Background: Many studies have demonstrated that orthotic treatment
is effective for the prevention of curve progression in patients with
adolescent idiopathic scoliosis. However, the effect of being overweight on
the outcome of orthotic treatment has not been reported. The purpose of the
present study was to determine whether orthotic treatment of adolescent
idiopathic scoliosis is less successful for patients who are overweight than
it is for those who are not overweight.
Methods: A ten-year multicenter retrospective review of patients in
whom adolescent idiopathic scoliosis had been treated with a Boston or a
custom-molded thoracolumbosacral orthosis was performed. The inclusion
criteria were no previous treatment, skeletal immaturity (a Risser sign of 0,
1, or 2), a curve of 25° to 40° at the time of orthotic initiation,
and follow-up to skeletal maturity. Patients were divided into two groups
according to body habitus, with overweight patients defined as those with a
body mass index in the eighty-fifth percentile or greater. Curve progression
was compared between the two groups. Successful orthotic treatment was defined
as no more than a 5° increase in the primary curve from the start of
orthotic wear to skeletal maturity. Absolute curve progression to 45° or
greater also was considered to be an adverse outcome.
Results: Two hundred and seventy-six consecutive patients from two
institutions were analyzed, and thirty-one patients were considered to be
overweight. The mean curve progression was 9.6° ± 7.3° for the
patients who were overweight, compared with 3.6° ± 9.4° for
those who were not overweight (p < 0.01). Overweight patients were 3.1
times more likely to have an unsuccessful result than those who were not
overweight. Curve progression to 45° or greater occurred in fourteen (45%)
of the thirty-one patients who were overweight, compared with sixty-nine (28%)
of the 245 patients who were not overweight.
Conclusions: The results of the present study suggest that
overweight patients with adolescent idiopathic scoliosis will have greater
curve progression and less successful results following orthotic treatment
than those who are not overweight. The ability of an orthosis to transmit
corrective forces to the spine through the ribs and soft tissue may be
compromised in overweight patients. This factor should be taken into
consideration when making treatment decisions. Additional study is warranted
to determine a threshold effect.
Level of Evidence: Therapeutic Level III. See
Instructions to Authors for a complete description of levels of evidence.