OBJECTIVES Complicated fracture healing is often associated with the severity of surrounding muscle tissue trauma. Since inflammation is a primary determinant of musculoskeletal health and regeneration, it is plausible that delayed healing and non-unions are partly caused by compounding local inflammation in response to concomitant muscle trauma. METHODS AND RESULTS To investigate this possib...

Sildenafil, a cyclic guanosine monophosphate (cGMP)-dependent phospodiesterase-5 inhibitor, has been shown to be a potent stimulator of angiogenesis through upregulation of pro-angiogenic factors and control of cGMP concentration. Herein, we determined whether sildenafil also influences angiogenic growth factor expression and bone formation during the process of fracture healing. Bone healing w...

The physiological mechanisms of fracture healing have been the topic of active investigation for many years. At the present time ample data exist on the histological, mechanical and biochemical aspects of this process. Most investigators now believe that many of the steps in fracture healing are a recapitulation of what happens in endochondral bone formation. What lies ahead for a better unders...

It is estimated that, of the 7.9 million fractures sustained in the United States each year, 5% to 20% result in delayed or impaired healing requiring therapeutic intervention. Following fracture injury, there is an initial inflammatory response that plays a crucial role in bone healing; however, prolonged inflammation is inhibitory for fracture repair. The precise spatial and temporal impact o...

OBJECTIVES In this study, we aimed to evaluate possible effects of leptin on fracture healing. MATERIALS AND METHODS Between November 2009 and May 2010, 54 male Sprague Dawley rats with a mean age of 16 weeks and a mean body weight of 323 g (range; 295-352 g) were included and randomly divided into three equal groups. Standardized tibial fractures were created to all rats. Group 1 was treated...

INTRODUCTION Human circulating CD34+ cells, an endothelial progenitor cell (EPC)enriched population [1], have been also reported to differentiate into osteoblasts [2]. Previously, we demonstrated that that human circulating CD34+ cells, systemically transplanted into immunodeficient rats with nonhealing fracture, were recruited into fracture sites, contributed to a favorable environment for fra...

Traditional and COX-2 selective non-steroidal anti-inflammatory drug (NSAID) treatment inhibits fracture healing in animal models. This indicates that either the inflammatory phase following a bone fracture is necessary for efficient or sufficient bone regeneration to heal the fracture or COX-2 may have a specific function during bone regeneration unrelated to inflammation. These observations a...

The anaphylatoxin receptor C5aR1 plays an important role not only in innate immune responses, but also in bone metabolism and fracture healing, being highly expressed on immune and bone cells, including osteoblasts and osteoclasts. C5aR1 induces osteoblast migration, cytokine generation and osteoclastogenesis, however, the exact role of C5aR1-mediated signaling in osteoblasts is not entirely kn...

Assessment of the restoration of load-bearing function is the central goal in the study of fracture healing process. During the fracture healing, two critical aspects affect its analysis: (1) material properties of the callus components, and (2) the spatio-temporal architecture of the callus with respect to cartilage and new bone formation. In this study, an inverse problem methodology is used ...

Radiography is the most common imaging method for assessing the progress of fracture healing. However, accurate assessment may be confounded by fracture complexity in which a combination of anatomic overlay and hypertrophic callous can be visually misleading. We present just such an instance in which delayed fracture healing was further elucidated using tomosynthesis.