We had a recent inquiry about the commonly accepted threshold of 45º – 50º for scoliosis surgery and our thoughts on the subject. It’s a topic we could discuss at length, but here’s a basic answer and some additional information to contemplate.
From what we can ascertain, the 45º – 50º Cobb angle is an arbitrary number surgeons assign based on an estimation of what may occur in younger patients. Estimations are determined based on a variety of factors; these contributing factors are stage of growth, current Cobb angle(s) and use of Lonstein and Carlson’s progression factor(1). The purpose of surgery is generally to try and stop progression, reduce curvature (via instrumentation and spinal fusion) and ultimately improve appearance for patients with adolescent idiopathic scoliosis (AIS).
From what we can surmise, scoliosis surgery at these levels has become a common practice which has become accepted as the norm. Evidence to support the practice of surgery at 45º – 50º does not exist. According to Westrick & Ward (2), “There are no long-term, prospective controlled studies that exist to support the hypothesis that surgical intervention for AIS is superior to natural history.”
Furthermore, there are few long-term follow-up studies on surgery for adolescent idiopathic scoliosis. According to the conclusions of Mueller and Gluch (3) regarding surgeries with Cotrel – Dubousset (CD) instrumentation,“Retrospectively, we documented for the first time a very high revision rate in patients with AIS and treated by CD instrumentation. Nearly half of the instrumentation had to be removed due to late infection and LOSP [late operative site pain].”
Finally, patients and parents of adolescents contemplating surgery should consider the natural history studies (4,5,6). These fifty-year studies did not find evidence to link untreated LIS (late-onset adolescent idiopathic scoliosis) with increased rates of mortality in general, or from cardiac or pulmonary conditions potentially related to the curvature.” These studies appear to be disregarded by some physicians.
We instruct patients wanting to learn to halt or reduce progression non-surgically using Schroth Best Practice® methods. Many individuals who participate in our program are adolescents or adults with Cobb angles in the 40ºs, 50ºs, 60ºs, 70ºs, 80ºs and higher. Adults living a full life without instrumentation have found that Schroth method management addresses pain, progression and pulmonary function (7). Adolescent and adult patients using Schroth method exercises can and do experience improvements in postural appearance as well. Adolescents have experienced Cobb angle reduction (even when accounting for the 5º margin of error when assessing Cobb angle).
Now that an effective alternative is available for those who are willing to put in the time and effort to manage scoliosis, we encourage patients to try these methods prior to rushing into surgery. Our patients are glad that they have ultimately avoided surgery and its risks – known (8) and unknown. Surgery should be used in only the most extreme cases (9).
It is important to note that conservative interventions, early, as opposed to ‘doing nothing’ is very much to the adolescent patient’s advantage. Schroth Best Practice® offers a proactive way to control scoliosis, even when scoliosis has already progressed. The application of conservative principles means that surgery need never become part of the scoliosis equation.
Additional recommended reading is the book by Dr. Martha C. Hawes: Scoliosis and the Human Spine: A critical review of clinical approaches to the treatment of spinal deformities in the United States and a proposal for change. This informative text is available from the National Scoliosis Foundation.
Do not take our word for it. Draw your own conclusions.
- Lonstein JE, Carlson JM . The prediction of curve progression in untreated idiopathic scoliosis during growth. J Bone Joint Surg AM. 1984 sep; 66(7):1061-71.
- Westrick ER, Ward WT: Adolescent idiopathic scoliosis: 5-year to 20-year evidence-based surgical results. J Pediatr Orthop. 2011 Jan-Feb;31(1 Suppl):S61-8.
- Mueller FJ, Gluch H: Cotrel-dubousset instrumentation for the correction of adolescent idiopathic scoliosis. Long-term results with an unexpected high revision rate. Scoliosis. 2012 Jun 18;7(1):13. doi: 10.1186/1748-7161-7-13
- Weinstein SL, Dolan LA, Spratt KF, Peterson KK, Spoonamore MJ, Ponseti IV. Health and function of patients with untreated idiopathic scoliosis: A 50 Year Natural History Study. JAMA 2003;289(5):559–567.
- Asher MA, Burton DC. Adolescent idiopathic scoliosis: natural history and long-term treatment effects. Scoliosis. 2006;1(1):2
- Danielsson, AJ. Natural history of adolescent idiopathic scoliosis: a tool for guidance in decision of surgery of curves above 50°. J Child Orthop. 2013 Feb;7(1):37-41.
- Weiss, HR. The Effect of an Exercise Program on Vital Capacity and Rib Mobility in Patients with Idiopathic Scoliosis. Spine. 1991 Jan; 16(1):88-93.
- Hawes M: Impact of spine surgery on signs and symptoms of spinal deformity. Pediatric Rehabilitation 2006;9(4):318-39.
- Weiss HR, Moramarco M, Moramarco K: Risks and long-term complications of adolescent idiopathic scoliosis surgery vs. non-surgical and natural history outcomes. Hard Tissue 2013, 2(3):27.
