Moiré topography--a method for school screening of scoliosis.

The moiré method is tested in school screening of scoliosis. Moiré topography registers a three-dimensional description of the shape of the back. In the straight spine, the moiré shadow pattern is equal on both halves of the back. In structural scoliosis, the moiré pattern differs more with the increasing deformity of the spine. This asymmetry is mainly caused by the rotational component of the scoliosis. These shadow patterns consist of contourlines, which can be compared with those on a relief map. By photographing the moiré shadow lines, the status of the back is documented. In 212 cases, the moiré findings are compared with radiograph observations. A statistically significant correlation is found between the moiré asymmetry (rotational component) and the radiograph findings (lateral deviation according to Cobb). The moiré method seems to fulfil the criteria for a screening method--diagnosis of even minor curves, small risk for false negative findings, simple to handle and can document the back in many children in a short time.