CT measured normative cartilage growth in children requiring costochondral grafting

Careful operative timing is required for children undergoing microtia repair using autologous costochondral grafting. This operation is performed as early as age 6 in efforts to treat children before school matriculation while allowing for sufficient rib growth. There remains a paucity of data regarding cartilaginous growth of the ribs and synchondrosis routinely harvested during microtia repair. This study employs CT imaging to generate normative costochondral growth characteristics in children.

A population-based study was performed.

Tertiary care children's hospital.

Chest CTs were reviewed in 360 children ages 3 to 20 years. Measurements included: length of ribs 6, 7, and 8 and the height and width of the synchondrosis between ribs 6 and 7. Growth charts are presented for gender and laterality.

At age 6: ribs 6, 7, and 8 measure 5.96 ± 0.69, 7.79 ± 0.84, and 6.33 ± 1.01 cm, respectively. In adulthood the mean length of ribs 6, 7, and 8 are 8.29 ± 1.00, 11.10 ± 1.19, and 8.95 ± 1.99 cm, respectively. The vertical height of the synchondrosis at years 6 and 20 are 2.42 ± 0.39 and 3.59 ± 0.53 cm, respectively. Ribs 6, 7, and 8 as well as the synchondrosis grow in a nearly linear fashion.

Cartilaginous growth of ribs 6 to 8 during early childhood is nearly linear. Synchondrosis height approaches adult auricle width at 8 years. Rib size is consistently larger in males and on the left side. These data are useful for the pediatric otolaryngologist and facial plastics and reconstructive surgeon performing microtia surgery.