Impact of patient-related factors on complications when treating mandibular fractures by load-sharing and load-bearing osteosynthesis.

The decision about the choice of load-sharing (LS) or load-bearing (LB) osteosynthesis is determined by an interplay of fracture-related and patient-related factors. In some situations a similar fracture in two different patients may be treated successfully by either of these methods. Our aim was to identify preoperative patient-related factors that may assist in deciding which form of osteosynthesis is employed. All adult patients who underwent open reduction and internal fixation of mandibular fractures (excluding condyle) between 1 October 2018 and 1 June 2021 were retrospectively identified. The odds of developing postoperative complications and requiring a return to theatre (RTT) were calculated for each method of fixation together with the following patient factors: smoking, excess alcohol, substance misuse, and severe mental health issues. Of 337 fractures treated using LS principles, 27 (8%) developed complications, of which 20 (6%) required a RTT for repeat osteosynthesis. Of 74 fractures treated using LB principles, seven (10%) developed complications and two (3%) required a RTT for repeat osteosynthesis. The only patient factor that had statistically significant increased odds of a complication requiring RTT was LS osteosynthesis in patients who admitted drinking excess alcohol (OR = 7.83, p = 0.00, 95% CI = 3.13 to 19.60). Complications when treating mandibular fractures are rarely reported in the literature, and lack standardisation in their clinical significance. Figures generally represent overall numbers of patients, whereas the number of individual fractures treated is more accurate. In our study complications occurred in 8% of treated fractures and 10% of patients. The RTT rate was 7% of patients, which compares favourably with a recently stated standard of 10% of patients, as suggested by the Getting it Right First Time (GIRFT) report.

Sphingosine-1-phosphate modulation of basal permeability and acute inflammatory responses in rat venular microvessels.

AIMS: Although several cultured endothelial cell studies indicate that sphingosine-1-phosphate (S1P), via GTPase Rac1 activation, enhances endothelial barriers, very few in situ studies have been published. We aimed to further investigate the mechanisms whereby S1P modulates both baseline and increased permeability in intact microvessels. METHODS AND RESULTS: We measured attenuation by S1P of platelet-activating factor (PAF)- or bradykinin (Bk)-induced hydraulic conductivity (L(p)) increase in mesenteric microvessels of anaesthetized rats. S1P alone (1-5 µM) attenuated by 70% the acute L(p) increase due to PAF or Bk. Immunofluorescence methods in the same vessels under identical experimental conditions showed that Bk or PAF stimulated the loss of peripheral endothelial cortactin and rearrangement of VE-cadherin and occludin. Our results are the first to show in intact vessels that S1P pre-treatment inhibited rearrangement of VE-cadherin and occludin induced by PAF or Bk and preserved peripheral cortactin. S1P (1-5 µM, 30 min) did not increase baseline L(p). However, 10 µM S1P (60 min) increased L(p) two-fold. CONCLUSION: Our results conform to the hypothesis that S1P inhibits acute permeability increase in association with enhanced stabilization of peripheral endothelial adhesion proteins. These results support the idea that S1P can be useful to attenuate inflammation by enhancing endothelial adhesion through activation of Rac-dependent pathways.