PTH and osteoporosis: However, he showed the persistence of a severe osteoporosis (in presence of a post-operative normocalcemic status and a correct PTH level) at two (lumbar spine T and Z-scores −3.9; femoral neck T-score −2.4 and Z-score −2.3; total femoral T and Z-scores −2.1) and three (lumbar spine T and Z-scores −3.5; femoral neck T-score −2.4 and Z-score −2.3; total femoral T and Z-scores −2.1) years after parathyroid surgery.