5. Challenges due to skeletal related events (SREs) and other complications

MM poses a diagnostic dilemma for the orthopedic surgeons because of the frequent skeletal manifestations." It is usually misdiagnosed as an orthopedic disease when in the real sense it is a hematologic disease with orthopedic complications. At advanced stage, it causes multiple lytic bone lesions with severe osteoporosis and pathological fracture. A recent observational study in Nigeria [14] found that about 84.6% of newly diagnosed multiple myeloma patients in Nigeria presented with multiple bone lesions. Pathological fracture constitutes about 42.3% of SREs in the MM patients in the region. It is surprising to note that 84.6% of all newly diagnosed MM are referrals from orthopedic wards [3, 14]. The key players of the bone lesions in multiple myeloma are cytokines namely IL-6 (Interleukin-6), TNF-alpha (tumor necrosis factor), vascular endothelial growth factor (VEGF), platelet derived growth factor (PDGF), and insulin-like growth factor (IGF). These cytokines, especially VEGF and PDGF, have angiogenic effect on the bone marrow microenvironment and this effect favors the growth of myeloma cells in the bone. IL-6, an important osteoclast-activating cytokine, plays an important role in the pathogenesis of osteoporosis in MM [21]. Annibali et al. [22], in their pilot study, described the roles of these cytokines in bone tissue destruction and the effect of zoledronic acid (a bisphosphonate) on their chemical behaviors in MM patients. Other complications such as anemia, hemiplegia, nephropathy, and constipation accounted for 61.5%, 35%, 23%, and 19% of newly diagnosed MM patients in same study. Anemia in MM results from bone marrow invasion by abnormal plasma cells that secret erythropoiesis-suppressive cytokines, and this anemia is usually anemia of chronic disorder [23].
