The natural history of spondylolysis and spondylolisthesis.

Spondylolysis and spondylolisthesis: a narrative review of etiology, diagnosis, and conservative management

“…[4][5][6] This lytic defect is almost always at the L5 level. [5][6][7] Caucasians are affected about 3 times more frequently than African Americans. 6 Males are twice as likely as females to be affected.…”

“…Fathers were affected 32% of the time, mothers 17%, and male siblings 34%. 5 In another study of first degree relatives of individuals with spondylolysis, it was found that defects were also present in 16% of parents, 14% of siblings, and 16% of children. 8 Studies of Eskimo populations, which could be considered as one large genetic pool due to their isolation, showed spondylolysis prevalence between 17-54%.…”

“…When the subjects were followed to adulthood, the incidence rose to 6%. 4,5 Therefore, twothirds of adults with spondylolysis developed it prior to reaching school age. The remaining third acquired the defect at some point during childhood or adolescence.…”

“…The remaining onethird that develop a pars defect during adolescence or early adulthood have symptoms during and around the time of its development. 5 In a study of inheritance and spondylolysis, only 4% of relatives of people with spondylolysis admitted to having any symptoms, but 19% were found to have a defect. 8 Thus, the majority of affected individuals are asymptomatic, displaying clinically inactive spondylolysis.…”

“…5 The question of whether spondylolisthesis is progressive in nature has been studied extensively and the conclusions tend to be very similar. Despite varying follow-up periods among the different studies, there is a very low degree of progressive slip.…”