According to the CDC, childhood obesity in the United States —
which is often defined as at or above the 95th percentile in body mass index
(BMI) — has more than tripled in the past 30 years. Among children ages 6
to 11 years, the prevalence of obesity increased from 6.5% in 1980 to 19.6% in
2008. Among adolescents ages 12 to 19 years, the prevalence of obesity
increased from 5% to 18.1% during that same time period. The consequences of
these staggering statistics range from increased risk of cardiovascular disease
to type-2 diabetes. Orthopedically, increased pain in the knee joints and bones
are associated with childhood obesity.
|© 2010 iStockphoto/Ljupco
Increased orthopedic risks
Based on growth charts of boys and fgirls, children are classified
according to BMI percentiles — healthy weight (55 to 84); overweight (85
to 94); obese (95 to 98) and severely obese (99), according to Sandra Smith,
MS, PT, director of rehabilitation services at Shriners Hospitals for Children,
Obese children and adolescents are at an increased risk of biomechanical
joint problems as well as more serious orthopedic conditions according to Jack
A. Yanovski, MD, PhD, head of the unit on growth and obesity at the National
Institute of Child Health and Human Development.
“There appears to be increased risks from childhood-onset obesity
for two serious orthopedic conditions — Blount’s disease and slipped
capital femoral epiphysiodesis, (SCFE),” Yanovski told O&P Business
Blount’s disease is a growth disorder of the tibia that causes the
lower leg to angle inward, resembling a bow leg. SCFE is a separation of the
ball of the hip joint from the femur at the growth plate of the bone, Yanovski
explained. Treatment options for Blount’s disease include orthotic braces,
if it is diagnosed before the age of 3 years. If the child is older, surgery is
usually required. SCFE requires surgery in order to prevent further slipping of
the femoral head, according to the NIH.
“We studied a large cohort of obese and lean children in 2006 and
found cases of SCFE and Blount’s disease only among the obese group,”
Yanovski said. “Others have also documented an increased likelihood for
reporting lower extremity and/or back pain among obese compared to lean
Yanovski and his co-authors studied 355 children and adolescents —
198 girls and 157 boys — between 1996 and 2004. The study also reported a
greater chance of observing fractures in obese children. These fractures were
usually located in the upper extremity.
“Reported fractures, musculoskeletal discomfort, impaired mobility
and lower extremity malalignment are more prevalent in overweight than
non-overweight children and adolescents,” researchers stated in the study.
“Because they affect the likelihood that children will engage in physical
activity, orthopedic difficulties may be may be part of the cycle that
perpetuates the accumulation of excess weight in children.”
Major concern for the disabled
For amputees, specifically lower extremity amputees, sudden or continual
weight gain can increase the pressure at the residual limb, causing pain in the
socket area. Pain at the residual limb site will likely lower the
patient’s motivation to exercise. Without daily exercise, a patient will
gain weight, increasing the pressure on the residual limb. The socket fit will
suffer, the pain will continue and the child will stop being active, according
to Robin Crandall, MD, Association of Children’s Prosthetic Orthotic
Clinics immediate past-president and director of limb deficiency service at
Shriners Hospitals for Children, Twin Cities.
“Obesity among young amputees is a major concern,” Crandall
explained. “It is difficult to make a good prosthesis for a child who is
overweight because it is hard to tell if the socket is fitting properly,
especially for an above-knee prosthesis.”
How can an obese adolescent amputee stay active when an ill-fitting
prosthesis causes exercise to be painful? One way to break this cycle is to
aggressively attack the problem at an early age. The earlier the problem is
recognized, the sooner the practitioner can discuss possible treatment options.
“When the patient is young, we try to have them meet with
dieticians early on in the process,” Crandall said. “We’ll go
over the issues with the family, but the key is to recognize at an early age
that there is a problem. Sometimes you can recognize those problems as young as
7 or 8 years old as they start to exceed statistical norms.”
Crandall has experienced situations where family members did not
recognize their child’s weight problem because they had weight issues of
“Generally, family members have similar eating habits and they are
just eating too many calories,” he said. “They need to be better
aware of their calorie intake. Sometimes education can go a long way. Sometimes
it does not help at all. It is a real dilemma.”
According to Smith, even a small weight gain can have a negative impact
on a disabled child’s function, as well as the development of future
“Disability compounds the risk of weight gain in these children as
they have even less options to play and be active,” she said.
Develop physical activities
In Yanovski’s study, 21.4% of the participants considered
overweight, complained of knee joint pain. This was the most common
self-reported joint complaint in the study among those questioned. Overweight
children who feel knee discomfort should consult with their physician before
developing a physical activity gameplan.
“At our hospital, a patient below or above healthy weight BMI
automatically triggers a consult with the nutritionist,” Smith explained.
“The entire team agrees that the patient must be motivated and the diet
and exercise component needs to be a family project in order to be
|Jack A. Yanovski|
According to Smith, exercise prescription should be based on which BMI
category the patient falls. For young overweight individuals who feel lower
extremity discomfort, non-weight bearing activities such as swimming may be
preferable. Stair steppers, cycling and/or general mat exercises also limit
knee joint pressure, Smith said.
“I believe any physical activity that is age-appropriate and fun,
which also includes peers or the entire family, is the best approach,”
Smith said. — by Anthony Calabro
For more information:
- Amputee Coalition of America. ACA/national limb loss information
center fact sheet: Overcoming childhood obesity. Available at:
www.amputee-coalition.org/fact_sheets. Accessed July 1, 2010.
- Taylor ED, Theim KR, Mirch MC, et al. Orthopedic complications of
overweight in children and adolescents. Pediatrics.
The child and adolescent obesity epidemic has certainly been brought to
the attention of many facets of the research industry over the recent years.
The short- and long-term physical ramifications of carrying excess weight at
such a young developmental age are still the subject of many investigations.
Nevertheless, the value of understanding the biomechanical impact of
carrying excess weight on the developing skeleton is often underestimated. In
addition to the pediatric conditions commonly associated with obesity in the
literature, such as SCFE or Blount’s Disease, there is now clinical
evidence that lower extremity malalignment, joint pains and fracture risk can
all be increased in severity by obesity in childhood. As these overweight youth
continue to develop into active adulthood, weight-bearing joints, including the
hip, knee and foot/ankle, will most certainly be at higher risk for development
of potentially disabling conditions.
It is my hope that clinical researchers and practitioners continue to
acknowledge the impact of the musculoskeletal complications of obesity in
children and adolescents and work together to develop improved treatment
algorithms and more importantly, methods for prevention.
— Erica Dianne Taylor, MD
physician, Department of Orthopaedic Surgery, University of Virginia