Klaus D. Schaser

Tibiotalocalcaneal Fusion Using the Hindfoot Arthrodesis Nail A Multicenter Study

Background: Tibiotalocalcaneal arthrodesis is a salvage option for severe ankle and hindfoot deformities, arthritis of the ankle and subtalar joints, avascular necrosis of the talus, failed total ankle arthroplasty, and Charcot arthropathy. This multicenter study reports clinical experience with the hindfoot arthrodesis nail (HAN) in the treatment of patients with severe ankle and foot abnormalities. Methods: Seven participating clinics from Europe and North America recruited 38 patients who underwent ankle/subtalar arthrodesis using retrograde nailing with the HAN. Information was collected regarding technical details, complications, and functional and quality of life outcomes (Short Form-36 [SF-36], American Academy of Orthopaedic Surgeons—Foot and Ankle Outcomes [AAOS-FAO], and numeric rating scale [NRS] for pain) after an average of 2 years of follow-up. Results: The rate of superficial wound infection was 2.4%. No deep soft tissue or bone infections were reported. The overall union rate was 84%. At the time of follow-up, low pain levels were reported, with a mean NRS of 2.2; the mean AAOS-FAO score was 38; and the SF-36 mean physical and mental health component scores were 41.2 and 52.5, respectively. All 13 patients who were unable to work prior to surgery were able to fully return to work. Conclusions: The HAN offered a safe and reliable salvage option for tibiotalocalcaneal arthrodesis in patients with severe ankle and hindfoot disease. It achieved acceptable functional outcome and low complication rates despite the challenging patient cohort. A considerable socioeconomic benefit appeared to result based on the high proportion of patients who were able to return to work postoperatively. Level of Evidence: Level IV, retrospective case series.

Noninvasive in vivo analysis of the human hepatic microcirculation using orthogonal polorization spectral imaging.

Background. Analysis of hepatic microvascular perfusion in humans by direct imaging has been impossible so far. Orthogonal polarization spectral (OPS) imaging represents a new technology that combines simultaneous epi-illumination of the subject with linearly polarized light and noninvasive imaging of the microcirculation by reflectance spectrophotometry. The aim of this study was to evaluate the feasibility of studying the human hepatic microcirculation by OPS imaging in vivo and to define microcirculatory parameters for physiologic conditions. Methods. The hepatic microcirculation was analyzed in four different regions of both liver lobes in 11 healthy individuals undergoing partial liver resection for living-donor liver transplantation. The optical probe was gently positioned on the liver surface and sequences of at least 20 sec per measurement were recorded by a charge-coupled device camera on videotape. Microhemodynamic parameters were quantified off-line by single-frame and frame-to-frame analysis using a computer-assisted image analysis system. Results. OPS images of the hepatic microcirculation showed an acceptable quality with good resolution. Quantitative analysis revealed a sinusoidal red blood cell velocity of 0.97±0.43 mm/sec, a sinusoidal diameter of 8.8±0.9 &mgr;m, a sinusoidal volumetric blood flow of 58.2±9.6 pL/sec, an intersinusoidal distance of 22.6±2.5 &mgr;m, and a mean functional sinusoidal density of 391±30 cm−1. Apart from the sinusoidal red blood cell velocity, all data of the parameters studied matched the pattern of normal distribution. Conclusions. OPS imaging enabled for the first time direct in vivo visualization and quantification of the human hepatic microcirculation, providing significant insight into microvascular physiology of the human liver, to the extent that these data can be considered to represent physiologic values for human hepatic microcirculation.

Diagnostic and prognostic potential of differentially expressed miRNAs between metastatic and non-metastatic renal cell carcinoma at the time of nephrectomy

BACKGROUND MicroRNAs are promising diagnostic and prognostic biomarkers in oncology. We aimed to evaluate the prognostic potential of selected microRNAs in primary clear cell renal cell carcinomas (ccRCC) as predictors of tumor recurrence after radical nephrectomy. METHODS miR-122, miR-141, miR-155, miR-184, miR-200c, miR-210, miR-224, and miR-514, validated as differentially expressed in a previous study, were measured by RT-PCR in matched malignant and non-malignant tumor samples after nephrectomy from 111 patients (89 without, 22 with metastases) and clinicopathological and outcome data were collected. Non-parametric statistical tests, receiver-operating characteristics, Kaplan-Meier-, and univariate as well as multivariate Cox regression analyses were performed. RESULTS Downregulation of miR-141/-184/-200c/-514 and upregulation of miR-122/-155/-210/-224 were not different between samples of non-metastatic and metastatic tumors except for miR-122 and miR-514. miR-514 was further downregulated in metastatic compared with non-metastatic tumors while the upregulation of miR-122 was significantly reduced in metastatic carcinomas. All miRNAs were suitable to discriminate malignant from non-malignant tissue. miR-122 and miR-514 were significantly related to the recurrence risk but only miR-514 provided independent prognostic information in the final model including relevant clinicopathological variables. CONCLUSIONS MiR-122 and miR-514 play a role in tumor recurrence after nephrectomy. Expression of miR-514 was particularly downregulated in primary metastatic tumor and those that recur and might be a suitable adjunct marker for predicting tumor recurrence.

Angular Stable Anterior Plating Following Thoracolumbar Corpectomy Reveals Superior Segmental Stability Compared to Conventional Polyaxial Plate Fixation

Study Design. Biomechanical in vitro testing of primary and secondary stability in 12 human thoracolumbar spinal specimens using a spine simulator. Objective. In a corpectomy model anterior plate systems were investigated for their ability to restore spinal stability particularly focusing on the influence of angular stability, bone mineral density (BMD) and failure mode. Summary of Background Data. The concept of isolated anterior column reconstruction following thoracolumbar fractures using newly developed minimally invasive spine surgical techniques has attracted major clinical interest. In analogy to angular stable plate systems in long bone fixation the application of locking plates to the spine is aimed to limit loss of reduction and to improve stability. Methods. Twelve human spinal specimens (Th11-L3) were tested in a 6-degree-of-freedom spine simulator under pure moments of 7.5 Nm to investigate primary and secondary stiffness of 2 different anterior reconstruction options: (1) Synex II cage and MACS TL polyaxial anterior plating system, (2) Synex II cage and ArcoFix angular stable anterior plating system. An increasing 4-step cyclic loading model was included. Results. The angular stable plate system showed superior stability compared to the nonangular system in axial rotation and lateral bending. Flexion/extension loading demonstrated no difference between the systems in range of motion. A positive correlation between BMD and the number of load cycles until failure for the nonangular stable system (R2 = 0.90) was found. Different failure modes were investigated for the plating systems. The MACS system showed loosening at the connection between screw and plate inducing tilting under flexural load and final failure. The ArcoFix system revealed increased stability under cyclic loading and failed by parallel sintering to the endplate. Conclusion. Anterior angular stable fixation showed higher primary and secondary stability following thoracolumbar corpectomy. In specimens with lower BMD the use of angular stable systems substantially increased stability. Angular stable systems, however, differ in the way of construct failure.

Oncosurgical results of multilevel thoracolumbar en-bloc spondylectomy and reconstruction with a carbon composite vertebral body replacement system.

Study Design. Retrospective clinical study for patients receiving multilevel en-bloc spondylectomy resection for sarcomas and solitary metastases of the thoracolumbar spine. Objective. Assess the clinical and radiologic outcome after multilevel en-bloc spondylectomy and reconstruction. Summary of Background Data. Monolevel en-bloc spondylectomies have proven their oncosurgical effectiveness while reports on multilevel resections for extracompartmental tumor localizations are rare. Methods. Patients treated by multilevel en-bloc spondylectomy and restoration with a carbon composite vertebral body replacement system were investigated. Patient charts, and clinical follow-up investigations were analyzed for histopathological tumor origin, preoperative symptoms, surgical peri- and postoperative data, applied adjuvant therapies, as well as the course of disease. Solitary metastases time until occurrence and prognostic scores were evaluated (Tomita/Tokuhashi Score). CT-scans were performed and analyzed at follow up. Oncological status was evaluated including local recurrence rates, cumulative disease specific, and metastases-free survival. Results. Multilevel (2–5 segments) en-bloc spondylectomy of the thoracolumbar spine was performed in 20 patients (15 sarcomas and 5 solitary spinal metastases 9 male/11 female, mean age at surgery: 54 ± 15 years.). Wide and marginal surgical margins were achieved in 7 and 13 patients, respectively. Mean follow-up period was 25.0 (9–53) months. Thirteen patients received adjuvant therapy. No implant breakage or loosening was observed. Local recurrence occurred in one patient. Thirteen of the 18 surviving patients showed no evidence of the disease, two died of systemic disease. Conclusion. Multilevel en-bloc spondylectomy offers a radical resection option for extracompartmental tumor involvement. It provides oncologically adequate resection margins with low local recurrence. However, the procedures are complex; the patients stress is high and metastatic disease developed in one-third of patients. A judicious patient selection and a realistic feasibility evaluation must precede the decision for surgery. Reconstruction using a carbon composite cage system showed low complication rates and offers advantages for oncosurgical procedures.

Temporal profile of inflammatory response to fracture and hemorrhagic shock: Proposal of a novel long-term survival murine multiple trauma model

Hemorrhagic shock (hS) interacts with the posttraumatic immune response and fracture healing in multiple trauma. Due to the lack of a long‐term survival multiple trauma animal models, no standardized analysis of fracture healing referring the impact of multiple trauma on fracture healing was performed. We propose a new long‐term survival (21 days) murine multiple trauma model combining hS (microsurgical cannulation of carotid artery, withdrawl of blood and continuously blood pressure measurement), femoral (osteotomy/external fixation) and tibial fracture (3‐point bending technique/antegrade nail). The posttraumatic immune response was measured via IL‐6, sIL‐6R ELISA. The hS was investigated via macrohemodynamics, blood gas analysis, wet‐dry lung ration and histologic analysis of the shock organs. We proposed a new murine long‐term survival (21 days) multiple trauma model mimicking clinical relevant injury patterns and previously published human posttraumatic immune response. Based on blood gas analysis and histologic analysis of shock organs we characterized and standardized our murine multiple trauma model. Furthermore, we revealed hemorrhagic shock as a causative factor that triggers sIL‐6R formation underscoring the fundamental pathophysiologic role of the transsignaling mechanism in multiple trauma.

Surgical intensive care unit—the trauma surgery perspective

PurposeThis review addresses and summarizes the key issues and unique specific intensive care treatment of adult patients from the trauma surgery perspective.Materials and methodsThe cornerstones of successful surgical intensive care management are fluid resuscitation, transfusion protocol and extracorporeal organ replacement therapies. The injury-type specific complications and unique pathophysiologic regulatory mechanisms of the traumatized patients influencing the critical care treatment are discussed.ConclusionsFurthermore, the fundamental knowledge of the injury severity, understanding of the trauma mechanism, surgical treatment strategies and specific techniques of surgical intensive care are pointed out as essentials for a successful intensive care therapy.

Are Pentraxin 3 and Transsignaling Early Markers for Immunologic Injury Severity in Polytrauma? A Pilot Study

BackgroundInflammatory-related conditions and organ failure (OF) lead to late trauma mortality. Cytokine profiles can predict adverse events and mortality, potentially guiding treatment strategies (damage control surgery versus early total care). However, the specific cytokines to predict the clinical course in polytraumatized patients are not fully identified.Questions/purposesWe investigated the early pentraxin 3 (PTX3), IL-6, soluble IL-6 receptor (sIL-6R), and transsignaling ratio (TSR) in polytraumatized patients to estimate immunologic injury severity and predict OF and survival.MethodsWe prospectively followed 58 patients with severe polytrauma, six patients with minor trauma, and 10 healthy volunteers. The mean Injury Severity Score (ISS) was 43 points and the mean Hannover Polytrauma Score (PTS) was 59 points, with a consequently high mortality rate (30%). Twenty-seven of the 58 polytraumatized patients (46%) developed OF, 67% systemic inflammatory response syndrome, and 38% sepsis.ResultsMean sIL-6R concentrations in polytrauma initially were low. Mean PTX3 concentrations were high and peaked at 24 hours. The mean TSR peaked at 6 hours; at that time, the mean value was higher for nonsurvivors. PTX3 concentrations at admission were associated with injury severity calculated by ISS and PTS. Higher PTX3 serum concentrations 24 hours after admission correlated with lower probability for survival.ConclusionsPTX3, sIL-6R, and TSR were early markers for posttraumatic inflammatory status, OF, injury severity, and TSR for survival after polytrauma. The temporal profile of PTX3 and TSR might be used to anticipate the total injury severity and the clinical course and thereby guide decision making in polytraumatized patients.Level of EvidenceLevel II, prognostic study. See Instructions for Authors for a complete description of levels of evidence.

Initial intramuscular perfusion pressure predicts early skeletal muscle function following isolated tibial fractures

BackgroundThe severity of associated soft tissue trauma in complex injuries of the extremities guides fracture treatment and decisively determines patients prognosis. Trauma-induced microvascular dysfunction and increased tissue pressure is known to trigger secondary soft tissue damage and seems to adversely affect skeletal muscle function.Methods20 patients with isolated tibial fractures were included. Blood pressure and compartment pressure (anterior and deep posterior compartment) were measured continuously up to 24 hours. Corresponding perfusion pressure was calculated. After 4 and 12 weeks isokinetic muscle peak torque and mean power of the ankle joint in dorsal and plantar flexion were measured using a Biodex dynamometer.ResultsA significant inverse correlation between the anterior perfusion pressure at 24 hours and deficit in dorsiflexion at 4 weeks was found for both, the peak torque (R = -0.83; p < 0.01) and the mean power (R = -0.84; p < 0.01). The posterior perfusion pressure at 24 h and the plantar flexion after 4 weeks in both, peak torque (R = -0.73, p =< 0.05) and mean power (R = -0.7, p =< 0.05) displayed a significant correlation.ConclusionThe functional relationship between the decrease in intramuscular perfusion pressures and muscle performance in the early rehabilitation period indicate a causative and prognostic role of early posttraumatic microcirculatory derangements and skeletal muscle function. Therapeutic concepts aimed at effective muscle recovery, early rehabilitation, and decreased secondary tissue damage, should consider the maintenance of an adequate intramuscular perfusion pressure.

When does intraoperative 3D-imaging play a role in transpedicular C2 screw placement?

INTRODUCTION The stabilization of an atlantoaxial (C1-C2) instability is demanding due to a complex atlantoaxial anatomy with proximity to the spinal cord, a variable run of the vertebral artery (VA) and narrow C2 pedicles. We perfomed the Goel & Harms fusion in combination with an intraoperative 3D imaging to ensure correct screw placement in the C2 pedicle. We hypothesized, that narrow C2 pedicles lead to a higher malposition rate of screws by perforation of the pedicle wall. The purpose of this study was to describe a certain pedicle size, under which the perforation rate rises. PATIENTS AND METHODS In this retrospective study, all patients (n=30) were operated in the Goel & Harms technique. The isthmus height and pedicle diameter of C2 were measured. The achieved screw position in C2 was evaluated according to Gertzbein & Robbin classification (GRGr). RESULTS A statistically significant correlation was found between the pedicles size (isthmus height/pedicle diameter) and the achieved GRGr for the right (p=0.002/p=0.03) and left side (p=0.018/p=0.008). The ROC analysis yielded a Cut Off value for the pedicle size to distinguish between an intact or perforated pedicle wall (GRGr 1 or ≥2). The Cut-Off value was identified for the isthmus height (right 6.1mm, left 5.4mm) and for the pedicle diameter (6.6mm both sides). CONCLUSION The hypothesis, that narrow pedicles lead to a higher perforation rate of the pedicle wall, can be accepted. Pedicles of <6.6mm turned out to be a risk factor for a perforation of the pedicle wall (GRGr 2 or higher). Intraoperative 3D imaging is a feasible tool to confirm optimal screw position, which becomes even more important in cases with thin pedicles. The rising risk of VA injury in these cases support the additional use of navigation.