Progression of the scoliotic curve in adolescent girls with moderate idiopathic scoliosis by more than 6 degrees can be predicted from 4 parameters.
Patient population: adolescent girls ages 10-15 with an initial curve 25-35 degrees
Endpoints are either skeletal maturity or increase in curvature by 6 degrees or more
Parameters:
(1) Risser's sign
(2) apical vertebra
(3) chronological age in years
(4) balance
Parameter |
Finding |
Points |
Risser's sign |
2 to 5 |
0 |
|
0 or 1 |
1 |
apical vertebra |
12th thoracic or 1st lumbar |
0 |
|
8, 10 or 11 thoracic |
1 |
chronological age in years |
> 13 years |
0 |
|
<= 13 years |
1 |
imbalance |
<= 10 mm to either side |
0 |
|
> 10 mm to either side |
1 |
where:
• Risser's sign refers to the chronological progression in the ossification of the iliac crest apophysis. Grade 0 indicates an age < 13 years, Grade 1 at 13 years, Grade 2 at 14 years, Grade 3 at 15 years, Grade 4 at 16 years and Grade 5 at 17-18 years.
• Imbalance is measured as the perpendicular distance (towards the midline) from a plumb line dropped from a spinous process of the 7th cervical vertebra to the crena ani (internatal cleft).
logit (P) =
= (-3.61) + (2.33 * (points for Risser sign)) + (2.35 * (points for apex)) + (0.80 * (points for chronological age)) - (0.85 * (points for imbalance))
probability of progression in scoliotic curve more than 6 degrees =
= EXP (logit(P)) / (1 + (EXP(logit(P)))
Specialty: Surgery, orthopedic