Derotational Osteotomy of the Distal Femur for the Treatment of Patellofemoral Instability Simultaneously Leads to the Correction of Frontal Alignment: A Laboratory Cadaveric Study

Background: Derotational osteotomy of the distal femur allows the anatomic treatment of patellofemoral maltracking due to increased femoral antetorsion. However, such rotational osteotomy procedures have a high potential of intended/unintended changes of frontal alignment. Purpose/Hypothesis: The purpose of this study was to perform derotational osteotomy of the distal femur and to demonstrate the utility of a novel trigonometric approach to address 3-dimensional (3D) changes on 2-dimensional imaging (axial computed tomography [CT] and frontal-plane radiography). The hypothesis was that 1-step single-cut osteotomy can simultaneously correct torsion and frontal alignment based on preoperatively calculated cutting angles. Study Design: Controlled laboratory study. Methods: Eight human cadaveric whole legs (4 lower limb torsos) underwent derotational osteotomy of the distal femur of 20°. A straight leg axis, determined as a mechanical femorotibial angle (mFTA) of 0°, was chosen as a goal for postoperative frontal alignment. The inclination of the cutting angle from the lateral view was calculated individually for each cadaveric leg and was represented by a simple 3D-printed cutting guide for surgery. Specimens underwent CT for the measurement of torsion, while the frontal leg axis was determined on an upright radiograph preoperatively and postoperatively. Preoperative and postoperative angles were compared with the mathematical prediction model. Results: The preoperative mFTA ranged from –3.9° (valgus) to +3.4° (varus) (mean, –0.2° ± 2.6°). A postoperative mean mFTA of 0.37° ± 0.69° (95% CI, –0.22° to 0.95°) was achieved ( P = .01). Derotation showed a mean of 19.1° ± 2.1° (95% CI, 17.3°-20.8°). The oblique cutting plane for the correction of valgus legs showed a mean of 5.9° ± 6.8° and, for the correction of varus legs, a mean of –10.0° ± 4.5° projected on the perpendicular plane to the virtual anatomic shaft axis from the sagittal view. Conclusion: Single-cut distal femoral osteotomy can be performed to simultaneously address rotational as well as frontal alignment using a preoperatively defined oblique cut, as determined by the presented reproducible calculation model. Clinical Relevance: This study adds important knowledge to the technique of derotational osteotomy. This approach provides an individual, oblique single cut for the correction of torsion and frontal axis within a clinically insignificant margin. Simplified tables for calculation and a surgical reference make this model reproducible and safe.

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Congenital internal rotation deformity of the distal femur presenting as patellofemoral instability and pain

Journal of ISAKOS Joint Disorders & Orthopaedic Sports Medicine ◽

10.1136/jisakos-2018-000260 ◽

2019 ◽

Vol 4 (2) ◽

pp. 93-97 ◽

Cited By ~ 2

Author(s):

Xinyuan Zhang ◽

John Attenello ◽

Marc R Safran ◽

David W Lowenberg

Keyword(s):

Internal Rotation ◽

Knee Pain ◽

Anterior Knee Pain ◽

Distal Femur ◽

Case Series ◽

Patellofemoral Instability ◽

Level Of Evidence ◽

Femoral Antetorsion ◽

Derotational Osteotomy ◽

Anterior Knee

ObjectivesFemoral antetorsion, defined as the angle of rotation of the femoral head and neck axis in relation to the transcondylar axis of the distal femur, is a cause for patellofemoral instability and anterior knee pain. Most clinical reports do not distinguish between antetorsion of the femur distal to the isthmus and anteversion of the proximal femur, which is another cause of femoral internal rotational deformity.MethodsThis retrospective observational case series evaluated four cases in three female patients who underwent evaluation of surgical intervention for chronic anterior knee pain since childhood. Physical examination and radiographic images supported the diagnosis of internal rotation deformity at the distal femora in all four cases. Distal femoral derotational osteotomy of 45°, 60° and 30° were performed, respectively. Kujala scoring system for patellofemoral pathology was used to assess the change in knee symptoms before and after the osteotomies.ResultsThis study demonstrated successful treatment of the resultant knee symptoms from femoral antetorsion with distal femur derotational osteotomy in all three patients.ConclusionsPatellofemoral syndrome is multifactorial, and the true anatomic reason for each patient’s individual pathology must be determined before surgery proceeds.Level of evidenceLevel V.

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Simulation of Cerebrospinal Fluid Leak Repair Using a 3-Dimensional Printed Model

American Journal of Rhinology and Allergy ◽

10.1177/19458924211003537 ◽

2021 ◽

pp. 194589242110035

Author(s):

Muhamed A. Masalha ◽

Kyle K. VanKoevering ◽

Omar S. Latif ◽

Allison R. Powell ◽

Ashley Zhang ◽

...

Keyword(s):

Cerebrospinal Fluid ◽

Great Part ◽

Cerebrospinal Fluid Leak ◽

Csf Leak ◽

Clinical Environment ◽

Training Tool ◽

3 Dimensional ◽

Clinical Scenarios ◽

Before And After ◽

3D Printed

Background Acquiring proficiency for the repair of a cerebrospinal fluid (CSF) leak is challenging in great part due to its relative rarity, which offers a finite number of training opportunities. Objective The purpose of this study was to evaluates the use of a 3-dimensional (3D) printed, anatomically accurate model to simulate CSF leak closure. Methods Volunteer participants completed two simulation sessions. Questionnaires to assess their professional qualifications and a standardized 5-point Likert scale to estimate the level of confidence, were completed before and after each session. Participants were also queried on the overall educational utility of the simulation. Results Thirteen otolaryngologists and 11 neurosurgeons, met the inclusion criteria. A successful repair of the CSF leak was achieved by 20/24 (83.33%), and 24/24 (100%) during the first and second simulation sessions respectively (average time 04:04 ± 1.39 and 02:10 ± 01:11). Time-to-close-the-CSF-leak during the second session was significantly shorter than the first (p < 0.001). Confidence scores increased across the training sessions (3.3 ± 1.0, before the simulation, 3.7 ± 0.6 after the first simulation, and 4.2 ± 0.4 after the second simulation; p < 0.001). All participants reported an increase in confidence and believed that the model represented a valuable training tool. Conclusions Despite significant differences with varying clinical scenarios, 3D printed models for cerebrospinal leak repair offer a feasible simulation for the training of residents and novice surgeons outside the constrictions of a clinical environment.

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3D-Printed Surgical Guiding System for Double Derotational Osteotomy in Congenital Torsional Limb Deformity

JBJS Case Connector ◽

10.2106/jbjs.cc.20.00468 ◽

2021 ◽

Vol 11 (1) ◽

pp. e20.00468-e20.00468

Author(s):

Luigi Sabatini ◽

Giulia Nicolaci ◽

Matteo Giachino ◽

Salvatore Risitano ◽

Andrea Pautasso ◽

...

Keyword(s):

Limb Deformity ◽

Derotational Osteotomy ◽

3D Printed ◽

Guiding System

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Strategies for inclusion of growth factors into 3D printed bone grafts

Essays in Biochemistry ◽

10.1042/ebc20200130 ◽

2021 ◽

Author(s):

Alessia Longoni ◽

Jun Li ◽

Gabriella C.J. Lindberg ◽

Jelena Rnjak-Kovacina ◽

Lyn M. Wise ◽

...

Keyword(s):

Growth Factors ◽

Bone Regeneration ◽

New Technologies ◽

Healing Process ◽

Bone Grafts ◽

Biological Properties ◽

3 Dimensional ◽

3D Printed ◽

Physical And Chemical ◽

Large Bone

Abstract There remains a critical need to develop new technologies and materials that can meet the demands of treating large bone defects. The advancement of 3-dimensional (3D) printing technologies has allowed the creation of personalized and customized bone grafts, with specific control in both macro- and micro-architecture, and desired mechanical properties. Nevertheless, the biomaterials used for the production of these bone grafts often possess poor biological properties. The incorporation of growth factors (GFs), which are the natural orchestrators of the physiological healing process, into 3D printed bone grafts, represents a promising strategy to achieve the bioactivity required to enhance bone regeneration. In this review, the possible strategies used to incorporate GFs to 3D printed constructs are presented with a specific focus on bone regeneration. In particular, the strengths and limitations of different methods, such as physical and chemical cross-linking, which are currently used to incorporate GFs to the engineered constructs are critically reviewed. Different strategies used to present one or more GFs to achieve simultaneous angiogenesis and vasculogenesis for enhanced bone regeneration are also covered in this review. In addition, the possibility of combining several manufacturing approaches to fabricate hybrid constructs, which better mimic the complexity of biological niches, is presented. Finally, the clinical relevance of these approaches and the future steps that should be taken are discussed.

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A 3-Dimensional Printed Aortic Arch Template to Facilitate the Creation of Physician-Modified Stent-Grafts

Journal of Endovascular Therapy ◽

10.1177/1526602818792266 ◽

2018 ◽

Vol 25 (5) ◽

pp. 554-558 ◽

Cited By ~ 10

Author(s):

Pawel Rynio ◽

Arkadiusz Kazimierczak ◽

Tomasz Jedrzejczak ◽

Piotr Gutowski

Keyword(s):

Aortic Arch ◽

Stent Graft ◽

Left Subclavian Artery ◽

Thoracic Endovascular Aortic Repair ◽

Stent Grafts ◽

Landing Zone ◽

3 Dimensional ◽

Improve Accuracy ◽

3D Printed ◽

Radiopaque Markers

Purpose: To demonstrate the utility of a 3-dimensional (3D) printed template of the aortic arch in the construction of a fenestrated and scalloped physician-modified stent-graft (PMSG). Case Report: A 73-year-old woman with descending thoracic aneurysm was scheduled for thoracic endovascular aortic repair after being disqualified for open surgery. Computed tomography angiography (CTA) revealed no proximal landing zone as the aneurysm began from the level of the left subclavian artery, so a fenestrated/scalloped PMSG was planned. To facilitate accurate placement of the openings in the graft, a 3D printed aortic arch template was prepared from the CTA data and gas sterilized. In the operating room, a Valiant stent-graft was inserted into the 3D printed template and deployed. Using ophthalmic cautery, a fenestration and a scallop were created; radiopaque markers were added. The PMSG was successfully deployed with no discrepancy between the openings and the target vessels. Conclusion: A 3D printed aortic arch template facilitates handmade fenestrations and scallops in PMSGs and may improve accuracy and quality.

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Novel On-Demand 3-Dimensional (3-D) Printed Tablets Using Fill Density as an Effective Release-Controlling Tool

Polymers ◽

10.3390/polym12091872 ◽

2020 ◽

Vol 12 (9) ◽

pp. 1872 ◽

Cited By ~ 4

Author(s):

Rishi Thakkar ◽

Amit Raviraj Pillai ◽

Jiaxiang Zhang ◽

Yu Zhang ◽

Vineet Kulkarni ◽

...

Keyword(s):

Drug Release ◽

Hydroxypropyl Methylcellulose ◽

Amorphous State ◽

Dosage Forms ◽

Water Soluble ◽

Patient Specific ◽

3 Dimensional ◽

Fused Deposition ◽

3D Printed ◽

The Impact

This research demonstrates the use of fill density as an effective tool for controlling the drug release without changing the formulation composition. The merger of hot-melt extrusion (HME) with fused deposition modeling (FDM)-based 3-dimensional (3-D) printing processes over the last decade has directed pharmaceutical research towards the possibility of printing personalized medication. One key aspect of printing patient-specific dosage forms is controlling the release dynamics based on the patient’s needs. The purpose of this research was to understand the impact of fill density and interrelate it with the release of a poorly water-soluble, weakly acidic, active pharmaceutical ingredient (API) from a hydroxypropyl methylcellulose acetate succinate (HPMC-AS) matrix, both mathematically and experimentally. Amorphous solid dispersions (ASDs) of ibuprofen with three grades of AquaSolveTM HPMC-AS (HG, MG, and LG) were developed using an HME process and evaluated using solid-state characterization techniques. Differential scanning calorimetry (DSC), powder X-ray diffraction (pXRD), and polarized light microscopy (PLM) confirmed the amorphous state of the drug in both polymeric filaments and 3D printed tablets. The suitability of the manufactured filaments for FDM processes was investigated using texture analysis (TA) which showed robust mechanical properties of the developed filament compositions. Using FDM, tablets with different fill densities (20–80%) and identical dimensions were printed for each polymer. In vitro pH shift dissolution studies revealed that the fill density has a significant impact (F(11, 24) = 15,271.147, p < 0.0001) and a strong negative correlation (r > −0.99; p < 0.0001) with the release performance, where 20% infill demonstrated the fastest and most complete release, whereas 80% infill depicted a more controlled release. The results obtained from this research can be used to develop a robust formulation strategy to control the drug release from 3D printed dosage forms as a function of fill density.

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Data driven design: An investigation into the fit between the individuality of people and the uniformity of mass manufactured items

10.26686/wgtn.17065241.v1 ◽

2021 ◽

Author(s):

◽

Alex Svend Christensen

Keyword(s):

3D Printing ◽

3D Scanning ◽

Digital Data ◽

Human Form ◽

3 Dimensional ◽

Manufacturing Efficiency ◽

3D Printed ◽

Body Shapes ◽

The Individual ◽

Motorcycle Rider

<p>Due to the economic advantage of mass manufacturing technology humans have designed a world of products built for the average body size and shape. This conformity of diverse body shapes to fixed 3 dimensional forms raises the question for this research; how can 3D scanning and additive manufacturing (AM) create a personal fit between an individual’s body and a product? This question challenges a tool driven standardised approach to manufacture by exploring the interface between a person and a mass produced product, in this case a motorcycle rider and a motorcycle. By taking advantage of digital data and the tool-less build process of 3D printing, every object produced can be different, tailoring it to the customer’s individual aesthetic or physical fit. This investigation into the space between the motorcycle and the human has produced a custom 3D printed seat designed for and inspired by the unique physicality of the individual rider. The following methods are employed. 3D scanning is used to obtain the geometry of the human form and motorcycle, 3D modelling and 3D printing to generate and evaluate ideas and concepts, and a pressure measurement system to evaluate the riders comfort and fit. This new relationship between body and object, rarely seen in mass produced products, questions the way we design and make products with consideration towards digital personalisation and manufacturing efficiency.</p>

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Morphological Classification of Trochlear Dysplasia Based On Three-Dimensional Models

10.21203/rs.3.rs-689781/v1 ◽

2021 ◽

Author(s):

Jiangfeng Lu ◽

Yanru Wang ◽

Gang Ji ◽

Fei Wang

Keyword(s):

Trochlear Dysplasia ◽

Three Dimensional ◽

Patellofemoral Instability ◽

Conventional Radiography ◽

3D Models ◽

Lateral View ◽

Lateral Condyle ◽

Level Of Evidence ◽

Three Dimensional Models ◽

Crossing Point

Abstract Background: Trochlear dysplasia (TD) is a common risk factor for the development of patellofemoral instability (PI). Dejour’s classification shows low agreement between conventional radiography and axial magnetic resonance imaging. The present study aimed to evaluate and categorize the true lateral view of three-dimensional (3D) femoral models in patients with TD. Methods: Computed tomography (CT) scans of 96 hip-knee-ankle joints (49 PI patients: 34 female, 15 male; mean age 19.1±6.7 years, range 12–41 years) during 2017–2019 were collected and analyzed. A senior orthopedic surgeon classified the true lateral views of femoral 3D models and raw CT images. The crossing-point site and lateral condyle/facet morphology (lateral condyle bump or supratrochlear spur) were the main criteria. Results: TD cases were classified into four types and their frequencies recorded: type 1 (7.3%) = crossing-point site in the proximal trochlear area and no lateral condyle bump or supratrochlear spur; type 2 (19.8%) = crossing-point site in the proximal trochlear area and presence of a lateral condyle bump or supratrochlear spur; type 3 (13.5%) = crossing-point site in the distal trochlear area and no lateral condyle bump or supratrochlear spur; type 4 (59.4%) = crossing-point site in the distal trochlear area and presence of lateral condyle bump or supratrochlear spur.Conclusion: The presentation of TD varies greatly among PI patients and can be categorized into four types. This new classification, based on true lateral views of 3D femoral models, may provide relatively reliable guidance when using trochleoplasty to treat TD. Level of Evidence: II, development of diagnostic or monitoring criteria in consecutive patients.

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Development of a 3-dimensional printed tube thoracostomy task trainer: An improved methodology

The Asia Pacific Scholar ◽

10.29060/taps.2021-6-1/sc2243 ◽

2021 ◽

Vol 6 (1) ◽

pp. 109-113

Author(s):

Wen Hao Chen ◽

Shairah Radzi ◽

Li Qi Chiu ◽

Wai Yee Yeong ◽

Sreenivasulu Reddy Mogali

Keyword(s):

3D Printing ◽

Chest Tube ◽

Fused Deposition Modelling ◽

3 Dimensional ◽

Fused Deposition ◽

Simulation Based ◽

3D Printed ◽

Medical Educators ◽

Based Instruction ◽

Training Modalities

Introduction: Simulation-based training has become a popular tool for chest tube training, but existing training modalities face inherent limitations. Cadaveric and animal models are limited by access and cost, while commercial models are often too costly for widespread use. Hence, medical educators seek a new modality for simulation-based instruction. 3D printing has seen growing applications in medicine, owing to its advantages in recreating anatomical detail using readily available medical images. Methods: Anonymised computer tomography data of a patient’s thorax was processed using modelling software to create a printable model. Compared to a previous study, 3D printing was applied extensively to this task trainer. A mixture of fused deposition modelling and material jetting technology allowed us to introduce superior haptics while keeping costs low. Given material limitations, the chest wall thickness was reduced to preserve the ease of incision and dissection. Results: The complete thoracostomy task trainer costs approximately SGD$130 (or USD$97), which is significantly cheaper compared to the average commercial task trainer. It requires approximately 118 hours of print time. The complete task trainer simulates the consistencies of ribs, intercostal muscles and skin. Conclusion: By utilising multiple 3D printing technologies, this paper aims to outline an improved methodology to produce a 3D printed chest tube simulator. An accurate evaluation can only be carried out after we improve on the anatomical fidelity of this prototype. A 3D printed task trainer has great potential to provide sustainable simulation-based education in the future.

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Feasibility of a 3D Surgical Guide Technique for Impacted Supernumerary Tooth Extraction: A Pilot Study with 3D Printed Simulation Models

Applied Sciences ◽

10.3390/app9183905 ◽

2019 ◽

Vol 9 (18) ◽

pp. 3905

Author(s):

Hyeonjong Lee ◽

Yong Kwon Chae ◽

Seulki Choi ◽

Myeong Kwan Jih ◽

Jung-Woo Lee ◽

...

Keyword(s):

Tooth Extraction ◽

Simulation Models ◽

Supernumerary Teeth ◽

Supernumerary Tooth ◽

University Hospitals ◽

Surgical Guide ◽

3 Dimensional ◽

Window Opening ◽

3D Printed ◽

Time Required

This study aimed to evaluate the feasibility of a 3-dimensional (3D) planned surgical guide technique designed for impacted supernumerary teeth (STs) extraction using 3D printed simulation models. In total, 17 participants from two university hospitals were recruited. Each participant performed surgery with both the conventional and surgical guide techniques. The following parameters were evaluated: (1) The time required for ST extraction, (2) the area of the window opening, and (3) the volume of the material removed. Time required for ST extraction was 213.65 ± 167.45 sec and 114.76 ± 42.87 sec in the conventional and surgical guide techniques, respectively, with significant differences (p = 0.028). The required area of the window opening was 48.10 ± 9.44 mm2 and 45.90 ± 8.17 mm2, respectively, in the conventional and surgical guide techniques, with no significant differences (p > 0.05). The required volume of the material removed was 121.65 ± 43.69 mm3 and 99.12 ± 17.88 mm3 in the conventional and surgical guide techniques, respectively, with significant differences (p = 0.031). The 3D planned surgical guide technique was effective for impacted ST extraction. Within the limits of this study, the surgical guide technique allows us to accomplish minimally invasive surgery within a shorter duration.

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