title: Patterns of Rib Growth in the Human Child.
abstract: BACKGROUND
  Whereas there is substantial information on the changes of the rib cage during childhood and asymmetry of the thorax in children with scoliosis, there are virtually no normative data on the growth of individual ribs throughout childhood.
  
  
  METHODS
  The Hamann-Todd (HT) Osteological Collection provided the bones of 32 human specimens aged 1-18 years. A total of 6,226 individual photographs of all vertebral bodies and ribs were obtained from these specimens. Quantitative measurements were taken with image analysis software and the results of 2 of the measurements, the outer costal length (OCL) and the base diameter (BD), are presented here.
  
  
  RESULTS
  With the exception of the ribs at T12, both the OCL and BD showed linear, statistically significant growth with age for all ribs. The relationship of OCL and BD to each other within each rib was obtained by multiplying and dividing these 2 measurements. The BD × OCL product indicates that the ribs grow through coupled symmetry, by which ribs in the upper and lower thorax start at the same size and grow at the same rate within the pair; ribs 1 and 12, 2 and 11, and 3 and 10. Each rib pair grows at a significantly different rate from all other pairs. Measurements of BD and OCL from a specimen with scoliosis from the collection compared with these normative values were greatly different. The principle that ribs resemble a known geometric form, called the logarithmic spiral, is introduced.
  
  
  CONCLUSIONS
  This article is 1 of the first studies of the change in length and shape of normal ribs in an osteology collection of a wide age range of pediatric specimens. The data provide a framework for determining the difference between ribs from normal children and those with scoliosis.
authors.affiliation: Division of Orthopaedics, University of Missouri Kansas City, University of Kansas, Children's Mercy Hospital, 2401 Gillham Road, Kansas City, MO 64108, USA. Electronic address: rmschwend@cmh.edu.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Schwend
authors.affiliation: K2M Inc., 751 Miller Drive SE, Leesburg, VA 20175, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Schmidt
authors.affiliation: K2M Inc., 751 Miller Drive SE, Leesburg, VA 20175, USA.
authors.forename: Julie L
authors.initials: JL
authors.lastname: Reigrut
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Florida College of Medicine, University of Florida Orthopaedics and Sports Medicine Institute, FL 32611-2727, USA.
authors.forename: Laurel C
authors.initials: LC
authors.lastname: Blakemore
authors.affiliation: University of California, 6190 Cornerstone CT, Ste 212, San Diego, San Diego, CA 92121, USA.
authors.forename: Behrooz A
authors.initials: BA
authors.lastname: Akbarnia
keywords: Chest; Growth; Rib; Scoliosis; Thorax