Prominent sub-endplate densities at multiple contiguous levels produce an alternating dense-lucent-dense appearance simulating the transverse bands of rugby sweater (rugger-jersey spine). This pattern is distinctive for hyperparathyroidism (like this case has secondary hyperparathyroidism due to chronic renal failure) though, there is similarity to some cases of osteopetrosis.

Reference: Youchum and Rowe’s: Essentials of Skeletal Radiology, 2005
Credit: Dr Ahmed Haroun