassuring for those wondering about their old metalwork.
What this means if you have a Harrington rod
If you were treated with a Harrington rod, the practical message is one of measured reassurance. Many people live full lives with their old instrumentation and never need anything further. If you develop new back pain, a sense of being pulled forward, difficulty standing upright, or leg symptoms, that is worth assessing, because it can occasionally reflect flatback or degeneration below the fusion, both of which are treatable. The right people to advise you are surgeons who deal with adult spinal deformity and revision surgery. I do not use Harrington instrumentation myself, and this page is intended to give historical and practical context rather than to describe anything I offer.
This page is for general education only and is not a substitute for personal medical advice. Harrington instrumentation is a historical technique that I do not perform. If you have concerns about old spinal instrumentation, seek assessment from a surgeon who manages adult spinal deformity and revision surgery.
Evidence & further reading
- —Harrington PR. J Bone Joint Surg Am. 1962. Original description of correction and internal fixation by spine instrumentation. PMID 14036052
- —Harrington PR. J Bone Joint Surg Am. 2002. Seminal/historical reprint of the 1962 classic. PMID 11861739
- —Potter BK, et al. J Bone Joint Surg Am. 2004. Prevention and management of iatrogenic flatback deformity. PMID 15292431
- —Louie PK, et al. Global Spine J. 2022. Revision strategies and outcomes after Harrington rod constructs. PMID 33000651
- —Barile F, et al. Musculoskelet Surg. 2025. Systematic review/meta-analysis: long-term outcomes of AIS surgery with Harrington instrumentation. PMID 38806854
- —Joo P, et al. Int J Spine Surg. 2022. Ultralong follow-up: Harrington instrumentation vs uninstrumented fusion. PMID 35878905
- —Brumat P, et al. Healthcare (Basel). 2023. ~11-year follow-up after Harrington rod removal: no significant progression. PMID 37107983
- —Simony A, et al. Scoliosis. 2015. Health-related quality of life 25 years after AIS treatment. PMID 26180541
- —Danielsson AJ, et al. Spine. 2003. Back pain and function 23 years after fusion for AIS. PMID 14501939
- —Götze C, et al. Z Orthop Ihre Grenzgeb. 2002. Long-term quality of life after Harrington distraction instrumentation. PMID 12226771
Frequently Asked Questions
Found this helpful? Share it
Discuss this with Mr Madi
Personalised, consultant-led advice
Every patient is different. The information on this page is a starting point — Mr Madi will tailor any plan to your specific imaging, symptoms and goals.