Advancement in the Treatment of Osteoporosis and the Effects on Bone Healing

Abstract

Osteoporosis (OP) is a major global health concern, with aging being one of the most important risk factors. Osteoarthritis (OA) is also an age-related disorder. Patients with OP and/or OA may be treated surgically for fractures or when their quality of life is impaired. Poor bone quality due to OP can seriously complicate the stability of a bone fixation construct and/or surgical fracture treatment. This review summarizes the current knowledge on the pathophysiology of normal and osteoporotic bone healing, the effect of a bone fracture on bone turnover markers, the diagnosis of a low bone mineral density (BMD) before surgical intervention, and the effect of available anti-osteoporosis treatment. Interventions that improve bone health may enhance the probability of favorable surgical outcomes. Fracture healing and the treatment of atypical femoral fractures are also discussed.

Keywords: bone-related surgeries; osteoporosis.

Figure 1

Bone healing in healthy bone and after atypical femoral fracture (AFF). There are four stages that describe the bone healing process: (1) hematoma formation with inflammation, (2) fibrocartilaginous callus formation, (3) bony callus formation, and (4) bone remodeling. During the first stage, a formed hematoma is composed of bone marrow and peripheral and intramedullary blood cells. The inflammatory cells (macrophages, neutrophils, lymphocytes, monocytes) and degranulating platelets infiltrate the hematoma between the fracture ends, causing acute inflammation and releasing cytokines and growth factors to stimulate the fracture healing process. During the fibrocartilaginous callus formation (stage 2), the soft callus is developed. The soft callus is a semi-rigid tissue able to provide mechanical support to the fracture and act as a template for the bony callus. The cartilaginous matrix is produced until the whole fibrinous/granulation tissue is replaced by cartilage. Angiogenic factors amplify the process of fracture healing vascularization. Further progress of bone regeneration occurs with the replacement of the primary soft cartilaginous callus with a hard bony callus during stage 3 (bony callus formation stage). The last stage represents bone remodeling that is characterized by high levels of bone resorption and formation markers and the migration of osteoblasts and osteoclasts with the hard callus that undergoes repeated remodeling. During this process, the central part of the callus is finally replaced by compact bone, whereas the callus edges are replaced by lamellar bone. See the test for more details.