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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.

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.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.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 include increased patient safety, reduction in radiation exposure and less invasive surgical procedures. However, among other disadvantages, initial costs are high.HINTERGRUND: Navigationssysteme sollen die Präzision erhöhen und den Operateur bei der Durchführung bestimmter Eingriffe unterstützen. Unterschieden werden eine bildbasierte und eine bildfreie Navigation. Bildbasierte Verfahren beruhen auf 2‑D- bzw. heutzutage meist auf 3‑D-Systemen. Bei der bildfreien Navigation wird u. a. der 3‑D-Druck eingesetzt.In der Literatur existieren zahlreiche Studien zu Navigationsverfahren in der Unfallchirurgie. Während sich die Navigation in der Extremitätenchirurgie nicht durchsetzen konnte, ist der Einsatz der 3‑D-Navigation in der Becken- und Wirbelsäulenchirurgie etabliert. Vor allem bei Frakturen des hinteren Beckenringes (SI-Verschraubung) und bei dorsalen Stabilisierungsoperationen der Halswirbelsäule wird die Navigation regelmäßig angewendet.Um die Navigation optimal einsetzen zu können, sollte die Lernkurve abgeschlossen sein und die Technik regelmäßig angewendet werden. Zudem sollte der Chirurg die Operationstechnik sicher in konventioneller Technik beherrschen, um potenzielle Fehler der Navigation zu erkennen.Vorteile sind neben der erhöhten Patientensicherheit, die reduzierte Strahlenbelastung sowie eine geringere Invasivität chirurgischer Eingriffe. Als Nachteile sind unter ökonomischen Gesichtspunkten u. a. die hohen Anschaffungskosten anzuführen.

Background: The aim of this study was to examine the correlation between the risk of increasing kyphosis as well as collapse of the osteoporotic vertebral body fractures and the intensity of the bone edema in magnetic resonance imaging (MRI) scans. Inclusion criteria included the following: age >18 years and osteoporotic vertebral body fracture grade I–IV according to OF classification. Exclusion criteria included the following: other pathological fractures due to primary tumors or metastasis, OF grade V fractures, and AO type B or C fractures. Methods: This was a retrospective study from pseudonymized data of a tertiary spine center. No additional imaging were performed. Measurements of bisegmental kyphosis angle of the fracture for involvement of both endplates and monosegmental angle for involvement of 1 endplate, as well as vertebral body height loss in initial radiographs and at follow-ups after 3 and 6 months have been performed. Also, the initial signal intensity of the vertebral body edema was measured using integrated tool of the DICOM viewer (Impax V6.5 Agfa, Brentford, UK) in addition to the signal intensity of the cerebrospinal fluid (CSF) as reference for T1, T2, and separate target illumination radar (STIR) sequences of the MRI scans. A quotient from the signal intensity of the vertebral body edema and the reference (CSF) has been generated. Patients have been divided to 4 groups according to the ratio ( 3) and compared in regards to the results of the degree of kyphosis and vertebral collapse at follow-ups and final examination. The statistical analysis was performed using linear regression using statistic software SPSS version 26. Results and Conclusions: Forty-four patients have been included: 9 males and 35 females with an average age of 71.5 years. The analysis showed a significant correlation between the increasing kyphosis at follow-ups and the quotient of the signal intensity for STIR and T2 weighing with P = .002 (SD ±2.664) for STIR and P = .001 (SD ±1.616) for T2 sequences. Furthermore, there was only a correlation between the intensity ratio and kyphosis for STIR weighting at last examination (P = .017; SD ±1.360). There was no correlation between the height loss and the signal intensity. Level of Evidence: Level 2

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.

BACKGROUND: Pedicle screw fixation is commonly used in the treatment of spinal pathologies. While the biomechanical factors that affect bone fixation have been frequently described, questions remain as to which imaging modality is the ideal medium for preoperative planning. Due to its perceived superiority in assessing bony changes, computed tomography (CT) scan is assumed to be the gold standard for preparative planning, and we hypothesize that magnetic resonance imaging (MRI) is sufficiently accurate to predict screw length and diameter compared to CT. METHODS: We retrospectively measured the length and diameter of vertebral bodies in the lumbar region in both MRI and CT and tested for differences between the modalities as well as for confounding effects of age, sex, and the presence of spondyloarthrosis. RESULTS: We found a significant difference in pedicle screw length between CT and MRI measurements for both sides. For the left pedicle, the mean difference was 1.89 mm (95% confidence interval [CI] −3.03 to −0.75; P < .002), while for the right pedicle, the mean difference was 2.05 mm (95% CI −3.27 to −0.84; P = .001). We also found a significant difference in diameter measurements between CT and MRI for the left pedicle (0.53 mm; 95% CI 0.13 to 0.93; P = .011) but not for the right pedicle (0.36 mm; 95% CI −0.06 to 0.78; P = .094). We identified no significant effect of sex, age or spondyloarthrosis on the results (P > .05). CONCLUSIONS: Pedicle screw planning measurements were more accurate using CT images compared to MRI images. CT scan remains the gold standard for pedicle screw planning in trauma surgery. When using MRI images, the surgeon should be aware of the differences in screw length and diameter compared to CT in order to avoid intra- and postoperative risks.

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.Die Spondylodiszitis und postoperative Wundinfektionen sind die häufigsten infektiösen Krankheitsbilder der Brust- und Lendenwirbelsäule. Jeder wirbelsäulenchirurgisch tätige Arzt wird im Laufe seiner Karriere mit ihnen in Kontakt kommen. Kenntnisse insbesondere der Diagnostik, konservativen und operativen Therapie sowie der mikrobiellen Aspekte der Antibiotikatherapie sind daher von besonderer Bedeutung und werden in diesem Beitrag vermittelt.

Background In elderly patients, displaced femoral neck fractures are mostly treated by arthroplasty; however for younger patients ( Methods and findings Three investigators (1 orthopaedic surgeons and 2 radiologists) measured the torsion of 20 legs on 10 patients using the Jarret method and a new geometric technique. To determine the intraobserver reliability the torsional angles were calculated again after 3 months. We applied a new geometric technique, without the need to include the femoral condyles in the measurement, to directly measure the angulation. For torsional difference, the interrater reliability -ICC (interclass correlation) between all investigators was 0.887 (good) (significance level: 95%CI, 0.668–0.969; p Conclusion The established methods may fail in assessing this special aspect of malrotation after femoral neck fractures. Here, the method presented results in a significant difference between the injured and uninjured side and shows significant differences in results compared to conventional measurement methods. The inter- and intraobserver reliability determined in this study is excellent and even higher in the assessment of torsional differences than the established method. We believe that the measurement method presented in this study is a useful tool to objectify the postoperative deformities in this area and making therapy recommendations in the future.

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.

OBJECTIVES: Malrotation after surgical treatment of femoral shaft fractures is a common problem and often leads to follow-up procedures with uncertain outcome. The aim of this study is the validation of a new device (Rotational Fixator) to perform the correction safely and accurately. METHODS: In an in-vitro study, we tested the Rotational Fixator on 21 corpse bones against a commercially available standard goniometer for measurement inaccuracies. For this purpose, we varied the rotation width from 10 to 30° in inside and outside rotation. RESULTS: We found a small measurement inaccuracy of 1–2° with increasing rotation. The smallest differences are found at 10° IR with 0.9524° (SD ± 1.0713; p = 0.001) difference and 10° ER with at 0.5952° (SD ± 0.6823; p = 0.001) difference and increase up to 30° (IR 1.6667°, SD ± 1.7121, p

This study aims to test the accuracy and feasibility of a measurement of femoral torsion of a 3D C-arm system (Linea aspera method) in a cadaver setting. A total of 11 intact femora were used. Schanz screws were inserted in the femoral bone in a parallel manner with the help of a fixed drill sleeve. Femur bones were then fractured in a controlled manner and three different internal and external torsion angles were fixed with the help of a Goniometer. After that, a 3D scan was performed. The 3D data set was analyzed using a radiologic software (Visage 7, Visage Imaging Inc, USA). Measurements were then compared in the two methods with a dependent t test. Specific measurements for different angles did not show any differences between those two utilities. Intraoperative estimation of femoral antetorsion using a 3D C-Arm system and the Linea aspera method seems to be an accurate and feasible method. Nevertheless, more studies with higher patient numbers, comparison to CT seems to be the next step and can be recommended.

Study Design:Prospective observational cohort study.Objectives:To analyze clinical and economic results in patients with degenerative disc disease in the lumbar area for patients who received combined anterior and posterior fusion or total disc replacement (TDR).Methods:The study included 75 patients, 38 in the fusion group and 37 in the TDR group, who received either anterior/posterior fusion or TDR for lumbar disc disease from January 2005 to December 2008 with a minimum follow-up of 24 months. We collected data with regard to clinical parameters, demographics, visual analogue scale scores, Oswestry Disability Index scores, SF-36 and SF-6D data, surgery time, amount of blood loss, transfusion of blood products, number of levels, duration of hospital stay, and complications. For cost analysis, general infrastructure, theatre costs, as well as implant costs were examined, leading to primary hospital costs. Furthermore, average revision costs were examined, based on the actual data. Statistical analysis was performed using t tests for normal contribution and Mann-Whitney test for skew distributed values. The significance level was set to .05.Results:There was a higher surgery time, more blood loss, and longer hospital stay for the fusion group, compared with the TDR group. In addition, the hospital costs for the primary procedure and revision were 35% higher in the fusion group. The clinical data in terms of SF-36 and SF-6D showed no difference between these 2 groups.Conclusions:TDR is a good alternative to anterior and posterior lumbar fusion in terms of short follow-up analysis for clinical data and cost analysis. General advice cannot be given due to missing data for long-term costs in terms of surgical treatment of adjacent level or further fusion techniques.

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.

Thoracic injuries are common in vehicle crashes, but only a few studies thus far have analysed the relationship between injury characteristics and collision details and discussed the possible implications for future vehicle design and prevention. In this study, the crash details were prospectively collected at the scene of injury between 2004 and 2009 for severely injured patients. The collected data included the type of collision, angle of impact and change of velocity on impact as well as injury characteristics and patient demographics, including abbreviated injury scale (AIS) and injury severity score (ISS).There were 5998 accidents involving 8830 patients over this five-year period; 31 met the inclusion criteria (23 males and eight females). The mean ISS was 37 ± 12.68, the mean AIS Thorax was 4.0. Lung contusions were found in 90% of the patients, pneumothoraces in 58% and rib fractures in 81%. There was a significant relationship between accident deceleration speed (ΔV), AIS Thorax (p = 0.02) and the incidence of pneumothoraces (p = 0.046). The analysis showed a high overall incidence of thoracic injuries in car passengers. Future improvements in automobile safety and design should seek to reduce the incidence of thoracic injuries by uniform vehicle deformation and further implementation of side airbags.

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.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 p0.05.14,072 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%; p0.05) and high-energy impacts as represented by delta-v (m/s) (Burns: 33.5 ± 21.4 vs. NoBurns: 25.2 ± 15.9; p0.05) were significantly different between groups as was mortality (Burns: 12.5% vs. NoBurns: 2.1%; p0.05). Type of patients' motor vehicles and type of crash opponent showed no differences.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.

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.

Treating segmental long-bone defects remains a major challenge. For defects3 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.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.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 (p0.01). Bone density in the cortical area was 75 ± 16 % of the contralateral side (p0.03). 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).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.

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. Copyright © 2013 John Wiley & Sons, Ltd.

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.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.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.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.

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.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]).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.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.

Purpose To investigate the relationship between preoperative and postoperative spinopelvic alignment and occurrence of DJK/DJF. Study design/setting This was a retrospective observational cohort study. Patient sample The sample included 40 patients who underwent posterior correction of SK from January 2006 to December 2014. Outcome measures Correlation analysis between the preoperative and postoperative spinopelvic alignment parameters and development of DJK over the course of the study period were studied. Methods Whole spine X-rays obtained before surgery, 3 months after surgery and at the latest follow-up were analyzed. The following parameters were measured: maximum of thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lower instrumented vertebra (LIV) and LIV plumb line. Development of DJK was considered as the primary end point of the study. The patient population was split into a control and DJK group, with 34 patients and 6 patients, respectively. Statistic analysis was performed using unpaired t test for normal contribution and Mann–Whitney test for skew distributed values. The significance level was set to 0.05. Results DJK occurred in 15% (n = 6) over the study period. There was a significantly lower postoperative TK for the group with DJK (42.4 ± 5.3 vs 49.8 ± 6.7, p = 0.015). LIV plumb line showed higher negative values in the DJK group (−43.6 ± 25.1 vs −2.2 ± 17.8, p = 0.0435). Furthermore, postoperative LL changes were lower for the DJK group (33.84 ± 13.86% vs 31.77 ± 14.05, p < 0.0001.) The age of the patients who developed DJK was also significantly lower than that of the control group (16.8 ± 1.7 vs 19.6 ± 4.9, p = 0.0024.) Conclusions SK patients who developed DJK appeared to have a significantly higher degree of TK correction and more negative LIV plumb line. In addition, there may be a higher risk for DJK in patients undergoing corrective surgery at a younger age.

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. Language: en

Study design: The current study involves a cadaveric specimen with navigated pedicle screw placement using conventional reference markers and isocentric 3D fluoroscopy and also minimally invasive reference marker use with a flat panel 3D scanner. Objective: To test the feasibility of a novel minimally invasive reference marker system for navigated pedicle screw placement in combination the use of a new imaging modality i.e. flat panel 3D imaging. Summary of background data: A major limiting factor of navigated pedicle screw placement is the requirement for intraosseous fixation of reference markers. This usually necessitates an open approach to the spinous process. To address this issue, the current authors have developed a minimally-invasive fixation device for spinal reference marker fixation. Methods: A fresh-frozen cadaver with no history of spinal injury or deformity was positioned prone on a radiolucent table. L3 and L4 vertebrae were randomly selected for conventional pedicle screw insertion while T5 and T6 were selected for the percutaneous technique. A flat detector 3D C-arm (Ziehm vision FD 3D; Ziehm, Nuremberg, Germany) was used to evaluate the position of the pedicle screws at the vertebral levels targeted in the study. Results: All screws placed within the lumbar spine involved conventional reference markers. The average depth deviation was 0.73 mm and the average axis deviation was 1.67 mm. Within the thoracic spine, the minimally-invasive marker fixation devices were used. The average depth deviation was 0.85 mm and the average axis deviation was 1.75 mm. In both cases, the plan and navigation were performed satisfactorily. The Y-jaw clamp for minimally-invasive reference fixation seemed to provide stable and robust fixation of the markers, requiring only two small incisions. Conclusions: The minimally invasive reference marker system produced results which were comparable to the conventional intra-osseous markers while the flat detector-based navigation was shown to be easier to use and faster than isocentric Iso-3D techonology.

Introduction: Recently, isocentric C-arm fluoroscopy (Iso-C 3D) has been introduced as a precise imaging modality for intraoperative evaluation and management of fractures and osteosyntheses. The Siemens Iso-C 3D collects multiple fluoroscopic images during a 190-degree arc of rotation around the anatomic region of interest and reconstructs them into sagittal, axial, and coronal planes. Like the Iso-C 3D, the new Ziehm Vario 3D imaging system reconstructs images in multiple planes, but only requires a 136-degree arc of rotation. The purpose of this study was to compare the image quality and range of applicability of these two imaging systems. Methods: All the tests were performed on a human cadaver. In the first part of the experiment, different bones and joints were scanned in their native condition using both the Iso-C 3D and Vario 3D. In the second part of the experiment, scans were performed in the same anatomic regions after simulated fractures and subsequent fixation. In some cases, suboptimal placement of hardware was intentionally undertaken. Direct visualization of the fracture construct and in certain cases computed tomographic (CT) imaging served as the gold standard. The scans from both imaging systems were analyzed using a DICOM viewer by five orthopedic trauma surgeons remdomized and blinded to the study. The evaluation was based on the overall image quality, delineation of cancellous and cortical bone, delineation of joint surfaces, presence of artifacts, visualization quality of intra-articular incongruities, quality of reduction and implant positioning, and clinical applicability of the scan. These items were rated using a visual analog scale and a points system. A total of 55 3D scans were made and evaluated. Results: There was no significant difference between the two imaging systems in terms of the overall image quality, delineation of cancellous and cortical bone, and the presence of artifacts. The delineation of joint surfaces was significantly better visualized with the Iso-C 3D. Furthermore, Iso-C 3D scans demonstrated a higher overall clinical applicability than Vario 3D images. However, the Vario 3D was able to provide superior quality with scans of the shoulder joint and the adipose tissue. There was no significant difference in the visualization of intra-articular incongruities, quality of reduction, and implant positioning. Conclusion: Although the Iso-C 3D imaging system was superior in delineating the joint surfaces, the image quality, and the overall clinical applicability, the study revealed that both devices provided 3D images with sufficient quality to the surgeon to assess clinically relevant questions, including the quality of fracture reduction and implant positioning. On the other hand, the Ziehm Vario 3D is capable of doing scans of the shoulder area, which could not be taken with the Siemens Iso-C 3D because of the isocentric design.

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 Language: de

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.

Posttraumatic stress disorder (PTSD) is possibly an overlooked diagnosis of victims suffering from traffic accidents sustaining serious to severe injuries. This paper investigates the incidence of PTSD after traffic accidents in Germany. Data from an accident research unit were analyzed in regard to collision details, and preclinical and clinical data. Preclinical data included details on crash circumstances and estimated injury severity as well as data on victims' conditions (e.g. heart rate, blood pressure, consciousness, breath rate). Clinical data included initial assessment in the emergency department, radiographic diagnoses, and basic life parameters comparable to the preclinical data as well as follow-up data on the daily ward. Data were collected in the German-In-Depth Accident Research study, and included gender, type of accident (e.g. type of vehicle, road conditions, rural or urban area), mental disorder, and AIS (Abbreviated Injury Scale) head score. AIS represent a scoring system to measure the injury severity of traffic accident victims. A total 258 out of 32807 data sets were included in this analysis. Data on accident and victims was collected on scene by specialized teams following established algorithms. Besides higher AIS Head scores for male motorcyclists compared to all other subgroups, no significant correlation was found between the mean maximum AIS score and the occurrence of PTSD. Furthermore, there was no correlation between higher AIS head scores, gender, or involvement in road traffic accidents and PTSD. In our study the overall incidence of PTSD after road traffic accidents was very low (0.78% in a total of 32.807 collected data sets) when compared to other published studies. The reason for this very low incidence of PTSD in our patient sample could be seen in an underestimation of the psychophysiological impact of traffic accidents on patients. Patients suffering from direct experiences of traumatic events such as a traffic accident and presenting with signs of clinically significant distress or impairment in social interactions should be treated in a team approach including not only trauma surgeons and surgical skilled staff but also psychophysiological experienced physicians.

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.

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.

Anatomical reconstruction of the coracoclavicular ligaments is a relatively new technique for acromioclavicular (AC) joint injuries.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.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.The accuracy of anatomical AC joint reconstruction can be improved using 3D C-arm flat detector navigation.

The operating room is a central unit in the structure of a hospital. It produces high costs, but in turn generates the highest income. The operating room is a very sensitive and thus stressful working environment and requires staff that is highly qualified. As opposed to aviation, for example, the workflow is more individualized, and especially in trauma surgery it is unpredictable because of emergencies. On top of that, un necessary stress can be caused by prolonged delays. Arthroscopy and endoscopy have become standard surgical interventions. Thanks to these techniques several other interventions have become more advanced and less invasive. Classically, arthroscopy and endoscopy are used for the bigger joints and for abdominal interventions, for example, cholecystectomy.

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.

Background Pre-existing wireless local area network (WLAN) infrastructures enable the implementation of a real-time location system (RTLS) in the clinical setting. RTLS enable clinics to capture and process patient position data and link it with clinical data. The improvements in workflow and treatment brought about by RTLS may improve patient satisfaction. The aim of this study was to analyze the impact of a WLAN-based RTLS on outpatient satisfaction in our Level I trauma center. Methods This investigation was performed under different study arms (termed “phase”): In phase 0, patient satisfaction was determined (with a questionnaire) without RTLS implementation. In phase I, patient tracking with RTLS was performed, and satisfaction was determined (with a questionnaire); however, medical personnel did not utilize information gathered by RTLS. In phase II, patients were tracked by RTLS and satisfaction was determined (with a questionnaire); however, unlike phase I, the RTLS-acquired data was utilized by medical personnel. Information obtained from the questionnaire included: treatment rendered, subjective estimation of length of visit, subjective estimation of the most time-consuming portions of the clinic visit, subjective estimation of time of medical treatment, overall contentment, and contentment with wait time. In phase I and phase II, position data was automatically collected and analyzed. Statistical analyses were performed using Student's t-test and one-way Anova test. Significance level was set at 0.05. Results and discussion In total, 1234 patients were included in our study (188 in phase 0, 540 in phase I, and 506 in phase II). Completed questionnaires were collected in 53% (654) of the patients. Statistically significant higher patient contentment and lower subjective wait times were noted in phase II patients as compared to phase I patients. However, no statistical differences in the questionnaire findings were noted between phase 0 and I patients. Conclusions WLAN-based RTLS can help alleviate process inefficiencies associated with traditional clinic workflow methods, which can lead to improved patient satisfaction.

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.

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.

Rotational malalignment after intramedullary nailing of femoral fractures remains an unresolved problem. Various techniques have been described to address this problem, with limited success. In this cadaveric study, we describe the determination of the femoral anteversion (FAV) angle utilizing a new imaging software program which allows us to generate and manipulate reformatted virtual images from standard DICOM (Digital Imaging and Communications in Medicine) images.Eleven intact femoral specimens were scanned by CT before and after fracture induction in standardized fashion. The obtained DICOM image datasets were uploaded to the new software tool. From this, we obtained reformatted virtual fracture fragment images, which enabled us to reconstruct the femoral anatomy and determine FAV measurements. We then compared FAV measurements before and after fracture induction to determine if there were any statistically significant differences.Fracture induction generated 5 AO type A and 6 AO type B fractures. In the specimens prior to fracture induction, we were able to determine the mean FAV to be 17.94° ± 4.48°. Additionally, analysis of the fractured femoral specimens revealed the new mean FAV to be 16.26° ± 4.83°. Statistical analysis of these two measurement groups did not demonstrate statistical significance. When a sub-analysis was performed of the FAV measurements between the two different AO fracture types, there also were no statistically significant differences.Through new imaging software that allows us to reformat standard DICOM images and generate virtual fracture fragments, we were able to determine the appropriate FAV. We feel that this technique can potentially be integrated into the imaging algorithm for femoral shaft fractures in the future, and can potentially optimize clinical outcomes by allowing the orthopaedic surgeon to determine precisely the appropriate native FAV.

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.

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

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 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.

Background: Intraoperative visualization of articular surfaces is technically demanding, and standard two-dimensional fluoroscopic imaging frequently does not provide adequate detail of nonplanar joints. New imaging modalities allow for intraoperative 3D visualization, which are useful in articular fractures. Purpose of this study was to evaluate the utility of 3D imaging in articular fracture reconstruction. Methods: In a prospective cohort study, we evaluated 248 consecutive patients with intra-articular fractures. After fracture fixation using standard fluoroscopy, 3D imaging was performed intraoperatively using the Iso-C3D system for all patients. Surgeons filled out questionnaires regarding the utility and perceived accuracy of the 3D system. Postoperative CT scans were performed on approximately half of the patients. Main outcome measurements were based on the surgeons decision to immediately revise the articular reduction or implant position. The setup time for the system was recorded. For patients with postoperative CT scans, articular surface gaps of 2 mm or intra-articular hardware placement was again evaluated. Results: In 19% of all cases, intraoperative image analysis resulted in immediate adjustment of the reduction or hardware exchange. These revisions were based on Iso-C3D views of the articular surface that were not visible using fluoroscopy. Of the 129 postoperative CT scans, five cases revealed a technical error of the joint reconstruction, and a secondary revision procedure was performed. Conclusion: In conclusion, the Iso-C3D was a valuable intraoperative tool, providing additional information about the articular surface compared with conventional fluoroscopy in a variety of anatomic regions.

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.