An Innovative Model of ISS-Based Multiple Fractures and Gastrointestinal Dysfunction Related to c-Kit Protein Expression on Interstitial Cells of Cajal.

OBJECTIVE: Gastrointestinal dysfunction seriously affects the prognosis and quality of life of patients with multiple fractures. However, experimental evidence of this relationship is lacking. Here we describe a newly developed mouse model of postoperative gastrointestinal dysfunction after multiple fractures. METHODS: Trauma severity was assessed using the injury severity score (ISS). Based on the ISS, a multiple fracture model was established in mice as follows: limb fractures with pelvic fractures and multiple rib fractures; limb fractures with multiple rib fractures; closed fracture of both forelegs with pelvic fracture and rib fractures; closed limb fractures; limb fracture with pelvic fracture; spinal fractures; hind leg fractures with pelvic fractures; pelvic fracture with multiple rib fractures; closed fracture of both fore legs with pelvic fracture; and closed fracture of both fore legs with multiple rib fractures. In each model group, gastrointestinal motility was assayed and the histopathology of the small intestine was examined. Western blot and immunohistochemical analyses of jejunal tissue were performed to detect c-kit protein expression, the level of which was compared with that of a control group. The results of ANOVA are expressed as mean ± standard deviation. RESULTS: In mice with multiple fractures, food intake was greatly reduced, consistent with histopathological evidence of an injured intestinal epithelium. The jejunal tissue of mice in groups a, c, f, and h was characterized by extensively necrotic and exfoliated intestinal mucosal epithelium and inflammatory cell infiltration in the lamina propria. In the gastrointestinal function assay, gastrointestinal motility was significantly reduced in groups a, b, c, f, and g; these group also had a higher ISS (p < 0.01). The expression of c-kit protein in groups with gastrointestinal dysfunction was significantly up-regulated (p < 0.001) compared with the control group. The close correlation between c-kit expression and the ISS indicated an influence of trauma severity on gastrointestinal motility. CONCLUSION: Gastrointestinal dysfunction after multiple fractures was successfully reproduced in a mouse model. In these mice, c-kit expression correlated with gastrointestinal tissue dysfunction and might serve as a therapeutic target.

Anterior horizontal rafting plate to treat complex osteoporotic tibial plateau fractures: a technical note.

Complex tibial plateau fractures in elderly patients exhibiting severe osteoporosis and articular surface collapse are challenging. Decision-making is difficult when the posterior column is involved. Open reduction and internal fixation of complex tibial plateau fractures in patients with severe osteoporosis are prone to failure. In this paper, we describe a new method for the maintenance of the articular surface of complex tibial plateau fractures in elderly patients. An anterior horizontal rafting plate (3.5-mm-thick reconstruction and locking plate [Zimmer Inc., Warsaw, IN, USA]) is placed via conventional posteromedial and anterolateral incisions. The plate is inserted between the anterior bony surface of the proximal tibia and the subpatellar fat pad; plate positioning is checked under direct vision. The patient is encouraged to begin functional recovery soon after operation. Progressive weight-bearing begins at 10 weeks postoperatively and is gradually increased during fracture healing. Clinical follow-up was performed at 4, 8, and 12 weeks, 6 and 12 months, and yearly thereafter. No articular collapse or fragment displacement was evident on three-dimensional computed tomography performed 6 months after surgery. The knee range of motion was 5-130º at the last follow-up (4 years after surgery). This technique may be a good option for treating complex tibial plateau fractures, especially in elderly patients with severe osteoporosis.