Predictive factors for docking site procedure in bone transport for large lower extremity segmental defects

BACKGROUND

Segmental bone transport is a common technique for treating large segmental bone defects. However, a docking site procedure is often necessary in segmental bone transport. To date, no prognostic factors for the need of docking site procedure have been reported. Thus, the decision is often made at random, based on the surgeon's subjective judgment and experience. The aim of this study was to identify prognostic factors for the need of docking site operation.

METHODS

Patients with segmental bone transport in lower extremity bone defects were included regardless of age, aetiology, and defect size. We excluded patients undergoing treatments that were not yet completed, and those who discontinued therapy by any reason. The need for docking site operation was modelled with logistical and linear regression as well as univariate analysis of variances (ANOVA). Receiver operating characteristics (ROC) curve analysis was also performed.

RESULTS

Twenty-seven patients from age 12 to 74 years (mean age: 39.07 ± 18.20 years) were included. The mean defect size was 76.39 ± 41.10 mm. The duration of transport (days) showed a significant influence (p = 0.049, 95%CI: 1.00-1.02) on the need for docking site operation. No other significant influences were detected.

CONCLUSION

A link between the duration of transport and the need for docking site operation was detected. Our data showed that if a threshold of about 188 days is exceeded, docking surgery should be considered.

Validation of direct CT measurement of malrotation in femoral neck fractures: A bone model study

BACKGROUND

While postoperative malrotation in the subtrochanteric region is a well-known problem, malrotation after osteosynthesis in proximal femoral fractures has not been extensively studied. In this context, many methods for perioperatively assessment of femoral torsion have been described, but none of them is applicable in the basicervical region of the proximal femur. As an important difference in femoral neck fractures, the discontinuous neck fails to serve as a significant "pointer" for measurements and malfunctions to be placed in relation to the condylar plane. Considering postoperative maltorsion at any location as a substantial negative effect on patients' outcome and functional expectations, precise and patient-friendly rotation measurement standards in femoral neck fractures are desired in clinical practice. Recently, a novel computed tomography (CT) based geometric technique was described named "direct measurement" with promising results covering this diagnostic disparity, but still requires validation. Thus, we aimed to validate the previously described technique using a controlled range of displacement in a femoral neck fracture Sawbone® model.

METHODS AND FINDINGS

A goniometer was designed to set retro- and anteversion of the proximal femur in a reproducible manner. Prospectively, all femurs underwent a CT scan and were measured 3D for displacement. The interclass correlation between the CT measurements and the goniometer measurements was calculated and was found to be very high (1.00, 95% confidence interval: 0.99-1.00; p < 0.001). For the mean of all measurements, the Pearson's correlation was 1.00 (p < 0.001). No significant differences in the measurements of both investigators were observed, with 20° of retroversion not significant (-1.20 ± 1.71; 95% confidence interval: -2.43-0.03; p = 0.054).

CONCLUSION

This CT-based 3D measurement technique may allow for perioperative malrotation assessment in basicervical femoral neck fractures and appears to be feasible in femoral neck fractures when it comes to rare cases of osteosynthesis. Further investigations are still needed to define the thresholds of malrotation provoking functional impairment after osteosynthesis in basicervical femoral neck fractures.

[Does navigation still have a value in trauma surgery?]

BACKGROUND

Navigation systems are supposed to increase precision and support surgeons while they perform certain interventions. 2D, or nowadays 3D, systems are used in image-based approaches. Image-free navigation uses 3D printing.

INDICATIONS

There are several studies on navigation procedures in trauma surgery. In contrast to limb surgery, the use of 3D navigation in pelvic and spine surgery is already well established. Navigation is especially regularly used to treat fractures of the posterior pelvic ring and for posterior stabilization of the cervical spine.

REQUIREMENTS

To be able to utilize navigation systems optimally, the learning curve should be completed, and the technique should be used regularly. In addition, the surgeon should know the surgical technique without navigation in order to recognize potential errors of the navigation.

ADVANTAGES AND DISADVANTAGES

Advantages include increased patient safety, reduction in radiation exposure and less invasive surgical procedures. However, among other disadvantages, initial costs are high.

[Common infectious challenges of the thoracic and lumbar spine : Spondylodiscitis and postoperative wound infection]

Spondylodiscitis and postoperative wound infections are the most frequent infectious diseases of the thoracic and lumbar spine. Every spinal surgeon will come into contact with such patients during his or her career. Knowledge particularly of the diagnostics, conservative and surgical treatment as well as microbiological considerations of antibiotic treatment are therefore of particular importance and are explained in this article.

Low Diagnostic Value of Synovial Aspiration Culture Prior to Reimplantation in Periprosthetic Joint Infection

BACKGROUND/AIM

We aimed to determine the diagnostic value of the synovial aspiration culture prior to reimplantation in two- (or more) stage exchange of periprosthetic joint infection.

PATIENTS AND METHODS

This was a retrospective study, spanning over ten years including all synovial cultures of patients with two- (or more) stage exchange due to periprosthetic joint infection.

RESULTS

A total of 183 patients were included, mean age was 66.6 years (range=12.8-93.4 years). Overall sensitivity of synovial aspiration cultures before reimplantation was 56.6%, specificity 84.6%, negative predictive value (NPV) 63.8%, positive predictive value (PPV) 80.2%, area under the curve (AUC) 70.6%. Sensitivity of the knee in comparison to the hip culture was significantly higher, as well as the NPV and the AUC (p=0.038). In case of complete removal of prosthesis, the sensitivity and AUC were significantly reduced, whereas the specificity was comparable with prosthesis in situ, partial removal or complete removal.

CONCLUSION

Due to the low sensitivity, obtaining several synovial cultures in the prosthesis-free interval to exclude persistence of infection, does not seem reasonable.

Computer-Assisted Orthopedic and Trauma Surgery

BACKGROUND

There are many ways in which computer-assisted orthopedic and trauma surgery (CAOS) procedures can help surgeons to plan and execute an intervention.

METHODS

This study is based on data derived from a selective search of the literature in the PubMed database, supported by a Google Scholar search.

RESULTS

For most applications the evidence is weak. In no sector did the use of computer-assisted surgery yield any relevant clinical or functional improvement. In trauma surgery, 3D-navigated sacroiliac screw fixation has become clinically established for the treatment of pelvic fractures. One randomized controlled trial showed a reduction in the rate of screw misplacement: 0% with 3D navigation versus 20.4% with the conventional procedure und 16.6% with 2D navigation. Moreover, navigation-assisted pedicle screw stabilization lowers the misplacement rate. In joint replacements, the long-term results showed no difference in respect of clinical/functional scores, the time for which the implant remained in place, or aseptic loosening.

CONCLUSION

Computer-assisted procedures can improve the precision of certain surgical interventions. Particularly in joint replacement and spinal surgery, the research is moving away from navigation in the direction of robotic procedures. Future studies should place greater emphasis on clinical and functional results.

[Minimally invasive stabilization of sacral fractures]

BACKGROUND

Sacral fractures can be of traumatic origin and can also occur as insufficiency fractures. While the therapeutic target of mechanically stable insufficiency fractures is mainly pain relief, mechanically unstable insufficiency fractures and traumatic sacral fractures following high-energy trauma require biomechanical stabilization. Various surgical strategies are available for this, whereby minimally invasive techniques are now preferred whenever possible.

OBJECTIVE

This article presents the clinical challenges and options for minimally invasive treatment of sacral fractures.

MATERIAL AND METHODS

Selected important study data are discussed and our own treatment approach is presented.

RESULTS

The most important minimally invasive techniques for operative treatment of sacral fractures are presented: sacroiliac screw osteosynthesis, lumbopelvic stabilization and sacroplasty. The selection of the surgical technique should be made on an individual basis. While sacroiliac screw osteosynthesis is the international gold standard, diverse authors have also published minimally invasive techniques for lumbopelvic stabilization. The latter enables a higher mechanical stability. In contrast, sacroplasty should only be used as an alternative treatment in insufficiency fractures. Comparative studies of the described techniques are still missing.

CONCLUSION

All surgical options have their indications. Nevertheless, the biomechanical stability which can be achieved differs widely. Therefore, an exact analysis should be carried out of what is necessary with respect to reduction and retention and what should be achieved when treating sacral fractures.

Dynamic stabilization for degenerative diseases in the lumbar spine: 2 years results

Following lumbar fusion, adjacent segment degeneration has been frequently reported. Dynamic systems are believed to reduce main fusion drawbacks. We conducted a retrospective study on patients with degenerative lumbar disease treated with posterior dynamic stabilization with monoaxial hinged pedicular screws and lumbar decompression. VAS and ODI were used to compare clinical outcomes. As radiological outcomes, LL and SVA were used. 51 patients were included with an average follow-up of 24 months. 13 patients were revised because of postoperative radiculopathy (n=4), subcutaneous hematoma (n=2), L5 screw malposition (n=1) and adjacent segment disease (n=6). The mean ODI score 41 preoperatively compared to 36 postoperatively. The mean VAS scores for back and leg pain were 5.3 and 4.2, respectively compared to 4.5 and 4.0 postoperatively. The mean SVA was 5.3 cm preoperatively, and 5.7 cm postoperatively. The mean LL was 47.5° preoperatively and 45.5° postoperatively. From our data, which fail to show significant improvements and reflect a high revision rate, we cannot generally recommend dynamic stabilization as an alternative to fusion. Comparative trials with longer follow-ups are required.

Kinetic therapy in multiple trauma patients with severe blunt chest trauma: an analysis at a level-1 trauma center

BACKGROUND AND OBJECTIVES

Chest trauma is a relevant risk factor for mortality after multiple trauma. Kinetic therapy (KT) represents a potential treatment option in order to restore pulmonary function. Decision criteria for performing kinetic therapy are not fully elucidated. The purpose of this study was to investigate the decision making process to initiate kinetic therapy in a well defined multiple trauma cohort.

METHODS

A retrospective analysis (2000-2009) of polytrauma patients (age > 16 years, ISS ⩾ 16) with severe chest trauma (AIS(Chest) ⩾ 3) was performed. Patients with AIS(Head) ⩾ 3 were excluded. Patients receiving either kinetic (KT+) or lung protective ventilation strategy (KT-) were compared. Chest trauma was classified according to the AIS(Chest), Pulmonary Contusion Score (PCS), Wagner Jamieson Score and Thoracic Trauma Severity Score (TTS). There were multiple outcome parameters investigated included mortality, posttraumatic complications and clinical data. A multivariate regression analysis was performed.

RESULTS

Two hundred and eighty-three patients were included (KT+: n=160; KT-: n=123). AIS(Chest), age and gender were comparable in both groups. There were significant higher values of the ISS, PCS, Wagner Jamieson Score and TTS in group KT+. The incidence of posttraumatic complications and mortality was increased compared to group KT- (p< 0.05). Despite that, kinetic therapy failed to be an independent risk factor for mortality in multivariate logistic regression analysis.

CONCLUSIONS

Kinetic therapy is an option in severely injured patients with severe chest trauma. Decision making is not only based on anatomical aspects such as the AIS(Chest), but on overall injury severity, pulmonary contusions and physiological deterioration. It could be assumed that the increased mortality in patients receiving KT is primarily caused by these factors and does not reflect an independent adverse effect of KT. Furthermore, KT was not shown to be an independent risk factor for mortality.

Intraoperative imaging of the shoulder: A comparison of two- and three-dimensional imaging techniques

BACKGROUND

Isocentric three-dimensional C-arms allow for more effective intraoperative fracture reduction control compared to two-dimensional imaging techniques. However, this design is not appropriate for shoulder scanning.

OBJECTIVE

To assess the feasibility of using a newer generation variable isocentric flat detector 3D C-arm for intraoperative glenohumeral and acromioclavicular joint assessment and to compare the accuracy of its intraoperative 3D imaging technology to a standard two-dimensional (2D) flat detector fluoroscope.

METHODS

Five whole-body human cadavers were used (ten shoulders). Native shoulder scans were obtained. A glenohumeral arthrotomy was performed and several injuries and procedures were simulated. Five independent orthopaedic surgeons reviewed each scan and filled out a questionnaire assessing the quality of the images using a visual analog scale (VAS) and a points scoring system.

RESULTS

The examiners rated the 3D images as very-good-to-excellent according to the established parameters: image quality; visualization of the corticalis and the spongiosa; delineation of the joint surface; presence of artifacts; and clinical assessment capability. This high quality of the images led to a higher interobserver reliability for 3D images compared to 2D images.

CONCLUSIONS

Variable isocentric 3D C-arm technology is feasible for intraoperative assessment of shoulder procedures. Assessment of 3D images in shoulder procedures showed better interexaminer reliability in this experiment compared to 2D images. With the aid of intraoperative 3D shoulder imaging, intraoperative 3D C-arm navigation could help improve accuracy in the clinical setting.

Vertebral fractures in motor vehicle accidents - a medical and technical analysis of 33,015 injured front-seat occupants

Spinal injuries pose a considerable risk to life and quality of life. In spite of improvements in active and passive safety of motor vehicles, car accidents are regarded as a major cause for vertebral fractures. The purpose of this study was to evaluate the current incidence of vertebral fractures among front-seat occupants in motor vehicle accidents, and to identify specific risk factors for sustaining vertebral fractures in motor vehicle accidents. Data from an accident research unit were accessed to collect collision details, preclinical data, and clinical data. We included all data on front-seat occupants. Hospital records were retrieved, and radiological images were evaluated. We analysed 33,015 front-seat occupants involved in motor vehicle accidents over a 24-year period. We identified 126 subjects (0.38%) with cervical spine fractures, 78 (0.24%) with thoracic fractures, and 99 (0.30%) with lumbar fractures. The mean relative collision speeds were 48, 39, and 40 kph in subjects with cervical, thoracic, and lumbar spine fractures, respectively, while it was 17.3 kph in the whole cohort. Contrary to the overall cohort, these patients typically sustained multiple hits rather than simple front collisions. Occupants with vertebral fractures frequently showed numerous concomitant injuries; for example, additional vertebral fractures. The incidence of vertebral fractures corresponded with collision speed. Safety belts were highly effective in the prevention of vertebral fractures. Apart from high speed, complex injury mechanisms as multiple collisions or rollovers were associated with vertebral fractures. Additional preventive measures should focus on these collision mechanisms.

Mechanisms of motor vehicle crashes related to burns--an analysis of the German In depth Accident Study (GIDAS) database

BACKGROUND

Patients of motor vehicle crashes (MVCs) suffering burns are challenging for the rescue team and the admitting hospital. These patients often face worse outcomes than crash patients with trauma only. Our analysis of the German In-depth Accident Study (GIDAS) database researches the detailed crash mechanisms to identify potential prevention measures.

METHODS

We analyzed the 2011 GIDAS database comprising 14,072 MVC patients and compared individuals with (Burns) and without (NoBurns) burns. Only complete data sets were included. Patients with burns obviously resulting of air bag deployment only were not included in the Burns group. Data acquisition by an on call team of medical and technical researchers starts at the crash scene immediately after the crash and comprises technical data as well as medical information until discharge from the hospital. Statistical analysis was done by Mann-Whitney-U-test. Level of significance was p < 0.05.

RESULTS

14,072 MVC patients with complete data sets were included in the analysis. 99 individuals suffered burns (0.7%; group "Burns"). Demographic data and injury severity showed no statistical significant difference between the two groups of Burns and NoBurns. Injury severity was measured using the Injury Severity Score (ISS). Direct frontal impact (Burns: 48.5% vs. NoBurns: 33%; p < 0.05) and high-energy impacts as represented by delta-v (m/s) (Burns: 33.5 ± 21.4 vs. NoBurns: 25.2 ± 15.9; p < 0.05) were significantly different between groups as was mortality (Burns: 12.5% vs. NoBurns: 2.1%; p < 0.05). Type of patients' motor vehicles and type of crash opponent showed no differences.

CONCLUSIONS

Our results show, that frontal and high-energy impacts are associated with a frequency of burns. This may serve automobile construction companies to improve the burn safety to prevent flames spreading from the motor compartment to the passenger compartment. Communities may impose speed limits in local crash hot spots.

Repair of segmental long-bone defects by stem cell concentrate augmented scaffolds: a clinical and positron emission tomography--computed tomography analysis

PURPOSE

Treating segmental long-bone defects remains a major challenge. For defects >3 cm, segmental transport represents the gold standard, even though the method is time consuming and afflicted with several complications. The aim of this study was to evaluate healing of such defects after grafting an osteogenic scaffold previously seeded with stem cell concentrate.

METHODS

We evaluated five patients with segmental long-bone defects (3-14 cm) treated with bone marrow aspirate concentrates (BMAC) seeded onto a bovine xenogenous scaffold. The healing process was monitored by X-rays and positron emission tomography-computed tomography (PET-CT) three months after surgery.

RESULTS

Centrifugation led to a concentration of leukocytes by factor 8.1 ± 7.5. Full weight bearing was achieved 11.3 ± 5.0 weeks after surgery. PET analysis showed an increased influx of fluoride by factor 8.3 ± 6.4 compared with the contralateral side (p < 0.01). Bone density in the cortical area was 75 ± 16 % of the contralateral side (p < 0.03). The patient with the largest defect sustained an implant failure in the distal femur and finally accomplished therapy by segmental transport. He also had the lowest uptake of fluoride of the patient collective (2.2-fold increase).

CONCLUSION

Stem cell concentrates can be an alternative to segmental bone transport. Further studies are needed to compare this method with autologous bone grafting and segmental transport.

Navigated vs arthroscopic-guided drilling for reconstruction of acromioclavicular joint injuries: accuracy and feasibility

BACKGROUND

Anatomical reconstruction of the coracoclavicular ligaments is a relatively new technique for acromioclavicular (AC) joint injuries.

METHODS

Eighteen procedures (nine non-navigated, nine navigated) of anatomical reconstruction were performed minimally invasively, using the Tight Rope system, on cadaveric shoulders. Two Kirschner wires were placed, freehand under fluoroscopic control (non-navigated) or 3D C-arm navigated. The insertion point on the clavicle as well as the position of the K-wire in the coracoid were measured in the axial and coronal planes; points were assigned for different zones. For statistical analysis, the significance level was set to p = 0.05.

RESULTS

The accuracy of the entry point in the clavicle was significantly more accurate for the conoidal (p = 0.022) and trapezoidal ( p = 0.0062) drillings. The positioning in the coronal (p = 0.037) and axial (p = 0.0416) planes also showed higher accuracy for the navigated procedures.

CONCLUSION

The accuracy of anatomical AC joint reconstruction can be improved using 3D C-arm flat detector navigation.

Improvement in the workflow efficiency of treating non-emergency outpatients by using a WLAN-based real-time location system in a level I trauma center

BACKGROUND

Patient localization can improve workflow in outpatient settings, which might lead to lower costs. The existing wireless local area network (WLAN) architecture in many hospitals opens up the possibility of adopting real-time patient tracking systems for capturing and processing position data; once captured, these data can be linked with clinical patient data.

OBJECTIVE

To analyze the effect of a WLAN-based real-time patient localization system for tracking outpatients in our level I trauma center.

METHODS

Outpatients from April to August 2009 were included in the study, which was performed in two different stages. In phase I, patient tracking was performed with the real-time location system, but acquired data were not displayed to the personnel. In phase II tracking, the acquired data were automatically collected and displayed. Total treatment time was the primary outcome parameter. Statistical analysis was performed using multiple linear regression, with the significance level set at 0.05. Covariates included sex, age, type of encounter, prioritization, treatment team, number of residents, and radiographic imaging.

RESULTS/DISCUSSION

1045 patients were included in our study (540 in phase I and 505 in phase 2). An overall improvement of efficiency, as determined by a significantly decreased total treatment time (23.7%) from phase I to phase II, was noted. Additionally, significantly lower treatment times were noted for phase II patients even when other factors were considered (increased numbers of residents, the addition of imaging diagnostics, and comparison among various localization zones).

CONCLUSIONS

WLAN-based real-time patient localization systems can reduce process inefficiencies associated with manual patient identification and tracking.

Navigated versus conventional transfixation of AC joint injuries: feasibility and accuracy

OBJECTIVE

Transfixation of the acromioclavicular (AC) joint is a well-established technique for treating Rockwood IV to VI lesions. However, several complications, including pin breakage or pin migration due to incorrect placement, have been reported in the literature. A cadaveric study was performed to investigate whether the use of 3D navigation might improve the accuracy of AC joint transfixation.

METHODS

Seventeen transfixations of the AC joint (8 non-navigated, 9 navigated) were performed minimally invasively in cadaveric shoulders. For the navigated procedures, a 3D C-arm (Ziehm Vision FD Vario 3D) and a navigation system (BrainLab VectorVision) were used. Reference markers were attached to the spina scapulae, then a 3D scan was performed and the data transferred to the navigation system. Two Kirschner wires (K-wires) were placed either freehand under fluoroscopic control (in the non-navigated group) or with the use of a navigated drill guide. Radiological analysis was performed with OsiriX software, measuring the distance of the K-wires from the center of the AC joint. For statistical analysis, Student's t-test was performed, with the significance level being set to p < 0.05.

RESULTS

The maximum distance of the K-wires from the center of the AC joint was 5.4 ± 1.1 mm for the freehand non-navigated group and 3.1 ± 1.6 mm for the navigated group (p = 0.0054). The minimum distance of the K-wires from the AC joint center was 3.0 ± 0.6 mm for the freehand group and 1.6 ± 0.6 mm for the navigated group (p = 0.0002). The radiation time was significant lower for the freehand group (41.25 ± 20.4 seconds versus 79.5 ± 13.3 seconds for the navigated group, p = 0.004). There was no statistical difference between the groups with respect to the time required for surgery (11.25 ± 3.6 min for the freehand group and 12.6 ± 4.6 min for the navigated group; p = 0.475). In the freehand group, the AC joint was penetrated by both K-wires in 87.5% of the procedures, compared to 100% in the navigated group. Both K-wires were placed completely intraosseously in the clavicula in 50% of the procedures in the freehand group, compared to 88% in the navigated group.

CONCLUSION

Three-dimensional navigation may improve the accuracy of AC joint transfixation techniques. However, the radiation time is increased when using the navigated procedure, while the overall operation time remains comparable. Nevertheless, a 3D C-arm with a variable isocentric design is recommended for the acquisition of the shoulder scans.

Bicyclist-bicyclist crashes--a medical and technical crash analysis

BACKGROUND

The purpose of this study was to analyze the actual injury situation of bicyclists focusing on accidents involving more than one bicyclist. A medical and technical analysis was performed as a basis for preventive measures.

METHODS

Technical and medical data were collected at the scene, shortly after the accident. Technical analysis included speed at crash, type of collision, impact angle, environment, lane used, and relative velocity. Medical analysis included injury patterns and severity (Abbreviated Injury Scale [AIS], Injury Severity Score [ISS]).

RESULTS

Five hundred seventy-eight injured bicyclists in 289 accidents from 1999 to 2008 were included into the study. Sixty-one percent were male (n = 350) and 39 percent were female (n = 228). Sixty-seven percent ranged between 18 and 64 years of age, 12 percent each between 13 and 17 years of age and older than 65 years, 8 percent between 6 and 12 years, and 1 percent between 2 and 5 years. Ninety-two percent of crashes took place in urban areas and 8 percent in rural areas. Ninety-seven percent of crashes occurred in dry conditions and 3 percent in wet conditions. Eighty-three percent of all accidents occurred during the daytime, 10 percent at night, and 7 percent at dawn. The helmet use rate was only 7.5 percent for all involved bicyclists. The mean Abbreviated Injury Scale (AIS) score was 1.31.

CONCLUSION

The prevalence of bicycle-to-bicycle crashes is high. Most of these accidents occur in urban areas. Bicyclists should be considered as minimally or unprotected road users, with an unsatisfactorily low rate of helmet use. Though the average level and patterns of injuries is moderate, most of the severe injuries involved the head and extremities. However, there was no significant correlation between frequent helmet use and sustained injuries to the head of major AIS.

Alcohol intoxication in road traffic accidents leads to higher impact speed difference, higher ISS and MAIS, and higher preclinical mortality

Alcohol is one of the most important personal risk factors for serious and fatal injuries, contributing to approximately one third of all deaths from accidents. It is also described that alcohol intoxication leads to a higher mortality in the clinical course. In this study, we hypothesized that alcohol intoxication leads to different accident kinematics, a higher ISS (Injury Severity Score), and higher preclinical mortality compared to sober patients. A technical and medical investigation of alcohol intoxicated road users was performed on the scene of the crash and at the primary admitting hospital. Alcohol testing was performed with either breath alcohol tests or measurement of blood alcohol concentration (BAC) in a standard laboratory test. Between 1999 and 2010, 37,635 road traffic accidents were evaluated by the Accident Research Unit. Overall 20,741 patients were injured, 2.3% of the patients were killed. Among the injured patients, 2.2% with negative BAC were killed, compared to 4.6% fatal injuries in patients with a positive BAC (p < 0.0001). Of the patients with a positive BAC, 8.0% were severely injured, compared to 3.6% in the BAC negative group (p < 0.0001). Regarding the relative speed at impact (Δv for motorized drivers, vehicle collision speed for pedestrians and bikers), there was a significant higher difference for BAC positive patients (30 ± 20) compared to the BAC negative patients (25 ± 19, p < 0.0001). Alcohol intoxication in trauma patients leads to higher preclinical mortality, higher impact speed difference, and higher injury severity. The subgroup analysis for different alcohol concentrations shows no difference in ISS, MAIS, and relative speed, but a correlation of increasing age of patients with higher alcohol concentrations.

Development of a WLAN-based real time localization system for patient tracking in a Level I Trauma center

BACKGROUND

Patient tracking helps improve workflow, decrease wait times, optimize costs, and enhance medical treatment in the outpatient setting. In that regard, real-time patient tracking may serve as a potential way to perform efficient patient care. In recent years, the increasing popularity of wireless local area networks (WLANs) has led to a growing number of devices utilizing wireless fidelity (WiFi) networks. This application has been used in various industries to enhance management processes. In that regard, we believe that this technology may enhance patient tracking, as the existing WLAN architecture in many clinics may allow for real-time tracking of patients. However, current literature regarding the clinical applicability of these devices is sparse. The aim of this study is to analyze the developmental process and feasibility of our protytope model for real-time patient tracking, using WLAN in the outpatient setting of our Level I Trauma center.

METHODS

We performed the study in various stages. First, we analyzed our current patient workflow, and then devised a study protocol and prototype model that implemented both this workflow schematic and our current technology infrastructure. Second, we implemented our prototype model to determine the accuracy, feasibility, and safety of data transmission in our clinical setting. The factors examined during prototype implementation included the accuracy of patient localization and the time spent by each patient in the various areas of our clinic (as determined by patient tracking).

RESULTS

In our outpatient clinic, our prototype was capable of localizing and automating patient data with excellent accuracy and security.

CONCLUSIONS

WLAN-based real-time patient localization systems can help overcome a number of common challenges and inefficiencies seen in the outpatient clinics. Real-time localization systems using WLAN technology performed adequately and safely in this pilot study. We believe that this will eventually lead to lower costs overall due to the improvements in efficiency. While the initial investment costs may be high, implemeting this system in a pre-existing WLAN and WiFi infrastructure should help minimize the start-up costs.

[Handling modern imaging procedures in a high-tech operating room]

Operating rooms are the central unit in the hospital network in trauma centers. In this area, high costs but also high revenues are generated. Modern operating theater concepts as an integrated model have been offered by different companies since the early 2000s. Our hypothesis is that integrative concepts for operating rooms, in addition to improved operating room ergonomics, have the potential for measurable time and cost savings. In our clinic, an integrated operating room concept (I-Suite, Stryker, Duisburg) was implemented after analysis of the problems. In addition to the ceiling-mounted arrangement, the system includes an endoscopy unit, a navigation system, and a voice control system. In the first 6 months (9/2005 to 2/2006), 112 procedures were performed in the integrated operating room: 34 total knee arthroplasties, 12 endoscopic spine surgeries, and 66 inpatient arthroscopic procedures (28 shoulder and 38 knee reconstructions). The analysis showed a daily saving of 22-45 min, corresponding to 15-30% of the daily changeover times, calculated to account for potential savings in the internal cost allocation of 225-450 EUR. A commercial operating room concept was evaluated in a pilot phase in terms of hard data, including time and cost factors. Besides the described effects further savings might be achieved through the effective use of voice control and the benefit of the sterile handle on the navigation camera, since waiting times for an additional nurse are minimized. The time of the procedure of intraoperative imaging is also reduced due to the ceiling-mounted concept, as the C-arm can be moved freely in the operating theater without hindering cables. By these measures and ensuing improved efficiency, the initial high costs for the implementation of the system may be cushioned over time.

Navigated femoral shaft fracture treatment: current status

Femoral malrotation is a common complication after internal fixation of a femoral shaft fracture. The only valid, objective monitoring method is computer tomography-assisted torsion measurement between the proximal and distal femur; unfortunately, this can only be carried out postoperatively. A difference of 15° compared to the contralateral femur is seen as an indication for revision. With the development of computer-assisted surgery, new possibilities for performing torsion control and correction intraoperatively has been introduced. These methods also allow for navigation-assisted definition of the optimal incision site, intramedullary access, femoral nail and interlocking. The main problem lies in the extra time of surgery, which is due to performing all the steps of the surgery navigated. The solution for this problem is "hybrid navigation", in which the surgeon can select the steps he needs from the navigation system, depending on his experience or surgical technique.

Progress towards intra-operative measurement of femoral antetorsion

Rotational malalignment following intramedullary nailing is a well-recognised problem. The threshold for clinically relevant malrotation has been established to be in the region of 15° whereas the incidence of significant malrotation following femoral nailing ranges from 22 to 43 percent. Many studies have been performed to address this issue with the major challenge acknowledged to be intraoperative control of femoral anteversion. In the current study, the investigators developed and analysed a novel method to estimate the femoral antetorsion based on computed tomography (CT) data. They hypothesized that this method would be intra-operatively feasible and repeatable without further radiation. CT scans (n=166) of femoral neck fractures performed between 2005 and 2010 were evaluated. Twenty patients had a femoral neck fracture and thus were excluded. Every femoral neck was measured according the method described by Jend et al. and the current authors. In contrast to the Jend method, the current authors described femoral antetorsion as the angle between the ventral cortex of the femoral neck and the posterior condylar line. To determine this angle, the axial cuts from computed tomography data were studied. In order to maximise measurement consistencty among cases, the axial cut which displayed the intertrochanteric crest was selected. Mean femoral antetorsion is 12.15°±10.04° according to Jend et al. In comparison, a mean angle of 12.61°±11.16° was demonstrated in the current study. The absolute difference in measuring the femoral neck angle when these different methods are compared was 4.44°. Statistically, there is no significant difference between the mean results for femoral antetorsion. The advantage of the method proposed in the current study, is the opportunity to enter the ventral femoral cortex during the surgical procedure without disturbing the process of femoral nailing. Thus, the surgeon can avail of continuous control of femoral rotation intra-operatively.

Mechanical stability analysis of reference clamp fixation in computer-assisted spine surgery

BACKGROUND

Pedicle screw misplacement is a common complication, while 7% may result in neurological complications. Computer-assisted navigation improves the rate of ideally placed screws. Inappropriate reference marker attachment can cause major problems in the outcome and duration of surgery.

OBJECTIVE

To improve fixation of reference bases by comparing different designs of spine clamps and measuring their stability against the relevant thoracic and lumbar anatomy.

METHODS

Force needed to dislocate the clamp from the processus spinosus using defined fixation of 0.79, 0.90 and 1.02 Nm torque was evaluated. Force transmission from clamp to the processus spinosus was also examined. Artificial thoracic and lumbar vertebral bodies were used for attaching spine clamps of three different designs. An instrument transmitted linear force onto the reference clamp and recorded the force when dislocation occurred. Another device determined transmitted force for each clamp utilizing 0.79, 0.90, 1.02, 1.13 and 1.24 Nm torque.

RESULTS

L-clamp had the most stable fixation in lumbar section for every torque and developed the greatest forces. These transmitted forces were similar to the less stable Y-design. I-design created the smallest forces and had the most stable fixation for thoracic spine. The Y- and the L-design caused a notably high number of fractures.

CONCLUSION

Great force leads to great stability, but also creates more fractures, favoring the use of smaller forces. Specific anatomy adaptation is important. Different clamp designs create different forces, while still differing in stability depending on their application in the thoracic or the lumbar spine.

The aseptic femoral and tibial shaft non-union in healthy patients - an analysis of the health-related quality of life and the socioeconomic outcome

Long bone non-unions may lead to recurrent surgical procedures and in-hospital stays. Thus, restrictions of the health-related quality of life and of socioeconomic parameters might be expected. Knowledge of the impact on several parameters of professional life is sparse. Therefore, we analyzed the outcome in patients following non-unions of the tibial and femoral shaft after fracture compared to patients with uneventful healing.

MATERIAL AND METHODOLOGY

51 patients following non-unions of the the femoral (FNU) or tibial shaft (TNU) were compared to 51 patients (groups FH and TH) with uneventful fracture healing. Physical and mental health was assessed using the Short-Form Health Survey (SF-12), Hospital Anxiety and Depression Scale (HADS) and the Impact of Event Scale (IES). We also analyzed employment status and the usage of medical aids.

RESULTS

Scores of the SF-12 physical and psychological were lower in group TNU compared to group TH, the score of SF-12 physical but not psychological was significantly lower in group FNU compared to FH. Compared to uneventful healing, a significantly more frequent usage of medical aids was found in both non-union groups. A higher incidence of early retirement and unemployment was found in group FNU but not in group TNU.

CONCLUSIONS

There is a profound influence on the quality of life following femoral or tibial non-unions after trauma. Compared to patients with uneventful fracture healing, patients with tibial and even more so femoral non-union show worse scores of the SF-12. Medical aids are frequently used following both, femoral and tibial non-unions. Not tibial, but femoral non-unions frequently lead to severe restrictions in professional life such as early retirement and unemployment.

[Comparison of early total care (ETC) and damage control orthopedics (DCO) in the treatment of multiple trauma with femoral shaft fractures: benefit and costs]

INTRODUCTION

Femoral fractures are common injuries in multiple trauma patients. The treatment concept of damage control orthopedics (DCO) is in competition with the concept of early total care (ETC).

PATIENTS AND METHODS

In a retrospective study (2003-2007) 73 multiple trauma patients with femoral shaft fractures were included. The cohort was subdivided according to the Injury Severity Score (ISS) (16-24, 25-39 and more than 40) and treatment strategy (ETC versus DCO). Patients were analyzed for outcome and cost aspects.

RESULTS

In the patient group with an ISS 16-24 ventilation time and intensive care treatment were longer after DCO treatment, overall costs and deficient cost cover were higher in the DCO group. In the patient group with an ISS 25-39 cost aspects showed a higher cover deficient in the DCO group.

CONCLUSION

From an economic point of view the cost deficits for the ETC group were lower than in the DCO group. The treatment strategy should be selected by the pattern of injuries. The costs should be addressed by the Institute for the Hospital Remuneration System (INEK).

[Conservative functional treatment of Achilles tendon ruptures]

The conservative functional treatment of Achilles tendon ruptures has developed further over the last 20 years and is basically possible for 60-80% of patients. The treatment leads to success if the indications obtained by dynamic sonography are correctly interpreted (adaptation of the tendon ends up to 20 degrees plantar flexion), if the patient presents sufficient compliance and the physiotherapy is increasingly intensified depending on tendon healing. Modern ortheses allow an increased equinus position and therefore improved protection of the healing tendon. If these factors are present a relatively low re-rupture rate of only 7% can be achieved. The decisive advantage of conservative functional therapy is the avoidance of specific operative risks, such as infection and injury to the sural nerve. After removal of the orthesis the tendon should continue to be modeled using shoe insoles and raised heels.

[Quad driving--life-endangering fun? A medical and technical analysis]

AIM

Quads or all-terrain vehicles do not seem to play a major role either in traffic accidents or in hospital admissions in Germany. However, reports about spectacular quad crashes in the press are not that infrequent. In contrast, no scientific survey or study regarding the issue of quad crashes in Germany has been published so far. Thus, this study aims to evaluate the present incidence of quad crashes, accident circumstances and resulting injury patterns, and to discuss possible consequences.

METHOD

At a level I trauma centre, data from accident and hospital records of quad drivers were analysed focusing on the following parameters: injury type, localisation and mechanism, treatment details, abbreviated injury scale (AIS) score, maximum AIS (MAIS) score, delta-v, collision speed, and other technical parameters. Comparisons to motorcycle accidents were performed. RESULT During a five-year period from 2005 to 2009, there were ten admissions of quad drivers out of around 11 000 emergency trauma patients (0.1 %). Five accidents had happened off-road, four were traffic accidents. Eight patients were male; the mean age was 30 years. The mean total hospital stay was 15 days; there was a mean of 1.5 stays per patients with 2.0 surgical procedures needed. One patient died, only two recovered fully. The accident research data bank revealed 14 cases of quad accidents out of 18 990 (0.1 %). The mean impact velocity was 35 km/h (motorcyclists 40.0 km/h). The most frequent injury mechanism was a collision with a car. The upper extremity was the predominant injured region (AIS 0.7), while it was the lower extremity for motorcyclists (AIS0.91). The maximum AIS were 1.4 in quad drivers and 1.49 in motorcyclists.

CONCLUSIONS

Although the absolute incidence of quad accidents in Germany is low, they pose a relatively high risk for severe injuries. Possible reasons are the comparatively low active and passive safety of quads as well as limited experience with quad driving and the "fun" aspect which might provoke risky driving behaviour. Larger series from the US report a high incidence of drug abuse among quad casualties as well as very limited use of helmets. In Germany, helmet usage has been mandatory since 2006. Possible additional measures to prevent a rise in quad accidents could be the total prohibition of alcohol consumption for quad drivers as well as special courses or driving licenses or an increase of the legal age for driving quads.

Use of a virtual 3D software for planning of tibial plateau fracture reconstruction

OBJECTIVE

Anatomical reconstruction of tibial plateau fractures is necessary to prevent pain, axial malalignment, knee join instability and posttraumatic arthritis. Computed tomography (CT) with 3D reconstruction is helpful in the accurate preoperative evaluation and reduction planning of the fracture site. The aim of this study was to describe the application of a virtual 3D reconstruction and segmentation software in the preoperative planning of tibial plateau fractures.

PATIENTS AND METHODS

CT scans of five tibial plateau fractures were preoperatively evaluated using the 3D planning software. Manual colour-coded segmentation was performed. The amount of time required for each planning session was recorded.

RESULTS

Successful 3D reconstruction and segmentation was achieved in all cases. The mean time required for 3D virtual planning was 174.8 min (range 69-124 min). The mean time required for 3D virtual planning of B-type fractures was 96.5 min (range 69-124 min; SD=38.891 min; CI=349.421). The mean time required for planning of C-type fractures was 227 min (range 167-294 min; SD=63.789 min; CI=158.460) (Table 1).

CONCLUSION

Successful segmentation was achieved in all cases. The 3D planning capabilities of this software may be a valuable tool for surgeons in learning about the nature of the injury in tibial plateau fracture cases and in formulating an appropriate surgical plan. However, the time requirement for the 3D reconstruction and segmentation analysis may be a current deterrent for its use in the clinical setting.

Tunnel widening after anterior cruciate ligament reconstruction: an experimental study in sheep

BACKGROUND

A common clinical concern after anterior cruciate ligament reconstruction is the expansion of the bone tunnels as seen radiographically. The etiology and clinical relevance of this phenomenon remain unclear.

HYPOTHESIS

Tunnel widening results in an increased anteroposterior translation, and there are specific histologic changes due to osteoclastic bone resorption associated with this phenomenon.

STUDY DESIGN

Controlled laboratory study.

METHODS

Thirty sheep (age, 4 months) underwent an anterior cruciate ligament reconstruction using a soft tissue graft. Graft fixation was achieved using the EndoButton and Suture Washer. Six animals each were sacrificed at 0, 3, 6, 12, and 24 weeks after surgery. Each anterior cruciate ligament-reconstructed knee was examined by computed tomography. Anteroposterior translation was determined using a universal force-moment sensor robot. The bone surrounding the tunnel was evaluated histologically. RESULTS The prevalence of tunnel enlargement on the femoral side was 77.3%. Animals with tunnel widening did not demonstrate increased anteroposterior translation. Widening of the femoral tunnel was significantly associated with a higher stiffness of the graft (P < .05) and hypertrophy of the graft throughout the remodeling process. The histologic evaluation of the bone tunnel walls demonstrated an increase of bone volume in animals with tunnel enlargement. No statistically significant correlation could be found between the number of osteoclasts and the presence of tunnel widening.

CONCLUSION

In this large animal model of anterior cruciate ligament reconstruction, animals with significant tunnel widening did not suffer increased anteroposterior translation. Tunnel widening was associated with a high stiffness of the graft, graft hypertrophy, and an increase in bone volume of the tunnel wall.

CLINICAL RELEVANCE

The present data correspond to the current opinion in humans that tunnel widening is not associated with knee instability. Further research is needed to understand the role of graft stiffness, graft hypertrophy, and the increase in bone volume in this phenomenon.

Utility of intraoperative three-dimensional imaging at the hip and knee joints with and without navigation

Intraoperative three-dimensional imaging in orthopaedic trauma care has achieved greater importance over the last few years in some specialized hospital centers. For various types of peripheral-extremity trauma, clinical studies have confirmed, on the basis of three-dimensional information, an intraoperative revision rate ranging from 7% to 19%. Three-dimensional C-arm imaging may be used to achieve adequate intraoperative information about the quality of fracture reduction, residual steps, and correct implant placement, and this technique has been described for use in both the hip joint (for acetabular fractures, isolated femoral head [Pipkin-type] fractures, three-dimensional navigated sacroiliac screw or acetabular column screw placements, and, less frequently, for navigated drilling of tumors or osteochondral lesions) and the knee joint (for tibial plateau fractures, complex distal femoral condylar fractures, and navigated targeting of osteochondral lesions in combination with the use of preoperative magnetic resonance imaging scans). Major limitations of this technology include increased intraoperative time requirements, limited image quality compared with that of computed tomographic scans, cost, specific positioning techniques, and the need for radiolucent operating-room tables. Although prospective studies have yet to be conducted, the ways in which the surgeon will benefit from the use of intraoperative three-dimensional imaging are apparent, but indications for combined three-dimensional C-arm navigated procedures at the hip and knee joint are still limited. Future directions may include the use of digital flat-panel detectors and even robotic-controlled C-arm motion.

[Injury situation of novice drivers in road traffic--a medical and technical analysis]

AIM

Novice drivers are at high risk for crash involvement. We performed an analysis of causations, injury patterns and distributions of novice drivers in cars and on motorcycles in road traffic as a basis for proper measurements.

METHOD

Data of accident and hospital records of novice drivers (licence < 2 years) were analysed focusing on the following parameters: injury type, localisation and mechanism, abbreviated injury scale (AIS), maximum AIS (MAIS), delta-v, collision speed and other technical parameters and compared with those of experienced drivers.

RESULTS

In 18 352 accidents in the area of Hannover (years 1985-2004), 2602 novice drivers and 18 214 experienced drivers were recorded as having an accident. Novice car drivers were more often and more severely injured whereas on motorcycles the experienced drivers were at higher risk. Novice drivers of both groups sustained more often extremity injuries. 4.5 % of the novice car drivers were not restrained by seatbelts as compared to 3.7 % of the experienced drivers and 6.1 % of the novice motorcycle drivers did not wear a proper helmet (versus 6.5 %). Severe injuries were sustained in 20 % at collision speeds below 30 km/h and in 80 % at collision speeds above 50 km/h. Novice car drivers drove significantly older cars. The risk profile of novice drivers is similar to that of drivers older than 65.

CONCLUSION

Structural protection and special lectures like skidding courses could be proper measurements next to harder punishment of violations.

Improved accuracy of navigated drilling using a drill alignment device

Drilling procedures are common in orthopedic surgery and are one specific task that may be aided by computer-assisted navigation. However, the inherent flexibility of drill bit bending may make this the limiting factor in achieving acceptable accuracy when using these systems. We designed an alignment device that was fit to a standard orthopedic drill that allowed an extension of the stabilizing point of a drill bit. In foam blocks with a similar density as cancellous bone, 208 total navigated drilling trials were performed, using four different sized drill bits (2.5, 3.2, 3.5, and 4.5 mm) with and without the alignment device. Drilling tracts of 80 mm were made towards an intended target on the other side of the block. Reduction in deviation from the intended target was significantly improved with the use of the guide, ranging from 33% to 45% for the four drill sizes. For the trails using the alignment device, the 2.5-mm drill bit was significantly less accurate than the three larger drills. Our results demonstrate that the use of external devices to augment drill bit stabilization can improve drilling accuracy. This may have particular importance when using navigation systems to drill into small anatomic confines.

Kosten- und Nutzenanalyse der intraoperativen 3D-Bildgebung

BACKGROUND

With intraoperative 3D imaging, inevitable corrections may be done already during the operation, and a second procedure can be avoided. The purpose of this study was to perform a cost-benefit analysis during the first year of intraoperative 3D application in order to provide a cost transparency for the surgeon within the current DRG system.

METHODS

On the basis of internal data and the literature, the annual operating costs of the ISO-C(3D) were calculated at 27,940 euros (purchase price, depreciation, maintenance, repair), the costs of an average revision as a secondary operation at 2,385 euros (costs avoided with the ISO-C(3D), Siremobil, Siemens, Erlangen, Germany), and the dynamic costs of an intraoperative 3D scan were averaged to 131.08 euros (draping, additional time, personnel).

RESULTS

In the year 2003 intraoperative 3D scanning was done in 126 patients, and intraoperative revision was performed in 24 (19%) due to the additional intraoperative 3D information provided by the Siremobil. In 11 (8.7%) patients the implant position was corrected and in 13 (10.3%) patients the reduction was improved. Taking only fixed costs into consideration, 29,311.52 euros could be saved, and when fixed and dynamic costs are taken into account 12,795.44 euros could be saved. Since the parameters for each hospital are different, the following formula for an individual computation is suitable. For the calculation of the cost the following mathematical relationship results: (annual fixed costs) + (costs per scan x number of cases) - (revision costs x revision rate [p]) x number of cases [N]) = 0.

DISCUSSION

Although the costs of an ISO-C(3D) are considerably high, an economic benefit can also accrue with frequent application and high rates of avoided revision. However, if the rate of avoided revision adds up to only 5%, a substantial deficit may result.