Characterization of the scoliosis that develops after pinealectomy in the chicken and comparison with adolescent idiopathic scoliosis in humans

Study Design. The characteristics of the scoliosis that develops after pinealectomy in young chickens were determined from weekly posteroanterior radiographs. These data were compared with similar data collected from human patients with adolescent idiopathic scoliosis. Objectives. To characterize the scoliosis produced in young chickens after pinealectomy and to compare these characteristics with those seen in human patients with adolescent idiopathic scoliosis. Summary of Background Data. Although it has been recognized that pinealectomy produces scoliosis in chickens, the characteristics of these curves have never been well described other than by simple visual descriptions. Methods. The characteristics of the scoliosis produced in chickens after pinealectomy done 3 days after hatching were measured from radiographs taken at weekly intervals. These characteristics were compared with similar data collected from human patients with adolescent idiopathic scoliosis. Results. Similarities included development of single and double curves, degree of curvature, stability of the curve, numbers of vertebrae involved, direction of rotation, and progression characteristics. Differences included wedge vertebrae in the chickens, in conjunction with curve development and increased variability in vertebrae involved. Conclusions. There are many similarities in the development of scoliosis in young chickens after pinealectomy and in children with adolescent idiopathic scoliosis. The few differences might be related to the different biomechanical properties associated with the spine in the two species.