Carolin Fuchs

Introduction: The anatomy of the distal tibiofibular joint (DTFJ) has been demonstrated to influence the radiological outcome of reduction with syndesmotic screw fixation in the course of ankle fracture treatment. The objective of this study was to describe the anatomy of the DTFJ and to analyze the effect of incisura anatomy on syndesmotic stabilization with suture button systems (SBS), also in the context of their flexible nature of fixation. Materials and Methods: Forty-four (21 females, 23 males) consecutive postoperative bilateral computed tomography scans after stabilization of the DTFJ by SBS in the course of operative treatment of unstable ankle fractures were retrospectively analyzed. The anatomy of the DTFJ was evaluated by examining the following parameters: depth of the tibial incisura (DI), rotation of the incisura (ROI), Nault talar dome angle (NTDA), Leporjärvi clear space (LCS), anterior tibiofibular distance (antTFD), and fibula engagement (FE). The side-to-side (Δ) of LCS, NTDA, and antTFD, which analyzed the reduction result, were correlated with DI, FE, ROI, and NTDA, as well as the transverse offset (TO), reflecting the flexible nature of fixation. Results: Patients with slight overtightening (ΔLCS > −1 mm) showed a fibula that protruded less into the incisura on the native side (smaller FE) compared to symmetrical reduced patients and to patients with slight diastasis (p < 0.05). There was no relationship between the parameters describing the anatomy of the incisura and parameters assessing the parameter of the “flexible nature of fixation” (rs < 0.300). Regarding the anatomical parameters, it was observed that there were inter-individual differences of more than 4 mm (p > 0.05). Conclusions: The considerable inter-individual anatomical variability of the DTFJ was confirmed. The morphological configuration of the incisura has no impact on the immediate radiological reduction result after SBS stabilization of the DTFG, as determined by CT. The extent of the flexible nature of fixation is also not affected by the morphology of the incisura. Stabilization of the DTFJ can be performed regardless of the anatomical configuration.

Trauma causes the breakdown of membrane phospholipids and the subsequent degradation of the released polyunsaturated fatty acids (PUFAs) to partially bioactive oxylipins. Here, we screened for circulating PUFAs and oxylipins in patients (n = 34) differing from those of uninjured controls (n = 25) and analyzed their diagnostic potential. Patients were followed up for 1 to 240 h after minor/moderate, severe, and very severe injuries. Of the targeted oxylipins, 13 out of 80 (13/80) were detected in almost all patients and controls. Injury caused a long-term decrease in 9- and 13-hydroxyoctadecadienoic acids and in several dihydroxyeicosatetraenoic acids, the stable derivatives of bioactive anti-inflammatory epoxyeicosatrienoic acids, compared to controls. Frequently, these oxylipins correlated inversely to injury severity, days in the intensive care unit and hospital, and/or procalcitonin and pro-inflammatory cytokine levels 48 up to 240 h after trauma. Notably, 20/80 oxylipins were detected in some patients but not or less often in controls. Many of these oxylipins increased transiently immediately after injury. Their level is partly correlated with adverse clinical parameters at this early time point. The circulating oxylipidome was markedly affected by trauma. Several oxylipins showed injury-dependent alterations at different time points in the post-traumatic course.

Introduction The anatomy of the distal tibio-fibular joint (DTFJ) has been demonstrated to influence the outcome of reduction with syndesmotic screw fixation. The objective of this study was to describe the anatomy of the DTFJ and to analyse the effect of incisura anatomy on syndesmotic stabilisation with suture button systems (SBS), also in the context of their "flexible nature of fixation". Materials and Methods Forty-four (21 females, 23 males) consecutive postoperative bilateral computed tomography scans after stabilisation of the DTFJ by SBS were retrospectively analysed. The anatomy of the DTFJ was evaluated by examining the following parameters: depth of the tibial incisura (DI), rotation of the incisura (ROI), Nault talar dome angle (NTDA), Leporjärvi clear space (LCS), anterior tibio-fibular distance (antTFD) and fibula engagement (FE). The side-to-side (Δ) of LCS, NTDA and antTFD, which analysed the reduction result, were correlated with DI, FE, ROI, NTDA as well as the transverse offset (TO), reflecting the "flexible nature of fixation". Results Patients with slight over-tightened (ΔLCS > -1 mm) showed a fibula that protruded less into the incisura on the native side (smaller FE) compared to symmetrical reduced patients and to patients with slight diastasis (p < 0.05). There was no relationship between the parameters describing the anatomy of the incisura and parameters assessing the parameter of the "flexible nature of fixation" (rs < 0.300). Regarding the anatomical parameters, it was observed that there were inter-individual differences of more than 4 mm (p>0.05). Conclusion The considerable inter-individual anatomical variability of the DTFJ was confirmed. The morphological configuration of the incisura has no impact on the immediate reduction result after dynamic stabilisation of the DTFG, as determined by CT. The extent of "flexible nature of fixation" is also not affected by the morphology of the incisura. Stabilisation of the DTFJ can be performed regardless of the anatomical configuration.

Trauma triggers a rapid innate immune response to aid the clearance of damaged/necrotic cells and their released damage-associated molecular pattern (DAMP). Here, we monitored the expression of EMR2/ADGRE2, involved in the functional regulation of innate immune cells, on circulating neutrophils in very severely and moderately/severely injured patients up to 240 h after trauma. Notably, neutrophilic EMR2 showed a uniform, injury severity- and type of injury-independent posttraumatic course in all patients. The percentage of EMR2⁺ neutrophils and their EMR2 level increased and peaked 48 h after trauma. Afterwards, they declined and normalized in some, but not all, patients. Circulating EMR2⁺ compared to EMR2⁻ neutrophils express less CD62L and more CD11c, a sign of activation. Neutrophilic EMR2 regulation was verified in vitro. Remarkably, it increased, depending on extracellular calcium, in controls as well. Cytokines, enhanced in patients immediately after trauma, and sera of patients did not further affect this neutrophilic EMR2 increase, whereas apoptosis induction disrupted it. Likely the damaged/necrotic cells/DAMPs, unavoidable during neutrophil culture, stimulate the neutrophilic EMR2 increase. In summary, the rapidly increased absolute number of neutrophils, especially present in very severely injured patients, together with upregulated neutrophilic EMR2, may expand our in vivo capacity to react to and finally clear damaged/necrotic cells/DAMPs after trauma.