Metabolic/endocrine
Paget’s disease is asymptomatic in 70-90% of cases but it can affect the axial skeleton and cause back and pelvic pain. Enlargement of vertebral bodies can cause compression of nerve roots, the cord, and the cauda equina. Pagetic sarcoma is rare, but any prolonged change in pain in a Paget’s disease patient demands investigation.64Hyperparathyroidism and renal osteodystrophy can cause pain due to spinal involvement, pathological fractures, and development of a ”brown tumor”.14 Osteomalacia causes generalized skeletal pain, especially of the back and pelvis
65 Ochronosis causes disc calcifications and herniation with generalized and advanced arthritic changes.66