“…36 It is also common to see elongated pedicles, especially in patients with the more severe types of OI, such as type III (Figure 44.12). 17,[37][38][39] The incidence of spondylolysis in the normal population has been reported to be 4.4% in the pediatric population, increasing to about 6% by adulthood. 34,35,[40][41][42][43] Spondylolisthesis is described and defined as a forward slippage of the vertebral body onto the vertebral body …”