Operative versus conservative treatment in pelvic ring fractures with sacral involvement.

BACKGROUND: To evaluate the performance in activities of daily living (ADL), level of pain, mortality and rate of complications in patients with a pelvic ring fracture with sacral involvement who were treated conservatively compared to a surgically treated patient collective using percutaneous iliosacral screw fixation. HYPOTHESIS: Conservative treatment does not result in inferior clinical outcome compared to operative treatment. PATIENTS AND METHODS: A retrospective study of 112 conservatively (n=46) or operatively (n=66) treated patients with an isolated posterior or a combined posterior and anterior pelvic ring fracture was performed. The analysis included: age, sex, mechanism of injury, fracture type according to AO/OTA classification, energy of trauma sustained (no-, low-, high-energy trauma), type of treatment (operative or conservative), complications as well as duration of in-hospital stay. To assess clinical and activity outcome, the visual analog scale for pain (VAS), Barthel Scale, American Society of Anaesthesiologists (ASA) scores as well as mortality were assessed. The mean follow-up was 29.3±14.6 months. Furthermore, a geriatric subgroup (n=68, age≥60, low-energy trauma only) was analyzed. RESULTS: The majority of the patients were female (79%) and suffered from low-energy trauma (n=64, 58%). There were no significant differences in the operative and the conservative groups and subgroups concerning VAS, Barthel scores and ASA scores. The survival analyses showed a significantly lower survival rate in the conservative group (41.8±3.6 months) compared to the operative group (55.9±2 months, p=0.002). Similar findings were encountered in the geriatric subgroup analysis. CONCLUSION: This study demonstrates equivalent clinical outcome in conservatively and surgically treated patients using a percutaneous iliosacral screw fixation at a mid-term follow-up. However, operatively treated patients showed decreased mortality. This needs to be carefully considered in clinical decision-making but must be further explored using a prospective randomized study approach. LEVEL OF EVIDENCE: III.

Conservative versus operative treatment of FFP II fractures in a geriatric cohort: a prospective randomized pilot trial.

A clear recommendation regarding treatment strategy of fragility fractures of the pelvic ring is missing. The most typical fracture pattern is a lateral compression type injury with non-displaced fractures of the anterior pubic rami and a unilateral os sacrum fracture (FFP II). We hypothesized that operative treatment would be superior to conservative treatment. From October 2017 to April 2020, a randomized prospective non-blinded trial with n = 39 patients was carried out. Two arms with 17 operative versus 22 conservative cases were created. Inclusion criteria were a posterior pelvic ring fracture FFP type II, age over 60 years and acute fracture (< 3 weeks). Barthel index, pain level (VAS), quality of life (EQ-5D-3L), and Tinetti-Gait Test were determined on admission, at discharge, and after 3, 6, 12 and 24 months. Median follow-up was 12.9 months. The Barthel index (= 0.325), VAS (p = 0.711), quality of life (p = 0.824), and Tinetti-Gait Test (p = 0.913) showed no significant differences between the two groups after 12 months. Two patients switched from the conservative to the operative arm due to persistent immobilization and pain. The one-year mortality rate showed no significant difference (p = 0.175). Our hypothesis that surgical treatment is superior was refuted. No significant benefit was shown in terms of quality of life, mortality and pain levels. The results suggest a more differentiated treatment approach in the future, with initial conservative treatment preferred. A larger multi-center trial is required to confirm these findings.Trial registration: The study was retrospectively registered with the German Clinical Trials Registry (DRKS00013703) on 10/12/2018.

Risk factors and injury patterns of e-scooter associated injuries in Germany.

Since the introduction of widely available e-scooter rentals in Hamburg, Germany in June of 2019, our emergency department has seen a sharp increase in the amount of e-scooter related injuries. Despite a rising number of studies certain aspects of e-scooter mobility remain unclear. This study examines the various aspects of e-scooter associated injuries with one of the largest cohorts to date. Electronic patient records of emergency department admissions were screened for e-scooter associated injuries between June 2019 and December 2021. Patient demographic data, mechanism of injury, alcohol consumption, helmet usage, sustained injuries and utilized medical resources were recorded. Overall, 268 patients (57% male) with a median age of 30.3 years (IQR 23.3; 40.0) were included. 252 (94%) were e-scooter riders themselves, while 16 (6%) were involved in crashes associated with an e-scooter. Patients in non-rider e-scooter crashes were either cyclists who collided with e-scooter riders or older pedestrians (median age 61.2 years) who tripped over parked e-scooters. While e-scooter riders involved in a crash sustained an impact to the head or face in 58% of cases, those under the influence of alcohol fell on their head or face in 84% of cases. This resulted in a large amount of maxillofacial soft tissue lacerations and fractures. Extremity fractures and dislocations were more often recorded for the upper extremities. This study comprises one of the largest cohorts of e-scooter associated injuries to date. Older pedestrians are at risk to stumble over parked e-scooters. E-scooter crashes with riders who consumed alcohol were associated with more severe injuries, especially to the head and face. Restricted e-scooter parking, enforcement of drunk driving laws for e-scooters, and helmet usage should be recommended.

Full endoscopic anterior intrapelvic plate osteosynthesis: a cadaveric feasibility study.

In this investigation, it was assumed that it must be possible to visualize the intrapelvic aspect as accustomed by pelvic surgeons using the anterior intrapelvic (modified Stoppa) approach. Moreover, it was hypothesized, that plate mountings will not only be possible for the symphysis but also at the supra- and infrapectineal aspect as well as to the posterior column. Ten anonymized cadaveric specimens were included in this study. A standard laparoscopic totally extraperitoneal (TEP) approach was used. A total of 10 landmarks were defined that are usually within reach in the open anterior intrapelvic (AIP) approach. Moreover, five different plate mountings were tested. The locations were chosen in accordance with the indication spectrum suitable for open surgery through the traditional AIP approach. It was possible to gain intrapelvic visibility in seven of ten cases. In all of those seven cases, it was technically possible to place plates to the symphysis, superior pubic ramus, as well as longer anterior column plates up to the aspect posterior of the acetabulum. In the last four of the seven cases, it was possible to mount plates to the infrapectineal aspect as well as the posterior column, too. The team, previously trained in arthroscopic surgical techniques as well as pelvic trauma surgery, observed a steep learning curve. This investigation demonstrated, that endoscopic anterior intrapelvic plate osteosynthesis was feasible in the majority of the cases in a series of ten cadaveric models. New instruments will be needed such as extra-long rasp elevators, ball-spikes as well as devices to hold and position plates and extra-long self-holding screwdrivers. With these, endoscopic pelvic surgery will likely be a realistic option for selected pelvic trauma cases in the future.

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.

A comparison of short term complication rate between 44 two- and 385 one-stage septic exchange arthroplasties in chronic periprosthetic joint infections.

BACKGROUND: Periprosthetic joint infection is a serious disease with severe consequences for the patient's life. It is not known whether one-stage or two-stage replacement arthroplasty is superior. So far, there have been no studies on short-term complications between both surgical procedures. Therefore, we performed a retrospective study aiming to determine: 1) Does two-stage septic exchange arthroplasty have a higher short-term complication rate than one-stage? 2) Is there a difference in length of hospital stay and the in-hospital mortality rate between two- and one-stage septic exchange arthroplasty? HYPOTHESIS: Two-stage septic exchange arthroplasty has a higher short-term complication rate than one-stage. PATIENTS AND METHODS: Retrospectively 429 patients who underwent a one- or two stage revision arthroplasty (288 hips and 141 knees) due to chronic PJI between January 2015 and December 2016 were recruited (one-stage: n=385, two-stage: n=44). Differences in postoperative complications, surgical therapy, ASA, Charlson Comorbidity Index (CCI), length of hospital, need for plastic surgery, pathogen, in-hospital morbidity and in-hospital mortality were compared using multiple logistic and Poisson regression. Regarding comorbidities, age, gender and BMI the groups were comparable. RESULTS: It was 3.5 times more likely to suffer from a medical complication if a two stage septic exchange was performed (OR 3.465, (95% CI: 2.573-4.358) [p<0.01]). In medical complications the two-stage group showed significantly more events (two-stage: 9 of 44=20.5%; one-stage: 30 of 385=7.8% [p=0.013]). The one-stage group showed more (not significant) nerve palsies after hip septic exchange. There was no difference in mortality between the groups (two-stage: 1/44=2.3%; one-stage: 3/385=0.8% [p=0.882]), the overall mortality was 0.93%. The duration of hospital stay was 23.9±19 days for the one-stage and 42.2±17.7 days for the two-stage group (p<0.001). CONCLUSION: We found that it is more likely to develop a medical complication after two-stage septic revision arthroplasty. There was no difference in overall surgical complications between the two surgical approaches. We did not find a significant difference in short term mortality between the two techniques, although the mortality rate was slightly higher in the two-stage group. LEVEL OF EVIDENCE: III, retrospective case control study.

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.

Synchronous Periprosthetic Joint Infections: The Need for All Artificial Joints to Be Aspirated Routinely.

BACKGROUND: Periprosthetic joint infection (PJI) is a severe complication with increasing incidence. However, we are not aware of any robust data on patients having PJI at the same time in ≥2 joints that had undergone total joint arthroplasty, referred to as synchronous PJI throughout this article. The aims of this study were to investigate the probability of the development of synchronous PJI of another prosthetic joint and to identify possible clinical risk factors for the development of synchronous PJI. In addition, we aimed to determine whether routine aspiration of all other prosthetic joints was warranted after a diagnosis of PJI in a single joint. METHODS: A total of 2,532 septic revision procedures were performed during the study period. In the final analysis, 644 patients (26 with synchronous PJI and 618 with non-synchronous PJI) with 1,508 prosthetic joints were included. The mean age (and standard deviation) was 71 ± 9.6 years. Using bivariate analyses, we calculated the odds of synchronous PJI as a function of various demographic and clinical variables. RESULTS: A suspicious clinical presentation of the non-primary joint had the strongest association with synchronous PJI (odds ratio [OR], 58.5 [95% confidence interval (CI), 22.4 to 152.8]). Additional associations with synchronous PJI were detected for a history of neoplasia (OR, 12 [95% CI, 3.9 to 37.2]), the use of immune-modulating therapy (OR, 9.5 [95% CI, 3.4 to 26.2]), the presence of systemic inflammatory response syndrome or sepsis (OR, 8.4 [95% CI, 2.8 to 25]), and having ≥3 prosthetic joints (OR, 3.0 [95% CI, 1.37 to 6.64]). CONCLUSIONS: Synchronous PJI is a rare but very serious complication and every prosthetic joint should be investigated meticulously. Suspicious clinical presentation, a history of neoplasia, sepsis, immune-modulating therapy, and ≥3 prosthetic joints were identified as risk factors and should increase the physician's vigilance. In the case of PJI, aspiration of each joint that had undergone total joint arthroplasty should be considered. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Impact of α-Defensin Test in Diagnosing Periprosthetic Infection After Total Ankle Arthroplasty.

Periprosthetic joint infection (PJI) after total ankle arthroplasty (TAA) is a serious complication, and a reliable diagnostic test to identify PJI is needed. The purpose of this study was to investigate the use of synovial α-defensin levels in identifying PJI of the ankle. Data from 33 patients were retrospectively collected between September 2015 and May 2018. Patients who had pain or suspected loosening after TAA and who had undergone joint aspiration were included in the study. Aspiration was performed in a semisterile theatre. Synovial fluid was processed in descending order for microbiological cultures, α-defensin, leukocyte esterase strip test, and cell count. A periprosthetic infection was defined by Musculoskeletal Infection Society criteria. The sensitivity, specificity, and overall accuracy were calculated, and based on a receiver operating characteristic curve, the quality of the α-defensin test was determined. The calculated area under the curve was 0.97 ± 0.32. Two of 33 patients fulfilled the 2014 Musculoskeletal Infection Society criteria and were scheduled for septic revision arthroplasty. Sensitivity, specificity, and overall accuracy of the α-defensin test were 100% (95% confidence interval [CI], 15.8% to 100%), 93.5% (95% CI, 78.6% to 99.2%), and 93.9% (95% CI, 79.8% to 99.3%), respectively. The positive predictive value was 50% (95% CI, 20.7% to 79.3%), and the negative predictive value was 100%. The α-defensin test seems to be the best available synovial test to detect a late-onset PJI after total ankle arthroplasty. Further prospective studies with a larger number of patients are required.

Current and Future Concepts for the Treatment of Impaired Fracture Healing.

Bone regeneration represents a complex process, of which basic biologic principles have been evolutionarily conserved over a broad range of different species. Bone represents one of few tissues that can heal without forming a fibrous scar and, as such, resembles a unique form of tissue regeneration. Despite a tremendous improvement in surgical techniques in the past decades, impaired bone regeneration including non-unions still affect a significant number of patients with fractures. As impaired bone regeneration is associated with high socio-economic implications, it is an essential clinical need to gain a full understanding of the pathophysiology and identify novel treatment approaches. This review focuses on the clinical implications of impaired bone regeneration, including currently available treatment options. Moreover, recent advances in the understanding of fracture healing are discussed, which have resulted in the identification and development of novel therapeutic approaches for affected patients.

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.

Congenital deformation of the posterior arch of the atlas: Subluxation of the atlanto-axial joint with temporary quadriplegia.

Instabilities of the craniocervical junction can be of rheumatic, traumatic, or congenital origin. The reported patient has a congenital malformation of the cervical spine, which is frequently observed in patients with Klippel-Feil syndrome. Her posterior arch of the atlas (C1) is hypoplastic and a chronic subluxation of the atlanto-axial joint would be possible. Although most common fusions in Klippel-Feil syndrome patients exist at C2/3, the majority of studies about Klippel-Feil syndrome deal with pediatric or adolescent individuals. Through extreme flexion of her neck, there was a compression of the spinal cord by the odontoid process. This led to a quadriplegia lasting about 10 min. Over the following weeks, all of her symptoms started to diminish. This situation turned out to be the third episode involving temporary neurological disorders in this 60-year-old female's life.

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.

Glenoid and rotator interval dimension in patients older than 40 years after traumatic anterior shoulder dislocation.

INTRODUCTION: The number of patients above 40 years suffering an anterior shoulder dislocation for the first time has recently increased. This study investigated the role of glenoid version, inclination and rotator interval dimension in patients older than 40 years with an anterior shoulder dislocation. We hypothesize that the rotator interval plays a more important role than the osseus alignment in older patients. MATERIALS AND METHODS: Patients aged older than 40 years with a traumatic shoulder dislocation were compared with patients who had undergone magnetic resonance imaging (MRI) for a different reason. The MRIs of 61 dislocation group patients were compared with MRIs of 73 comparison group patients. Two shoulder surgeons measured glenoid version, inclination, height and width, rotator interval (RI) height, base (width) and area. The study and comparison group consisted of 61 patients with a mean age of 59 ± 9 years and 73 patients with a mean age of 57 ± 12, respectively. RESULTS: The mean glenoid version of the dislocation group was - 4.9° ± 4.4° (retroversion) and mean inclination was 9.8° ± 8° (reclination). Mean rotator interval base, height and the rotator interval area was 46 ± 6 mm, 14 ± 5 mm and 33 ± 14 mm2, respectively. The comparison group had a mean glenoid version of - 5.4° ± 5.4° and a mean inclination of 10.8° ± 6.2°. The rotator interval base was 41 ± 6 mm, the height was 16 ± 4 mm and the area was 34 ± 11 mm2. The between-group differences were statistically significant for rotator interval height and base (p < 0.0001). A significant difference was revealed for the height-width ratio of the glenoid (p = 0.0001). CONCLUSIONS: In patients older than 40 years who have suffered anterior shoulder dislocation, the shape of the glenoid rather than its spatial position is of significance. A wide and high rotator interval promotes anterior shoulder dislocation in these patients.

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.