C. Tschauner et al., MATURATION CURVE OF THE SONOGRAPHIC ALPHA -ANGLE ACCORDING TO GRAPH WITHIN THE 1ST YEAR OF LIFE, Zeitschrift fur Orthopadie und Ihre Grenzgebiete, 132(6), 1994, pp. 502-504
In addition to Graf's classification into different hip-types a matura
tion-curve of the sonographic alpha-angle was established in order to
optimize the differentiation between mature hip joints and those ones
which need follow-up and those ones which need treatment at any time w
ithin the first year of life. The results obtained are confirming our
present knowledge about the spontaneous maturation of physiolo0gically
immature hip joints: The mean-value of the alpha-angle crosses the 60
degrees-borderline at about the age of two months, then reaches an ab
out 64 degrees-level at about four months. This 64-degrees-level is mo
re or less unchanged up the end of the first year of life.