Risk of suprascapular nerve injury in open Trillat procedure: an anatomical study.

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 (ß 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 ß 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 ß 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.

Evaluating the safe zone for lumbar pedicle screws: are midline crossing screws indicative of pedicle breach?

BACKGROUND CONTEXT: 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. OBJECTIVE: 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. STUDY DESIGN/SETTING: Retrospective Anatomical Study. PATIENT SAMPLE: Adult patients in the from "The Cancer Imaging Archive" (TCIA) database who have not had thoraco-lumbo-sacral fusion. OUTCOME MEASURES: Physiologic measures obtained through 3D analysis of CT images and virtual pedicle screws. METHOD: 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). RESULTS: 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). CONCLUSIONS: 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.

Predicting Instability Risk Following Hemiarthroplasty for Femoral Neck Hip Fractures in Geriatric Patients.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Determination of a Safe Zone for Ischial Screw Placement in Total Hip Arthroplasty.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: The ASIS, center of the acetabulum, and acetabular rim provide identifiable intraoperative landmarks for guiding ischial screw placement in hip arthroplasty.

Cup safe zone and optimal stem anteversion in total hip arthroplasty for patients with highly required range of motion.

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.

How common is extra-articular knee deformity? How to achieve a ''safe zone'' alignment total knee arthroplasty in patients with extra-articular deformity.

The need for total knee arthroplasty is increasing considerably and one of the goals is to achieve post-surgical coronal alignment. Robotic surgical assistance achieves a functional alignment, which is a hip-knee-ankle angle of 0°. However, it is not possible to provide robotic assisted surgery to all our patients so we must include the full-length hip-to-ankle AP weight-bearing radiograph in preoperative planning to obtain a "safe zone" alignment, which is a post-surgical hip-knee-ankle Angle of 0 ± 3°. How can we achieve a "safe zone" alignment total knee arthroplasty in patients with extra-articular deformity?

La necesidad de artroplastia total de rodilla está aumentando considerablemente y uno de los objetivos es lograr la alineación coronal postquirúrgica. La asistencia quirúrgica robótica consigue una alineación funcional, que es un ángulo cadera-rodilla-tobillo de 0°. Sin embargo, no es posible ofrecer cirugía asistida por robot a todos nuestros pacientes, por lo que debemos incluir la radiografía AP de soporte de peso de cadera a tobillo de cuerpo entero en la planificación preoperatoria para obtener una alineación de "zona segura", que es un ángulo postquirúrgico cadera-rodilla-tobillo de 0 ± 3°. ¿Cómo podemos conseguir una artroplastia total de rodilla con alineación de "zona segura" en pacientes con deformidad extraarticular?

Safe range of femoral neck system insertion and the risk of perforation.

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.

Optimal hinge level in opening wedge high tibial osteotomy: Biomechanical analysis using finite element method.

BACKGROUND: While the concept of a safe zone, which can minimize the hinge fracture when performing opening wedge high tibial osteotomy, has been introduced, there is a lack of understanding of the biomechanical environment at the lateral tibial cortex. This study aimed to evaluate the effect of the hinge level on the biomechanical environment at the lateral cortex of the tibia with heterogeneous finite element models. METHODS: Finite element models of biplanar opening wedge high tibial osteotomy based on computed tomography images of a control subject and three patients with medial compartment knee osteoarthritis were created. In each model, three different hinge levels (proximal, middle, and distal) were set. The process of opening the gap during the operation was simulated, and the maximum von Mises stress values at the lateral tibial cortex were calculated for each hinge level and correction angle. FINDINGS: The maximum von Mises stress value at the lateral tibial cortex was the lowest when the hinge was at the middle, while the value was the highest when the hinge was at the distal level. Furthermore, it was demonstrated that a higher correction angle yielded a higher probability of lateral tibial cortex fracture. INTERPRETATION: The findings of this study demonstrate that the hinge at the point where the upper end of the articular cartilage of the proximal tibiofibular joint is located provides the least possibility of lateral tibial cortex fracture, as this is an anatomically independent position from the fibula.

A novel algorithm to efficiently calculate the impingement-free range of motion of irregularly-shaped total hip arthroplasty components.

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.

Safe zone of supraclavicular nerve during clavicle fixation and its anatomical variations, a cadaveric study.

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.

Does Individualization of Cup Position Affect Prosthetic or Bone Impingement Following Total Hip Arthroplasty?

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

A new posterosuperior screw placement strategy to avoid in-out-in screws in femoral neck fractures.

Objective: The inverted triangle configuration of the three cannulated screws is the classic fixation method most commonly performed for undisplaced femoral neck fractures in young and geriatric patients. However, the posterosuperior screw has a high incidence of cortical breach, known as an in-out-in (IOI) screw. In this study, we present a novel posterosuperior screw placement strategy to prevent the screw from becoming IOI. Methods: Using computed tomography data and image-processing software, 91 undisplaced femoral neck fractures were reconstructed. The anteroposterior (AP), lateral, and axial radiographs were simulated. To simulate the intraoperative screw placement process, participants used three screw insertion angles (0°, 10°, and 20°) to place the screw on the AP and lateral views of the radiograph according to the three established strategies. On the AP radiograph, a screw was placed abutting (strategy 1), 3.25 mm away from (strategy 2), or 6.5 mm away from (strategy 3) the superior border of the femoral neck. On the lateral radiograph, all the screws were placed abutting the posterior border of the femoral neck. Axial radiographs were used to evaluate the screw position. Results: In strategy 1, all the placed screws were IOI regardless of the screw insertion angle. In strategy 2, 48.3% (44/91) of IOI screws occurred at a 0° screw insertion angle, 41.7% (38/91) of IOI screws occurred at a 10° screw insertion angle, and 42.9% (39/91) of IOI screws occurred at a 20° screw insertion angle situation. In strategy 3, no IOI screw occurred, and the screw insertion angles did not affect the safety and accuracy of screw placement. Conclusions: Screws placed according to strategy 3 are safe. The reliability of this screw placement strategy is unaffected by a screw insertion angle of less than 20 degrees.

Application of transverse acetabular ligament in total hip arthroplasty: a systematic review.

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.

How common is extra-articular knee deformity? How to achieve a «safe zone¼ alignment total knee arthroplasty in patients with extra-articular deformity / ¿Qué tan común es la deformidad extraarticular de rodilla? ¿Cómo lograr una artroplastia total de rodilla con alineación de «zona segura¼ en pacientes con deformidad extraarticular?

Abstract: The need for total knee arthroplasty is increasing considerably and one of the goals is to achieve post-surgical coronal alignment. Robotic surgical assistance achieves a functional alignment, which is a hip-knee-ankle angle of 0o. However, it is not possible to provide robotic assisted surgery to all our patients so we must include the full-length hip-to-ankle AP weight-bearing radiograph in preoperative planning to obtain a «safe zone¼ alignment, which is a post-surgical hip-knee-ankle Angle of 0 ± 3o. How can we achieve a «safe zone¼ alignment total knee arthroplasty in patients with extra-articular deformity?

Resumen: La necesidad de artroplastia total de rodilla está aumentando considerablemente y uno de los objetivos es lograr la alineación coronal postquirúrgica. La asistencia quirúrgica robótica consigue una alineación funcional, que es un ángulo cadera-rodilla-tobillo de 0o. Sin embargo, no es posible ofrecer cirugía asistida por robot a todos nuestros pacientes, por lo que debemos incluir la radiografía AP de soporte de peso de cadera a tobillo de cuerpo entero en la planificación preoperatoria para obtener una alineación de «zona segura¼, que es un ángulo postquirúrgico cadera-rodilla-tobillo de 0 ± 3o. ¿Cómo podemos conseguir una artroplastia total de rodilla con alineación de «zona segura¼ en pacientes con deformidad extraarticular?

Safe-zone schools and the academic performance of children in mixed-status households: Evidence from the 'between the lines' study.

In response to the intensification of immigration enforcement in the interior of the USA, some school districts have implemented 'safe-zone' policies to protect students' academic progression and well-being. Using primary data from a sample of US-born children of unauthorized migrants, we document the detrimental effect of stricter immigration enforcement on children's educational outcomes and the benefits of safe-zone policies. Our analyses show that restricting immigration authorities' access to schools and providing counseling on immigration-related issues are crucial policy components in strengthening children's focus, effort, expectations, parental involvement, and relationships. These findings highlight the damaging impact of immigration enforcement on US-citizen children in mixed-status households and advance our understanding of the role of local policies in mitigating these effects.

An Assessment of the Reduction of Submental Fullness With ATX-101 (Deoxycholic Acid Injection) in the Expanded Safe Zone.

Background and objective Facial aesthetics have a huge impact on how individuals view themselves and are viewed by society. The aesthetics of the face are tremendously influenced by the shape of the chin and neck. In this study, we aimed to observe the outcomes in individuals after the use of ATX-101 (deoxycholic acid injection) in an expanded safe zone for submental fullness. To ensure optimal outcomes and reduce the risk of adverse events, appropriate patient selection is the key. ATX-101 treatment may be administered in combination with hyaluronic acid fillers, botulinum toxins, cryolipolysis, and radiofrequency treatment. This is the first study of its kind to be carried out at the national level in Pakistan. Materials and methods This was a quasi-experimental study conducted at the Rawalian Burn and Reconstructive Surgery Unit, Holy Family Hospital, Rawalpindi, Pakistan for a period of nine months, from 10-1-2021 to 11-10-2021. A total of 62 patients who fulfilled the inclusion criteria were enrolled. We recorded if any complications had occurred or not. Moreover, the total number of treatment sessions, the volume of injectables used, and the interval between sessions were also documented. ATX-101 package was injected into the treatment area. Due care was taken to avoid the region of the marginal mandibular nerve. After the procedure, outcomes and complications were observed. Results In this study, patient satisfaction was reported in 59 (95.2%) patients. After the fourth session, final improvement was observed in 59 (95.16%) patients. Tenderness was found in seven (11.3%) patients, bruising was noted in four (6.5%), edema was found in seven (11.3%), numbness was noted in one (1.6%), whereas paresis and alopecia were not found in any of the patients. Conclusion Our study concluded that ATX-101 is a very useful modality with fewer complication rates and is associated with significant improvement in the expanded safe zone for submental fullness.

Achieving Precise Cup Positioning in Direct Anterior Total Hip Arthroplasty: A Narrative Review.

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.

Does Intra-operative Fluoroscopy Significantly Improve Component Position in a Primary Total Hip Arthroplasty? Our Experience in a Tertiary Care Hospital.

Background: Optimal component placement, equalization of leg lengths, and recreation of offset are important surgical objectives during total hip arthroplasty (THA). Historically, many surgeons have aimed for the Lewinnek's " safe zone," which is defined as 30°-50° of abduction and 5°-25° of anteversion. Methods for optimizing cup position include anatomic landmarks, room landmarks, acetabular cup coverage, and ischial or pubis palpation. Malposition of the acetabular component after total hip arthroplasty (THA) is related to dislocation of the prosthetic femoral head, increased polyethylene liner wear, and limited range of motion. The orientation of the acetabular component comprises inclination and anteversion. Although the inclination of the acetabular component can be easily measured on plain radiographs, the calculation of the anteversion is difficult. This study evaluates the effect of intra-operative fluoroscopy on component position, mainly anteversion and inclination of the acetabular cup, during a total hip arthroplasty. Methods: 106 hips undergoing total hip arthroplasty were assessed, and the decision to use fluoroscopy assistance was randomized based on a simple randomization technique. A total of 48 patients were operated on with fluoroscopy assistance and 58 patients without fluoroscopy assistance. All patients were evaluated postoperatively for version of component on anteroposterior radiographs of the hip using the method of Liaw et al. and for inclination of component on anteroposterior radiographs using the method of Woo and Morrey. Results: The mean version for the non-fluoroscopy (NF) group was 15.62° and the mean inclination was 44.22°, with 15.5% (9 out of 58) of the patients who did not fit into Lewinnek's safe zone for version and 25.9% (15 out of 58) of the patients who were outliers for inclination of the acetabular cup position. The mean version for the fluoroscopy group (F) was 11.80° and the mean inclination was 47.05°, with 0% (0 out of 48) of the patients who did not fit into Lewinnek's safe zone for version and 12.5% (6 out of 48) of the patients who were outliers for inclination of the acetabular cup position. Conclusion: While the mean version and inclination of the acetabular component were comparable for both groups, outliers for version and inclination were far more common in the group of patients who underwent surgery without intra-operative fluoroscopic assistance. Therefore, intra-operative fluoroscopy imaging confirms appropriate inclination (abduction) and version of acetabular cup position according to Lewinnek's safe zone and prevents undesirable component position during a total hip arthroplasty while adding a maximum of 5 min to the operative time.

Bi-Cortical transhumeral drilling for biceps tenodesis - Is it safe?

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.

Incidence and pattern of concurrent capitellum fracture associated with radial head and neck fractures.

BACKGROUND: Radial head and neck fracture is a common fracture around the elbow. It is mostly caused by axial or valgus loading after a fall in elbow extension and forearm pronation. When a radial head and neck fracture occurs, the capitellum collides with the radial head and experiences a shear force, leading to capitellum fracture. The primary aim of this study was to evaluate the incidence of concurrent capitellum fracture and analyze its patterns among patients treated for radial head and neck fractures based on computed tomography. Secondary aim is to determine factors associated with concurrent capitellum fractures. HYPOTHESIS: Capitellum fractures are more common than expected in radial head and neck fractures and show a consistent pattern. With the higher the Mason type fracture, the higher the incidence of concurrent capitellum fracture will be shown. METHODS: A total of 101 patients treated surgically (27 patients) or non-surgically (74 patients) for radial head and neck fractures from January 2017 to December 2020 were retrospectively analyzed. Initial computed tomography was reviewed to identify concurrent capitellum fractures. A fracture was diagnosed when the bone continuity was lost in two consecutive images in any one of the three directions of computed tomography scan images. Seventeen patients with capitellum fractures were classified as group 1 and 84 patients without capitellum fractures as group 2. Each group of patients was assessed using Mason classification, whether fracture extended to the radial neck or not, fracture location, and treatment method. To determine the fracture location, radial head was trisected using three anatomical landmarks: safe zone, posteromedial zone, and anteromedial zone. And it was determined as the location where the fracture was most comminuted. RESULTS: The average age of the 101 patients was 44.6 years old. There were 54 (53.5%) males and 47 (46.5%) females. Capitellum fracture was accompanied in 17 cases. Its incidence was 16.8%. The rate of accompanying capitellum fracture was 9.5% (6/63) for Mason type 1, 25.0% (6/24) for Mason type 2, and 41.7% (5/12) for Mason type 3. The ratio of radial neck extension of fracture was significantly higher in group 2. There was no isolated radial neck fracture in group 1. However, there were 33 in group 2. After eliminating isolated radial neck fracture patients, significantly more fractures were located in the safety zone in group 1. Group 1 had a significantly higher rate of surgical treatment than group 2 (52.9% (9/17) vs. 21.4% (18/84) p=0.007). CONCLUSION: For radial head and neck fractures, the higher the Mason type fracture, the higher the incidence of concurrent capitellum fracture. When the fracture extended to the radial neck, the comorbidity of the capitellum fracture was decreased. Among radial head fractures, when the fracture was located in the safe zone, the comorbidity of capitellum fracture was increased. The rate of surgical treatment was higher in radial head and neck fracture patients with concurrent capitellum fractures. LEVEL OF EVIDENCE: IV; diagnostic study.