[Clinical studies in trauma surgery and orthopedics: read, interpret and implement]. / Klinische Studien in Unfallchirurgie und Orthopädie: lesen, interpretieren und umsetzen.

Informative, participatory clinical decision-making needs to combine both skills and expertise as well as current scientific evidence. The flood of digital information makes it difficult in everyday clinical practice to keep up to date with the latest publications. This article provides assistance for coping with this problem. A basic understanding of prior and posterior probabilities as well as systematic error (bias) makes it easier to weigh up the benefits and risks, e.g. of a (surgical) intervention compared to a nonsurgical treatment. Randomized controlled trials (RCT, with all modern modifications) deliver undistorted results but in orthopedic and trauma surgery can lead to a heavily selected nonrepresentative sample and the results must be confirmed or refuted by further, independent RCTs. Large-scale observational data (e.g. from registries) can be modelled in a quasi-experimental manner and accompany RCTs in health technology assessment.

Trauma management incorporating focused assessment with computed tomography in trauma (FACTT) - potential effect on survival.

BACKGROUND: Immediate recognition of life-threatening conditions and injuries is the key to trauma management. To date, the impact of focused assessment with computed tomography in trauma (FACTT) has not been formally assessed. We aimed to find out whether the concept of using FACTT during primary trauma survey has a negative or positive effect on survival. METHODS: In a retrospective, multicentre study, we compared our time management and probability of survival (Ps) in major trauma patients who received FACTT during trauma resuscitation with the trauma registry of the German Trauma Society (DGU). FACTT is defined as whole-body computed tomography (WBCT) during primary trauma survey. We determined the probability of survival according to the Trauma and Injury Severity Score (TRISS), the Revised Injury Severity Classification score (RISC) and the standardized mortality ratio (SMR). RESULTS: We analysed 4.817 patients from the DGU database from 2002 until 2004, 160 (3.3%) were from our trauma centre at the Ludwig-Maximilians-University (LMU) and 4.657 (96.7%) from the DGU group. 73.2% were male with a mean age of 42.5 years, a mean ISS of 29.8. 96.2% had suffered from blunt trauma. Time from admission to FAST (focused assessment with sonography for trauma)(4.3 vs. 8.7 min), chest x-ray (8.1 vs. 16.0 min) and whole-body CT (20.7 vs. 36.6 min) was shorter at the LMU compared to the other trauma centres (p < 0.001). SMR calculated by TRISS was 0.74 (CI95% 0.40-1.08) for the LMU (p = 0.24) and 0.92 (CI95% 0.84-1.01) for the DGU group (p = 0.10). RISC methodology revealed a SMR of 0.69 (95%CI 0.47-0.92) for the LMU (p = 0.043) and 1.00 (95%CI 0.94-1.06) for the DGU group (p = 0.88). CONCLUSION: Trauma management incorporating FACTT enhances a rapid response to life-threatening problems and enables a comprehensive assessment of the severity of each relevant injury. Due to its speed and accuracy, FACTT during primary trauma survey supports rapid decision-making and may increase survival.

Significance of Elecsys S100 immunoassay for real-time assessment of traumatic brain damage in multiple trauma patients.

BACKGROUND: The neuroprotein S100 released into the circulation has been suggested as a reliable marker for primary brain damage. However, safe identification of relevant traumatic brain injury (TBI) may possibly be hampered by S100 release from peripheral tissue. The objective of this study was to measure early S100 levels using the Elecsys S100 immunoassay for real-time assessment of severe TBI in multiple trauma. METHODS: Consecutively admitted multiple trauma patients (injury severity score >or=16 points) were stratified according to the results of the initial cerebral computed tomography (CCT) examination. S100 serum levels were determined at admission and at 6, 12, 24, 48 and 72 h after trauma. Data were correlated to creatine phosphokinase (CK) and lactate dehydrogenase (LDH) serum levels. Using receiver operating characteristic (ROC) analysis, the discriminating power of S100 measurement was calculated for the detection of CCT+ findings. RESULTS: Median S100 levels of CCT+ patients (n=9; 37 years) decreased from 3.30 microg/L at admission to 0.41 microg/L 72 h after trauma. They revealed no significant differences to CCT- patients (n=18; 44 years), but remained elevated compared to controls. Median CK and LDH levels correlated with the corresponding S100 levels during the first 24 h after trauma. ROC analysis displayed a maximum area under the curve of only 0.653 at 12 h after trauma. No significant difference was calculated for the differentiation between CCT+ and CCT- patients. CONCLUSIONS: Measurements of S100 serum levels using the Elecsys S100 immunoassay are not reliable for the real-time detection of severe TBI in multiple trauma patients. Due to soft tissue trauma or bone fractures, S100 is mainly released from peripheral sources such as adipocytes or skeletal muscle cells.

Quantitative scanning acoustic microscopy compared to microradiography for assessment of new bone formation.

Recently, it has been shown that quantitative scanning acoustic microscopy (SAM) is a powerful tool to image the acoustic impedance of even inhomogeneous materials like bone. Therefore, the aim of our study was to compare SAM to conventional microradiography with respect to histomorphometrical assessment of undecalcified sections of newly formed bone. Forty specimens were harvested 12 weeks after implantation of either autogenous cancellous bone graft or 5.0 mg of Osteogenic Protein-1 (BMP-7) in a critical-sized defect model in sheep. Undecalcified transverse bone sections of 500 microm thickness were investigated with conventional microradiography and SAM. Linear regression analysis was carried out to compare the measurements of the area of new bone formation within the defect sites. Both methods allowed for good discrimination between newly formed bone and cortical bone at the edges of the former defect. Images obtained with SAM revealed a better resolution and sharpness compared to that of microradiographs since SAM imaging unlike microradiography does not depend on the thickness of bone sections. The results of quantitative histomorphometric analysis obtained by both methods showed no significant differences, and it was possible to predict 90% of the variability of each method (coefficient of determination r2 = 0.90; P < 0.0001). In conclusion, SAM offers comparable quantitative histomorphometric information with a better spatial resolution than conventional microradiography. Thus, SAM is a promising new micro-visualizing technique for basic bone research.

Assessment of early brain damage in carotid endarterectomy: evaluation of S-100B serum levels and somatosensory evoked potentials in a pilot study.

The release of the neuronal protein S-100B into the circulation has been suggested as an early indication of cellular brain damage. The objective of this prospective pilot study was to determine S-100B serum levels in patients undergoing cross-clamping during carotid endarterectomy (CEA) and to correlate the results with the monitoring of somatosensory evoked potentials (SSEP) and the neurological short-term outcome. Arterial blood samples of 21 patients were drawn before oral intubation, cross-clamping, and unclamping, as well as before extubation and 6 hours later. Recording of SSEP was obtained during carotid occlusion and reperfusion. If loss of SSEP appeared, cerebral ischemia was assumed and an intraluminal shunt was placed. During cross-clamping, S-100B serum levels of 14 patients increased significantly from 0.05 ng/ml to 0.21 ng/ml, but returned to baseline levels after unclamping. In 5 cases, loss of SSEP amplitudes occurred but was reversed by the shunt insertion. No significant differences of S-100B serum values, neurological examination, and carotid duplex surveillance became obvious in this group when compared to the patients with undisturbed SSEP. However, 2 patients with complete disappearance of postcentral SSEP components suffered from neurological deficits in the postoperative period. S-100B serum levels remained highly elevated 6 hours after extubation (0.78 ng/ml and 0.41 ng/ml) compared to the baseline values (0.15 ng/ml and 0.07 ng/ml). During CEA a transitory increase of the S-100B serum levels appears to present an impairment of the blood-brain barrier integrity without any neurological deficits. In contrast, persistently elevated S-100B serum levels seem to be associated with transient loss of SSEP and development of neurological deficits.