A rupture of the anterior cruciate ligament (ACL) usually leads to an altered stretch reflex excitability of the thigh muscles that stabilize the knee. The purpose of this study was to quantitatively assess reflex activity in the m. semitendinosus/semimembranosus after anterior tibial translation in 21 patients with isolated ACL ruptures. The patients were divided into a group with "giving way" symptoms (noncopers, n = 12) and a group without "giving way" symptoms (copers, n = 9). While the patients were standing upright with 30 degrees knee flexion, a force of 300 N was applied to the knee to induce posterior-anterior tibial translation. Activity of m. semitendinosus/semimembranosus was measured using surface electromyography (EMG). A linear potentiometer was placed on the tibial tuberosity and measured maximum tibial translation during standing (i.e., functional condition). In addition, knee laxity was assessed with a KT1000 arthrometer under passive conditions. After ACL rupture, the short-latency response (SLR) latency remained unchanged (P = 0.21), whereas for the medium-latency response (MLR) it was significantly longer (P < 0.001). Significantly longer MLR latencies were noted for noncopers compared with copers (P < 0.01), whereas SLR latencies were similar. Significant differences between healthy and injured legs were noted after tibial translations using KT1000 (P < 0.001) and during stance (P < 0.001). Mechanical knee instability was found to be unchanged between copers and noncopers (KT1000: P = 0.97; tibial translation: P = 0.31). These results indicate that ACL rupture is associated with altered stretch reflex excitability, which may lead to "giving way" symptoms, and that altered stretch reflex excitability may be more important for the development of "giving way" than the mechanical instability of the knee.

BackgroundThe use of a double lumen cannula for veno-venous extracorporeal membrane oxygenation (v.v. ECMO) offers several advantages such as cannulation with only one cannula, patient comfort and the earlier mobilization and physiotherapy. The cannulation should be performed under visual wire and cannula placement into the right atrium, which is associated with risks of malposition and right ventricular perforation. The aim of this patient series is to describe the use of double lumen cannula in trauma patients with posttraumatic ARDS.Material and methodsCriteria for the v.v ECMO treatment were defined as hypoxaemia (pO2/FiO2 < 200 mmHg, FiO2 0.8-1,0); tidal volume >4-6 ml/kg ideal body weight; mean inspiratory pressure (Pinsp) >32-34 mmHg; respiratory acidosis pH <7.25; and arterial saturation (SaO2) <90%. The analysis included the Injury Severity Score (ISS), the types of injury, time of treatment, complications and outcomes.ResultsA total of 24 patients with major trauma were treated for posttraumatic ARDS with v.v. ECMO. The double lumen cannula (Avalon®, Fa. Maquet, Rastatt, Germany) was used in six male patients. The mean ISS was 31 (20–48). The ECMO therapy was started in an average on the third day after trauma. The mean ECMO run time was 7 days ± 5 (6–18), and the hospital stay was in mean of 60 days ± 34 (21–105).ConclusionThe use of double lumen cannula for v.v ECMO therapy in trauma patients is a feasible treatment option. No higher risk of bleeding could be found in this case series. A PTT-controlled heparinization is recommended using double lumen cannula. Therefore the use of this cannula type in trauma patients with high risk of bleeding is to discuss controversially.

A traumatic infra-renal aortic dissection is a rare but life-threatening injury that follows deceleration injuries. The mechanism of blunt abdominal aortic injury involves both direct and indirect forces. The successful management of patients with traumatic injuries depends on a prompt suspicion of the injury and early diagnosis and therapy. Missed injuries in trauma patients are well-described phenomena and implementation of the ATLS® trauma schedule led to a decrease in the number of missed injuries, but trauma computed tomography (CT) scans in injured patients are still not standard. We report on a 54-year old Caucasian female patient who was involved in a car accident. The fellow passenger of the car was seriously injured. The patient had been previously treated at two different hospitals, and a dislocated acetabular fracture had been diagnosed. Because of this injury, the patient was transferred to our institution, a level 1 trauma-center where, according to the nature of the accident as a high-energy trauma, a complete polytrauma management was performed at the time of admission. During the body check, a moderate tension of the lower parts of the abdomen was detected. During the CT scan, an aneurysm of the infra-renal aorta with a dissection from the height of the second lumbar vertebral body to the iliac artery was observed. The patient required an operation on the day of admission. After 19 days post-trauma care the patient was able to leave our hospital in good general condition. Therefore, missed injuries in multiple injury patients could be fatal, and it is essential that the orthopedic surgeon leaves room for suspicion of injuries based on the nature of the trauma. Traumatic injuries of the abdominal aorta are rare. According to the ATLS® trauma schedule, all of the patients who have experienced high-energy trauma and associated fractures should undergo routine screening using a trauma CT scan with contrast agents to detect potential life-threatening injuries. In case of abdominal trauma, an aortic dissection, which can easily be overlooked, has to be considered.