Fracture displacement of lateral compression type 1 (LC1) Pelvic Ring Injuries: Which measurement methods are reliable and does displacement correlate with adverse events?

PURPOSE: To determine the interobserver reliability of perceived displacement (PD) ≥ 1 cm of lateral compression type 1 (LC1) pelvic ring fractures and to determine if PD correlated with published methods of measuring fracture displacement and adverse events. METHODS: The injury and follow-up radiographs of 10 patients with nonoperative minimally displaced LC1 injuries were reviewed by 27 orthopaedic trauma surgeons to determine if they perceived an interval fracture displacement ≥ 1 cm. Perceived displacement (PD) was compared to 11 measurements of displacement: the difference in heights of iliac crests (IC), sourcils, and ischial tuberosities on AP/outlet radiographs; the distance from femoral head (FH) to the sacral midline and the distance between the radiographic teardrops (TD) on the AP; the distance from the TD to sacral midline and the difference in distances between the SI joints and the contralateral TD on the inlet. The interobserver reliability and correlation of PD and measured displacement was calculated. The association between PD and adverse events was also evaluated. RESULTS: PD had weak interobserver reliability (kappa = 0.46). Many of the measurements of displacement were poorly sensitive for PD. The magnification-corrected AP TD measurement had the highest sensitivity (100%) for PD and excellent interobserver reliability (Intraclass correlation 0.97), but had a low specificity (57.1%). All three patients with PD had adverse events while patients without PD had uneventful recoveries (p = 0.008). CONCLUSIONS: The AP TD measurement detected all cases of PD and had excellent reliability. PD was associated with adverse events, suggesting that accurate and reliable measurements of displacement are warranted. LEVEL OF EVIDENCE III: Diagnostic.

The effect of pelvic ring rotation and tilt on the radiographic teardrop distance: an important consideration in the assessment of dynamic displacement on stress radiographs.

PURPOSE: The purpose of this study was to determine the effect of rotation and tilt on the radiographic teardrop distance (TD) on anteroposterior (AP) pelvis radiographs. METHODS: Radiographic examination of a pelvis models was conducted utilizing increasing degrees of beam rotation and tilt on portable C-arm fluoroscopy. The TD, x-plane rotation (symphyseal-mid-sacrum distance (SMS)), and y-plane tilt (sacroiliac joint-symphysis distance (SIS)) were measured by four independent observers. Interobserver reliability was assessed using intraclass correlations. RESULTS: TD was altered by less than 2 mm with up to 7.5° fluoroscopic rotation (SMS: 3 cm) and up to 30° of inlet and 15° of outlet (SIS: ± 3.3 cm). SMS distance effectively corresponded to the degree of rotation present (r = 1.00, CI: 0.97 to 1.00, p < 0.0001) and was strongly correlated to TD (r = -0.95, CI: -0.99 to -0.67, p = 0.001). SIS distance effectively corresponded to the degree of tilt present (r = -0.97, CI: -0.99 to -0.88, p < 0.0001) and was correlated to TD (r = 0.94, CI: 0.75 to 0.99, p = 0.0001). Linear regression models determined that, with every degree of rotation and tilt, TD was altered by 0.4 mm and 0.09 mm, respectively (p = 0.0004, r2 = 0.93 and p < 0.0001, r2 = 0.94, respectively). Interobserver reliability among observers was excellent (0.92). CONCLUSION: The TD has excellent interobserver reliability and is minimally impacted by up to 7.5° of rotation, 30° inlet tilt, and 15° of outlet tilt. Utilization of these thresholds may ensure reliability of TD measurements when assessing pelvis stress radiographs.

Protein expression of the tear film of domestic cats before and after inoculation with Toxoplasma gondii.

BACKGROUND: Tear film (TF) helps maintain and protect ocular function against damage to the ocular surface. Proteins are one of its main constituents, whose expression pattern can be used as a biomarker of ocular changes and systemic diseases. The aim of this study was to evaluate the expression of proteins in the TF of domestic cats before and after infection with Toxoplasma gondii, in the phases of acute infection and chronicity. Twelve healthy cats received orally homogenized brain matter obtained from mice inoculated with T. gondii oocysts, strain ME49. Cat feces were collected daily from the third day after infection to assess the release of oocysts. TF samples were obtained from cats, by Schirmer's Tear Test 1, on day 0 (before infection), day 5 after infection (acute phase of infection, with maximum peak release of oocysts in feces) and on day 21 after infection (start of chronic phase, 7 days after total absence of oocyst release in feces). Tear samples were also submitted to proteomic analysis in a Q-Tof-Premier mass spectrometer. RESULTS: A total of 37 proteins with scores equal to or greater than 100 were identified on D0, followed by 36 on D5 and 42 on D21. Of these, 27 were common to D0 and D5, 33 to D0 and D21, 27 to D5 and D21, and 26 were common to the three groups, totaling 54 proteins. The most abundant proteins were lipocalin allergen Fel d, serum albumin, aldehyde dehydrogenase, lactoperoxidase and lactotransferrin. There was no significant difference in the abundance of proteins found on D0 and D5, but there was a statistical difference between D0 and D21 for ACT1_AEDAE, CERU_HUMAN and GELS_HUMAN. Regarding D5 and D21, there were significant differences for KV1_CANLF, LAC_PIG, TRFL_PIG, ACT1_AEDAE, CERU_HUMAN, GELS_HUMAN and OVOS2_HUMAN. CONCLUSIONS: The main proteins identified in the TF of domestic cats are similar to those found in humans and other animal species. Most are part of the ocular surface defense system against injuries. The most expressed proteins in animals in the chronic phase of T. gondii infection are associated with the immune response to the parasite.

Tear-drop technique in iliac screw placement: a technical analysis.

BACKGROUND: Instrumentation of the lumbosacral region is one of the more challenging regions due to the complex anatomical structures and biomechanical forces. Screw insertion can be done both navigated and based on X-ray verification. In this study, we demonstrate a fast and reliable open, low exposure X-ray-guided technique of iliac screw placement. METHODS: Between October 2016 and August 2019, 48 patients underwent sacropelvic fixation in tear-drop technique. Screw insertion was performed in open technique by using an X-ray converter angulated 25-30° in coronal and sagittal view. The anatomical insertion point was the posterior superior iliac spine. Verification of correct screw placement was done by intraoperative 3D scan. RESULTS: In total, 95 iliac screws were placed in tear-drop technique with a correct placement in 98.1%. CONCLUSIONS: The tear-drop technique showed a proper screw position in the intraoperative 3D scan and therefore may be considered an alternative technique to the navigated screw placement.

Anatomical landmarks for acetabular abduction in adult hips: the teardrop vs. the inferior acetabular rim.

PURPOSE: The purpose of this study is to compare the acetabular teardrop (the structure located inferomedially in the acetabulum, just superior to the obturator foramen. The medial lip is the interior, and the lateral lip is the exterior of the acetabular wall) with the inferior acetabular rim as anatomical landmarks to measure the acetabular abduction angle (AAD) using coronal CT images from different levels. METHODS: Our retrospective study included 120 pelvic CT scans from patients with non-orthopedic pathologies or stress fractures of the proximal femur. The patients included 60 females with a mean age of 48 years (range 40-66) and 60 males with a mean age of 46 years (range 38-65). Each AAD was measured using coronal plane CT slices from five levels: AAD (+ 10) (10 mm anterior to the femoral head center), AAD (+ 5) (5 mm anterior to the femoral head center), AAD (0) (through the femoral head center), AAD (- 5) (5 mm posterior to the femoral head center), and AAD (- 10) (10 mm posterior to the femoral head center). The measurements were then divided into two groups: teardrop-based AADs [AAD (+ 10), AAD (+ 5), and AAD (0)] and rim-based AADs [AAD (- 5) and AAD (- 10)]. RESULTS: There were no mean significant differences in AAD within the groups, whereas the difference between the groups was significant. The mean teardrop-based AAD was quite significantly different from the mean rim-based AAD due to the use of different anatomical landmarks. Teardrop-based AADs are lower than rim-based AADs, leading to measurement differences of more than 10°. CONCLUSIONS: AAD measurements considering the inferior acetabular rim can be more accurate than those considering the acetabular teardrop because the inferior rim represents the nearly hemispheric acetabulum better than does the teardrop. It is recommended to differentiate between the teardrop and the inferior acetabular rim when measuring AAD to avoid confusion regarding acetabular abduction.

Impact of acetabular reaming depth on reconstruction of rotation center in primary total hip arthroplasty.

PURPOSE: To study the impact of acetabular reaming depth on reconstruction of rotation center (RC) in unilateral primary total hip arthroplasty (UPTHA) and guide individualized preoperative design. METHODS: 200 postoperative standard bilateral hip anteroposterior radiographs after UPTHA were included, which were collected from January, 2013 to June, 2017 in our hospital. Osteonecrosis of femoral head was the only diagnosis in this cohort. The parameters were measured on the anteropoterior radiographs by using RadiAnt DICOM viewer. RESULTS: The average of the thickness of the teardrop is about 6.13 ± 1.42 mm. The parameter a (the difference value of the distance of bilateral RC and midline) was positively correlated with the parameter e (the acetabular reaming depth), and the Pearson correlation coefficient was 0.49 when P = 0.05. Furthermore, the value of parameter (e) was 8.25 mm when a2 (the distance from the center of the prosthesis femoral head to the vertical line across the midpoint of pubic symphysis) equaled a1 (the distance from RC of the healthy femoral head to the vertical line across the midpoint of pubic symphysis). CONCLUSIONS: The reaming depth of the acetabulum could influence the reconstruction of RC during UPTHA. When the medial margin of the cup was placed about 2 mm to the lateral border of the ipsilateral teardrop (the bottom of the ovum), the rotation center would be accurately restored.

[A new method of measuring leg length discrepancy on radiograph in patients undergoing total hip arthroplasty].

Objective: To investigate the reliability of the distance between the tip of the greater trochanter and inter-teardrop line (GT-IT) in evaluating the leg length discrepancy (LLD) in patients underwent total hip arthroplasty (THA). Methods: Patients who underwent THA in Xi'an Honghui Hospital from August 2015 to February 2016 were enrolled in this study.The patients were measured for bilateral hips anterior-posterior (AP) radiograph preoperatively and postoperatively.Four distances measured, included: GT-IT, the tip of lesser trochanter and bi-ischial line (LT-BI); LT-IT and the anterior superior iliac spine and the medial malleolus (ASIS-MM). Magnification factor was considered when calculating absolute values.Intraclass correlation coefficient (ICC) was used to detect the reliability of the measurement data.Single factor analysis and paired t test were performed to compare data among the methods. Results: The ICC values of the four groups were greater than 0.80, which showed excellent agreement in the measurements.Single factor analysis of variance showed there were no statistically significant differences in the LLDs of the four groups preoperatively and postoperatively (F=0.914, 0.886, both P>0.05). There was no significant differences in preoperative and postoperative LLD between group GT-IT and group ASIS-MM, LT-BI or LT-IT(t=-1.544-1.114, all P>0.05). The LLDs were comparable between group LT-BI, ASIS-MM and LT-IT both preoperatively and postoperatively (t=1.577, 0.976, 1.344, -0.087, all P>0.05). And the LLD in group LT-IT and ASIS-MM were equivalent preoperatively and postoperatively (t=0.130, 1.063, both P>0.05). Bland-Altman plot illustrated high level of agreements between the four methods. Conclusion: Great reliability can be obtained with the GT-IT in evaluating the LLD in patients undergoing THA.

Quantifying the Relationship Between the Transverse Acetabular Ligament and the Radiographic Teardrop.

BACKGROUND: The transverse acetabular ligament (TAL) has been described as an anatomic landmark to guide in the positioning of the acetabular component during total hip arthroplasty. On plain films, the radiographic teardrop (RT) has similarly been used as a measure of appropriate cup positioning. The goal of this study is to quantify the distance and location between the anatomic TAL and RT landmarks to aid in the positioning of acetabular component. METHODS: Sixteen randomly selected cadaveric pelvises (eight males, eight females) underwent dissection. Radiographic markers were placed bilaterally at the anteromedial insertions of the TAL, and true anteroposterior pelvic radiographs of the cadavers were obtained. Distances between the markers and the lateral borders of the RT were measured. RESULTS: The mean distance between the anteromedial insertion of the TAL and the lateral border of the RT in the male specimens was 11.8 (99% confidence interval, 11.4-12.2) mm. In the female specimens, the TAL to RT distance was shorter, with a mean of 8.4 (99% CI, 7.2-9.6) mm. There was a statistically significant difference between male and female cadavers (P < .01). CONCLUSION: The distance between the RT and TAL differs between males and females. Understanding the distance between these anatomic and radiographic landmarks should aid surgeons in obtaining a more accurate degree of acetabular component medialization and can serve as a guide to minimize overmedialization in order to achieve more accurate and reproducible placement of acetabular components during a total hip arthroplasty.

Teardrop Alignment Changes After Volar Locking Plate Fixation of Distal Radius Fractures With Volar Ulnar Fragments.

BACKGROUND: We assessed factors associated with change in radiographic teardrop angle following volar locking plate (VLP) fixation of volarly displaced intra-articular distal radius fractures with volar ulnar fragments (VUF) within the ICUC database. The primary outcome was change in radiographic alignment on follow-up imaging, defined as a change in teardrop angle from intra-operative fluoroscopy greater than 5°. METHODS: Patients with distal radius fractures treated with a VLP within the ICUC database, an international collaborative and publicly available dataset, were identified. The primary outcome was volar rim loss of reduction on follow-up imaging, defined as a change in radiographic alignment from intra-operative fluoroscopy, teardrop angle less than 50°, or loss of normal radiocarpal alignment. Secondary outcomes were final range of motion (ROM) of the affected extremity. Radiographic Soong classification was used to grade plate position. Descriptive statistics were used to assess variables' distributions. A Random Forest supervised machine learning algorithm was used to classify variable importance for predicting the primary outcome. Traditional descriptive statistics were used to compare patient, fracture, and treatment characteristics with volar rim loss of reduction. Volar rim loss of reduction and final ROM in degrees and as compared with contralateral unaffected limb were also assessed. RESULTS: Fifty patients with volarly displaced, intra-articular distal radius fractures treated with a VLP were identified. Six patients were observed to have a volar rim loss of reduction, but none required reoperation. Volar ulnar fragment size, Soong grade 0, and postfixation axial plate position in relation to the sigmoid notch were significantly associated (P < .05) with volar rim loss of reduction. All cases of volar rim loss of reduction occurred when VUF was 10.8 mm or less. CONCLUSIONS: The size of the VUF was the most important variable for predicting volar rim loss of reduction followed by postfixation plate position in an axial position to the sigmoid notch and the number of volar fragments in the Random Forest machine learning algorithm. There were no significant differences in ROM between patients with volar ulnar escape and those without.

A Novel Method to Calculate Functional Pelvic Tilt Using a Standing Anteroposterior Pelvis Radiograph.

Background: Functional patient-specific acetabular component positioning is important in total hip arthroplasty. We preoperatively evaluate the pelvic tilt (PT) on standing anteroposterior (AP) pelvis radiographs using a novel measurement and then recreate this intraoperatively using imaging. The purpose of this study was to determine if there is a linear correlation between this novel measurement and the actual PT. Methods: A retrospective study of 200 patients was performed, measuring PT on standing lateral radiographs as the angle between the anterior superior iliac spines and the pubic symphysis. On the AP pelvis radiographs, the trans-teardrop (TT) line was drawn between the teardrops. The vertical distance between the TT line and the top of the pubic symphysis (TTPS) was then measured. A ratio was made between the lengths of both lines to account for the overall size of the pelvis (TTPS/TT). Linear regression analysis was then performed between PT and TTPS/TT. Results: There was a strong linear correlation between the TTPS/TT ratio on AP pelvis radiographs and PT on lateral radiographs (r = 0.785, r2 = 0.616, P < .001). On subanalysis of the female cohort, the correlation became even stronger (r = 0.864, r2 = 0.747, P < .001). Using regression analysis, a linear equation was created (PT = 97.32 [TTPS/TT] - 5.51), to calculate the PT using the TTPS/TT ratio. Conclusions: There is a strong linear correlation between the TTPS/TT ratio and PT. Using this information, a surgeon can reliably use the distance between the TT line and the superior pubic symphysis on an AP radiograph to recreate the patient's functional PT intraoperatively, allowing for a more accurate patient-specific placement of the acetabular component.

Suction cannula design for safe microneurosurgery.

INTRODUCTION: Suction cannula (SC) is an important instrument for a neurosurgeon. Currently used suction control valves, kept in the sterile field, are controlled by the surgeon, for which he needs to leave the surgical dissection or by assistant or by operation room personnel to adjust the pressure of the equipment (suction machine or central suction), which lies in the unsterile field. Authors studied relationships of the different diameters of SC and the thumb hole (TH) of the SC and present their findings. METHODS: Seven SC with various diameters of their lumen and TH were used for the study. Suction pressures were measured with suction tip open, immersed in saline and TH open and closed. TH of 2 SC were made smaller using adhesive tape over the TH and making smaller hole over the tape and two additional measurements were taken using changed SC with modified TH. SPSS Statistics 23.0 (IBM India Pvt Ltd, Bangaluru, India) was used for statistical analysis of the pressure recordings and SC features. RESULTS: Pressure and diameter of ST or TH were related in opposite direction. As the diameter increases the pressure decreases. A strong negative association was observed between the diameter of TH and the pressure. CONCLUSION: TH diameter of SC is important to control suction pressure with any size of SC. One should use tear-drop type TH or appropriate diameter of the circular type of TH to contemplate safe microneurosurgery.

Different Moro Zones of Psoas Major Affect the Clinical Outcomes after Oblique Lumbar Interbody Fusion: A Retrospective Study of 94 Patients.

Oblique lumbar interbody fusion (OLIF) has been driven to the maturity stage in recent years. However, postoperative symptoms such as thigh paresthesia resulting from intraoperative retraction of the psoas major (PM) have sometimes occurred. The aim of this study was to assess the different positions and morphology of PM muscles and their relationship with clinical outcomes after OLIF by introducing the Moro zones. Patients who underwent L4-5 OLIF at our institution between April 2019 and June 2021 were reviewed and all data were recorded. All patients were grouped by Moro zones into a Moro A cohort and a Moro I and II cohort based on the front edges of their left PM muscles. A total of 94 patients were recruited, including 57 in the Moro A group and 37 in the Moro I and II group. Postoperative thigh pain or numbness occurred in 12 (21.1%) and 2 (5.4%) patients in the Moro A group and the Moro I and II group, respectively. There was no difference in the psoas major transverse diameter (PMTD) between groups preoperatively, while longer PMTD was revealed postoperatively in the Moro A group. The operating window (OW) and psoas major sagittal diameter (PMSD) showed significant differences within and between groups. Thirteen patients had teardrop-shaped PM muscles, with 92.3% in the Moro A group showing significantly worse clinical scores at 1-week follow-up. The Moro zones of the PM affected the short-term outcomes after OLIF. Preoperative measurements and analysis of OW, PMSD and PM morphology should be performed as necessary to predict short-term outcomes.

The Transverse Mechanical Axis of the Pelvis for Post-Operative Evaluation of Total Hip Arthroplasty.

Currently, orthopedic surgeons mainly use the inter-teardrop line (IT-line) as the transverse mechanical axis of the pelvis (TAP) for postoperative evaluation of total hip arthroplasty (THA). However, the teardrop is often unclear in the pelvis anteroposterior (AP) radiographs, which makes postoperative evaluation of THA difficult. In this study, we attempted to identify other clear and accurate axes for postoperative evaluation of THA. We calculated the mean and standard deviation of these angles and tested the significance of these angles using t-tests. The inter-teardrops line (IT line) and the upper rim of the obturator foramen (UOF) had smaller angles with the IFH line. The bi-ischial line (BI line) was relatively inaccurate in measurements. We recommend using the IT line as the TAP when the lower boundary of the teardrops is clear and the shapes of the teardrops on both sides of the pelvis are symmetrical. When there is no deformation of the obturator foramen on pelvic AP radiographs, the UOF is also a good choice for the TAP. We do not recommend the BI line as the TAP.

Anterior C2-3 fusion with internal fixation for unstable teardrop fracture of the axis: a retrospective cohort study.

Background: Teardrop fracture of the axis (TDFA) is rare in cervical injuries. The treatment for TDFA is controversial, and few prior studies exist. C2-3 fusion with internal fixation could provide anterior support and ensure immediate stability. The aim of this study was to evaluate the clinical outcome of anterior C2-3 fusion with internal fixation for unstable TDFA. Methods: Fifteen patients with unstable TDFA were treated by anterior C2-3 fusion with internal fixation between October 2012 and June 2018. Radiological parameters, including the avulsed ratio of the inferior endplate of the axis, the average rotation angle, and the displacement of the avulsed fragment, were measured before the operation. Clinical parameters, including the visual analogue scale (VAS) and the Neck Disability Index (NDI), were assessed before the operation; 3 days, 1 month, and 3 months after the operation; and at the final follow-up. Perioperative complications were also recorded. Results: The mean follow-up time was 42.4 months (24-60 months). The mean operation time was 81.0 minutes (62-104 minutes), and the intraoperative blood loss was 61.3 mL (30-100 mL). Two patients complained of mild dysphagia after the operation and recovered at postoperative 1 month. Two patients classified as American Spinal Injury Association (ASIA) impairment scale grade D both improved to ASIA grade E postoperatively. The VAS score decreased from a preoperative value of 8.2±1.2 to a postoperative value of 1.7±0.9 (P<0.001), and maintained at 1.5±0.6 at last follow-up (P=0.51). The NDI score decreased from a preoperative value of 79.3±14.1 to a postoperative value of 16.5±4.3 (P<0.001), and maintained at 17.1±4.6 at last follow-up (P=0.62). No loosening or rupture of implantation was observed during the follow-up period. Bony union and fusion were achieved in all patients. Conclusions: The clinical and radiological outcomes of anterior C2-3 fusion with internal fixation for the treatment of unstable TDFA were satisfactory. Anterior C2-3 fusion with internal fixation could be considered as a safe and effective method for managing TDFA.

Teardrop and sourcil line (TSL): a novel radiographic sign that predicts residual acetabular dysplasia (RAD) in DDH after closed reduction.

Background: Residual acetabular dysplasia (RAD) is a major problem of developmental dysplasia of the hip (DDH) after closed reduction (CR). Several parameters have been investigated as ways of predicting RAD; however, prediction of RAD remains controversial. The purpose of this study was to evaluate the radiographic sign of teardrop and sourcil line (TSL) in pediatric patients with DDH to enable prediction of RAD after CR. Methods: One hundred and twenty-five hips with DDH treated with CR and followed up for at least 2 years were included in this study. The mean age at CR was 18.3 months (range, 9 to 32 months) and the average follow-up time was 50.2 months (range, 24 to 89 months). The acetabular index (AI) was measured at different time points. The cases were divided into two groups according to whether TSL became continuous or not. The relationships among TSL, AI and RAD were analyzed. Results: The RAD incidence was 73.6% (92/125) at the last follow-up. AI at CR and TSL were the prognostic factors for RAD (P=0.017 and 0.001, respectively). Thirty-four hips showed a continuous TSL. There was a lower RAD rate in the TSL continuous group (P<0.001). There was no statistical difference in the AI at CR between the TSL continuous and discontinuous groups; however, the level of AI after CR was lower in the TSL continuous group. The TSL of 74% (20/27) hips became continuous after acetabular osteotomy surgery. Conclusions: The TSL continuous group had a lower AI and incidence of RAD than the discontinuous group. The TSL can be a predictive factor of RAD in DDH after CR and restore the continuous of TSL maybe a potential parameter that can help surgeons to make a judgment intra-operation.

Safety effects of roundabout conversions in Carmel, Indiana, the Roundabout City.

INTRODUCTION: Roundabouts are a proven safety countermeasure for intersection safety. This study examined the safety effects of roundabout conversions in Carmel, Indiana, also known as the "Roundabout City." Doing so is of particular interest because Carmel has a high density of roundabouts and its drivers understand their effectiveness and are familiar with navigating them. This study also adds to the current state of knowledge about innovative double-teardrop roundabouts (i.e., linked roundabouts with teardrop-shaped central islands). METHOD: Negative binomial models accounting for correlation within site pairs were applied to evaluate the safety effects of converting conventional intersections to roundabouts on total crashes, injury crashes, and property-damage-only (PDO) crashes between study sites and control sites for different roundabout types (single-lane, multi-lane, and double-teardrop). We compared crash data from a 2-year period before the installation of the roundabouts with the 2-year period after the conversions. RESULTS: Injury crashes were 47% lower than what would have been expected without the roundabout conversions. The effects were strongest at the double-teardrop roundabouts, where injury crashes were significantly reduced by 84% and total crashes by 63%. Single-lane roundabouts experienced significant decreases of 51% in total crashes and 50% in PDO crashes (and a nonsignificant decrease of 50% in injury crashes). Multi-lane roundabouts were associated with increases in total and PDO crashes but a 15% decrease in injury crashes, though all were nonsignificant. CONCLUSIONS: Overall, the City of Carmel's roundabout program is associated with reductions in injury crashes, which indicates improvements to safety. Single-lane and double-teardrop roundabouts are associated with improvements in the occurrence and severity of crashes. PRACTICAL APPLICATIONS: Double-teardrop roundabouts should be considered for installation at interchange terminals to improve highway safety.

A New Parameter of Hip Instability in Developmental Dysplasia of the Hip (DDH): Teardrop Distance.

Background: Hip instability is one of the etiologies of accelerated onset of osteoarthritis in developmental dysplasia of the hip (DDH). There are some radiological parameters for hip instability in hip dysplasia like broken shenton's line, elevated acetabular index, reduced lateral center edge angle (LCEA), upsloping lateral sourcil. We have discovered a new index of teardrop distance (TD) for assessing instability. Herein, we hypothesized that increased TD could be used as evidence of hip instability in DDH patients, which we verified using TD as an auxiliary diagnostic parameter for DDH, from supine to standing position. Methods: Female DDH patients undergoing Bernese periacetabular osteotomy (PAO) were enrolled in the DDH group, and normal female volunteers were in the control group. Anteroposterior radiographs of the pelvis in the supine and standing positions were taken, and LCEA, Tönnis angle (TA), sharp angle (SA), and TD were tested using Stata software to analyze the changes between supine and standing anteroposterior pelvic radiographs. Results: There were 26 female volunteers with 52 hips in the control group: supine TD 6.80 ± 0.98 mm, standing TD 6.65 ± 1.3 mm (P > 0.05). A total of 78 patients with 135 hips were included in the DDH group: supine TD 10.51 ± 3.50 mm, standing TD 10.93 ± 4.23 mm (P < 0.05). In either supine or standing position, TD in the DDH group was significantly wider than that in the control group (P < 0.05). In the DDH group, TD was correlated with TA and LCEA (rp 0.494-0.588, P < 0.05); TD was not correlated with SA, weight, or BMI (P > 0.05). There was a weak correlation between TD difference and standing LCEA (rp -0.276, P < 0.05). Conclusion: TD > 10 mm was a common imaging feature of DDH. It increased from supine to standing position, thus indicating hip instability in DDH patients. The hip parameters of both positions should be compared, fully considering the factors of hip stability.

Use of human teardrop fluid for the determination of trace elements in healthy individuals and diabetic patients.

BACKGROUND: The use of unconventional biological materials in human trace element studies has increased in terms of published research studies. The aim of present study was to develop and validate the use of teardrop fluid for determining trace element levels in the human body. No study has been published in this area yet. This is a new non-invasive approach in the possible early diagnosis of the pathogenesis of type 2 diabetes. MATERIALS AND METHODS: Human teardrop fluid samples were obtained from Karbala (Iraq) (n = 111) healthy individuals and with type 2 diabetes (n = 44); and London (UK) healthy individuals (n = 18). The levels of V, Cr, Mn, Fe, Cu, Zn, As, Sr and Cd were determined using an inductively coupled plasma mass equipped with collision cell technology for polyatomic ion correction (ICP-MS). STATISTICAL ANALYSIS: Discriminate function analysis (DFA) was carried out to determine the set of variables that discriminated between the trace elements in teardrop fluid samples from healthy individuals and diabetic patients. RESULTS: The trace element levels of human teardrop fluid are similar for many elements to that reported for human blood serum in the literature. This is interesting since they have different physiological functions, although overall they are mainly water containing electrolytes (∼ 90 %) and solids (antibodies, hormones, etc). In general, for the study groups in Karbala, Iraq, significantly higher teardrop fluid levels of Mn and Sr were found in type 2 diabetic patients when compared with healthy individuals (evaluated using an F-test and a two-tailed t-test). The levels of V, Cu and As were found to be significantly higher (P < 0.05) in healthy individuals than type 2 diabetic patients. Although the levels of Fe and Zn were slightly higher in type 2 diabetic patients than healthy cases, the differences were not statistically significant (P > 0.05). Cr and Cd were found to have similar levels for both study groups. Significantly higher teardrop fluid levels of V, Cr, Mn, Fe, Zn, As and Sr were found in healthy individuals from Karbala (Iraq) when compared with those from London (UK). In contrast, the levels of Cd observed to be significantly higher in London (UK) than Karbala. No statistical difference was found for Cu between the two healthy groups. STATISTICAL ANALYSIS: Discriminate analysis showed that human teardrop fluid V, Mn, Zn, As, Sr and Cd levels could be used to discriminate between healthy and type 2 diabetes study groups in Karbala, Iraq (83 % of cases correctly classified). CONCLUSION: The use of human teardrop fluid for determining the trace element levels of human health conditions has been evaluated. Trace elemental levels are like that for blood serum which is widely used as an invasive method for assessing human health conditions. Sample collection for teardrop fluid is non-invasive and the application has potential for determining the trace element levels in healthy individuals and disorder conditions (like type 2 diabetes) in countries where cultural and gender sensitivity are issues with respect to the collection methods used for other body fluid samples.

A Rare Case Report of Flexion Teardrop Cervical Fracture with Blunt Vertebral Artery Injury Leading to Stroke.

Non penetrating trauma to vertebral artery is a known complication in craniovertebral trauma. They are mainly reported with facet dislocations or injuries involving the foramen transversarium. Such a type of injury is rarely seen with flexion injuries. We report such a case leading to cerebellar stroke in a young male presenting to us with hemiparesis. A 43-year-old male presented to us 1 month post trauma after a motor vehicular accident with complaint of weakness of right half of the body since the trauma. He suffered blunt trauma to head and neck and complained of a flail right upper limb since trauma and weakness of the right lower limb which had partly improved. He was conservatively managed elsewhere. Radiographic investigations revealed complete occlusion of the right vertebral injury above the level of 6th cervical vertebra and flexion teardrop fracture of 5th cervical vertebra. He was managed conservatively for the vertebral artery injury (VAI) and corpectomy of C5 vertebra with anterior cervical plating and fusion. Such a rare type of injury can present with unexplained neurodeficit which needs appropriate radiological investigations for diagnosis before ascribing the cause to cord trauma. Hence, all high velocity motor vehicular accidents with associated fractures and neurodeficit should be screened for blunt VAIs.

Reduction and Open Fixation of a Cervical Teardrop Fracture: A Technical Note.

BACKGROUND: Cervical teardrop fractures are hyperflexion and axial loading injuries associated with significant ligamentous disruption. Patients sustaining these types of injury are classically treated with a cervical corpectomy and anterior fusion. However, there are notable disadvantages of this approach, namely, disruption of the patient's true anatomic alignment and a reduction in the number of fixation points available for cervical fusion. Here we present a novel method of open reduction and internal fixation in a neurologically intact patient with cervical teardrop fracture. CASE DESCRIPTION: A 34-year-old man presented to Ryder Trauma Center after a helmeted motorcycle accident. The patient was found to be neurologically intact on arrival, and imaging demonstrated a C5 teardrop fracture without bony retropulsion. The patient was taken to the operating room for an open reduction and internal fixation of the fracture using a novel technique. This technique used traditional diskectomies at the C4-5 and C5-6 levels, along with a temporary, unicortical screw into the C5 body to capture the anteriorly displaced fragment. A bicortical screw was then placed into the contralateral side, and now, having fully reduced the fracture, the first (temporary) screw was replaced with a bicortical screw. The patient was neurologically intact postoperatively, with 2-month follow-up computed tomography scan demonstrating stable reduction of the fracture. CONCLUSIONS: Here we present a novel technique for open reduction and internal fixation of a cervical teardrop fracture that does not require cervical corpectomy. This technique is particularly useful in patients with an anteriorly displaced fragment and without neurologic deficit or compromise.