The conclusions of this retrospective case series aren't terribly surprising, but raise some important considerations for front line physicians.
Source: Goodbody CM, Sankar WN, and Flynn JM. Presentation of adolescent idiopathic scoliosis: the bigger the kid, the bigger the curve. J Pediatr Orthop. 2017;37(1):41–46. doi:10.1097/BPO.0000000000000580. See AAP Grand Rounds commentary by Dr. William Hennrikus (subscription required).
These researchers looked at adolescents referred to a tertiary center for scoliosis concerns, and found that overweight and obese adolescents presented with significantly larger spinal curves at a higher degree of skeletal maturity, meaning their conditions would be less amenable to non-surgical intervention.
The authors point out that physical exam techniques, such as Adam's forward bend test, are technically more difficult in obese patients, making it more difficult to screen this population for scoliosis. They suggest more liberal use of a scoliometer, or perhaps screening radiographs, in this population.
I'd like to highlight 2 study design issues that can limit the utility of the information. First, note that the study was performed at a tertiary care center on patients referred specifically for scoliosis concerns. That's a very different group of patients than what a primary care provider sees, where for the most part scoliosis is uncovered via routine screening of a presumably health population. That's called spectrum bias, most often seen when a study originates in a tertiary center and therefore usually is focused on patients with more severe forms of a disease.
Second, I was puzzled to see that the investigators chose to divide their patient groups into 3 body mass index (BMI) categories: normal weight, overweight, and obese patients. By doing this, they are taking a continuous variable (BMI) and converting it to an categorical variable. This can sometimes result in lost information that might be informative, and I wish the authors had presented their rationale for this approach. This is a nuanced point, I realize, but little things like this always give me pause about the reliability of a scientific report.
Until we have better prospective studies on screening in primary care, front line providers should have a higher degree of vigilance for scoliosis in obese adolescents, and consider more focused screening methods.
