OBJECTIVE: to determine the variance of Cobb angle measurements in adolescent idiopathic scoliosis with two types of goniometer: a fixed and an articulated one, both were previously calibrated. METHODS: eight digital radiographs of patients with adolescent idiopathic scoliosis, with severe primary curve (over 30 degrees) were selected. Each one of the eight scoliosis images selected was processed 26 times and printed in a radiographic film, adding up 228 images. A total of 17 curves, primary and secondary, were measured by six orthopedic surgeons experienced in spine surgery. Each examiner received a pencil, eight scoliosis images and the same goniometer. The six orthopedists measured each curve in six different occasions, three times with the articulated and three with the fixed goniometer. The cranial and caudal vertebras to be measured were pre-established, so the choose of wrong levels could be avoided. The statistic analysis was done with "parametric tests" to determine the variance of the measures between different goniometer and the same examiner. RESULTS: among the 17 evaluated (A a Q), only the curve M showed a statistically significant difference between the angles measured by the two goniometers (mean of 33,3+9,1 degrees) with the articulated and (27,9+4,2 degrees) with the fixed one p=0,009. CONCLUSION: No significant differences were found between values obtained with goniometer articulated with the goniometer fixed in 16 of the 17 curves evaluated in this sample. The differences observed between the goniometer on the curve "M" does not appear to be related to the equipment used.
Scoliosis; Scoliosis; Adolescent
