Splenectomy delays fracture healing by affecting the level of tumor necrosis factor alpha, interleukin 6 and bone morphogenetic protein

Abstract

Background. Abdominal injuries combined with bone fractures are increasing. Splenectomies are often required, but have prolonged healing time for bone fracture. Objectives. The aim of the study was to explore the molecular mechanism for splenectomy delaying fracture healing. Material and methods. Eighty-four patients (42 received splenectomy) who received hip fractures operations were recruited in our hospital. One-year follow-up analysis was performed. To ensure the results, an animal model was established. Sprague-Dawley (SD) rats were randomly divided into 5 groups: group A: experimental group, femoral fractures + splenectomy; group B: femoral fractures; group C: splenectomy; group D: femoral fracture + sham splenectomy; group E: sham fracture. After the femoral fracture surgery, the callus status was evaluated by X-ray. Results. After 1-year follow-up, the healing index and bone quality was higher in the fracture-operated-only group than in the splenectomy group. In contrast, the rate of healing complications was lower in the fracture-operated-only group than in the splenectomy group. Biomarker analysis showed that the serum levels of tumor necrosis factor alpha (TNF-a), interleukin 6 (IL-6) and bone morphogenetic protein (BMP) were higher in the fracture-operated-only group than in the splenectomy group. No difference of the callus status was found among the rats in groups B, D and E (p > 0.05), while there were significant differences of the callus status of the rats in groups A and C at different stages (p < 0.05). On the other hand, the levels of TNF-a, IL-6 and BMP increased, reached peak after 7-day splenectomy surgery, and then decreased significantly in groups A and C (p > 0.05). Conclusions. Splenectomy delays fracture healing by affecting the levels of TNF-a, IL-6 and BMP.