Normal vertical and horizontal offset is essential for hip biomechanics, muscle functioning and gait pattern. Total hip arthroplasty (THA) should aim to restore normal offset with implantation of femoral and acetabular components. This would be possible with proper preoperative planning, templating and ensuring implant options are available for offset restoration. Templating is essential for understanding the vertical and horizontal offset change, especially in hip arthritis presenting late with significant limb length discrepancy at THA. Planning should include appropriate soft tissue releases and the use of ideal implants to achieve restoration of horizontal and vertical offset. Under correction of horizontal offset at THA for fracture neck of femur could result in abductor fatigue, limp and increased wear. Restoration of horizontal offset is imperative at THA for a fractured neck of the femur to achieve optimal abductor function. Horizontal offset is necessary for optimal abductor muscle tension and function. Revision THA for acetabular bone loss would require hip center restoration with the acetabular and femoral offset correction to achieve limb length correction and abductor length. The inability to achieve vertical and horizontal offset correction could lead to dislocation or signs of abductor fatigue. Careful vertical and horizontal femur offset restoration is required for normal hip biomechanics, decreased wear and increased longevity.

Adults requiring total hip arthroplasty (THA) for childhood disorder sequelae present with shortening, limp, pain, and altered gait. THA, which can be particularly challenging due to altered anatomy, requires careful planning, assessment, and computed tomography evaluation. Preoperative templating is essential to establish the appropriate acetabular and femoral size. Information regarding neck length and offset is needed to ensure the proper options are available at THA. Hip centre restoration must be planned preoperatively and achieved intraoperatively with appropriate exposure, identification, and stable fixation with optimum-size components. Identifying the actual acetabular floor is essential as changes include altered anatomy, distortion of the margins and version changes. Proximal femur changes include anatomical variation, decreased canal diameter, cortical thickness, changes in anteversion, and metaphyseal and diaphyseal mismatch. Preoperative assessment should consist of limb assessment for variations due to prior surgical procedures. Evaluation of the shortening pattern with the relationship of the lesser trochanter to the teardrop would help identify and plan for subtrochanteric shortening osteotomy, especially in high-riding hips. The surgical approach must ensure adequate exposure and soft tissue release to achieve restoration of the anatomical hip centre. The femoral components may require modularity to enable restoration of anteversion and optimum fixation.

OBJECTIVE: Templating is the first step in achieving a successful total hip arthroplasty. We hypothesize that native head size is highly correlated with implanted cup size. Therefore, the purpose of this study is to look for a correlation between sizes of the intra-operative measurement of the femoral head and the implanted cup.
METHODS: This is a monocentric observational study conducted from December 2018 till January 2023. All patients admitted for a primary total hip arthroplasty were included and retrospectively reviewed. Intra-operative femoral head measurement, radiographic femoral head diameter, templated (planned) cup size, and definitive implanted cup size were recorded.
RESULTS: The sample included 154 patients (85 female and 69 males) with a mean age of 66.2 ± 10.4 years. There were 157 THA cases; 82 on the right side and 75 on the left side. The native head size and acetate template on digital radiographs were the most significantly positively correlated with cup size (P < 0.0001) while the radiological head size was significantly negatively correlated with cup size (P = 0.009). The implanted cup was on average 2 ± 2 mm bigger than the native head size measured intra-operatively.
CONCLUSIONS: The native femoral head diameter measured intra-operatively is a simple and reliable tool to help the surgeons choose the proper size of the acetabular cup, preventing complications during surgery hence optimizing results post operatively. This technique would contribute to a more ecofriendly orthopaedic reconstructive surgery.

Fine-tuning nucleation and growth of colloidal liquid crystalline (LC) droplets, also known as tactoids, is highly desirable in both fundamental science and technological applications. However, the tactoid structure results from the trade-off between thermodynamics and nonequilibrium kinetics effects, and controlling liquid-liquid crystalline phase separation (LLCPS) in these systems is still a work in progress. Here, a single-step strategy is introduced to obtain a rich palette of morphologies for tactoids formed via nucleation and growth within an initially isotropic phase exposed to a gradient of depletants. The simultaneous appearance is shown of rich LC structures along the depleting potential gradient, where the position of each LC structure is correlated with the magnitude of the depleting potential. Changing the size (nanoparticles) or the nature (polymers) of the depleting agent provides additional, precise control over the resulting LC structures through a size-selective mechanism, where the depletant may be found both within and outside the LC droplets. The use of depletion gradients from depletants of varying sizes and nature offers a powerful toolbox for manipulation, templating, imaging, and understanding heterogeneous colloidal LC structures.

Templating is essential in hip arthroplasty preparation, facilitating implant size prediction and surgical rehearsal. It ensures the selection of suitable implants according to patient anatomy and disease, aiming to minimize post-operative complications. Various templating methods exist, including traditional acetate templating on both analog and digital images, alongside digital templating on digital images, which is categorized into 2D and 3D approaches. Despite the popularity of acetate templating on digital images, challenges such as the requirement for physical templates and result preservation persist. To address these limitations, digital templating with software like OrthoSize and Orthoview has been suggested, although not universally accessible. This technical note advocates for Microsoft PowerPoint as an effective alternative for 2D digital templating, highlighting its user-friendly features for image manipulation without needing specialized software. The described method involves scanning acetate templates, adjusting the images in PowerPoint 365 for size, position, and calibration on patient radiographs, and demonstrating reliability through preliminary assessments, with intraclass correlation coefficient (ICC) values indicating a high level of agreement for cup and stem size (ICC = 0.860, 0.841, respectively) but moderate for neck length (ICC = 0.592). We have introduced a method for performing 2D digital templating in the clinical field without the need for specialized software dedicated to digital templating. We believe this method significantly improves the accessibility to 2D digital templating, which was previously limited by the need for digital templating software. Additionally, it enables surgeons to easily establish arthroplasty plans and share them, overcoming the limitations of acetate templates.

The petal effect is identified as a non-wetting state with high drop adhesion. The wetting behavior of petal surfaces is attributed to the papillose structure of their epidermis, which leads to a Cassie-Baxter regime combined with strong pinning sites. Under this scenario, sessile drops are pearl shaped and, unlike lotus-like surfaces, firmly attached to the surface. Petal surfaces are used as inspiration for the fabrication of functional parahydrophobic surfaces such as antibacterial or water-harvesting surfaces. In this work, two types of rose petals were replicated by using a templating technique based in Polydimethylsiloxane (PDMS) nanocasting. The topographic structure, the condensation mechanism under saturated environments and the wetting properties of the natural rose petal and their negative and positive replicas were analyzed. Finally, we performed prospective ice adhesion studies to elucidate whether petal-like surfaces may be used as deicing solutions.

Liquid crystals (LCs) have been adopted to induce tunable physical properties that dynamically originated from their unique intrinsic properties responding to external stimuli, such as surface anchoring condition and applied electric field, which enables them to be the template for aligning functional guest materials. We fabricate the fiber array from the electrically modulated (in-plain) nematic LC template using the chemical vapor polymerization (CVP) method. Under an electric field, an induced defect structure with a winding number of -1/2 contains a periodic zigzag disclination line. It is known that LC defect structures can trap the guest materials, such as particles and chemicals. However, the resulting fibers grow along the LC directors, not trapped in the defects. To show the versatility of our platform, nanofibers are fabricated on patterned electrodes representing the alphabets \'CVP.\' In addition, the semifluorinated moieties are added to fibers to provide a hydrophobic surface. The resultant orientation-controlled fibers will be used in controllable smart surfaces that can be used in sensors, electronics, photonics, and biomimetic surfaces.

UNASSIGNED: Intramedullary (IM) screw insertion into the distal humerus provides fixation for a novel, uncemented elbow arthroplasty. A multitude of screw sizes is required to accommodate variable humeral morphology. The goal of this study was to use computed tomography (CT) for IM screw sizing and to validate this templating by inserting screws into three-dimensionally (3D) printed models.
UNASSIGNED: Computed tomography humerus scans for 30 patients were reformatted in the plane of the distal IM canal. Screw size was templated by measuring the canal diameter at 3 locations corresponding to the lengths of the screws being tested. Interrater and intrarater reliabilities of the measurements were assessed. Three-dimensional models of 5 humeri were printed, and IM screws were placed to achieve a secure endosteal fit.
UNASSIGNED: We identified combinations of body components and IM screw length and diameter for all patients to seat this uncemented elbow arthroplasty. The measurements and screw width determinations were reliable. Canal diameter correlated with age but was unrelated to sex. Screws were inserted into five 3D-printed models which matched the templates and demonstrated mechanical and radiographic evidence of secure fit.
UNASSIGNED: This study characterizes distal humerus anatomy in the context of IM screw fixation. Humerus CT scans of 30 patients were able to be templated, and validation via implantation of IM screws into 3D models was successful. Computed tomography templating will allow surgeons to predict the optimal screw size prior to implantation. A broad range of screw lengths and diameters is critical for implantation of this novel elbow arthroplasty.

BACKGROUND: The use of three-dimensional (3D) planning before a total hip arthroplasty (THA) procedure is becoming increasingly popular as it offers several theoretical benefits: better restoration of a patient\'s anatomy, fewer intraoperative problems, and lower THA cost. It is said to be more accurate than two-dimensional (2D) planning, but as far as we know, no study has investigated how well the implant sizes match between 3D and 2D planning for a surgeon who is just starting to use 3D planning. Consistent implant sizes would make it easier for a surgeon to transition from one system to another. This led us to conduct a retrospective comparative study to: (1) compare how well the implant sizes match between a 3D planning system and a 2D planning method (conventional radiography using templates); (2) determine if the sizes planned on the 3D system match the implants that were used in the patient; (3) determine if the sizes planned with the 2D method match the implants that were used in the patient.
OBJECTIVE: There is a good match in the implant sizes between the 3D and 2D planning.
METHODS: A retrospective observational, single-surgeon study was done with patients who underwent THA between January 2019 and September 2021 at a single teaching hospital. For each patient, the size of the THA implants was planned preoperatively in 3D using proprietary software (Optimized Positioning System™, Corin) and 2D templating. These patients were the first to be operated on by this surgeon based on 3D planning.
RESULTS: Forty-nine patients were included. The implant size matched exactly between the two planning methods for 20% (10/49) of cups [one size larger with 3D in 35% of hips (17/49) and two sizes larger in 20% of hips (10/49)], for 53% (26/49) of femoral stems [one size smaller with 3D in 53% of hips (26/49)] and for 14% (7/49) of complete THA implant systems (cup, femoral stem, femoral head). The size planned in 3D was the same as the cup size implanted in 51% (25/49) of hips, as the femoral stem size in 65% (32/49) and as the complete THA system in 22% (11/49). The cup was within one size in 88% (43/49) of hips and the femoral stem was within one size in 98% (48/49) of hips. The size planned in 2D was the same as the cup size implanted in 45% (22/49) of hips, as the femoral stem size in 63% (32/49) and as the complete THA system in 18% (9/49). The cup was within one size in 86% (42/49) of hips and the femoral stem was within one size in 96% (47/49) of hips with 2D templating. There was no statistically significant difference in the size matching between the 2D and 3D techniques for either the implanted cup (p=0.5) or the implanted femoral stem (p=0.8).
CONCLUSIONS: There is a poor match between the implant sizes determined by 3D and 2D planning. Based on our findings, the shift from 2D templating to 3D planning must be done gradually given the learning curve associated with 3D systems.
METHODS: III; comparative retrospective study.

For successful nasal reconstruction using a forehead flap, three-dimensional (3D) nasal defects need to be translated into a two-dimensional (2D) forehead surface. For this study, a patient-specific 3D-printed forehead flap guide that could precisely translate a virtually simulated nasal shape into a 2D flap template was developed. The study aimed to evaluate the feasibility and efficacy of a 3D-printed forehead flap guide for nasal reconstructions. The 3D nasal surface was scanned using a 3D camera, and a \'digital clay\' process was performed to correct the nasal deformity. The 3D morphology was flattened into a 2D forehead flap guide. The guide was 3D-printed and used for the forehead flap design. Photographic records were used to conduct anthropometric and aesthetic evaluations. Between October 2016 and August 2020, forehead flaps were performed using the forehead flap guide (guide group) and traditional templating method (control group) in 16 and 15 patients, respectively. The alar shape was more symmetric in the guide group than in the control group, with smaller right-to-left differences in alar width (p = 0.01) and height (p = 0.05). Regarding aesthetic evaluations, nose contour (p = 0.02) and nasal symmetry (p = 0.033) were better in the guide group than in the control group. The mean operative time was significantly shorter (91.9 ± 10.7 min) in the guide group than in the control group (116.4 ± 13.6 min) (p = 0.001). Our findings suggest that a 3D-printed forehead flap surgical guide can be effectively used in nasal reconstruction to reduce operative time and improve aesthetic outcomes.