Accuracy of magnetic resonance imaging in assessing knee cartilage changes over time in patients with osteoarthritis: A systematic review.

Magnetic resonance imaging (MRI) is a technique useful for the diagnosis of cartilage damage due to high sensitivity to identify subchondral bone abnormalities and full-thickness cartilage lesions. The lack of a study on knee cartilage changes over time in patients with osteoarthritis (OA) by MRI technique led us to investigate the accuracy of MRI in identifying knee cartilage changes over time in patients with OA in a systematic review. In the present systematic review, started from the beginning of 2020 in one of the University Hospitals in Iran, the databases of CINAHL, Ovid, Elsevier, Scopus, PubMed, Science Direct, and Web of Science were searched using the keywords MRI, OA, Cartilage Lesion, Imaging Techniques. A total of 169 articles were retrieved in the initial search, and after reviewing the titles, abstracts, and full-texts, finally, seven were enrolled in the systematic review. Review of the selected papers showed that a total of 1091 subjects were studied, of which 355 were males. The results of all the studies, except one, indicated the high accuracy of MRI to identify knee cartilage changes over time. MRI technique can show cartilage changes with high accuracy in patients with knee OA over time. We proved the potential of MRI to identify articular cartilage injuries in patients with OA and its importance to the evaluation of articular cartilage lesions along with other available techniques.

Tibial plateau fracture: does fracture classification influence the choice of surgical approach? A retrospective multicenter analysis.

PURPOSE: The role of classification systems for the choice of surgical approach and the management of tibial plateau fractures remains unclear. The purpose of this study was to investigate the potential of classification systems to choose the appropriate operative approach. Current surgical management strategies were investigated in a large multicenter assessment. METHODS: In this study, we retrospectively analyzed all patients with tibial plateau fractures that have received surgical treatment in one of the five Level I trauma facilities between 2012 and 2015. Fractures were classified in each center by a senior orthopedic surgeon using the AO/OTA and the Luo classification. Demographics, trauma mechanism, as well as the surgical approach were recorded. RESULTS: 538 patients (46.1% male, 53.9% female) were included. The anterolateral approach was used most frequently with 54.8% of all single approaches; 76.2% of all combined approaches used anterolateral as part of the approach. Combined approaches were used in 22.5% of the cases; a combination of the anterolateral and medial (10%), anterolateral, and posteromedial approach (5.8%) were used most frequently. The lowest number was found for the posterolateral (1.3%) and the combined approaches dorsal/anterolateral and medial/dorsal (1.7%, 1.1%). The AO/OTA classification showed a peak for 41.B2 (21.9%) and B3 (35.5%) fractures. Regarding the Luo classification, the dorsal column was involved in 45.7%. In contrast, only 14.7% of the surgical approaches used were able to address the dorsal tibial plateau potentially. CONCLUSION: The use of dorsal approach seems to be of minor importance than expected in daily clinical practice in this multicenter study. It was not possible to specify whether the AO/OTA or the Luo classification can reliably predict the choice of surgical approach. The operative treatment strategy of tibial plateau fractures seems to rather rely on the surgeons' experience, education, and preferences.

Accuracy of navigated and conventional iliosacral screw placement in B- and C-type pelvic ring fractures.

INTRODUCTION: The objective of this study is to report the institutions experiences with standardized 2D computer-navigated percutaneous iliosacral screw placement (CNS), as well as the conventional fluoroscopically assisted screw placement method (CF) over a period of 10 years. PATIENTS AND METHODS: A total of 604 patients with sacral fractures (OTA B and C) were treated at the institution. Cases with both, a preoperative and postoperative CT scan were included for further analysis. With this prerequisite, a total of 136 cases were included. The quality of screw positioning, length of operation and intraoperative radiation exposure were recorded and compared. Moreover, it was analyzed whether the presence of dysmorphic sacra influenced the precision of screw positioning. RESULTS: Two hundred and thirty-two screws were implanted in 136 patients (100 navigated, 36 conventional). The duration of the average procedure was similar in the two groups [49.8 min (p = 0.7) conventional group (CF) vs. 48.0 min computer-navigated (CNS) group]. With computer navigation, radiation exposure was significantly reduced by almost half [128.3 vs. 65.2 s (p = 0.023)]. Screw placement was more accurate in the navigation group (79.03% CF vs. 86.47% CNS). The presence of dysmorphic sacral foramina or an increased alar slope increased the incidence of screw malpositioning. CONCLUSION: The conventional percutaneous method and a standardized 2D navigated method have similar rates of malpositioning. Dysmorphic upper sacral foramina and increased alar slope were identified as risk factors for screw malpositioning. Radiation exposure rates were reduced by half when using computer navigation. Therefore, computer navigation in iliosacral screw placement is recommended as method of choice.

The intra- and interobserver reliability of the Tile AO, the Young and Burgess, and FFP classifications in pelvic trauma.

INTRODUCTION: Several different systems of classification have been developed to understand the complexity of pelvic ring fractures, to facilitate communication between physicians and to support the selection of appropriate therapeutic measures. The purpose of this study was to measure the inter- and intraobserver reliability of Tile AO, Young and Burgess, and FFP classification in pelvic ring fractures. The Rommens classification system (FFP) is analyzed for the first time. MATERIALS AND METHODS: Four reviewers (2 × senior pelvic trauma surgeon, 1 × resident, 1 × medical student) separately analyzed and classified 154 CT scans of patients with pelvic fracture. The Tile AO, the Young and Burgess, and the FFP classifications (subgroup with patients ≥ 60 years) were compared. Another blinded re-evaluation was carried out after 2 months to determine intraobserver reliability. RESULTS: The overall interobserver agreement was fair for all classification systems (ICC: OTA 0.55, Young and Burgess 0.42, FFP 0.54). For specific categories, (e.g. type B or C fractures), there was a substantial agreement between the experienced surgeons (kappa: OTA 0.64, Young and Burgess 0.62, FFP 0.68). For inexperienced observers, there was a fair agreement in all systems (kappa: OTA 0.23, Young and Burgess 0.23, FFP 0.36). CONCLUSIONS: All three classifications reach their maximum reliability with advanced expertise in the surgery of pelvic fractures. The novel FFP classification has proved to be at least equivalent when directly compared to the established systems. The FFP classification system showed substantial reliability in patients older than 60 years.

Determination of bone density in patients with sacral fractures via CT scan.

BACKGROUND: Gold standard to diagnose osteoporosis is standard dual-energy X-ray absorptiometry (DXA). CT is a standard diagnostic tool to detect injuries to the pelvic ring. The aim of the study was to collect information on bone density without DXA by determination of Hounsfield units (HU) in CT scans of patients with sacral fractures, to draw conclusions on the prevalence of osteoporosis in patients admitted to the investigating institution. HYPOTHESIS: Is the determination of HU in CT scans a useful method to gain more information about bone density in patients with sacral fractures? PATIENTS AND METHODS: We performed a retrospective analysis of all patients treated from 2004-2014 with sacral fractures confirmed with a CT scan. A total of 531 patients (398 female, 133 male) were included in the study. Bone density was measured with CT scans in Hounsfield units in vertebral body L5. The assessment was performed by placing a single oval over the trabecular bone in the axial view. In the sagittal plane, the correct position in the middle of the vertebral body was checked. As in previously published studies, we defined bone of less than 100 HU as osteoporotic, 100-150 HU as osteopenic and above 150 HU as normal. RESULTS: In 71.6% of the patients, bone density was reduced. Seventy-five percent of patients aged 65 or more exhibited manifest osteoporosis. With each additional year of age, bone density decreased by 2.7 Hounsfield units (p˂0.001). Female patients were predominant in the patient group with osteoporotic bone (p˂0.001). CONCLUSIONS: There is significant prevalence of reduced bone density in the investigated patient group. The methodology used in this study is an uncomplicated procedure to further assess bone quality in patients with fractures of the pelvic ring. Fractures of the posterior pelvic ring in women over 65 years with low-energy trauma are most probably osteoporotic. LEVEL OF EVIDENCE: III.

Growth of Cutibacterium acnes is common on osteosynthesis material of the shoulder in patients without signs of infection.

Background and purpose - Cutibacterium acnes, formerly known as Propionibacterium acnes, is often isolated from deep tissues of the shoulder. It is recognized as an important causative agent of foreign-material associated infections. However, the incidence and significance of its detection in tissues from patients without clinical evidence for infection is unclear. We assessed the incidence of C. acnes colonization of osteosynthesis material in asymptomatic patients, and evaluated the short-term outcome in relation to the microbiological findings. Patients and methods - We microbiologically analyzed osteosynthesis material of 34 asymptomatic patients after surgery on the clavicle. Material obtained from 19 asymptomatic patients after osteosynthesis of the fibula served as a control group. Patients were clinically followed up for 3-24 months after removal of the osteosynthesis material. Results - Bacteria were recovered from devices in 29 of 34 patients from the clavicle group. 27 of 29 positive samples grew C. acnes. Isolation of C. acnes was more common in male than in female patients. No bacterial growth was observed on foreign material from patients in the fibula group. All patients remained asymptomatic at follow-up. Interpretation - Growth of C. acnes is common on osteosynthesis material of the shoulder, especially in males. Samples were positive irrespective of clinical signs of infection. Therefore, detection of C. acnes in this clinical setting is of questionable clinical significance. The high positivity rate in asymptomatic patients discourages routine sampling of material in cases without clinical evidence for infection.

The Anterior Intrapelvic Approach for Acetabular Fractures Using Approach-Specific Instruments and an Anatomical-Preshaped 3-Dimensional Suprapectineal Plate.

OBJECTIVES: Anatomical acetabular plates the anterior intrapelvic approach (AIP) were recently introduced to fix acetabular fractures through the intrapelvic approach. Therefore, we asked the following: (1) Does the preshaped 3-dimensional suprapectineal plate interfere with or even impair the fracture reduction quality? (2) How often does the AIP approach need to be extended by the first (lateral) window of the ilioinguinal approach? DESIGN: Observational case series. SETTING: Two Level 1 trauma centers. PATIENTS/PARTICIPANTS: Patients with unstable acetabular fractures in 2014. INTERVENTION: Fracture fixation with anatomical-preshaped, 3-dimensional suprapectineal plates through the AIP approach ± the first window of the ilioinguinal approach. OUTCOME MEASUREMENTS: Fracture reduction results were measured in computed tomography scans and graded according to the Matta quality of reduction. Intraoperative parameters and perioperative complications were recorded. Radiological results (according to Matta) and functional outcome (modified Merle d'Aubigné score) were evaluated at 1-year follow-up. RESULTS: Thirty patients (9 women + 21 men; mean age ± SE: 64 ± 8 years) were included. The intrapelvic approach was solely used in 19 cases, and in 11 cases, an additional extension with the first window of the ilioinguinal approach (preferential for 2-column fractures) was performed. The mean operating time was 202 ± 59 minutes; the fluoroscopic time was 66 ± 48 seconds. Fracture gaps and steps in preoperative versus postoperative computed tomography scans were 12.4 ± 9.8 versus 2.0 ± 1.5 and 6.0 ± 5.5 versus 1.3 ± 1.7 mm, respectively. At 13.4 ± 2.9 months follow-up, the Matta grading was excellent in 50%, good in 25%, fair in 11%, and poor in 14% of cases. The modified Merle d'Aubigné score was excellent in 17%, good in 37%, fair in 33%, and poor in 13% of cases. CONCLUSION: The AIP approach using approach-specific instruments and an anatomical-preshaped, 3-dimensional suprapectineal plate became the standard procedure in our departments. Radiological and functional early results justify joint preserving surgery in most cases. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Prospective evaluation of the Eppendorf-Cologne Scale.

OBJECTIVES: Early diagnosis of traumatic brain injury and reliable prediction of outcome are essential for determining treatment strategies and allocating resources. This study re-evaluates the Eppendorf-Cologne Scale (ECS) and its predictive accuracy for outcome compared with the Glasgow Coma Scale (GCS). METHODS: A prospective cohort analysis of severely injured trauma patients registered in the Trauma Registry of the German Society for Trauma Surgery from 2012-2013 was carried out. Only directly admitted patients alive on admission with complete data on GCS, ECS and outcome in terms of survival to hospital discharge or death were included. The predictive accuracy in terms of the outcome of the ECS and the GCS was modelled using area under the receiver operating characteristic (AUROC) curve analysis. RESULTS: A total of 17 616 patients fulfilled the study inclusion criteria. The ECS outmatched the predictive accuracy of the GCS for outcome (AUROC, 0.853, 95% confidence interval, 0.831-0.854; and AUROC 0.836; 95% confidence interval, 0.825-0.848, respectively; P=0.062). An ECS score of 8 was associated with a 25-fold higher mortality compared with an ECS score of 0. Patients who had an ECS score of 8 had a 1.5-fold higher mortality compared with patients allocated a GCS score of 3. CONCLUSION: The ECS shows a higher accuracy for prediction of outcome compared with the GCS and enables further differentiation within the critical GCS 3 collective.

Acromioclavicular joint dislocations: coracoclavicular reconstruction with and without additional direct acromioclavicular repair.

PURPOSE: To evaluate different stabilisation techniques for acromioclavicular (AC) joint separations, including direct AC repair, and to compare the properties of the stabilised and native joints. METHODS: An established in vitro testing model for the AC joint was used to analyse joint stability after surgical reconstruction [double TightRope (DTR), DTR with AC repair (DTR + AC), single TR with AC repair (TR + AC), and PDS sling with AC repair (PDS + AC)]. Twenty-four human cadaveric shoulders were randomised by age into four testing groups. Joint stiffness was measured by applying an axial load during defined physiological ranges of motion. Similar tests were performed for the native joints, after dissecting the coracoclavicular and AC ligaments, and after surgical reconstruction. Cyclic loading was performed for 1000 cycles with 20-70 N and vertical load to failure determined after cyclic testing. RESULTS: Axial stiffness for all TR groups was significantly higher than for the native joint (DTR 38.94 N/mm, p = 0.005; DTR + AC 37.79 N/mm, p = 0.015; TR + AC 45.61 N/mm, p < 0.001 vs. native 26.05 N/mm). The axial stiffness of the PDS + AC group was similar to that of the native joint group (21.4 N/mm, n.s.). AC repair did not significantly influence rotational stiffness. Load to failure was similar and >600 N in all groups (n.s.). CONCLUSION: Reconstruction of AC dislocations with one or two TRs leads to stable results with a higher stiffness than the native joints. For the PDS + AC group, axial stiffness was similar to the native situation, although there might be a risk of elongation. Direct AC repair showed no significantly increased stability in comparison with reconstructions without direct AC repair. Thus, a direct AC repair seems to be dispensable in clinical practice, while TRs or PDS cerclages appear to provide sufficiently stable results.

On-table decision-making in intracapsular hip fracture surgery: mid-term results of a pilot study.

INTRODUCTION: At the present time, it is generally recommended to use hip replacement in dislocated fractures to avoid failure after internal fixation. A problem is that previous research has demonstrated that observers have problems in discriminating between dislocated and undislocated fractures. A possible solution to this problem would be to use arthroplasty in the majority of the cases. However, this also means that many fractures with the potential for uneventful healing would be replaced. MATERIALS AND METHODS: In the current investigation, the mid-term outcome was recorded for patients with intracapsular hip fractures who were treated with either internal fixation or arthroplasty. A novel treatment algorithm was employed. After careful exclusion of cases with known risk factors for failure after internal fixation, a technique called on-table decision was used to identify suitable patients for internal fixation. RESULTS: A total of 72 patients with intracapsular hip fractures were studied with a median follow-up time of 12 months (IQR 8-15.25 months). Nineteen (19) patients (26 %) were excluded in the selection process, leaving 53 (74 %) for on-table decision-making. Thirty patients (42 %) were identified as suitable for internal fixation and gave anatomically stable closed reductions. Two of these patients (7 %) exhibited non-unions and one (3 %) avascular necrosis. CONCLUSIONS: The mid-term outcome after internal fixation is promising. The careful selection process may be helpful in identifying fracture patterns for which internal fixation may be considered as a safe and less invasive alternative to hip arthroplasty.

Determination of Femoral Neck Angle and Torsion Angle Utilizing a Novel Three-Dimensional Modeling and Analytical Technology Based on CT Datasets.

INTRODUCTION: Exact knowledge of femoral neck inclination and torsion angles is important in recognizing, understanding and treating pathologic conditions in the hip joint. However, published results vary widely between different studies, which indicates that there are persistent difficulties in carrying out exact measurements. METHODS: A three dimensional modeling and analytical technology was used for the analysis of 1070 CT datasets of skeletally mature femurs. Individual femoral neck angles and torsion angles were precisely computed, in order to establish whether gender, age, body mass index and ethnicity influence femoral neck angles and torsion angles. RESULTS: The median femoral neck angle was 122.2° (range 100.1-146.2°, IQR 117.9-125.6°). There are significant gender (female 123.0° vs. male 121.5°; p = 0.007) and ethnic (Asian 123.2° vs. Caucasian 121.9°; p = 0.0009) differences. The median femoral torsion angle was 14.2° (-23.6-48.7°, IQR 7.4-20.4°). There are significant gender differences (female 16.4° vs. male 12.1°; p = 0.0001). Femoral retroversion was found in 7.8% of the subjects. CONCLUSION: Precise femoral neck and torsion angles were obtained in over one thousand cases. Systematic deviations in measurement due to human error were eliminated by using automated high accuracy morphometric analysis. Small but significant gender and ethnic differences were found in femoral neck and torsion angles.

High incidence of osteochondral lesions after open reduction and internal fixation of displaced ankle fractures: Medium-term follow-up of 100 cases.

BACKGROUND: The incidence of osteochondral lesions (OCLs) in association with displaced ankle fractures has only been examined in two previous studies. In both studies magnetic resonance imaging (MRI) was performed prior to open reduction and internal fixation (ORIF). Because MRI may overdiagnose or overestimate the extent of OCLs in an acute trauma setting the aim of this study was to determine the incidence of OCLs after ORIF of displaced ankle fractures using MRI at medium-term follow-up, and to analyse if the severity of fracture or the clinical outcome correlates with the incidence of OCLs. PATIENTS AND METHODS: Following institutional review board approval a total of 100 patients (mean age, 41.3 years; range, 17.9-64.3 years) with a displaced ankle fracture who had undergone ORIF according to the AO principles were included in this study. The American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score was used to quantify the clinical outcome and MR images were evaluated for OCLs of the talus and distal tibia after a mean of 34.5 months (range, 17.5-54.1 months). RESULTS: OCLs were found in 40.4% of the patients. Logistic regression revealed a significant correlation between the severity of fracture and the incidence of OCLs. Patients with a trimalleolar fracture (p=0.04) or an ankle fracture dislocation (p=0.003) had a significantly higher risk for developing an OCL compared to those with a type B fracture. Logistic regression also demonstrated a significant correlation between the clinical outcome (AOFAS score) and the incidence of OCLs (p=0.01). The risk for developing an OCL increases up to 5.6% when the AOFAS score decreases by one point. CONCLUSION: OCLs were frequently found in association with acute ankle fractures at medium-term follow-up, and the severity of fracture was associated with an increased number of OCLs. Considering the disadvantages of MRI including the high cost and limited availability, the results of this study may help to explain why anatomic surgical realignment of displaced ankle fractures may still be associated with poor clinical outcomes.

Isolated syndesmotic injuries in acute ankle sprains: diagnostic significance of clinical examination and MRI.

PURPOSE: Acute ankle sprains are frequently accompanied by syndesmotic injuries. These injuries are often overlooked in clinical examinations. The aim of this study was (1) to evaluate the incidence of syndesmotic injuries in acute ankle sprains using MRI, (2) to determine the accuracy of common clinical diagnostic tests, (3) to analyse their inter-rater reliability, and (4) to evaluate the role of clinical symptoms in the diagnosis of syndesmotic injuries. METHODS: A total of 100 patients with acute ankle sprain injury without associated fractures in plane radiographs were enrolled. The clinical assessment was performed by two independent examiners. Local findings, ankle ligament palpation, squeeze test, external rotation test, Drawer test, Cotton test, and the crossed-leg test (two examiners) were compared with MRI results (read by two blinded radiologists) as a reference standard. RESULTS: Ninety-six participants (57% male) met the inclusion criteria. MRI detected a ruptured anterior inferior tibiofibular ligament (AITFL) in 14 patients (15%); 9 partial tears and 5 complete tears were evident. Evidence of pain at rest was found to predict syndesmotic injuries most accurately (p = 0.039). The palpation test over the proximal fibula produced the highest inter-rater correlation (κ = 0.65), but the lowest sensitivity for syndesmotic injuries of 8%. All other clinical tests demonstrated moderate to fair inter-rater reliabilities (κ = 0.37-0.52). Low sensitivity values were found with all clinical tests (13.9-55.6%). CONCLUSION: In this study, clinical examination was insufficient to detect syndesmotic injuries in acute ankle sprains. MRI scanning revealed a syndesmotic lesion in 15% of patients. MRI scanning should be recommended in patients with ongoing pain at rest following ankle sprains. LEVEL OF EVIDENCE: I.

A novel electromagnetic navigation tool for acetabular surgery.

BACKGROUND: Acetabular fracture surgery is demanding and screw placement along narrow bony corridors remains challenging. It necessitates x-ray radiation for fluoroscopically assisted screw insertion. The purpose of this cadaver study was to evaluate the feasibility, accuracy and operation time of a novel electromagnetic navigation system for screw insertion along predefined acetabular corridors. METHODS: A controlled laboratory study with a total of 24 electromagnetically navigated screw insertions was performed on 8 cadaveric acetabula. 3 peri-acetabular bony corridors (QSS, Quadrilateral Surface Screw; IAS, Infra-Acetabular Screw; PCS, Posterior Column Screw) were defined and screws were placed in a defined order without fluoroscopy. Operation time was documented. Postoperative CT scans were performed to analyse accuracy of screw placement. RESULTS: Mean cadaver age was 70.4 ± 11.7. Successful screw placement was accomplished in 22 out of 24 (91.7%) cases. The overall mean time for all 3 acetabular screws was 576.6 ± 75.9s. All 3 complications occurred during the placement of the IAS due to an impassable narrow bony corridor. QSS mean length was 50 ± 5mm, IAS mean length was 85 ± 10mm and PCS mean length was 120 ± 5mm. CONCLUSION: In this cadaver study the novel electromagnetic navigation system was feasible to allow accurate screw placement without fluoroscopy in defined narrow peri-acetabular bony corridors.

What is the frequency of nerve injuries associated with acetabular fractures?

BACKGROUND: Acetabular fractures and surgical interventions used to treat them can result in nerve injuries. To date, only small case studies have tried to explore the frequency of nerve injuries and their association with patient and treatment characteristics. High-quality data on the risk of traumatic and iatrogenic nerve lesions and their epidemiology in relation to different fracture types and surgical approaches are lacking. QUESTIONS/PURPOSES: The purpose of this study was to determine (1) the proportion of patients who develop nerve injuries after acetabular fracture; (2) which fracture type(s) are associated with increased nerve injury risk; and (3) which surgical approach was associated with the highest proportion of patients developing nerve injuries using data from the German Pelvic Trauma Registry. Two secondary aims were (4) to assess hospital volume-nerve-injury relationship; and (5) internal data validity. METHODS: Between March 2001 and June 2012, 2236 patients with acetabular fractures were entered into a prospectively maintained registry from 29 hospitals; of those, 2073 (92.7%) had complete records on the endpoints of interest in this retrospective study and were analyzed. The neurological status in these patients was captured at their admission and at the discharge. A total of 1395 of 2073 (67%) patients underwent surgery, and the proportions of intervention-related and other hospital-acquired nerve injuries were obtained. Overall proportions of patients developing nerve injuries, risk based on fracture type, and risk of surgical approach type were analyzed. RESULTS: The proportion of patients being diagnosed with nerve injuries at hospital admission was 4% (76 of 2073) and at discharge 7% (134 or 2073). Patients with fractures of the "posterior wall" (relative risk [RR], 2.0; 95% confidence interval [CI], 1.4-2.8; p=0.001), "posterior column and posterior wall" (RR, 2.9; CI, 1.6-5.0; p=0.002), and "transverse+posterior wall" fracture (RR, 2.1; CI, 1.3-3.5; p=0.010) were more likely to have nerve injuries at hospital discharge. The proportion of patients with intervention-related nerve injuries and that of patients with other hospital-acquired nerve injuries was 2% (24 of 1395 and 46 of 2073, respectively). They both were associated with the Kocher-Langenbeck approach (RR, 3.0; CI, 1.4-6.2; p=0.006; and RR, 2.4; CI, 1.4-4.3; p=0.004, respectively). CONCLUSIONS: Acetabular fractures with the involvement of posterior wall were most commonly accompanied with nerve injuries. The data suggest also that Kocher-Langenbeck approach to the pelvic ring is associated with a higher risk of perioperative nerve injuries. Trauma surgeons should be aware of common nerve injuries, particularly in posterior wall fractures. The results of the study should help provide patients with more exact information on the risk of perioperative nerve injuries in acetabular fractures. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Electromagnetic navigation provides high accuracy for transcoracoid-transclavicular drilling.

PURPOSE: A novel radiation-free electromagnetic navigation system (ENS)-based method was developed, and its feasibility and accuracy for transclavicular-transcoracoid drilling procedures were evaluated in an experimental setting. METHODS: Sixteen arthroscopically assisted electromagnetic navigated transcoracoid-transclavicular drilling procedures with subsequent TightRope device implantation were performed on eight human cadavers. Post-operative fluoroscopy and CT-scan analysis were acquired to determine tunnel placement accuracy. Optimal tunnel placement was defined as both the coracoid entry and exit point of the tunnel localized in the centre position of the coracoid base without cortical breach or fracture. RESULTS: Successful tunnel placement was accomplished in all 16 cases. The mean overall operation time was 30.3 ± 5.0 min. Regarding the coracoid exit point, 15 of 16 tunnels (93.8%) were localized in the desired base-centre position. During the navigated drilling procedure, no misguidance of the drill requiring directional readjustments or restarts occurred. No cortical breach, no fractures and no complications occurred. CONCLUSIONS: The electromagnetically navigated transcoracoid-transclavicular drilling procedure used in this study demonstrated high targeting accuracy, required no intraoperative radiographs, was associated with no complications and provided user-friendliness.

Foudroyant Course of an Extensive Clostridium septicum Gas Gangrene in a Diabetic Patient with Occult Carcinoma of the Colon.

Background. Spontaneous gas gangrene is a rare disease in which Clostridium septicum frequently can be detected. After an incubation period of 5-48 hours, a very painful swelling is accompanied by a rapidly spreading toxic-infectious clinical picture ultimately leading to septic shock and multiple organ failure. We present a case of a completely documented rare infectious disease with triage findings including initial vital signs, initial medical findings, and the emergency lab., radiological, intraoperative, histopathological, microbiological, and postmortem results. After initial diagnosis of the underlying disease, the patient has been immediately transferred to the operating theatre. The laboratory findings reflect the devastating effect of toxin α which is a toxin typically produced by C. septicum. The patient presented both an anaemia and a manifest coagulopathy as well as an onset of multiple organ failure. Despite the aggressive medical and surgical measures that have been taken, this patient could not be saved. Discussion. The case presented vividly emphasises the difficulty to identify these cases early enough to save a patient. This documentation may help health care providers to identify this life threatening disease as early as possible in future cases.

Biomechanical evaluation of 3 stabilization methods on acromioclavicular joint dislocations.

BACKGROUND: Traumatic acromioclavicular (AC) joint dislocations can be addressed with several surgical stabilization techniques. The aim of this in vitro study was to evaluate biomechanical features of the native joint compared with 3 different stabilization methods: locking hook plate (HP), TightRope (TR), and bone anchor system (AS). HYPOTHESIS: The HP provides higher stiffness than the anatomic reconstruction techniques. STUDY DESIGN: Controlled laboratory study. METHODS: A new biomechanical in vitro model of the AC joint was used to analyze joint stability after surgical repair (HP, TR, and AS). Eighteen cadaveric specimens were randomized for bone density and diameter in the midclavicle section. Joint stiffness was measured by applying an axial load and a defined physiological range of motion for internal and external rotations and upward and downward rotations. Data were recorded at 3 stages: for the native joint after dissecting the AC ligaments, directly after repair, and after axial cyclic loading (1000 cycles with 20 and 70 N at 1 Hz). To evaluate which implant mimics physiological joint properties best, axial stiffness of vertical stability was assessed in combination with rotation. Finally, static loading in the superior direction was applied until failure of the joints occurred. RESULTS: Axial stiffness of the TR and AS groups was 2-fold higher than for the HP group and the native joint (67.1, 66.1, and 22.5 N/mm, respectively; P < .004). Decreased load-to-failure rates were recorded in the HP group compared with the TR and AS groups (248.9 ± 72.7, 832.0 ± 401.4, and 538.0 ± 166.1 N, respectively). The stiffness of the rotations was not significantly different between the treatment methods but was lower in horizontal and downward rotations compared with the native state. Thus, native AC ligaments contributed a significant share to joint stiffness. CONCLUSION: The TR and AS groups demonstrated higher vertical load capacity. Compared with the TR and AS, the HP demonstrated an axial stiffness closest to the native joint. For restoring physiological properties, reconstruction of the AC ligaments may be necessary. CLINICAL RELEVANCE: The results show different biomechanical properties of the HP and anatomic reconstructions.

A comparative biomechanical analysis of fixation devices for unstable femoral neck fractures: the Intertan versus cannulated screws or a dynamic hip screw.

BACKGROUND: First introduced in 2005, the "Intertan" (IT), an intramedullary nail with two cephalocervical screws, has become an increasingly popular option for treating intertrochanteric fractures. The purpose of this study was to identify the utility of this device for stabilization of unstable femoral neck fractures compared with cannulated screws (CS) and a dynamic hip screw (DHS). METHODS: Twenty-four human cadaveric femurs were harvested and assigned to three groups that were matched with regard to bone mineral density (BMD). Standardized Pauwels-Type-III fractures were osteomized with a custom-made saw guide and fixated by an "IT," three CS, or a DHS. All constructs were biomechanically tested in a servohydraulic testing machine with a physiologic mechanical axis loading of the femoral head (700 N), cyclical compression to 1,400 N (10,000 cycles; 2 Hz), and loading to failure. All specimens were compared with respect to the number of survived cycles, mechanical strength, head displacement, load to failure, and failure mechanism. RESULTS: Regardless of the fixation, the mechanical strength of the stabilized femurs was significantly decreased to 71% compared with the intact femurs (100%). During cyclical testing 46% of the constructs (6 CS, 4 DHS, and 1 IT) failed. There was no difference between the mechanical strength of all survived constructs regarding the BMD, but the BMD of the failed specimens was significantly reduced compared with the surviving femurs (0.71 g/cm² ± 0.18 g/cm² vs. 1.07 g/cm² ± 0.33 g/cm²; p < 0.05). IT femurs survived significantly longer than CS specimens (IT, 9,063 cycles ± 2,480 cycles vs. CS, 3,325 cycles ± 3,885 cycles vs. DHS, 5,716 cycles ± 4,448 cycles; p < 0.01), endured higher failure loads (IT, 4,929 N ± 1,105 N vs. CS, 3,421 N ± 20 N vs. DHS, 3,505 N ± 905 N; p < 0.05), and presented a less inferior head displacement (IT, 8.5 mm ± 1.6 mm vs. CS, 16.4 mm ± 6.7 mm vs. DHS, 14.5 mm ± 6.4 mm; p < 0.05). CONCLUSION: Our results suggest that (1) none of the tested devices restore a comparable mechanical strength in the fractured specimens compared with the intact femurs, and (2) the "IT" possesses some biomechanical benefits for internal fixation of unstable femoral neck fractures compared with DHS and CS. Because the IT constructs failed with an inferior femoral neck fracture, complicating the mandatory anchorage of a prosthetic stem in a revision operation, more biomechanical experiments using the IT in the presence of a posterior comminution defect are required, along with clinical outcome studies.