OPERATIVE CORRECTION OF IDIOPATHIC SCOLIOSIS IN BOYS: A FUNCTIONAL AND RADIOGRAPHIC OUTCOME COMPARISON TO GIRLS

Daniel J. Sucato, MD, MS;
Daniel Hedequist, MD;
Lori A. Karol, MD
Texas Scottish Rite Hospital, Dallas, TX, USA

INTRODUCTION:
The results of spinal arthrodesis and instrumentation for adolescent idiopathic scoliosis (AIS) have been well studied in females. To our knowledge, there is no published data on the outcome of operative correction of AIS in boys. The purpose of our study is to analyze the radiographic and functional outcome following surgical correction of AIS in boys and to compare them with girls.

METHODS:
From 1986 to 1996 all males who had operative correction for AIS at a single institution were identified. A matched group of adolescent girls, who had surgery during the same period, were then selected for comparison. Patients were matched for curve type (King classification) and curve magnitude. Duration of surgery and blood loss was recorded for each patient. Preoperative, postoperative and final follow–up radiographs were measured with the Cobb method in the coronal and sagittal planes and trunk shift was determined. An SRS questionnaire was completed at final follow–up at an average of 6.6 years for boys and 7.4 years for girls.

RESULTS:
There were 52 patients in each group. The curve types for each group were: King I–1, II–19, III–18, IV–3, V–3, double major–5 and thoracolumbar–3. Posterior segmental spinal instrumentation and fusion with iliac crest graft was used in all curve types except the thoracolumbar curves in which single TSRH anterior rod instrumentation and rib graft was used. Since the groups were matched, there was no difference with respect to curve type, preoperative curve (60 degrees), trunk shift (18mm to right) or sagittal profile. Boys were slightly older at presentation (13.9 vs 12.2 yrs) and at the time of surgery (15.9 vs 13.9 yrs). There was no difference in the preoperative flexibility of the primary curve between boys (37.5%) and girls (38.9%). The duration of surgery was significantly longer (292 vs 263 min) and blood loss was greater (1148 vs 944 cc) in boys. The postoperative curve correction (50.8 vs 61.0%) and final curve correction (41.8 vs 52.3%) was less in boys resulting in larger final curve magnitudes (36.8 vs 28.4 degrees).(p< .05) However, coronal and sagittal trunk balance was similar between groups. The incidence of complications (pseudoarthrosis, infection, hardware failure, extension of fusion levels) was the same although 3 girls and only 1 boy had hardware removal because of pain. At final follow–up, there was no difference in the SRS outcome questionnaire with respect to pain, self image, or satisfaction, however, there was a trend toward better function in girls.

CONCLUSIONS:
When planning operative correction of idiopathic scoliosis in boys, longer surgical times with greater blood loss and less correction of the curve should be expected when compared to girls. However, balance in the coronal and sagittal planes should be achieved, and complication rates and functional outcomes should be similar.