This is a case that demonstrates multiple vertebral pathologies in a single image.

The primary pathology of this patient is her renal disease, while her advanced age and bilateral L5 sacralization play a contributory role.

Flexibility at the lumbosacral junction is reduced due to sacralization of L5, and this allowed L4 vertebra to slip over L5 when the patient fell on the floor.

Advanced age itself causes osteoporosis in women, which is aggravated by her chronic kidney disease (CKD). That is how a simple slip on the floor (so simple that the patient and her family did not feel the need to seek medical advice at that time) resulted in pars fracture (L4) as well as compression fracture (L5).