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Purpose: Although many factors were suggested to affect acetabular cup positioning during primary total hip arthroplasty, the effect of surgeon handedness was rarely evaluated. We aimed primarily to assess the difference in cup positioning (inclination and anteversion) between the right and left sides during primary THA. Secondly, to check the difference in the percentages of cups positioned in the safe zone for inclination and anteversion and if there will be a difference in cup positioning according to the type of cup fixation (cemented vs. cementless). Methods: Cup inclination and anteversion of 420 THAs were radiographically evaluated retrospectively. THAs were performed by a senior right-handed surgeon, who operated through a direct lateral approach in a lateral decubitus position using manual instruments and freehand technique for cup placement. Patients were assigned to two groups: Group A (right, or dominant side), and Group B (left, or non-dominant side), with equal cases of THAs (n = 210) in each group. Results: No difference was found in patients' basic characteristics, preoperative diagnosis, and cup fixation (54.3% cemented and 45.7% cementless) between the two groups. There was a significant difference in cup inclination between Groups A and Group B (40.1° ± 6.3° vs. 38.2° ± 6.1°) (P = 0.002). No significant difference was revealed in anteversion between the two groups (11.7° ± 4.4° vs. 11.8° ± 4.7°) (P = 0.95). The percentage of cups located within the safe zone in terms of both inclination and anteversion was 85.2% vs. 83.8% and 69% vs. 73.3% for Group A and Group B, according to Lewinnek and Callahan's safe zones, respectively. There existed a significant difference in the cemented cup inclination between Group A and Group B (40.8° ± 6.4° vs. 38.3° ± 6.3°) (P = 0.004). Conclusion: Cup inclination is affected by the surgeon's handedness when operating through a direct lateral approach and using a freehand technique, while anteversion is less affected. Furthermore, the difference is greater with cemented cups. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusion The long‐term effectiveness of total hip arthroplasty (THA) largely depends on the accuracy of acetabular prosthesis placement. To improve the accuracy of acetabular prosthesis placement, we utilized a new surgical navigation system: visual treatment solution (VTS). The purpose of this study was to verify the efficacy and safety of this system in assisting THA.This was a prospective, multicenter, randomized controlled trial. One hundred and twenty‐four patients undergoing primary THAs were included. The experimental group underwent VTS‐assisted THA, and the control group underwent traditional surgical techniques. The main efficacy evaluation indicators were the proportion of anteversion and inclination angles in the Lewinnek safe zone, and secondary evaluation indicators included operation time, Western Ontario and McMaster University Osteoarthritis index (WOMAC) score, Harris score, short‐form‐36 (SF‐36) score, and hip dislocation rate. Statistical analysis was performed mainly by t‐test and chi‐square test.The proportion of both anteversion and inclination angles in the safe zone was 93.1% in the experimental group and 50.9% in the control group; the difference was significant (p < 0.01). The average operation time was 112.5 min in the experimental group and 92.6 min in the control group; the difference was significant (p < 0.01). There were no significant differences in WOMAC score, Harris score, or SF‐36 score between the experimental and control groups at 3 months after the operation (p > 0.05). The dislocation rate was 0% in the experimental group and 1.6% in the control group; the difference was not significant (p > 0.05).VTS‐assisted THA can significantly improve the accuracy of acetabular prosthesis placement. However, there were no differences in short‐term clinical outcomes or dislocation rates between the two groups. [ABSTRACT FROM AUTHOR]

Abstract Purpose Although many factors were suggested to affect acetabular cup positioning during primary total hip arthroplasty, the effect of surgeon handedness was rarely evaluated. We aimed primarily to assess the difference in cup positioning (inclination and anteversion) between the right and left sides during primary THA. Secondly, to check the difference in the percentages of cups positioned in the safe zone for inclination and anteversion and if there will be a difference in cup positioning according to the type of cup fixation (cemented vs. cementless). Methods Cup inclination and anteversion of 420 THAs were radiographically evaluated retrospectively. THAs were performed by a senior right-handed surgeon, who operated through a direct lateral approach in a lateral decubitus position using manual instruments and freehand technique for cup placement. Patients were assigned to two groups: Group A (right, or dominant side), and Group B (left, or non-dominant side), with equal cases of THAs (n = 210) in each group. Results No difference was found in patients’ basic characteristics, preoperative diagnosis, and cup fixation (54.3% cemented and 45.7% cementless) between the two groups. There was a significant difference in cup inclination between Groups A and Group B (40.1° ± 6.3° vs. 38.2° ± 6.1°) (P = 0.002). No significant difference was revealed in anteversion between the two groups (11.7° ± 4.4° vs. 11.8° ± 4.7°) (P = 0.95). The percentage of cups located within the safe zone in terms of both inclination and anteversion was 85.2% vs. 83.8% and 69% vs. 73.3% for Group A and Group B, according to Lewinnek and Callahan’s safe zones, respectively. There existed a significant difference in the cemented cup inclination between Group A and Group B (40.8° ± 6.4° vs. 38.3° ± 6.3°) (P = 0.004). Conclusion Cup inclination is affected by the surgeon’s handedness when operating through a direct lateral approach and using a freehand technique, while anteversion is less affected. Furthermore, the difference is greater with cemented cups.

Cyclically for several centuries in Bosnia and Herzegovina, there have been carried out crimes against humanity, serious violations of the Geneve Conventions and violations of the laws and customs of war and other crimes aginst the protected persons and social groups. Crimes are usually committed during armed conflicts. The mass crimes committed in Bosnia and Herzegovina in the previous two centuries were primarily determined by the ideologies of territorial nationalism and the projects for their realisations by the neighbouring Croatia and Serbia. Additionally, in the armed conflict in Bosnia and Herzegovina in the period 1992-1995 numerous crimes against humanity, serious violations of the Geneva Conventios, violations of the laws and costums of war and other crimes against protected objects, in its individual and mass nature, were also committed including the most serious crime that humanity has experienced since its inception- the crime of genocide. The Serbian-Montenegrin aggressor committed numerous forms of crimes against humanity and international law in all occupied towns and cities of the internationally regonised state and and a member of the United Nations (UN). The attacks on the area of the municipality of Rogatica whach are the subject of this research are considered to be the pattern which the aggressor (Federal Republic of Yugoslavia) and its collaborators (Bosnian Serbs) used in order to completely exterminate Bosniaks from the territory of the Republic of Bosnia and Herzegovina which they intended to occupy militarily. The intention and method of committing Serbian crimes in the area of Podrinje, which also included the municipality of Rogatica, during the Greater Serbian aggression in 1992-1995 are the same as the chetnik crimes against the Bosniak population during the World War II. Zepa, the largest of the ten local communities in the municipality of Rogatica, became a small Bosnian enclave during the aggression against the Republic of Bosnia and Herzegovina that resisted the attacks and blows of a far superior enemy until the middle of 1995. Resolution No.824 declaring Zepa a „safe zone” of the United Nations was adopted on May 6, 1993 by the UN Security Council. The aggressor continued the coordinated and systematic „cleansing” of the Bosniak population from that area consciously ignoring the fact that Zepa was declared a „safe zone” by the UN. The attacks on the Bosniaks of Zepa were not of different character compared to the attacks on other areas of the Republic of Bosnia and Herzegovina, especially Podrinje. Attacks on Bosniaks as an ethnic, national, national and religious group as a whole, and therefore those from the area of Zepa, were an integral part of the Greater Serbian ideology, policy and practice of creating the so-called Great Serbia. This research aims to shed light on the importance and status of the UN „safe zone”, the attitude of the international community towards the aggressor and the victims, the aggressor's activities up to the complete occupation of this „safe zone” and the crimes committed against Bosniaks.

This exploratory qualitative research focuses on the experiences of those who facilitate lesbian, gay, bisexual, transgender, queer/questioning (LGBTQ+) social justice educational interventions (SJEIs), such as safe zone, safe space, and ally training. Although persistent in higher education LGBTQ+ SJEIs remain an understudied area for empirical research, especially how facilitators describe the benefits and challenges of this role. Findings reveal how these benefits and challenges are paradoxical in that participants are hopeful for the impact of the work while burdened by the endeavor. Implications illuminate how participants approach engagement with campus communities through SJEIs as a potential opportunity for increasing inclusion efforts and how participants act as tempered radicals within this facilitator role in higher education. [ABSTRACT FROM AUTHOR]

To avoid dislocation after total hip arthroplasty, it is desirable to avoid implant impingement during activities of daily living. Numerous simulation studies have been performed at 30° of internal rotation (IR) with 90° of flexion. However, these studies may not reflect the impingement that occurs during activities such as floor sitting, which require a larger IR during flexion. The purpose of this study was to assess the impact of varying IR angles during flexion on the impingement‐free safe zone and optimal stem anteversion. In this study, implant impingement simulation was evaluated in computer simulation. The prosthesis used a flat liner, and a 32‐ or 40‐mm femoral head and stem. Three patterns of required IR angle (30° IR/40° IR/50° IR with 90° flexion) combined with 13 directions of the required range of motion were simulated. The optimal stem anteversion to maximize the safe zone was analyzed. Increasing the required IR at 90° flexion decreased the safe zone, particularly with small stem anteversion angles. With a 32‐mm head, the desirable stem anteversion at 40° of cup inclination was 15°/25°/35° in required 30° IR/40° IR/50° IR with 90° flexion, respectively. The safe zone area of the 32‐mm head was smaller than that of the 40‐mm head. For patients who require a larger IR with 90° flexion, the stem and cup target anteversion should be adjusted according to the implant design, head diameter, and patient's required IR at flexion in their lifestyle. [ABSTRACT FROM AUTHOR]

Background: To analyze the anatomical characteristics of a posterior area in the mandible localized distally to the second molars and extending in the vestibular direction toward the bony step, which we define as "buccal step", in a patient with different skeletal patterns for mini-screw insertion. Methods: The sample included 85 CBCT (cone beam computed tomography) records selected from the digital archive. Analysis focused on the buccal step area. Sections were obtained in axial view using reference lines, and measurements of cortical and total bone were taken at specific points M0 (starting point, 6 mm apical from CEJc—cementoenamel junction crest), M2 (located 2 mm posterior to M0 in the apical direction), and M4 (positioned 4 mm posterior to M0 in the apical direction) in both directions. Six measurements were recorded for each scan root plane, assessing cortical and total bone depth. Results: The thickness of the bone increases toward the inside of the mouth at all tested sites (M0, M2, M4), which is good for placing mini-screws. Cortical bone thickness decreases toward the inside of the mouth, with no significant differences among the sites except for M0 vs. M4. People with a particular jaw shape (hypo-divergent) have a thicker cortical bone, indicating that facial structure affects bone thickness. Conclusions: The posterior buccal step insertion site has biomechanical advantages and reduces the risk of damaging roots during mini-screw insertions. [ABSTRACT FROM AUTHOR]

Background: To analyze the anatomical characteristics of a posterior area in the mandible localized distally to the second molars and extending in the vestibular direction toward the bony step, which we define as “buccal step”, in a patient with different skeletal patterns for mini-screw insertion. Methods: The sample included 85 CBCT (cone beam computed tomography) records selected from the digital archive. Analysis focused on the buccal step area. Sections were obtained in axial view using reference lines, and measurements of cortical and total bone were taken at specific points M0 (starting point, 6 mm apical from CEJc—cementoenamel junction crest), M2 (located 2 mm posterior to M0 in the apical direction), and M4 (positioned 4 mm posterior to M0 in the apical direction) in both directions. Six measurements were recorded for each scan root plane, assessing cortical and total bone depth. Results: The thickness of the bone increases toward the inside of the mouth at all tested sites (M0, M2, M4), which is good for placing mini-screws. Cortical bone thickness decreases toward the inside of the mouth, with no significant differences among the sites except for M0 vs. M4. People with a particular jaw shape (hypo-divergent) have a thicker cortical bone, indicating that facial structure affects bone thickness. Conclusions: The posterior buccal step insertion site has biomechanical advantages and reduces the risk of damaging roots during mini-screw insertions.

Purpose: The open Trillat Procedure described to treat recurrent shoulder instability, has a renewed interest with the advent of arthroscopy. The suprascapular nerve (SSN) is theoretically at risk during the drilling of the scapula near the spinoglenoid notch. The purpose of this study was to assess the relationship between the screw securing the coracoid transfer and the SSN during open Trillat Procedure and define a safe zone for the SSN. Methods: In this anatomical study, an open Trillat Procedure was performed on ten shoulders specimens. The coracoid was fixed by a screw after partial osteotomy and antero-posterior drilling of the scapular neck. The SSN was dissected with identification of the screw. We measured the distances SSN-screw (distance 1) and SSN-glenoid rim (distance 2). In axial plane, we measured the angles between the glenoid plane and the screw (α angle) and between the glenoid plane and the SSN (β angle). Results: The mean distance SSN-screw was 8.8 mm +/-5.4 (0–15). Mean α angle was 11°+/-2.4 (8–15). Mean β angle was 22°+/-6.7 (12–30). No macroscopic lesion of the SSN was recorded but in 20% (2 cases), the screw was in contact with the nerve. In both cases, the β angle was measured at 12°. Conclusion: During the open Trillat Procedure, the SSN can be injured due to its anatomical location. Placement of the screw should be within 10° of the glenoid plane to minimize the risk of SSN injury and could require the use of a specific guide or arthroscopic-assisted surgery. [ABSTRACT FROM AUTHOR]

Follicular unit excision (FUE) is an increasingly popular hair restoration technique. In many instances, it surpasses linear strip excision (LSE) surgery in terms of number of procedures and clinics dedicated to performing FUE. The rise in popularity relates primarily to a somewhat misguided perception that FUE produces less evidence of a surgical procedure having been performed. This is based on the fact that a linear scar is avoided. The procedure is easier to learn and "less invasive" as compared to LSE harvesting and requires less staff and capital expense. The FUE procedure is aggressively marketed often as "scarless surgery." This false statement, along with the ease of starting an FUE practice, has resulted in various ethical issues related to evaluation, methodology, and business practices. In this chapter, we discuss the ethical issues surrounding FUE hair restoration surgery and the examination of the mathematics of donor management as it relates to the ethical management of the FUE patient. [ABSTRACT FROM AUTHOR]

• Pedicle Screw can cross the midline of the vertebrae without causing a pedicle screw breach. • Screw safety cone angle increase from L1 to L5. • L4 allows the most screw crossing from midline. Pedicle screw breach (PSB) is not uncommon following lumbar instrumentation, and in some instances, it may lead to vascular and/or neurologic complications. Previous literature suggested that screws crossing the vertebral midline on an anterior-posterior (AP) radiograph (or midsagittal on CT) are concerning for medial pedicle breach. Our primary aim was to map out the safe zones (SZ) of bilateral pedicle instrumentation and their relationship at each lumbar vertebral level. Our secondary aim was to evaluate the presence of SZs' intersection at each lumbar level, denoting safe midline pedicle screw crossing not otherwise associated with medial pedicle breach. Retrospective Anatomical Study. Adult patients in the from "The Cancer Imaging Archive" (TCIA) database who have not had thoraco-lumbo-sacral fusion. Physiologic measures obtained through 3D analysis of CT images and virtual pedicle screws. CT scans of 51 patients were randomly selected from "The Cancer Imaging Archive" (TCIA) online database for analysis. The Sectra 3D Spine software was used to create 3D renderings, place virtual screws, and make measurements. At each lumbar vertebra, the right and left pedicle corridors were mapped. At each pedicle, two screw positions were templated, the "medial limit screw" (MLS) and the "lateral limit screw" (LLS). Each limit screw was the most extreme position that the screw could exist in without causing a medial or lateral breach. The safe zone was defined as the zone between MLS and LLS. Measurements were taken for each level (between L1 and L5) and side (Left, Right). A total of 253 lumbar vertebrae from 51 patients (mean age 53.1, 56.9% male) were included. Two vertebrae from two patients were removed for poor image quality. Out of the 506 screw positions analyzed in our study, 97.4% had overlapping SZ and crossed the midplane without medial pedicle breach. The significant factors (p<.01) for safe midplane-crossing screws included: the screw length (L1–L5); the laterality of the screw entry point (L1–L4); and the pedicle diameter (L2 and L5). A midline crossing pedicle screw on a lumbar AP radiograph is not necessarily indicative of a medial pedicle screw breach. Anatomical (ie, larger pedicle diameter) and technical (ie, longer screws, and lateral entry points) factors allow for safety zone intersections and indicate safe midline crossing by pedicle screws. [ABSTRACT FROM AUTHOR]

Although a rare complication, dislocation following hemiarthroplasty (HA) for a femoral neck hip fracture is associated with increased mortality, readmission, and possible revision surgery. To date many of the specific risk factors have been difficult to demonstrate. Patient factors, surgical factors, as well as morphological factors need to be assessed. Therefore, the purpose of this study was to elucidate the risk factors for dislocation of HA following femoral neck hip fractures in the geriatric population. This was a retrospective review of 270 patients who had hip fractures. Medical records between the years 2016 and 2022 informed binomial regression predictive models. The discriminative ability of variables in the final model and acetabular anteversion to predict dislocation was assessed with area under the curve (AUC) estimates. Center edge angle (odds ratio 1.23), abduction angle (odds ratio 1.17), and depth width ratio (2.96e-11) were significant predictors of dislocation (P =.003,.028, and <.001, respectively). Center edge angle and depth width ratio (<44.1 ° and.298), respectively, were cut scores for risk. Dementia had a high discriminative of ability, as did men (AUC = 0.617, 0.558, respectively). Acetabular anteversion was not predictive of dislocation (P =.259) and theorized anteversion safe zones had poor discriminative ability with AUCs of 0.510 and 0.503, respectively. Morphological factors related to hip dysplasia and a shallow acetabulum, which can be assessed with a radiograph alone, were found to be predictors of instability following HA in the elderly. Hemiarthroplasty implant design and manufacturer, and also acetabular version did not contribute to instability risk. [ABSTRACT FROM AUTHOR]

The study analyzed 20 elbows from 10 preserved male human cadavers (10 right and 10 left), which were selected based on strict inclusion criteria. Cadavers with a history of prior surgery, infection, trauma or deformity were excluded from the sample. The average age of the cadavers was 46 years, ranging from 28 to 64 years. The precise measurements were obtained using the Microscribe-G2X device, renowned for its accuracy of up to one-thousandth of a millimeter. The length from the pivot point of the radial nerve in the sulcus nervi radialis to the distal end of the humerus is measured, along with the transverse diameter between the lateral epicondyle and the radial nerve and the length of the humerus itself. The length from the pivot point of the radial nerve in the sulcus nervi radialis to the distal end of the humerus is measured, along with the transverse diameter between the lateral epicondyle and the radial nerve and the length of the humerus itself. The length from the pivot point of the radial nerve in the sulcus nervi radialis to the distal end of the humerus is measured, along with the transverse diameter between the lateral epicondyle and the radial nerve and the length of the humerus itself. The right and left sides were measured to be 30.54±0.65cm and 30.54±0.59cm, respectively, with no considerable difference between them. The distance from the pivot point of the radial nerve in the sulcus nervi radialis to the distal part of the humerus was 15.07±1.27cm on the right side and 15.34±1.21cm on the left side. On the right, the distance was 15.07±1.27cm, while on the left, it was 15.34±1.21cm. Moreover, the transverse diameter between the lateral epicondyle and the radial nerve was measured at 2.95±0.14cm on the right side and 3.05±0.13cm on the left side. We contend that comprehension of the safe zone in distal humerus surgery can greatly improve surgical safety. [Med-Science 2023; 12(4.000): 1297-300]

Implantation of acetabular components with supplemental screw fixation is commonly performed to improve osteointegration and long-term stability in total hip arthroplasty (THA). Placement of ischial screws improves stability in biomechanical studies, but can be technically challenging. The study aimed to provide a safe zone for ischial screw placement with reference to easily identifiable intra-operative landmarks. A retrospective review of patients was performed and 27 preoperative pelvis computed tomography scans were collected. After converting these images to 3-dimensional reconstructions of the pelvis, a safe zone for ischial screw placement was established with reference to the anterior superior iliac spine (ASIS) and the acetabular center and rim. The safe zone of an ischial screw in the en face sagittal plane was a median of 17 degrees (interquartile range [IQR]: 11,23) anterior to 13 degrees (IQR: 10,18) posterior to the reference line from the ASIS through the center of the acetabulum. The safe zone in the coronal plane was 34 degrees (IQR: 18,68) medial to 13 degrees (IQR: 8,19) lateral from a start point 1 centimeter medial to the inferior acetabular rim with a screw length of 25 millimeters. An ischial screw optimized for length directed down the center of the ischium was qualitatively demonstrated to have a start point unobtainable intraoperatively, originating within the cotyloid fossa. The ASIS, center of the acetabulum, and acetabular rim provide identifiable intraoperative landmarks for guiding ischial screw placement in hip arthroplasty. [ABSTRACT FROM AUTHOR]

This research used general qualitative descriptive to explore LGBTQ+ social justice education interventions (SJEIs) facilitator experiences—commonly named safe zones—and how that role influenced their self-awareness, and perceptions of campus and campus constituents. This article signals the importance of general qualitative descriptive as a queerly robust approach to stand as its own sufficient methodology. The article focuses only on participants who facilitated LGBTQ+ SJEIs on their campus (81 of 87 participants), using social justice education pedagogy and praxis as our conceptual frameworks. Our findings highlight how the role affirms facilitators' queer and trans identities. Additionally, our findings reveal how facilitation focused on catering to cis and heterosexual fragility and attendee desires to remain passive, not active, allies. [ABSTRACT FROM AUTHOR]

Copyright of Al-Adab / Al-ādāb is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study analyzed 20 elbows from 10 preserved male human cadavers (10 right and 10 left), which were selected based on strict inclusion criteria. Cadavers with a history of prior surgery, infection, trauma or deformity were excluded from the sample. The average age of the cadavers was 46 years, ranging from 28 to 64 years. The precise measurements were obtained using the Microscribe-G2X device, renowned for its accuracy of up to one-thousandth of a millimeter. The length from the pivot point of the radial nerve in the sulcus nervi radialis to the distal end of the humerus is measured, along with the transverse diameter between the lateral epicondyle and the radial nerve and the length of the humerus itself. The length from the pivot point of the radial nerve in the sulcus nervi radialis to the distal end of the humerus is measured, along with the transverse diameter between the lateral epicondyle and the radial nerve and the length of the humerus itself. The length from the pivot point of the radial nerve in the sulcus nervi radialis to the distal end of the humerus is measured, along with the transverse diameter between the lateral epicondyle and the radial nerve and the length of the humerus itself. The right and left sides were measured to be 30.54±0.65cm and 30.54±0.59cm, respectively, with no considerable difference between them. The distance from the pivot point of the radial nerve in the sulcus nervi radialis to the distal part of the humerus was 15.07±1.27cm on the right side and 15.34±1.21cm on the left side. On the right, the distance was 15.07±1.27cm, while on the left, it was 15.34±1.21cm. Moreover, the transverse diameter between the lateral epicondyle and the radial nerve was measured at 2.95±0.14cm on the right side and 3.05±0.13cm on the left side. We contend that comprehension of the safe zone in distal humerus surgery can greatly improve surgical safety. [ABSTRACT FROM AUTHOR]

Abstract Background Internal fixation of the femoral neck carries a risk of perforation due to the presence of the isthmus of the femoral neck. At present, there are few studies on the safe and risk zones of the femoral neck system (FNS) implantation. This study aimed to recommend the safe range of injection of FNS in the lateral wall of the proximal femur, parallel to the axis of the femoral neck, during FNS treatment of femoral neck fracture (FNF). Methods Femoral computed tomography (CT) data of 80 patients (male: 40; female: 40) who met the inclusion criteria were collected. Mimics 21.0 software was used to complete the modeling. 3-Matic 13.0 software was used to establish the axis of the femoral neck and its vertical plane, perform the cutting of the femoral neck, and project it on the vertical plane of the femoral neck axis. After matching a rectangle for each projection map, all sample sizes (80 cases) were standardized and superimposed to obtain gradient maps of the safe zone (SZ) and dangerous zone (RZ), thereby securing edge key points and safe FNS insertion range. Results In the 80 samples, the mean diameter of the smallest femoral neck section was 33.87 ± 2.32 mm for men and 29.36 ± 1.92 mm for women. All 80 femoral necks had safe and risky areas. The SZ/S × 100% was 77.59 (± 2.22%), and the RS/S × 100% was 22.39% (± 2.22%). The risk area was composed of four parts: (1), (2), (3), and (4), respectively, corresponding to 3.45 ± 1.74%, 5.51 ± 2.63%, 6.22 ± 1.41%, and 7.22 ± 1.39%. Four marginal key points, perforation risk, and safe ranges (SR) of FNS were analyzed on the lateral wall of the femoral neck. Conclusions The SR of FNS placement was recommended by digital simulation. In addition, Regions (3) and (4) posed a higher risk of penetrating the cortex. Using the gradient map of RZ for preoperative evaluation is recommended to avoid iatrogenic perforation.

ObjectiveTo propose a method based on intraoperative ankle acupoint X-ray fluoroscopy to determine the safe area of screw fixation surgery for posterior ankle fractures using the posteromedial vertical syndesmotic line(PVSL). MethodsA retrospective analysis was conducted on the clinical data of 21 cases of Lauge-Hansen type Ⅲ-Ⅳ posterior malleolar fractures fixed with hollow screws in Danyang peoples Hospital from October 2019 to June 2021. During the operation, the radiological safety area was determined the screw which located within 1-2 mm of the tibia side of PVSL under ankle acupoint fluoroscopy of C-arm X-ray machine, and the quality of screw placement was evaluated by three-dimensional reconstruction of multi-slice spiral CT scan after operation. ResultsUnder intraoperative X-ray fluoroscopy, the posterior ankle screw was inserted within 1-2mm of the tibial side of the PVSL, and no screw entered the lower tibiofibular joint. The posterior ankle fracture block was effectively fixed. The follow-up time was 12-18(15.24 ±4.37） months. Among 21 patients, there were no complication such as sural nerve injury, abnormal hallux flexion, and all incisions healed in grade A. There was no re-displacement, delayed union, or non union of the fractures. One year after surgery, the ankle joint AOFAS score was(86.74 ± 10.84), and the excellent and good rate was 95.2%. ConclusionUnder intraoperatiue X-ray fluoroscopy, the placement of posterior ankle screws within 1-2mm of the tibial side of PVSL can improve the accuracy of screw placement and avoid injury caused by screw entry into the lower tibiofibular joint. PVSL can provide an imaging reference for the safe range of implant placement in posterior ankle fractures.

Study Design. Retrospective chart review Objective. Identify demographic and sagittal alignment parameters that are independently associated with femoral nerve position at the L4-L5 disk space. Summary of Background Data. Iatrogenic femoral nerve or lumbar plexus injury during lateral lumbar interbody fusion (LLIF) can result in neurological complications. The LLIF "safe zone" is the anterior half to two third of the disk space. However, femoral nerve position varies and is inconsistently identifiable on magnetic resonance imaging. The safe zone is also narrowest at L4-L5. Methods. An analysis of patients with symptomatic lumbar spine pathology and magnetic resonance imaging with a visibly identifiable femoral nerve evaluated at a single large academic spine center from January 1, 2017, to January 8, 2020, was performed. Exclusion criteria were transitional anatomy, severe hip osteoarthritis, coronal deformity with cobb >10 degrees, > grade 1 spondylolisthesis at L4-L5 and anterior migration of the psoas. Standing and supine lumbar lordosis (LL) and its proximal (L1-L4) and distal (L4-S1) components were measured. Femoral nerve position on sagittal imaging was then measured as a percentage of the L4 inferior endplate. A stepwise multivariate linear regression of sagittal alignment and LL parameters was then performed. Data are written as estimate, 95% CI. Results. Mean patient age was 58.2±14.7 years, 25 (34.2%) were female and 26 (35.6%) had a grade 1 spondylolisthesis. Mean femoral nerve position was 26.6± 10.3% from the posterior border of L4. Female sex (-6.6, -11.1 to -2.1) and supine proximal lumbar lordosis (0.4, 0.1--0.7) were independently associated with femoral nerve position. Conclusions. Patient sex and proximal LL can serve as early indicators of the size of the femoral nerve safe zone during a transpsoas LLIF approach at L4-L5. [ABSTRACT FROM AUTHOR]

There is great difficulty in quickly calculating the impingement‐free range of motion (IFROM) of hip components with complex shapes after total hip arthroplasty. We have established a new algorithm to investigate the effect of different shapes of hip components on the IFROM and impingement‐free safe zone (IFSZ). Then find the best combination of hip prosthesis and the optimal mounting position of the elevated‐rim liner under different radiographic anteversion (RA) and radiographic inclination (RI) of the cup. We found the larger the opening angle of the beveled‐rim liner and the smaller the cross‐sectional area of the stem neck with an inverted teardrop cross‐sectional shape, the greater the IFROM of the hip component. The beveled‐rim liner in combination with the stem neck with an inverted teardrop‐shaped cross‐section could provide the greatest IFSZ (excluding the flat‐rim liner). The optimal orientation of the elevated‐rim liner was the posterior‐inferior side (RI ≤ 37°), posterior‐superior side (RI ≥ 45°), and posterior side (37° ≤ RI ≤ 45°). Our novel algorithm provides a solution to analyze the IFROM of any hip prosthesis with any complex shape. The shape and size of the cross‐section of the stem neck, the orientation of the elevated rim, and the shape and opening angle of the liner are all critical factors for the quantitative calculation of the IFROM and mounting safe zone of the prosthesis. Stem necks with inverted teardrop cross‐section and beveled‐rim liner improved the IFSZ. The optimal direction of the elevated rim is not constant but varies with RI and RA. [ABSTRACT FROM AUTHOR]

Copyright of Leisure/Loisir: Journal of the Canadian Association for Leisure Studies is the property of Routledge and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Internal fixation of the femoral neck carries a risk of perforation due to the presence of the isthmus of the femoral neck. At present, there are few studies on the safe and risk zones of the femoral neck system (FNS) implantation. This study aimed to recommend the safe range of injection of FNS in the lateral wall of the proximal femur, parallel to the axis of the femoral neck, during FNS treatment of femoral neck fracture (FNF). Methods: Femoral computed tomography (CT) data of 80 patients (male: 40; female: 40) who met the inclusion criteria were collected. Mimics 21.0 software was used to complete the modeling. 3-Matic 13.0 software was used to establish the axis of the femoral neck and its vertical plane, perform the cutting of the femoral neck, and project it on the vertical plane of the femoral neck axis. After matching a rectangle for each projection map, all sample sizes (80 cases) were standardized and superimposed to obtain gradient maps of the safe zone (SZ) and dangerous zone (RZ), thereby securing edge key points and safe FNS insertion range. Results: In the 80 samples, the mean diameter of the smallest femoral neck section was 33.87 ± 2.32 mm for men and 29.36 ± 1.92 mm for women. All 80 femoral necks had safe and risky areas. The SZ/S × 100% was 77.59 (± 2.22%), and the RS/S × 100% was 22.39% (± 2.22%). The risk area was composed of four parts: (1), (2), (3), and (4), respectively, corresponding to 3.45 ± 1.74%, 5.51 ± 2.63%, 6.22 ± 1.41%, and 7.22 ± 1.39%. Four marginal key points, perforation risk, and safe ranges (SR) of FNS were analyzed on the lateral wall of the femoral neck. Conclusions: The SR of FNS placement was recommended by digital simulation. In addition, Regions (3) and (4) posed a higher risk of penetrating the cortex. Using the gradient map of RZ for preoperative evaluation is recommended to avoid iatrogenic perforation. [ABSTRACT FROM AUTHOR]

Background: Supraclavicular nerve injury is usually at risk during clavicular fracture fixation. This study aimed to examine the anatomical features and estimate the precise location of supraclavicular nerve branches related to adjacent structural landmarks and to evaluate the differences between sex and side. To highlight the clinical purposes and surgical relevance, this study attempted to define a surgical safe zone that would probably protect the supraclavicular nerve during clavicle fixation. Method: A total of 64 shoulders obtained from 15 female and 17 male adult cadavers were examined, identifying the branching patterns of the supraclavicular nerve, measuring the clavicle length and the course of the supraclavicular nerve referring to the sternoclavicular (SC) and acromioclavicular (AC) joint. Data were categorized by sex and side, and their differences were evaluated using Student T-Test and Mann–Whitney U Test. Clinically relevant predictable safe zones were also statistically analyzed. Result: The results revealed 7 branching patterns of the supraclavicular nerve. The medial and lateral nerve branches formed a shared trunk, and the medial nerve branches separated to form the intermediate branch, i.e., the most frequent pattern (67.19%). The safe zones were determined to be 6.1 mm among both sexes of the SC joint medially, and 0.7 mm among females and 0 mm among males of the AC joint laterally. Surgical incisions between 29.3 to 51.2% and 60.5 to 79.7% of the clavicle length from the SC joint were the safe zones at the midclavicular shaft among both sexes. Conclusion: The findings of this study have provided new insights into the anatomy of the supraclavicular nerve and its variations. It has been revealed that the terminal branches of the nerve consistently pass over the clavicle in a predictable pattern, emphasizing the importance of considering the supraclavicular nerve's safe zones during clinically relevant surgeries. Nevertheless, due to individual anatomical variations, meticulous dissection between these safe zones is necessary to avoid iatrogenic nerve injury among patients. Level of Evidence: Basic Science Study, Anatomic Study. [ABSTRACT FROM AUTHOR]

Abstract Introduction In total hip arthroplasty (THA), the correct position of the acetabular component directly determines the outcome of the surgery, or the success of the surgery. Therefore, how to accurately locate the position of the acetabular component has become a very critical step in THA. As an important anatomical structure of the hip joint, the transverse acetabular ligament (TAL) is helpful for acetabular component orientation in THA. The aim of this systematic review was to investigate application of TAL in THA. Materials and methods A systematic literature search of PUBMED, EMBASE, and Cochrane Library was performed (January and February 2023) using keywords “total hip arthroplasty,” “total hip replacement,” “total hip replacements,” “total hip arthroplasties,” “total hip prosthesis,” and “transverse acetabular ligament” in all possible combinations. Reference lists of included articles were reviewed. Study design, surgical approach, patient demographics, TAL identification rate, appearance of the TAL, anteversion and inclination angle and rate of dislocations were recorded. Results In total, 19 studies met the screening criteria. Study designs were prospective cohorts (42%), retrospective cohorts (32%), Case series (21%), and randomized controlled trial (5%). Twelve of the 19 (63.2%) studies investigated the application of TAL as an anatomical landmark for locating acetabular component position in THA. Analysis revealed that TAL is a reliable anatomical landmark for acetabular component orientation within the safe zone in THA. Conclusions TAL can reliably be used to align the acetabular component in the safe zone for anteversion and inclination in THA. However, TAL has individual variation influenced by some risk factors. More randomized controlled studies with larger numbers of patients are needed to investigate the precision and accuracy of TAL as an intraoperative landmark in THA. Level of evidence IV.

Safe zones, initially established as practical tools for refugee protection, have evolved into diplomatic instruments. Through the case of Northern Syria in a historical-comparative perspective, this article explains the link between border politics and host state-induced return to the safe zones; and questions the viability of return within this politicised environment. Considering the earlier experiences of six cases in Sri Lanka, Iraq, Somalia, Bosnia, Rwanda, and Afghanistan, it shows how safe zones and refugee return have become venues for power struggles, not only between the origin and host states but also amongst regional and global powers; established with respect to their economic, political and strategic interests. The Northern Syrian case is distinguished by Turkey's pressure for returns during the conflict, which makes conditions for return dependent on Turkish military presence. Without international support or a UNSC decision, Turkey's self-proclaimed safe zone lacks international legitimacy, and refugee returns remain dependent on unilateral efforts by the Turkish government. Lack of security, rule of law, access to basic services, reconstruction, and overall prospects undermine the feasibility of safe, voluntary and sustainable returns. And as all actors involved place their military objectives above civilian governance, conditions for security in the safe zone remain precarious. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the femoral length as a predictor in the location of the superior gluteal nerve in the transgluteal approach to the hip joint. Materials and methods: A cadaveric dissection study was carried out in 15 gluteal regions corresponding to 10% formalized adult cadaveric specimens. Through the transgluteal approach, the SGN and its superior and inferior terminal branches were identified. The distance between the apex of the greater trochanter (GT) and the inferior terminal branch of the SGN was measured, as well as the femoral length. Analysis of variance (ANOVA) was performed to determine significant differences between the GT-SGN distance according to gender and multiple regression to establish whether femoral length and gender are significant predictors of the GT-SGN distance. Results: The mean GT-SGN distance was 49.05 mm (range 39.2 to 59.7 mm) and the mean femoral length for both genders was 41.92 cm. The analysis of variance did not show significant differences in the GT-SGN distance according to sex (p=0.82) and the multiple regression analysis found no significant relationship between femoral length and the GT-SGN distance (p=0.93). Conclusions: The results of this study did not establish a significant correlation between femoral length and the distance between the superior gluteal nerve and the greater trochanter in the transgluteal approach to the hip joint. [ABSTRACT FROM AUTHOR]

Spinopelvic (SP) mobility patterns during postural changes affect three-dimensional acetabular component position, the incidence of prosthetic impingement, and total hip arthroplasty (THA) instability. Surgeons have commonly placed the acetabular component in a similar "safe zone" for most patients. Our purpose was to determine the incidence of bone and prosthetic impingement with various cup orientations and determine if a preoperative SP analysis with individualized cup orientation lessens impingement. A preoperative SP evaluation of 78 THA subjects was performed. Data were analyzed using a software program to determine the prevalence of prosthetic and bone impingement with a patient individualized cup orientation versus 6 commonly selected cup orientations. Impingement was correlated with known SP risk factors for dislocation. Prosthetic impingement was least with the individualized choice of cup position (9%) versus preselected cup positions (18%-61%). The presence of bone impingement (33%) was similar in all groups and not affected by cup position. Factors associated with impingement in flexion were age, lumbar flexion, pelvic tilt (stand to flexed seated), and functional femoral stem anteversion. Risk factors in extension included standing pelvic tilt, standing SP tilt, lumbar flexion, pelvic rotation (supine to stand and stand to flexed seated), and functional femoral stem anteversion. Prosthetic impingement is reduced with individualized cup positioning based on SP mobility patterns. Bone impingement occurred in one-third of patients and is a noteworthy consideration in preoperative THA planning. Known SP risk factors for THA instability correlated with the presence of prosthetic impingement in both flexion and extension. [ABSTRACT FROM AUTHOR]

Background: Biceps tenodesis is an effective procedure performed to treat shoulder pain originating from the long head biceps tendon. In arthroscopic biceps tenodesis unicortical drilling of the humerus is more commonly practiced as it is considered safe to the vital structures lying posterior to the proximal humerus. Many surgeons are wary of the bi-cortical approach as it poses a risk to these vital structures. The aim of this study was to establish whether bi-cortical drilling in proximal humerus is safe or not. Our second purpose was to find a safe zone (if any) for bi-cortical drilling if bi-cortical drilling is safe. Methods: This study is a descriptive study conducted on cadaveric shoulders. Bilateral shoulders and arms of ten fresh-frozen cadavers (mean age 77.7 y) were dissected. Four landmarks in the dissected humerus were identified. They were superior margin of the bicipital groove, center of the bicipital groove, upper and lower border of pectoralis major insertion. Bi-cortical trans-humeral pinning was done in the humerus at all these points so that the pin exited through the posterior cortex of the humerus. The shortest distance between the pin and the nearest vital structure namely axillary nerve, radial nerve, articular surface of the humeral head, and cephalic vein was calculated from each fixed landmark. Results: We established that bi-cortical drilling in proximal humerus was safe. The safe zone established for bi-cortical biceps tenodesis is at the middle of bicipital groove, which is 18.00 ± 4.02 mm inferior to the groove’s upper border. The boundaries of the safe zone lie 9.39 mm superiorly and 9.40 mm inferiorly to the middle of the bicipital groove. Conclusion: The center of the established safe zone for bi-cortical trans-humeral pinning was 18 mm inferior to the bicipital groove’s upper border.

Introduction: In total hip arthroplasty (THA), the correct position of the acetabular component directly determines the outcome of the surgery, or the success of the surgery. Therefore, how to accurately locate the position of the acetabular component has become a very critical step in THA. As an important anatomical structure of the hip joint, the transverse acetabular ligament (TAL) is helpful for acetabular component orientation in THA. The aim of this systematic review was to investigate application of TAL in THA. Materials and methods: A systematic literature search of PUBMED, EMBASE, and Cochrane Library was performed (January and February 2023) using keywords "total hip arthroplasty," "total hip replacement," "total hip replacements," "total hip arthroplasties," "total hip prosthesis," and "transverse acetabular ligament" in all possible combinations. Reference lists of included articles were reviewed. Study design, surgical approach, patient demographics, TAL identification rate, appearance of the TAL, anteversion and inclination angle and rate of dislocations were recorded. Results: In total, 19 studies met the screening criteria. Study designs were prospective cohorts (42%), retrospective cohorts (32%), Case series (21%), and randomized controlled trial (5%). Twelve of the 19 (63.2%) studies investigated the application of TAL as an anatomical landmark for locating acetabular component position in THA. Analysis revealed that TAL is a reliable anatomical landmark for acetabular component orientation within the safe zone in THA. Conclusions: TAL can reliably be used to align the acetabular component in the safe zone for anteversion and inclination in THA. However, TAL has individual variation influenced by some risk factors. More randomized controlled studies with larger numbers of patients are needed to investigate the precision and accuracy of TAL as an intraoperative landmark in THA. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Copyright of Balikesir Health Sciences Journal / Balıkesir Sağlık Bilimleri Dergisi is the property of Balikesir Health Sciences Journal (BAUN Health Sci J) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: The aim was to investigate the contribution of robotics assisted total hip arthroplasty (THA) through direct anterior approach (DAA) in improving radiographic precision, functional results and complications. Methods: This retrospective study compared 100 primary conventional THA (cTHA) to 50 primary robotic THA (rTHA) through DAA. All cups were placed with the objective of having no anterior overhang while respecting the safe zones (SZ). Radiographic analysis included cup inclination and anteversion, vertical and horizontal changes of the rotation centre (ΔVCOR, ΔHCOR), acetabular and femoral offset. SZ were 30–50° of inclination and 10–30° of anteversion. Outliers were defined as medial displacement of the COR > 5 mm, vertical displacement of the COR > 3 mm superiorly. Harris hip score (HHS) and complications were compared at one year of follow-up. Results: The robotic cups were better oriented with 98% in the global SZ versus 68% in the cTHA group (p = 0.0002). The COR was on average better restored in the robotic group in both the horizontal and vertical planes (Δ HCOR = − 5.0 ± 5.0 vs − 3.4 ± 4.9, p = 0.03; Δ VCOR = 1.6 ± 3.3 vs 0.2 ± 2.7, p = 0.04). There were fewer outliers in the rTHA group concerning VCOR (28% versus 10%, p = 0.03). There was no significant difference in HHS and complication rate at one year. Conclusion: The use of robotics for THA by DAA provided an advantage in controlling the orientation of the cup and the restoration of its rotation centre. Thanks to the 3D planning on CT scan, it allowed to respect the thresholds while avoiding the anterior overhangs. [ABSTRACT FROM AUTHOR]

Objective.: A magnetic resonance neurography (MRN) study was conducted to assess the neurological safety of endoscopic transforaminal lumbar intervertebral fusion (endo-TLIF). Materials and Methods.: A total of 56 healthy volunteers (29 men, 27 women; average age, 44 yr; age range, 21–60 yr) were included in the study. Coronal MRN images were collected from L2/L3 to L5/S1. The working triangle, modified working zone, and safest working zone areas, as well as the vertical and horizontal safe operation diameters, were measured. Linear regression analyses were conducted to explore the correlations between general characteristics (sex, age, height, body mass index) and the measured radiographic indicators. Results.: MRN can effectively evaluate the operation zone of endo-TLIF. The safest working zone, modified working zone, and working triangle areas were largest at L4/L5 (92.4±23.4, 136±35.6, and 197±41.7 mm2, respectively) and smallest at L2/L3 (45.5±12.9, 68.1±19.5, and 92.6±24.4 mm2, respectively). The vertical safe operation diameter was large at L4/L5 and L2/L3 (5.34±0.8 and 5.42±0.9 mm, respectively) and smallest at L5/S1 (2.94±0.9 mm). The horizontal safe operation diameter was large at L4/L5 (7.28±1.2 mm) and smaller at L5/S1 and L2/L3 (4.28±1.0 and 4.77±0.8 mm, respectively). Conclusions.: L4/L5 has the lowest risk of nerve injury, and may be the safest level for beginners initiating endo-TLIF in their practice. We recommend that coronal MRN is routinely performed before endo-TLIF to minimize the risk of neurological injury. [ABSTRACT FROM AUTHOR]

Background: Existing state-of-the-art "safe zone" prediction methods are statistics-based methods, image-matching techniques, and machine learning methods. Yet, those methods bring a tension between accuracy and interpretability. Purpose: To explore the model explanations and estimator consensus for "safe zone" prediction. Material and Methods: We collected the pelvic datasets from Orthopaedic Hospital, and a novel acetabular cup detection method is proposed for automatic ROI segmentation. Hybrid priors comprising both specific priors from data and general priors from experts are constructed. Specifically, specific priors are constructed based on the fine-tuned ResNet-101 convolutional neural networks (CNN) model, and general priors are constructed based on expert knowledge. Our method considers the model explanations and dynamic consensus through appending a SHapley Additive exPlanations (SHAP) module and a dynamic estimator stacking. Results: The proposed method achieves an accuracy of 99.40% and an area under the curve of 0.9998. Experimental results show that our model achieves superior results to the state-of-the-art conventional ensemble classifiers and deep CNN models. Conclusion: This new screening model provides a new option for the "safe zone" prediction of acetabular cup. [ABSTRACT FROM AUTHOR]

Malpositioned implants in total hip arthroplasty are associated with impingement, increased wear, and dislocations, thus precise cup positioning is crucial. However, significant deviations between targeted and actually achieved cup positions have been found even in patients operated by experienced surgeons. When aiming for higher accuracy, various methods based on freehand positioning lead by anatomic landmarks, C-arm fluoroscopy, imageless navigation, or robotic-assisted-surgery have been described. There is a constant development of new products aiming to simplify and improve intraoperative guidance. Both the literature and expert opinions on this topic are often quite controversial. This article aims to give an overview of the different methods and systems with their specific advantages and potential pitfalls while also taking a look into the future of cup positioning in anterior hip replacements. [ABSTRACT FROM AUTHOR]

LGBTQ college students have historically experienced hostile campus climates during their time in higher education. While there has been advancement in LGBTQ inclusion, many universities and colleges still do not provide adequate support and services for LGBTQ students. This paper used the results from 14 qualitative interviews that explored the lived experiences of LGBTQ college students' experiences of campus support and resources at a public university. Despite the presence of a student organization and the university's commitment to inclusion, I found students wanted more LGBTQ representation and community; experienced homophobia, transphobia, and discrimination; and had mixed feelings about the Safe Zone program. Based on these findings, the paper concludes with proposals for increasing LGBTQ representation, facilitating campus education, and creating inclusive policies. [ABSTRACT FROM AUTHOR]

Background: Dislocation is a complicated process and associated with multivariate etiology and risk factors. The purpose of this study was to verify if radiologic restoration inaccuracy increases postoperative dislocation in primary total hip arthroplasty (THA) individually or synergistically. Methods: From 2017 to 2020, we identified 76 (1.9%) patients who suffered postoperative dislocations from 3926 THAs in our institution. After excluded patients with previously proven patient-related and implant-related risk factors, the remaining patients were used to match a 1:1 control patients who were without dislocation. The cup position (inclination and anteversion angles), hip offset (HO), leg length discrepancy (LLD), and abductor lever arm (ALA) were analyzed by univariate analyses and multivariate logistic regressions. Results: Measurements on radiographs showed excellent interobserver agreement (intraclass correlation coefficient (ICC) 0.922–0.952) and intraobserver agreements (ICC 0.933–0.967). HO restoration inaccuracy (without ± 5 mm) was associated with higher dislocation risk (OR 4.241 95% CI 1.440–12.492, P = 0.009). The restoration inaccuracy of the cup position, LLD, or ALA could not increase the dislocation risk individually. When combining the radiologic restoration inaccuracy factors, the HO + LLD restoration inaccuracy and HO + ALA restoration inaccuracy increased the odds of postoperative dislocation (OR 12.056, 95% CI 1.409–103.127, P = 0.023; OR 4.770, 95% CI 1.336–17.028, P = 0.016, respectively). Combining the four risk factors of cup safe zone, HO, LLD, and ALA, patients with 3 or 4 radiologic restoration inaccuracy factors showed a higher risk of dislocation (OR 13.500, 95% CI 1.340–135.983, P = 0.027). Conclusion: Hip offset (HO) restoration inaccuracy increased the risk of dislocation following primary THA. Multivariate radiologic restoration accuracy is critical for the prevention of dislocation and needs to be valued by surgeons. [ABSTRACT FROM AUTHOR]

Abstract Background Because of the broad anatomic variation in the course of the axillary nerve, several cadaveric studies have investigated the acromion-axillary nerve distance and its association with the humeral length to predict the axillary nerve location. This study aimed to analyze the acromion-axillary nerve distance (AAND) and its relation to the arm length (AL) in patients who underwent internal plate fixation for proximal humerus fractures. Methods The present prospective study involved 37 patients (15 female, 22 male; the mean age = 51 years, age range 19–76) with displaced proximal humerus fractures treated by open reduction and internal fixation. After anatomic reduction and fixation were achieved, the following parameters were measured in each patient before wound closure without making an extra incision or dissection: (1) the distance from the anterolateral edge of the acromion to the course of the axillary nerve was recorded as the acromion-axillary nerve distance and (2) the distance from the anterolateral edge of the acromion to the lateral epicondyle of the humerus was recorded as arm length. The ratio of AAND to AL was then calculated and recorded as the axillary nerve index (ANI). Results The mean AAND was 6 ± 0.36 cm (range 5.5–6.6), and the mean arm length was 32.91 ± 2.9 cm (range 24–38). The mean axillary nerve ratio was 0.18 ± 0.02 (range 0.16 to 0.23). There was a significant moderate positive correlation between AL and AAND (p = 0.006; r = 0.447). The axillary nerve location was predictable in only 18% of the patients. Conclusion During the anterolateral deltoid-splitting approach to the shoulder joint, 5.5 cm from the anterolateral edge of the acromion could be considered a safe zone to prevent possible axillary nerve injury.

The invention of the surgical robot enabled accurate component implantation during total hip arthroplasty (THA). However, a preoperative surgical planning methodology is still lacking to determine the acetabular cup alignment considering the patient-specific hip functions during daily activities such as walking. To simultaneously avoid implant edgeloading and impingement, this study established a kinematic–kinetic compliant (KKC) acetabular cup positioning method based on preoperative gait kinematics measurement and musculoskeletal modeling. Computed tomography images around the hip joint and their biomechanical data during gait, including motion tracking and foot–ground reaction forces, were collected. Using the reconstructed pelvic and femur geometries, the patient-specific hip muscle insertions were located in the lower limb musculoskeletal model via point cloud registration. The designed cup orientation has to be within the patient-specific safe zone to prevent implant impingement, and the optimized value selected based on the time-dependent hip joint reaction force to minimize the risk of edgeloading. As a validation of the proposed musculoskeletal model, the predicted lower limb muscle activations for seven patients were correlated with their surface electromyographic measurements, and the computed hip contact force was also in quantitative agreement with data from the literature. However, the designed cup orientations were not always within the well-known Lewinnek safe zone, highlighting the importance of KKC surgical planning based on patient-specific biomechanical evaluations. [ABSTRACT FROM AUTHOR]

Objective To describe the anatomical feature positioned beneath the psoas muscle at the lateral aspect of the lower lumbar, and to create a new location system to identify the risk factors of lateral lumbar interbody fusion. Methods Six cadavers were dissected and analyzed. The anatomy and neurovascular distribution beneath the psoas major from L3 to S1 was observed and recorded, with particular focus on the L4/5 disc and below. The psoas major surface was divided homogeneously into four parts, from the anterior border of psoas major to the transverse process. The cranial‐to‐caudal division was from the lower edge of the psoas muscle attachment on the L4 vertebrae to the upper part of the S1 vertebrae, and was divided into five segments. Then a grid system was used to create 20 grids on the psoas major surface, from the anterior border of the muscle to the transverse process and from L4 to superior S1, which was used to determine the anatomical structures' distribution and relationship beneath the psoas major. Results A cleft was identified beneath the psoas major, from the level of L4/5 downwards. It was filled with loose connective tissue and neurovascular structures. We termed it the cleft of psoas major (CPM). The sympathetic trunk, ascending lumbar vein, iliolumbar vessels, obturator nerve, femoral nerve and occasionally the great vessels are contained within the CPM, although there is significant interpersonal variation. The grid system on the psoas major surface helped to identify the anatomical structures in CPM. There was a considerably lower frequency of occurrence of neurovascular structures in the grids of I/II at the L4/5 level where can be considered the “safe zones” for the lateral lumbar interbody fusion. In contrast, the distribution of neurovascular structures at the L5S1 level is dense, where the operation risk is high. Conclusion The CPM exists lateral to the vertebral surface from L4 and below. Although the occurrence and distribution of neurovascular structures within the CPM is complex and varies greatly, it can provide a potential cavity for visualization during lateral lumbar interbody fusion. Using psoas major as a reference, this novel grid system can be used to identify the risk factors in CPM and thus identify a safe entry point for surgery.

Purpose: When revising acetabular cups, it is often necessary to provide additional stabilisation with screws. In extensive defect situations, the placement of screws caudally in the ischium and/or pubis is biomechanically advantageous. Especially after multiple revision operations, the surgeon is confronted with a reduced bone stock and unclear or altered anatomy. In addition, screw placement caudally is associated with greater risk. Therefore, the present study aims to identify and define safe zones for the placement of caudal acetabular screws.Methods: Forty-three complete CT datasets were used for the evaluation. Sixty-three distinctive 3D points representing bone landmark of interests were defined. The coordinates of these points were then used to calculate all the parameters. For simplified visualisation and intra-operative reproducibility, an analogue clock was used, with 12 o'clock indicating cranial and 6 o'clock caudal.Results: A consistent accumulation was found at around 4.5 ± 0.3 hours for the ischium and 7.9 ± 0.3 hours for the pubic bone.Conclusions: The anatomy of the ischium and pubis is sufficiently constant to allow the positioning of screws in a standardised way. The interindividual variation is low - regardless of gender - so that the values determined can be used to position screws safely in the ischium and pubis. The values determined can provide the surgeon with additional orientation intra-operatively when placing caudal acetabular screws. [ABSTRACT FROM AUTHOR]

The functional parameters pelvic tilt (PT) and hip joint force (HJF) are required to calculate patient‐specific target zones based on the range of motion (ROM) and implant loading for preoperative planning of total hip arthroplasty (THA). Both functional parameters may change after THA. The preoperative prediction of the postoperative PT and HJF is associated with a specific amount of uncertainty. The prediction uncertainty has to be considered in the preoperative planning process to avoid a suboptimal implantation. So far, very little attention has been paid to the necessary reduction of patient‐specific target zones by the prediction uncertainties of postoperative functional parameters. Prediction models for the postoperative PT in standing position and for the HJF during one‐leg stance as a surrogate for the peak force phase during level walking were used to quantify the reduction of the ROM‐ and load‐based target zones of 196 Japanese THA patients. The prediction uncertainty was about 14° for the postoperative standing PT and ranged from 17% body weight to 37% body weight for the components of the HJF. On average, the prosthetic ROM‐based target zone had to be significantly reduced by 43% and the load‐based target zone by 39%. This led to a median reduction of the combined prosthetic ROM‐ and load‐based target zone of 96%. The study sharpens the awareness for the substantial reduction of ROM‐ and load‐based target zones by prediction uncertainties of the postoperative PT and HJF and highlights the importance of further research to improve prediction models for both functional parameters. [ABSTRACT FROM AUTHOR]

Background Context: Lumbosacral fixation is commonly used for the management of lumbosacral instability. As the sacrum mainly consists of cancellous bone, bicortical fixation, in which the pedicle screw penetrates the anterior sacral cortex, can help increase the strength of fixation. However, this method carries a risk to the L5 nerves which lie anterior to the sacrum at this level.Purpose: The goal of this study is to determine a safe zone for the placement of S1 pedicle screws to decrease the likelihood of L5 nerve injury.Study Design: Retrospective imaging review.Patient Sample: This study evaluated imaging data of patients who underwent lumbar spine magnetic resonance imaging (MRI) at our institute between September 1, 2020 and September 1, 2021.Outcome Measures: T1-weighted axial MRIs were measured at the level of S1 pedicle screw placement. The space medial and lateral to the L5 nerve root on the anterior sacrum were measured and defined as safe zones. Additionally, the nerve width and sacral lengths were measured at this level.Methods: The distribution of the measurements were evaluated to determine a medial and lateral safe zone, as well as the average nerve width at the level of S1 pedicle screw placement. Correlation analysis was performed to determine a relationship between safe zone sizes and sacral size.Results: A total of 400 MRIs were analyzed. The average medial safe zone measured was 32.8 mm (95% CI: 32.2-33.4) with no nerves lying within 22.3 mm of the midline sacrum. The average lateral safe zone measured was 17.7 mm (95% CI: 17.1-18.2), with no nerves within 5.3 mm of the lateral border of the sacrum. The average nerve root width was 6.2 mm (95% CI: 6.13-6.34). An increased sacral length was associated with a larger medial (p<.001) and lateral (p<.001) safe zone.Conclusions: Our study revealed lateral and medial safe zones for the placement of S1 pedicle screws to avoid iatrogenic nerve injury in a retrospective cohort of 400 patients. There were no L5 nerve roots found within 22.3 mm of the sacrum's mid-axis or within 5.3 mm of the sacrum's anterolateral border. These defined safe zones can be used during pedicle screw planning and placement to decrease the risk of injury to the L5 nerve root. [ABSTRACT FROM AUTHOR]

Introduction: Retropubic hematomas are a common development in cases of pelvic ring trauma and post- operative repair of fractures to the anterior column of the pelvis. Early detection and diagnosis of such events using computed tomography angiography (CTA) are critical for successful intervention and patient recovery, especially when bleeding is a result of injury to the corona mortis (CM). The CM is the communication between the obturator vessels and the external iliac vessels typically via an accessory obturator vessel. This communication of vessels is identified as a major hindrance in anterior approaches to the pelvis., Materials and Methods: This study investigated the incidence of CM and mapped out safe zones for the anastomosis in a South African sample using 73 adult angiograms from the Department of Diagnostic Radiology, Universitas Academic Hospital. After careful observation of the iliac system, the incidence of CM was documented. The distance from the CM to clinically relevant bony landmarks were recorded to formulate safe zones., Results: The incidence of CM was observed in 33.1 % of the sample, with 20 % being venous and 13.1 % being arterial anastomoses. Statistically significant differences between the sexes were noted for safe zones between all landmarks except for the pubic tubercle (p ≥ 0.26). The safe zone between the CM and the pubic tubercle were documented as 46.88 mm and the average diameter for all anastomotic vessels was noted as 2.83 mm (Range: 1.75 - 4.61 mm)., Conclusion: The inconsistencies presented in angiogram studies compared to cadaver studies suggest that angiograms should be limited to a diagnostic and therapeutic role of identifying the CM or injury thereof in the retropubic region. However, measurements concerning safe zones should rather be extracted from cadaveric studies., Competing Interests: Declaration of competing interest The authors have no conflicts of interest relevant to this article., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Aims: Pelvic tilt (PT) can significantly change the functional orientation of the acetabular component and may differ markedly between patients undergoing total hip arthroplasty (THA). Patients with stiff spines who have little change in PT are considered at high risk for instability following THA. Femoral component position also contributes to the limits of impingement-free range of motion (ROM), but has been less studied. Little is known about the impact of combined anteversion on risk of impingement with changing pelvic position. Methods: We used a virtual hip ROM (vROM) tool to investigate whether there is an ideal functional combined anteversion for reduced risk of hip impingement. We collected PT information from functional lateral radiographs (standing and sitting) and a supine CT scan, which was then input into the vROM tool. We developed a novel vROM scoring system, considering both seated flexion and standing extension manoeuvres, to quantify whether hips had limited ROM and then correlated the vROM score to component position. Results: The vast majority of THA planned with standing combined anteversion between 30° to 50° and sitting combined anteversion between 45° to 65° had a vROM score > 99%, while the majority of vROM scores less than 99% were outside of this zone. The range of PT in supine, standing, and sitting positions varied widely between patients. Patients who had little change in PT from standing to sitting positions had decreased hip vROM. Conclusion: It has been shown previously that an individual’s unique spinopelvic alignment influences functional cup anteversion. But functional combined anteversion, which also considers stem position, should be used to identify an ideal THA position for impingement-free ROM. We found a functional combined anteversion zone for THA that may be used moving forward to place total hip components.

Objectives: The study aimed to elucidate target cup orientation and stem anteversions to avoid impingement between the liner and stem neck even at hip rotation with adduction during the deeply flexed posture.Methods: A computer simulation analysis was performed on 32 total hip arthroplasty patients applying patient-specific orientation of the components and in vivo hip kinematics obtained from three-dimensional analysis of the squatting motion. The anterior/posterior liner-to-neck distance and impingement were evaluated based on a virtual change in internal/external rotation (0°–60°) and adduction/abduction (0°–20°) at actual maximum flexion/extension during squatting. Cutoff values of cup orientations, stem anteversion, and combined anteversion to avoid liner-to-neck impingements were determined.Results: The anterior liner-to-neck distance decreased as internal rotation or adduction increased, and the posterior liner-to-neck distance decreased as external rotation or adduction increased. Negative correlations were found between anterior/posterior liner-to-neck distances at maximum flexion/extension and internal/external rotation. Anterior/posterior liner-to-neck impingements were observed in 6/18 hips (18/56%) at 45° internal/external rotation with 20° adduction. The range of target cup anteversion, stem anteversion, and combined anteversion to avoid both anterior and posterior liner-to-neck impingements during squatting were 15°–18°, 19°–34°, and 41°–56°, respectively.Conclusion: Simulated hip rotations caused prosthetic impingement during squatting. Surgeons could gain valuable insights into target cup orientations and stem anteversion based on postoperative simulations during the deeply flexed posture.

Background: While previously considered unsuitable for revision total hip arthroplasty (rTHA), the direct anterior approach (DAA) can be extended to allow for safe acetabular component revision. In primary hip arthroplasty, the DAA and its associated fluoroscopy, has been shown to produce more acceptable component positioning. However, there is little data comparing the DAA to the posterior approach (PA) for rTHA. We hypothesised that, the DAA with intraoperative fluoroscopy would allow for more precise acetabular component positioning when compared to those performed using a PA. Methods: 50 consecutive patients (25 DAA and 25 PA) undergoing rTHA were included. Radiographic analysis of postoperative acetabular component position was then performed. Univariate and multivariate analyses was performed to assess the contribution of approach on cup positioning inside classically defined "safe zones". Results: Baseline patient characteristics were similar. The PA was associated with more cups placed outside the Lewinnek (48% vs. 12%, p = 0.005) and the Danoff (52% vs. 28%, p = 0.083) "safe zones" when compared to the DAA. Multivariate analysis revealed that operative approach was the only patient or surgical factor associated with component position outside of the "safe zones" (Lewinnek [OR = 13.6; 95% CI, 2.12-87.9, p = 0.006] and Danoff [OR = 7.7; 95% CI, 1.48-40.1, p = 0.015]). Conclusion: Our results suggest that the DAA allows for more reproducible and precise cup placement in RTHA. The safe-zone paradigm remains a useful index of accurate cup positioning and the DAA, with use of intraoperative fluoroscopy, offers more consistent acetabular component positioning when compared to the PA. [ABSTRACT FROM AUTHOR]