Background: The outcomes following surgical treatment of adolescent
idiopathic scoliosis have traditionally been assessed on the basis of
radiographic parameters and, more recently, functional outcome measures.
However, we know of no published studies in which radiographic and functional
outcomes following surgery were compared between male and female patients.
Methods: Fifty-two male patients who had had surgery for adolescent
idiopathic scoliosis were compared retrospectively with two groups of female
patients: a random sample of 130 female patients who had had surgical
treatment for adolescent idiopathic scoliosis during the same time period and
a subgroup of fifty-two of these female patients who had been matched to the
male patients with regard to curve type and magnitude. Radiographic parameters
were compared between the male and female patients, and the Scoliosis Research
Society outcome questionnaire was used to compare functional results between
the male patients and the matched female group.
Results: Compared with the random sample of female patients, the
male patients were older at the time of presentation (average [and standard
deviation], 13.9 ± 1.9 compared with 12.8 ± 1.4 years) and at
the time of surgery (average, 15.9 ± 2.0 compared with 14.2 ±
1.4 years) (p < 0.05). The male and female patients presented with primary
coronal curves of similar magnitudes (average, 48° ± 19°
compared with 47° ± 13°), but the male patients had larger
curves at the time of surgery (average, 62° ± 11° compared with
56° ± 10°) with greater coronal plane imbalance. Compared with
the subset of female patients matched for curve type and magnitude, the male
patients had, on average, a longer surgical time (263 ± 61 compared
with 202 ± 40 minutes), greater intraoperative blood loss (1148
± 660 compared with 944 ± 408 mL), and less curve correction in
the coronal plane (from 62° ± 11° to 31° ± 11°
compared with from 59° ± 10° to 23° ± 9°) (p
< 0.05). The loss of coronal plane correction, the final coronal balance,
all measured sagittal plane parameters, and the prevalence of complications
were the same in these two groups. With regard to functional outcome, the
scores were similar with the exception that the male patients had lower scores
in the category of "function from back condition" when compared
with the matched female patients (3.8 ± 0.2 compared with 4.3 ±
0.3 points) (p < 0.05).
Conclusions: Adolescent idiopathic scoliosis is identified at a
later age in male patients than in female patients with similar curve types.
The curve magnitudes in the male patients are greater at the time of surgery.
When surgeons are planning operative correction of adolescent idiopathic
scoliosis in male patients, they should expect longer operative time, greater
blood loss, and less coronal plane correction of the primary curve. However,
balance in the coronal and sagittal planes should be achieved and complication
rates and functional outcomes can be expected to be similar to those in female
Level of Evidence: Prognostic study, Level II-1
(retrospective study). See Instructions to Authors for a complete description
of levels of evidence.