Edge Angle Research Articles

Birmingham Royal Orthopaedic Hospital (BROH) Femoral Offset-An Ancillary Measure of Adult Dysplasia of the Hip.

Introduction Adult dysplasia of the hip (ADH) is a disorder of abnormal development of the hip joint resulting in a shallow acetabulum and uncovering of the femoral head. Several radiological measurements such as the Tönnis angle (acetabular index), lateral center edge angle of Wiberg, and cross-sectional imaging parameters exist to calculate hip dysplasia. Aims The aim of this article was to describe a new ancillary linear measure of ADH on cross-sectional imaging, the Birmingham Royal Orthopaedic Hospital (BROH) Femoral offset. Patients and Methods Anteroposterior radiographs of the pelvis and computed tomography imaging of 100 consecutive patients with suspected hip dysplasia were reviewed. Demographic details and clinical indications were recorded. Tönnis angle was utilized to measure hip slope on radiographs and the BROH femoral offset was calculated for each patient. Student's t -test and one-way analysis of variance (ANOVA) were performed. Intraclass correlation coefficient analysis was evaluated to assess the reliability between observers. Results There was a total of 100 patients (128 hips) included in the study (60 with normal Tönnis angle, 53 had dysplasia, and 15 had decreased Tönnis angle). The average BROH femoral offset in the dysplastic cohort was increased in comparison to the normal cohort with a statistically significant p -Value of 0.0001. The p -value was 0.00031 on ANOVA. The BROH femoral offset calculation revealed good intra- and interobserver reliability of 0.9 and 0.9, respectively. Conclusion The BROH femoral offset can be an additional index for measuring ADH that is easier to calculate, and reproducible with good intra- and inter-observer reliability on cross-sectional imaging.

Clinical use of autologous adipose-derived stromal vascular fraction cell injections for hip osteoarthritis

IntroductionCurrently, studies on adipose-derived stromal vascular fraction (SVF) cells are attracting increasing attention because they have the potential to differentiate into a subset of cell types, such as bone marrow-derived mesenchymal stromal cells (MSCs), and are easier to harvest than MSCs, thus making them easier to apply clinically. This study evaluated the short-term clinical outcomes of SVF cell therapy for hip osteoarthritis (OA). MethodsForty-two patients were enrolled in this study; these patients received a single injection comprising an average of 3.8 (standard deviation [SD], ±1.3) × 107 SVF cells into the hip joint. All patients were followed-up for at least 6 months. The mean age of the patients was 60.2 years (SD, ±9.4 years). Kellgren–Lawrence (KL) grades II, III, and IV based on radiography were 13, 13, and 16 patients, respectively. SVF cells were obtained from the subcutaneous fat of the abdomen or breech using a Celution® 800/CRS system. The average cell viability of SVF cells was 90.8% (SD, ±2.8%). Clinical assessments were performed using the Harris Hip Score (HHS), Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) score, and visual analog scale (VAS) score to evaluate pain. Images were evaluated using radiography, and T2 mapping values were obtained using a 1.5-T magnetic resonance imaging system. These clinical and imaging assessments were followed from preoperatively to 6 months postoperatively. ResultsThe HHS, JHEQ score, and VAS score improved significantly from 22.5 (SD, ±16.6), 26.6 (SD, ±11.3), and 75.5 (SD, ±15.8) preoperatively to 46.8 (SD, ±27.2), 39.4 (SD, ±19.7), and 46.5 (SD, ±27.9), respectively, at 6 months postoperatively. KL grade II showed significant improvement in clinical outcome from preoperative to postoperative, while KL grade IV showed slight or little improvement. The center edge angle, acetabular head index on the radiographs, and T2 mapping values did not change significantly from preoperatively to 6 months postoperatively. ConclusionsSVF cell injection in the hip joint showed good short-term clinical efficacy for reducing hip OA symptoms. SVF cell therapy is thus an innovative and effective treatment for hip OA.

High-homogeneity double-focusing stigmatic analyzer magnet for electromagnetic isotope separator

An electromagnetic Isotope Separator (EMIS) is used for separating isotopes by magnetic dispersion method. A dipole-bending magnet performs the fundamental function of separation and is an essential building block of EMIS. Unlike mass spectrometers and ion implantation systems, the EMIS prefers ribbon beams for effective mass separation and collection. The bending magnet described in this paper has an inbuilt hexapole and a tunable quadrupole doublet. This magnet separates the charged particles based on the mass-to-charge ratio, performs chromatic correction, and focuses the beam in both axes. All sector magnets focus the beam in the radial direction, the introduction of edge angle results in the vertical focusing of the beam at the expense of radial focusing. The exit pole of the magnet is rotatable for adjusting the focal point. The entry pole is curved for ensuring stigmatism correction in the beam and works like a hexapole. High magnetic field homogeneity is a key requirement for this magnet. This enhances the mass resolution. As per beam simulations, magnetic field non-homogeneity shall not exceed 200 ppm in good field region (GFR) of 200 mm (radial) and 60 mm(vertical). The paper discusses the design, production, installation, testing, and commissioning of a double-focusing Stigmator dipole magnet. A method for achieving low non-homogeneity by using non-magnetic cavities and compensation coils is described and implemented. Very high homogeneity magnets can be designed using this technique. The paper also describes an efficient method for the Magnetic qualification of bending magnets. Based on the design, a double-focusing stigmatic dipole magnet is produced, characterized, and installed.

Acetabular Rim Ossification Variants Are Found in Almost 20% of Patients Presenting With Hip Pain

To determine the prevalence of 4 different types of acetabular rim ossifications, including partial labral ossification or punctate calcification, true os acetabuli, acetabular rim stress fracture, and complete labral ossification, and to determine whether different types of periacetabular ossifications are linked to demographic or radiological factors. We retrospectively reviewed the medial records of patients presenting for hip-related complaints at 2 sports medicine practices from September 2007 to December 2009. An anteroposterior radiograph of both hips and a lateral radiograph of each hip was obtained for all patients and reviewed for findings of cam and pincer femoroacetabular impingement, degenerative changes (Tönnis grade), and periacetabular calcifications for both hips. These parameters were also evaluated with respect to symptoms, sex, and age. Four hundred ninety-one consecutive patients (982 hips) presented to 2 orthopaedic surgeons at 2 centers for "hip"-related complaints. There were 223 males and 268 females (age 39 ± 14 years). The overall prevalence of periacetabular calcifications in hips was 17.6%, with 56.6% of calcifications in the symptomatic hip and 43.4% in the contralateral hip. Four basic patterns of calcification were identified: punctuate calcifications within the labrum (8.0% hips), large rounded calcifications (os acetabuli) (4.2% hip), large fragments with a vertical line of the superior-lateral acetabular rim, consistent with healed or non-healed stress fracture (2.0% hips), and complete ossification of the labrum (3.4% hips). Overall, male sex (P= .002), increased lateral center-edge angle (P= .046), and higher Tönnis grade (P < .001) statistically predicted the presence of periacetabular ossification. Punctate calcifications were more prevalent in males (P= .002). Higher Tönnis grade (P=.029) and increased alpha angle (P= .046) were more prevalent with os acetabuli. Younger age (P= .001), male sex (P= .048), increased alpha angle (P= .012), and increased lateral center-edge angle (P < .001) were more prevalent in acetabular rim fractures. No factors were statistically significant at predicting the presence of an ossified labrum. Periacetabular calcifications are not uncommon. Four particular patterns of calcification are identified: punctate labral calcifications (8%), larger rounded calcifications (i.e., os acetabuli) (4.2%), acetabular rim stress fractures (2%), and complete ossification of the labrum (3.4%) for a combined prevalence of 17.6% in patients presenting to an orthopaedic surgeon with "hip"-related complaints. Nearly half were in the asymptomatic hip. Male sex had a higher prevalence of periacetabular calcifications. An increased lateral center edge angle and higher Tönnis grade also had a higher prevalence of periacetabular calcifications. Younger male patients are more likely to have acetabular rim stress fractures. Patients with an increased alpha angle have a higher prevalence of os acetabuli and rim stress fractures. This study aims to identify, quantify, and categorize periacetabular calcifications about the hip. Their clinical relationships and relevance have been discussed, but no study has distinctly categorized the various types and their prevalence. This study provides a framework for identification and categorization.

Mean 14-year Outcomes of Hybrid Total Hip Arthroplasty Using Bulk Femoral Head Autografts for Acetabular Reconstruction

BackgroundWe aimed to evaluate the mean 14-year outcomes of hybrid total hip arthroplasty (THA) with cementless acetabular cups using bulk femoral head autografts in acetabular reconstruction and specify the radiological characteristics of cementless acetabular cups using this technique. MethodsThis retrospective study included 98 patients (123 hips) who underwent hybrid THA with a cementless acetabular cup using bulk femoral head autografts for bone deficiency in acetabular dysplasia and who were followed-up for a mean of 14 years (range, 10 to 19.6). The percentage of bone coverage index (BCI) and cup center–edge (CE) angles were evaluation radiologically of acetabular host bone coverage. The survival rate of the cementless acetabular cup and autograft bone ingrowth were assessed. ResultsThe survival rate with all revisions of cementless acetabular cups was 97.1% (95% confidence interval: 91.2 to 99.1). The autograft bone was remodeled or reoriented in all cases except in 2 hips where the bulk femoral head autograft collapsed. Radiological evaluation revealed a mean cup CE angle of −17.8° (range, −52 to −7°) and a BCI of 44.4% (range, 10 to 75.4%). ConclusionCementless acetabular cups using bulk femoral head autografts for bone deficiency of the acetabular roof remained stable even if the average BCI was 44.4% and the average cup CE angle was −17.8°. Cementless acetabular cups using these techniques showed good 10-year to 19.6-year outcomes and viabilities of graft bones.

Modified Capsulorrhaphy Technique in Open Reduction of Developmental Dysplasia of the Hip.

Neglected patients with developmental dysplasia of the hip (DDH) are not uncommon. Various treatment modalities have been used. Capsulorrhaphy is one of the most critical steps during the process of open reduction of DDH. Inadequate capsulorrhaphy technique can increase the failure rate of open reduction procedures. This study presented the clinical and radiographic results of using a new capsulorrhaphy technique. Between November 2005 and March 2018, 540 DDH in 462 patients were retrospectively reviewed. The mean age at surgery was 31 months. All patients underwent a modified capsulorrhaphy technique developed by the main author (with or without additional pelvic or femoral procedures). Postoperative patient assessment during the follow-up period was performed both clinically and radiologically. Follow-up period ranged between 36 months and 12 years. Based on the modified McKay score, good and excellent outcomes were obtained in 90.3%. Functional results were better in younger age (less than 39mo). Both acetabular index and lateral center edge angle showed significant improvement at 3 years follow-ups. Proximal femoral growth disturbance (PFGD) was encountered in 92 hips. Classes 2 and 3 did not affect the functional results, whereas patients with PFGD classes 4 and 5 had fair to poor functional outcomes. There were 12 hips with redislocation. Revision was done using the same capsulorrhaphy technique. Using the index technique of capsulorrhaphy in DDH surgery is safe, reliable, and yields good functional and radiologic outcomes with a relatively low complication rate. Level IV-therapeutic retrospective case series.

Treatment of borderline hip dysplasia with triple pelvic osteotomy: preoperative values of acetabular index and lateral center edge angle can indicate overcorrection

IntroductionAfter pelvic osteotomy for the treatment of symptomatic hip dysplasia, the longevity of the hip joint can be compromised by acetabular overcorrection. This iatrogenic pincer-type deformity is considered to be one of the major risk factors for persistent pain and progressing osteoarthritis. There is evidence that acetabula in the borderline range, defined by a lateral center edge angle (LCEA) between 18° and 25°, are more delicate to be orientated physiologically. The aim of this study was to assess the quality of acetabular orientation by triple pelvic osteotomy (TPO), established by Tönnis and Kalchschmidt, especially with respect to acetabular overcorrection.Materials and methodsA retrospective examination on 368 consecutive hips treated with TPOs was conducted. On the preoperative pelvic radiograph and the radiographic control 5 days after surgery, LCEA, acetabular index (AI), and anterior (AWI) and posterior wall index (PWI) were measured. According to the above-mentioned definition, the hips were divided into a borderline (n = 196) and a dysplastic (n = 172) group. Acetabular overcorrection was defined as when LCEA exceeded 35°, AI was below 0° and AWI exceeded 0.60, postoperatively. The postoperative occurrence of a relevant femoroacetabular impingement was correlated to these thresholds. Statistics comprised a priori power analysis, correlation analyses and receiver operating characteristics (ROC).ResultsIn the borderline group, in 64 hips (32.7%), LCEA and AI indicated lateral overcorrection. In the dysplastic group, in 14 hips (8.1%), solely AI indicated overcorrection. In none of the hips, relevant anterior overcorrection was detected since AWI never exceeded 0.60. Chi-square test demonstrated a significant correlation between the occurrence of a postoperative femoroacetabular impingement and LCEA exceeding 35°, as well as AI below 0° (p < 0.001, resp.). Bravais–Pearson’s analysis showed a significant correlation between the pre- and postoperative values of all parameters in the borderline and the dysplasia group (p < 0.001). Thus, ROC analysis could be performed and provided preoperative cutoff values for LCEA (23°) and AI (12.5°), hinting at postoperative overcorrection.ConclusionThe comparison of radiographic parameters after TPO showed a considerably greater percentage of laterally overcorrected acetabula in the borderline hips than in the dysplastic hips. According to the wall indices, anterior overcorrection was not observed. ROC analysis anticipated unfavorable lateral overcorrection when preoperative LCEA was above 23° and AI below 12.5°. These findings should sensitize the surgeon to the delicate acetabular correction in borderline dysplastic hips.

Influence of Leading and Trailing Edge Angle on Impeller Blades of a Pump as Turbine

A pump as turbine (PAT) is a turbomachine that converts hydraulic energy into electricity. One of the study topics in PAT is the efficiency due to centrifugal pumps are not designed to operate in reverse mode. Geometric variations of the impeller have been studied in the literature. However, it was not possible to evidence the influence of the inclination of the blade leading and trailing edge. Therefore, the objective of this work is to analyze numerically and fluid dynamically the inclination angle of the blade leading and trailing edge of a centrifugal pump, in pump and turbine mode. First, the characteristic curve was validated. Then, the inclination of the leading and the trailing edge was modified, in a range of 25° to 90°, obtaining head, efficiency, and power graph. As a result, in pump mode was evidenced that an angle close to 90° on the blade trailing edge provides a higher efficiency of 50.26% and decreases until 40.77% when the angle approaches 30°, reducing the head to around 20%, while power remained constant. In turbine mode, an inverse effect was obtained, where the maximum efficiency was 60.9% and the generated power increased up to 4.76 kW in the blade leading edge. Therefore, the angular variation of the leading and the trailing edge is adequate in turbine mode, while in pump mode there is a loss of capacity.

Combining Shelf Osteotomy With Proximal Femoral Reconstruction After Oncologic Resection

Introduction: Oncologic proximal femoral resection and reconstruction in skeletally immature children remains a formidable task due to the risk of developing hip instability with patient growth or interval leg lengthening through the prosthesis. Shelf pelvic osteotomy increases femoral head coverage and containment, and favorable long-term results have been reported in the setting of developmental dysplasia of the hip and Perthes disease. We present a technique of combining shelf osteotomy with expandable proximal femoral endoprosthesis reconstruction in pediatric limb-sparing surgery. Materials and Methods: Four surgeons at 2 centers from 2012 to 2020 performed proximal femoral reconstruction with shelf osteotomy. Data were collected retrospectively on operative technique, radiographic measurements, and complications including dislocation, subluxation, implant loosening, pain, function, and radiographic outcomes. Results: Five patients were included in the study. The mean follow-up was 49 months (range: 17 to 104 mo). The mean lateral center edge angle status postproximal femoral resection and reconstruction shelf osteotomy was 56.1 degrees (±30.5). There were no reported incidences of subluxations, dislocations, periprosthetic fractures, or soft tissue complications. The 3 patients with the longest follow-up at 3, 5, and 8 years tolerated serial lengthening of the endoprosthesis totaling 1 cm, 7.25 cm, and 9 cm, respectively, and demonstrated earlier triradiate cartilage closure in the operative side compared with the nonoperative side. All patients have returned to independent ambulation. Discussion: Combining proximal femoral reconstruction with shelf osteotomy in limb salvage pediatric orthopedic oncology may help to improve hip stability with serial lengthening and patient growth.

Wind tunnel measurements on the effects of leading edge geometry on surface pressures and wake flow of finite blunt plate

In this paper, the surface wind pressure distribution and wake flow of finite blunt plates with different leading edge geometries are investigated. Particle image velocimetry and surface pressure measurement are performed on five typical leading-edge plates in a uniform wind. The results show that the wind pressure distribution on the blunt plate surface is largely affected by the leading-edge geometry. Specifically, as the leading edge angle increases from 60° to 180°, the peak values of the mean pressure coefficient and peak suction pressure coefficient decrease by 20.1 % and 11.6 % respectively. Meanwhile, the peak value of the r.m.s pressure coefficient increases from 0.041 to 0.126 and gradually approaches the mid-axis of blunt plate. In addition, larger separation angles lead to an increase in the reattachment length from 0.7d to 5.26d, but monotonically decrease the characteristic frequency of the plate. The analysis of the wake velocity field shows that an increase in leading-edge angle leads to an increase in the length of the low-velocity recirculation zone in the wake from 0.7d to 1.1d, and both the turbulent kinetic energy and Reynolds stress are larger in this region. Meanwhile, the flow streamlines and vorticity distribution become more unstable and complex, exhibiting a faster rate of evolution. Furthermore, the extraction of the wake structure using a proper orthogonal decomposition shows that the aerodynamic shape of leading edge has a limited effect on the large-scale vortex structure, but significantly affects small-scale vortex structure of high-order modes.

Midterm Development of Ultrasound-unstable Hip Joints After Overhead Traction and Treatment With Tübingen Splint and Fettweis Plaster: A Radiologic Follow-up Analysis Over 5.5 Years.

The aim of this study was to determine the success rate for treatment of ultrasound unstable hips (type D, III and IV) with Fettweis plaster in terms of a midterm follow-up from the very beginning in the neonatal period until the age of 4 to 8 years. In total, 69 unstable hips, which were successfully treated with Fettweis plaster and after with a flexion-abduction splint, were included into the study. Hip delvelopment was followed by determining the acetabular index (ACI) on routine pelvic radiographs at the age of 12 to ≤24, 24 to ≤48 and 48 to ≤96 months and the center edge angle on the latter, and classifying both angles according to Tönnis. After initially successful treatment, the first radiograph at the age of 12 to ≤24 months showed 39.1% (n=27) hips with normal findings, 33.2% (n=23) hips with slightly dysplastic findings, and 27.5% (n=19) hips with severe dysplastic findings. Comparison between first and second radiograph showed improvement of the ACI in 9/69 hips and between the second and third time point in 20/69 hips. Overall, 20 hip joints showed deteriorations. Hereby, 16 deteriorations took place after the first radiograph and 4 after the second radiograph. Deteriorations were observed independently of the initial hip type (D, III, and IV). Midterm results indicate that radiologic controls should be provided to detect deteriorations after finishing treatment. ACI and center edge angle are helpful parameters in the assessment of hip joint development in the age range of 4 to 8 years. Level III.

Phase-shifting by polarizer rotations in a right-angle prism interferometer

In this manuscript it is presented what we believe to be a novel and simple phase-shifting technique based on polarizer rotations, using a right angle prism as the interferometric device. It is possible to generate interference when the right angle edge of the prism is placed parallel to a linearly polarized collimated beam. In this configuration optical phase changes are presented due to the internal reflections in the prism; therefore, a linearly polarized beam turns into elliptical polarization. If the output elliptically polarized interference beam passed through a lineal polarizer, phase-shifting is generated if it rotates by an angle theta. This proposal will be sustained with simulated and experimental shifted interference patterns and with the calculation of wrapped and unwrapped phases.

Experimental Study on the Cutting Process of Single Triticale Straws.

This paper presents experimental research on cutting a single stalk of triticale straw for the production of biofuel in the process of its compaction using the piston technique. In the first stage of the experimental study of cutting single triticale straws, the variable parameters were the moisture contents of the stem equal to 10% and 40%, the offset between the blade and the counter-blade g, and the linear velocity of the knife blade V. The blade angle and rake angle were equal to α = 0° and β = 0°. In the second stage, the variables, including the blade angle values α = 0°, 15°, 30°, and 45° and the rake angle values β = 5°, 15°, and 30°, were introduced. Taking into account the analysis of the distribution of forces on the knife edge leading to the determination of the force quotients Fc″/Fc and Fw/Fc, and on the basis of the optimization performed and the adopted optimization criteria, the optimal knife edge angle α can be determined (at values g = 0.1 mm and V = 8 mm/s) at α ≅ 0° and the angle of attack β within the range of 5-26°. What the value will be in this range depends on the value of the weight adopted in the optimization. The choice of their values may be decided by the constructor of the cutting device.

Evaluation of the anterior acetabular coverage with a false profile radiograph considering appropriate range of positioning

This study aimed to (1) set a reference value for anterior center edge angle (ACEA) for preoperative planning of periacetabular osteotomy (PAO), (2) investigate the effects of pelvic rotation and inclination from false profile (FP) radiographs on the measured ACEA, and (3) determine the “appropriate range of positioning” for FP radiograph. This single-centered, retrospective study analyzed 61 patients (61 hips) who underwent PAO from April 2018 and May 2021. ACEA was measured in each digitally reconstructed radiography (DRR) image of the FP radiograph reconstructed in different degrees of pelvic rotation. Detailed simulations were performed to determine the “appropriate range of positioning” (0.67 < ratio of the distance between the femoral heads to the diameter of the femoral head < 1.0). The vertical-center-anterior (VCA) angle was measured on the CT sagittal plane considering the patient-specific standing positions, and its correlation with the ACEA was investigated. The reference value of ACEA was determined by receiver operating characteristic (ROC) curve analysis. The ACEA measurement increased by 0.35° for every 1° pelvic rotation approaching the true lateral view. The pelvic rotation with the “appropriate range of positioning” was found at 5.0° (63.3–68.3°). The ACEA on the FP radiographs showed a good correlation with the VCA angle. The ROC curve revealed that an ACEA < 13.6° was associated with inadequate anterior coverage (VCA < 32°). Our findings suggest that during preoperative PAO planning, an ACEA < 13.6° on FP radiographs indicates insufficient anterior acetabular coverage. Images with the “appropriate positioning” can also have a measurement error of 1.7° due to the pelvic rotation.

Progress in diagnosis and hip arthroscopic treatment of borderline developmental dysplasia of hip with Cam-type femoroacetabular impingement

To summarize the biomechanical characteristics, diagnosis, and hip arthroscopic treatment of borderline developmental dysplasia of hip (BDDH) with Cam-type femoroacetabular impingement (Cam FAI). The literature on BDDH with Cam FAI at home and abroad in recent years was extensively reviewed and analyzed. In patients with BDDH and Cam FAI, the femoral neck anteversion angle and femoral neck shaft angle increase, the pelvis tilts, and the acetabulum rotates, resulting in instability of the hip joint. In order to maintain the stability of the hip joint, the direction of biomechanical action of the hip joint has changed, which further affects the anatomical structures such as the proximal femur and acetabular morphology. BDDH with Cam FAI can be diagnosed clinically by combining lateral center edge angle, anterior center edge angle, and acetabular index. BDDH with Cam FAI can be effectively treated through arthroscopic polishing of the edges of the acetabular proliferative bone, excision of Cam malformations, and minimally invasive repair of the glenoid lip and cartilage of the hip joint. Currently, there is no unified standard for the diagnosis and treatment of BDDH with Cam FAI. Minimally invasive treatment of the hip under arthroscopy can achieve good early- and medium-term effectiveness, and has certain advantages in repairing and maintaining the integrity of the glenoid lip and suturing/compression joint capsule. However, the long-term effectiveness needs to be further followed up to determine. The timing of surgery, intraoperative bone edge depth polishing, and joint capsule suturing/compression techniques also need to be further explored.

The effect of pre-fracture proximal femur geometry on hip fracture type in elderly patients.

This study aimed to analyze the relationship between fracture type by determining data on the geometry of the proximal femur in the pre-fracture period in patients over 65 years of age who had hip fractures as a result of low-energy trauma. A total of 127 patients who were admitted to the hospital for reasons other than hip pathology within 1 year before the occurrence of hip fracture and who had an anterior-posterior pelvic X-ray were included in the study. Measurements were made to evaluate the proximal femur geometry, neck shaft angle, central edge angle, femoral head diameter, femoral neck diameter, femoral neck length, femoral offset length, femoral neck axial length, hip axis length, and femoral shaft diameter. As a result of these measurements, analyses were performed to determine the relationship between the control group and fracture types. The mean Neck shaft angle scores were significantly higher in both fracture types than in the control group (P = .034, P = .002). The mean Femoral offset length values of both fracture types were lower than those of the control group (P = .002, P = .011, respectively). Multiple logistic regression analysis revealed that the risk of collum femoris fracture increased as the Femoral head diameter value increased. (OD = 0.21, P = .002). The geometric parameters of the proximal femur play an important role in the formation of hip fracture types. Therefore, differences in proximal femur geometry in hip fracture types should be considered, and patient-focused choices should be made regarding the surgical procedures and implants to be used during fracture fixation.

Facteurs influençant la reprise du sport après ostéotomie acétabulaire rotationnelle excentrique

BackgroundAlthough eccentric acetabular rotation osteotomy (ERAO) is an effective treatment for developmental dysplasia of the hip (DDH), there is little information about return to sports after ERAO. This study aimed to investigate 1) the patient factors that influence the return to sports after ERAO, 2) whether postoperative sports participation will affect future osteoarthritis progression. HypothesisSome factors affect the return to sports after ERAO. Patients and methodsOf 503 patients who underwent ERAO from 1990 to 2010, 124 who had been continuously participating in sports preoperatively (average 13.2 years after surgery) were included. Patient demographics of sex, age, body mass index, unilateral to bilateral case ratio, history of treatment for childhood DDH, preoperative Kellgren-Lawrence (KL) grade, center edge angle, joint congruency, Harris hip score, complications and the survival rate were compared between the S group (patients who participated in the same sports preoperatively) and N group (patients who could not participate in sports postoperatively). ResultsSeventy-two (58%) and 52 patients (42%) in the S and N groups, respectively, had an overall return to sports rate of 64% (79 patients). The most common sports that patients participated in were swimming (30 patients [24%]), jogging (12 [10%]), and golf (10 [8%]) preoperatively, and swimming (14 patients [11%]), golf (8 [6%]), and jogging (8 [6%]) postoperatively. There were no significant differences between both groups in terms of sex, age, body mass index, unilateral to bilateral case ratio, history of treatment for childhood DDH, preoperative KL grade, and joint congruency. There was a significant difference in patient factors between the S (11 joints [14%]) and N (20 joints [38%]) groups only when the preoperative center edge angle was <0°. There was no significant difference in the preoperative Harris hip score and the final survey between the S (73.2±4.6 and 93.4±7.2) and N (72.5±4.8 and 92.1±7.4) groups. Complications showed no significant differences between the five patients (7%) in the S group and six patients (13%) in the N group. The KL grade progressed in 10 cases (grade II to III in 2 cases and grade III to IV in 8) in the S group and 8 cases (grade II to III in 1 case and grade III to IV in 7 cases) in the N group. The 10-year and 20-year joint survival rates with THA conversion as the endpoint were 98.1% (95% CI: 87.4%–99.7%) and 83.7% (95% CI: 62.6%–93.4%) in the S group and 100% (95% CI: 70.7%–99.3%) and 95.2% (95% CI: 12.6%–92.6%) in the N group, respectively. In the evaluation of factors affecting sports return by logistic regression analysis, only one significant factor (odds ratio 3.42, 95% confidence interval: 1.58–7.42, p<0.01) was the preoperative center edge angle <0°. DiscussionThe chief factor affecting the return to sports after surgery was a preoperative center edge angle <0°; moreover, the continuation of sports did not affect the subsequent progression of osteoarthritis or THA conversion. Level of evidenceLevel III, cohort study.

Towards understanding the wear mechanisms of turning with FreeTurn

For many years, tool wear has been a critical issue with respect to productivity, cost, and part quality, particularly for superalloy machining. The underlying wear mechanisms of a new turning tool, FreeTurn, is revealed in this paper towards its potential for a more sustainable way of metal cutting. It is a specially designed turning tool that is held by the tool spindle and has a working plane perpendicular to the centreline of the tool spindle, making it rotatable on its working plane. Owing to the unique feature of FreeTurn compared with conventional turning tools, the focus of this study is on the effect of dynamic tool–workpiece engagement on tool wear. The tool path strategy is first set to achieve a cylindrical surface in longitudinal turning with a rotatable FreeTurn tool. Series of experiments with different tool path strategies are performed on a turn–milling machine, using Inconel 718 as an example of workpiece material. The results indicate that the coupling effect between notch and flank wear is the decisive factor of tool wear in free turning with respect to its rotation and feeding directions. While the tool wear can be significantly reduced if the tool feeds with increasing cutting edge angle, the tool will soon be worn out if it feeds with decreasing cutting edge angle. Tool rotation in free turning plays a key role in reducing adhesion on the cutting tool and increasing the tool rotation speed can further improve this effect. Additionally, a more sustainable solution that uses both sides of the cutting edge becomes possible with FreeTurn as well, improving the tool utilisation. The results demonstrate considerable guiding significance for exploring the potential of this new turning tool towards a longer tool life.

Effect of Femoroacetabular Impingement on Hip Fractures

AIM: The aim of this study is to find out if there is a relationship between femoroacetabular syndrome and the risk of hip fractures that have been known with high morbidity and mortality rates.&#x0D; MATERIAL AND METHOD: Between January 1st of 2015 and January 1st of 2020, data of 243 patients with intertrochanteric fracture, 126 patients with femoral neck fracture and 250 trauma patients of over 65 years old that had admitted to our hospital’s emergency department but had no fracture on both pelvis AP x-ray and pelvis CT, were evaluated retrospectively. While central edge angle, acetabular index and singh index were measured on AP x-ray of pelvis, alfa-angle, anterior offset and anterior offset ratio were measured on pelvis CT.&#x0D; RESULTS: No significant differences were found between the groups forming the hip fracture and the control group in terms of gender, age and Singh index, indicating that these factors were homogeneously distributed between the groups and had no effect on the factors investigated (p&gt;0.05). The central edge angle, acetabular index, alpha angle, anterior offset and anterior offset ratio were found to be significantly different (p

Optimization study on the influence of rearview mirror and side window glass on interior noise

Based on the LES model, the compressible transient CFD simulation combined with the acoustic finite element method optimizes the effect of the rearview mirror and side window glass on in-vehicle noise from the perspective of sound source and transmission. The primary and secondary orders of the influence of different mirror shape and side window glass geometric parameters on the noise in the car were obtained through the design and analysis of orthogonal experiments, and the results of the flow and sound fields were compared. The following results are presented: acoustic source noise reduction from the rearview mirror is mainly affected by acoustic pressure excitation. The proportion of the mirror body of the rearview mirror, the angle of the lower edge, and the length of the mirror column affect the noise in the car in turn. The noise reduction control with PVB laminated glass as the transmission path is mainly limited by the low frequency turbulent pressure excitation. The inner and outer thicknesses of PVB laminated glass have different influences on the noise in the car under different frequency bands, and the results in the full frequency band are mainly affected by the low frequency band.