A comparison between Asians and Caucasians in the dimensions of the femoral isthmus based on a 3D-CT analysis of 1189 adult femurs.

INTRODUCTION: For successful intramedullary implant placement at the femur, such as nailing in unstable proximal femur fractures, the use of an implant that at least reaches or exceeds the femoral isthmus and yields sufficient thickness is recommended. A number of complications after intramedullary femoral nailing have been reported, particularly in Asians. To understand the anatomical features of the proximal femur and their ethnic differences, we aimed to accurately calculate the femoral isthmus dimensions and proximal distance of Asians and Caucasians. METHODS: In total, 1189 Asian and Caucasian segmented 3D CT data sets of femurs were analyzed. The individual femoral isthmus diameter was precisely computed to investigate whether gender, femur length, age, ethnicity or body mass index have an influence on isthmus diameters. RESULTS: The mean isthmus diameter of all femurs was 10.71 ± 2.2 mm. A significantly larger diameter was found in Asians when compared to Caucasians (p < 0.001). Age was a strong predictor of the isthmus diameter variability in females (p < 0.001, adjusted r2 = 0.299). With every year of life, the isthmus showed a widening of 0.08 mm in women. A Matched Pair Analysis of 150 female femurs showed a significant difference between isthmus diameter in Asian and Caucasian femurs (p = 0.05). In 50% of the cases the isthmus was found in a range of 2.4 cm between 16.9 and 19.3 cm distal to the tip of the greater trochanter. The female Asian femur differs from Caucasians as it is wider at the isthmus. CONCLUSIONS: In absolute values, the proximal isthmus distance did not show much variation but is more proximal in Asians. The detailed data presented may be helpful in the development of future implant designs. The length and thickness of future standard implants may be considered based on the findings.

The influence of bone quality on radiological outcome in 50 consecutive acetabular fractures treated with a pre-contoured anatomic suprapectineal plate.

PURPOSE: To investigate the range of indications of an anatomical-preshaped three-dimensional suprapectineal plate and to assess the impact of the bone mass density on radiologic outcomes in different types of acetabular fractures. PATIENTS AND METHODS: A consecutive case series of 50 acetabular fractures (patient age 69 ± 23 years) treated with suprapectineal anatomic plates were analyzed in a retrospective study. The analysis included: Mechanism of injury, fracture pattern, surgical approach, need for additional total hip arthroplasty, intra- or postoperative complications, as well as bone mass density and radiological outcome on postoperative computed tomography. RESULTS: Most frequently, anterior column fracture patterns with and without hemitransverse components as well as associated two column fractures were encountered. The anterior intrapelvic approach (AIP) was used in 98% (49/50) of the cases as primary approach with additional utilization of the first window of the ilioinguinal approach in 13/50 cases (26%). Determination of bone density revealed impaired bone quality in 70% (31/44). Postoperative steps and gaps were significantly greater in this subgroup (p < 0.05). Fracture reduction quality for postoperative steps revealed anatomic results in 92% if the bone quality was normal and in 46% if impaired (p < 0.05). In seven cases (14%), the plate was utilized in combination with acute primary arthroplasty. CONCLUSION: A preshaped suprapectineal plate provides good radiological outcomes in a variety of indications in a predominantly geriatric cohort. Impaired bone quality has a significantly higher risk of poor reduction results. In cases with extensive joint destruction, the combination with total hip arthroplasty was a valuable option.

Accident Mechanisms and Injury Patterns in E-Scooter Users­A Retrospective Analysis and Comparison With Cyclists.

BACKGROUND: E-scooter sharing systems were initiated in Hamburg in June 2019. The number of persons injured in Hamburg in e-scooter accidents rose thereafter. The goal of this study was to determine the typical accident mechanisms and injury patterns after e-scooter accidents in Germany, and to compare these with bicycle accidents. METHODS: In a retrospective study, accidents with e-scooters and bicycles that occurred from June 2019 to June 2020 were registered and analyzed with respect to demography, accident mechanisms, diagnostics, patterns of injury, emergency medical care, operations, and inpatient hospitalizations. RESULTS: 89 persons sustained e-scooter accidents (mean age 33.9 years, standard deviation [SD] 14 years); 435 persons who sustained bicycle accidents (mean age 42.5 years, SD 17 years) served as a comparison group. E-scooter accidents more commonly occurred at night (37% versus 14%), and 28% of the persons who sustained them were under the influence of alcohol (cyclists: 6%). 54% of the injured e-scooter riders suffered trauma to the head or face; 14% had a severe head injury and 16% had a severe facial injury. Fractures of the upper limbs were more common than fractures of the lower limbs (18% versus 6%). On initial assessment in the emergency room, injured cyclists were more frequently classified as needing immediate treatment than injured e-scooter riders (7% versus 1%). CONCLUSION: The head, face, and upper limbs are the most commonly affected parts of the body in e-scooter accidents. Compared to bicycle accidents, e-scooter accidents more commonly occur on weekends and in association with alcohol. From a medical point of view, abstaining from alcohol consumption and wearing a helmet when using an e-scooter is strongly recommended.

All-suture anchor pullout results in decreased bone damage and depends on cortical thickness.

PURPOSE: To evaluate the influence of cortical and cancellous bone structure on the biomechanical properties of all-suture and conventional anchors and compare the morphological bone damage after their failure. The hypothesis of the study is that all-suture anchor pullout is less invasive and that the pullout force is influenced by the cortical thickness. METHODS: Thirty human humeri were biomechanically tested as follows: starting with a load cycle from 20 to 50 N, a stepwise increase of the upper peak force by 0.05 N for each cycle at a rate of 1 Hz was performed. Analysis included maximum pullout strength for three different anchor implantation angles (45°, 90°, 110°) of the two anchor types. After anchor pullout, every sample underwent micro-CT analysis. Bone mineral density (BMD) and cortical thickness were determined at the anchor implantation site. Furthermore, the diameter of the cortical defect and the volume of the bone cavity were identified. RESULTS: The maximum pullout strength of all-suture anchors demonstrates a strong correlation to the adjacent cortical thickness (r = 0.82, p ≤ 0.05) with at least 0.4 mm needed to withstand 200 N. No correlation could be seen in conventional anchors. Moreover, no correlation could be detected for local BMD in both anchors. All-suture anchors show a significantly narrower cortical defect as well as a smaller bone cavity following pullout (4.3 ± 1.3 mm vs. 5.3 ± 0.9 mm, p = 0.037; 141 mm3 vs. 212 mm3; p = 0.009). The cortical defect is largest if the anchors are placed at a 45° angle. CONCLUSION: In contrast to conventional anchors, the pullout force of all-suture anchors depends on the thickness of the humeral cortex. Furthermore, all-suture anchors show a significantly smaller cortical defect as well as decreased bone damage in the case of pullout. Therefore, the clinical implication of this study is that all-suture anchors are advantageous due to their bone preserving ability. Also, intraoperative decortication should not be performed and cortical thickness should be preoperatively evaluated to decrease the risk of anchor failure.

Obesity in spontaneous spondylodiscitis: a relevant risk factor for severe disease courses.

Spondylodiscitis is a serious and potentially life-threatening disease. Obesity is a risk factor for many infections, and its prevalence is increasing worldwide. Thus, the aim of this study was to describe characteristics of obese patients with spondylodiscitis and identify risk factors for a severe disease course in obese patients. Between December 2012 and June 2018, clinical records were screened for patients admitted for spondylodiscitis. The final analysis included 191 adult patients (mean age 64.6 ± 14.8 years). Patient data concerning demographics, comorbidities, surgical treatment, laboratory testing, and microbiological workup were analysed using an electronic database. Patients were grouped according to body mass index (BMI) as BMI ≥ 30 kg/m2 or < 30 kg/m2. Seventy-seven patients were classified as normal weight (BMI 18.5-24.9 kg/m2), 65 as preobese (BMI 25-29.9 kg/m2), and 49 as obese (BMI ≥ 30 kg/m2). Obese patients were younger, had a higher revision surgery rate, and showed higher rates of abscesses, neurological failure, and postoperative complications. A different bacterial spectrum dominated by staphylococci species was revealed (p = 0.019). Obese patients with diabetes mellitus had a significantly higher risk for spondylodiscitis (p = 0.002). The mortality rate was similar in both cohorts, as was the spondylodiscitis localisation. Obesity, especially when combined with diabetes mellitus, is associated with a higher proportion of Staphylococcus aureus infections and is a risk factor for a severe course of spondylodiscitis, including higher revision rates and sepsis, especially in younger patients.

The three-dimensional bone mass distribution of the posterior pelvic ring and its key role in transsacral screw placement.

To optimize the placement of iliosacral screws in osteoporotic bone it is essential to know where to find the best purchase. The aim of this study was to determine and visualize the distribution of bone mass in the posterior pelvic ring by using a color-coded thermal map, to differentiate the bone distribution patterns in normal pelvises and in pelvises with impaired bone density and to identify zones in S1 and S2 with particularly good bone quality, in both healthy and osteoporotic pelvises. A total of 324 pelvises were included. The bone density of the posterior pelvic ring, the fifth lumbar vertebral body (L5) and screw corridors S1 and S2 were visualized. Each individual pelvis was measured with a 3D automated program. Two groups were selected - patients with mean bone density in L5 of ≤100 HU (group 1, n = 52) and those with mean bone density >100 HU (group 2, n = 272). Color-coded thermal maps are presented of the bone density distribution in the pelvises. Bone density in L5 correlated significantly with S1 and S2; bone density was significantly higher in the S1 than in the S2 corridor (p < 0.001). Bone was denser in the posterior and upper parts of the S1 body. Bone density was significantly lower in group 2 than in group 1 (p < 0.001). The color-coded "thermal" maps of bone mass distribution can help surgeons to decide where sacroiliac screws are likely to find optimal purchase.

Conventional rotator cuff versus all-suture anchors-A biomechanical study focusing on the insertion angle in an unlimited cyclic model.

PURPOSE: The purpose of this study was to compare the biomechanical properties of an all-suture anchor to a conventional anchor used commonly in rotator cuff repairs. Furthermore, the biomechanical influence of various implantation angles was evaluated in both anchor types in a human cadaveric model. METHODS: 30 humeri were allocated into three groups with a similar bone density. The two different anchor types were inserted at a predefined angle of 45°, 90° or 110°. Biomechanical testing included an initial preload of 20N followed by a cyclic protocol with a stepwise increasing force of 0,05N for each cycle at a rate of 1Hz until system failure. Number of cycles, maximum load to failure, stiffness, displacement and failure mode were determined. RESULTS: 27 anchors failed by pullout. There was no significant difference between the conventional and the all-suture anchor regarding mean pullout strength. No considerable discrepancy in stiffness or displacement could be perceived. Comparing the three implantation angles no significant difference could be observed for the all-suture or the conventional anchor. CONCLUSION: All-suture anchors show similar biomechanical properties to conventional screw shaped anchors in an unlimited cyclic model. The exact insertion angle is not a significant predictor of failure.

Biomechanical analysis of conventional anchor revision after all-suture anchor pullout: a human cadaveric shoulder model.

HYPOTHESIS AND BACKGROUND: The possibility of implanting a conventional anchor at the pullout site following all-suture anchor failure was evaluated in a biomechanical cadaveric model. The hypothesis of the study was that anchor revision would yield equal biomechanical properties. METHODS: Ten human humeri were obtained, and bone density was determined via computed tomography. After all-suture anchor (n = 5) and conventional 4.5-mm anchor (n = 5) insertion, biomechanical testing was conducted. Following all-suture anchor pullout, a conventional 5.5-mm anchor was inserted at the exact site of pullout (n = 5) and biomechanical testing was reinitiated. Testing was conducted using an initial preload of 20 N, followed by an unlimited cyclic protocol, with a stepwise increasing force of 0.05 N for each cycle at a rate of 1 Hz until system failure. The number of cycles, maximum load to failure, stiffness, displacement, and failure mode, as well as macroscopic observation at the failure site including diameter, shape, and cortical destruction, were registered. RESULTS: The defect following all-suture pullout showed a mean diameter of 4 mm, and conventional revision was possible in each sample. There was no significant difference between the initial all-suture anchor implantation and the conventional anchor implantation or the conventional revision following all-suture failure regarding mean pullout strength, stiffness, displacement, or total number of cycles until failure. CONCLUSION: Conventional anchor revision at the exact same site where all-suture anchor pullout occurred is possible and exhibits similar biomechanical properties.

Implementation of a multidisciplinary infections conference affects the treatment plan in prosthetic joint infections of the hip: a retrospective study.

INTRODUCTION: Establishing a systematic multidisciplinary approach in the treatment of prosthetic joint infections (PJI) of the hip and analyzing its effect on clinical decision-making. PATIENTS AND METHODS: Forty-six patients diagnosed with PJI of the hip were included in the retrospective study. The treatment plan was either established by a single-discipline approach (n = 20) or by a weekly multidisciplinary infections conference (n = 26) consisting of at least an orthopedic surgeon, microbiologist and pathologist. Recorded data included the length of hospital stay, number and type of surgeries, medical complications, recovered organisms as well as the number of applied antibiotics. RESULTS: Patients discussed in the multidisciplinary infections conference showed a significantly shorter in-hospital stay (29 vs 62 days; p < 0.05), a significant reduction in surgeries (1.8 vs 5.1; p < 0.05) and a smaller number of antibiotics required (2.8 vs 4.2; p < 0.05). No significant difference could be found comparing inpatient complications between the two groups. Staphylococcus aureus and coagulase-negative staphylococci were the most frequently recovered organisms in both patient groups. CONCLUSION: This study demonstrates the successful implementation of a weekly infections conference as an instrument to introduce a multidisciplinary approach to PJI of the hip. Implementation of these conferences significantly improves the treatment plan compared to a single-discipline approach, which we therefore highly recommend for other institutions. Multidiscipline may even affect clinical outcome which needs to be further investigated.

Femoral antecurvation-A 3D CT Analysis of 1232 adult femurs.

INTRODUCTION: For optimal treatment of femoral fractures, it is essential to understand the anatomical antecurvation of the human femur. Recent clinical studies have highlighted the problem of distal anterior encroachment or even perforation of the nail tip. The aim of this study was to accurately describe the femoral antecurvation in a large cohort. Another objective was to identify the most important influences on femoral antecurvation, such as age, femur length, gender and ethnicity. METHODS: A three dimensional modelling and analytical technology was applied for the analysis of 1,232 femurs. Individual femoral antecurvation was precisely computed to determine whether gender, femur length, age, ethnicity or body mass index influence the radius of curvature (ROC). RESULTS: The calculated mean ROC for all femurs was 943 mm. The lowest ROC of 826 mm was found in female Asian femurs. A regression analysis demonstrated that age and femur length could predict the variability of the curvature, with femoral length as most powerful predictor. A matched pair subgroup analysis between Asians and Caucasians could not show any significant differences of ROC values. CONCLUSIONS: The mean radius of the femoral antecurvation may be smaller than previously reported revealing a significant mismatch between the actual individual anatomy and existing implants. In opposite to existing literature, this study suggests, that antecurvation differences between various ethnicities may exclusively be attributed to differences in femoral length and age. The findings of this study may be found helpful in the development of novel designs for intra- and extramedullary implants.

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.

SERPINB5 Promoter Hypomethylation Differentiates Pancreatic Ductal Adenocarcinoma From Pancreatitis.

OBJECTIVES: The diagnosis of pancreatic ductal adenocarcinoma (PDAC) is challenging in the setting of pancreatitis. We investigated SERPINB5 for its impact on PDAC tumor biology and its use as a diagnostic marker for PDAC in the setting of pancreatitis. METHODS: Patient samples from PDAC primary tumors, PDAC lymph node metastases, and pancreatitis were investigated for SERPINB5 promoter methylation by methylation-specific polymerase chain reaction (PCR). Six PDAC cell lines were investigated in vitro and in vivo using an orthotopic mouse model to generate primary tumors and metastases. SERPINB5 mRNA expression, protein expression, and promoter methylation were determined by quantitative reverse transcriptase-PCR, methylation-specific PCR, and Western Blot. RESULTS: In patient samples, detection of an unmethylated SERPINB5 promoter differentiated pancreatitis from PDAC with a sensitivity of 57% and a specificity of 95% (P < 0.001). SERPINB5 was not deregulated in primary tumors versus metastases, but primary tumors without SERPINB5 protein expression had significantly reduced viability (P = 0.02). CONCLUSIONS: SERPINB5 seems to assume an oncogenic role in PDAC. In clinical samples, detection of unmethylated SERPINB5 was a specific marker for PDAC even in the context of pancreatitis and may provide the basis for a liquid biopsy option to detect PDAC.