Is scoliosis reversible? In Vivo observations of reversible morphological changes in the production of scoliosis in mice.

Without altering the osseous or muscular structure of Balb/c mice, the author was able to produce and reverse scoliotic deformation during the period of growth and development. Two series of investigations were performed, each involving extensive histological, morphological, and roentgenographic documentation: (1) control mice were maintained and sacrificed for examination at designated intervals and (2) experimental mice, whose right hind- and forequarters were surgically bound to allow only unilateral motion, were sacrificed and examined at corresponding intervals. The unilateral restriction of experimental animals were released at scheduled 5-day intervals during the 45-day period. These mice were then examined for restoration of normal histological and roentgenographic appearance. Changes in vertebral morphology were apparent after 35 days of restriction. Release at this time allowed restoration of normal vetebral appearance with the exception of a slight, measurable reduction in size. The results indicate that (1) limited activity retarded growth and (2) unilateral restriction caused geometrical variations (structural and morphological). Both of these alterations proved reversible once normal function (reciprocal motion) was restored to the murine spine.