Multiple sites of bone puncture are necessary to confirm the diagnosis of retrovascularization. Retrovascularization is a bone marrow failure disease that requires a bone marrow biopsy to detect the degree of bone marrow activity. A single bone marrow biopsy is not enough to confirm the diagnosis. Multiple bone marrow biopsies at different levels are needed to confirm the presence of a remyelination or to determine the severity of the disease, thus preventing “sampling error”. The bone marrow is used to extract hematopoietic stem cells from the bone marrow, and the activity of the bone marrow can be affected by a variety of factors, and if the bone marrow is less active or if the bone marrow is fibrotic, the site of the bone puncture needs to be changed, so it is necessary to perform bone punctures several times and at different sites to confirm the diagnosis of remittent fever.