Abstract
Nachemson (1996), drawing upon the theses of Sahlstrand (1977) and Lidström (1988), articulated the view there are more girls than boys with progressive AIS for the following reason. The maturation of postural mechanisms in the nervous system is complete about the same time in boys and girls. Girls enter their skeletal adolescent growth spurt with immature postural mechanisms – so that if they have a predisposition to develop a scoliosis curve, the spine deforms. In contrast boys enter their adolescent growth spurt with mature postural mechanisms so that they are protected from developing a scoliosis curve. There is evidence that postural sway improves with age in boys and girls until about 10 years of age after which it is similar between the sexes (Hirashawa 1973, Odenrick and Sandstedt 1984) findings which need further evaluation. We term Nachemson’s concept the neuro-ossesous timing of maturation (NOTOM) hypothesis. It may have an evolutionary basis through natural selection towards sexual and skeletal development during adolescence being earlier in girls and later in boys.
The NOTOM hypothesis suggests a treatment to prevent progression of late-juvenile idiopathic scoliosis, early-AIS, and some secondary scolioses based on delaying the onset of puberty used therapeutically in girls with idiopathic precocious puberty (IPP, Grumbach and Styne 1998). The proposal is to administer a gonadorelin analogue which in the pituitary down-regulates the receptors to hypothalamic gonadotropin-releasing hormone (GnRH) causing a fall in both luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which in turn causes a fall in oestrogens and androgens, and thereby delays or stops menarche and slows bone growth – as in girls and boys with IPP (Galluzzi et al 1998). Expert scrutiny of this therapeutic proposal is currently in progress.
Abstracts prepared by Mr J. Dorgan. Correspondence should be addressed to him at the Royal Liverpool Children’s Hospital, Alder Hey, Eaton Road, Liverpool L12 2AP, UK
President’s Lecture: Natural history and management of Congenital Kyphosis and Kyphoscoliosis M.J. McMaster, Edinburgh, Scotland, UK
Greg Houghton Lecture: Idiopathic Scoliosis – Alternatives to traditional surgery R.R. Betz, Philadelphia, USA
Instructional Lecture:New thoughts on the treatment of paralytic scoliosis R.R. Betz, Philadelphia, USA
Keynote Lectures: Idiopathic Scoliosis – How to manage the patient R.A. Dickson, Leeds, UK
Concave or convex approach for Kyphoscoliosis J. Dubousset, Paris, France Surgery or bracing for moderate AIS. How long term follow-up studies change your perspective A. Nachemson, Göteborg, Sweden
