Efficiency and Accuracy of 3D Printed Patient-specific Guides for Angular Limb Deformity Correction in Dogs

Category: Ankle,Ankle Arthritis,Basic Sciences/Biologics,Trauma Introduction/Purpose: Large lower extremity bony defects, complex foot and ankle deformities, and high-risk arthrodesis situations can be difficult to treat. These challenging pathologies, often require a critical-sizes and/or shaped structural bone void filler which may not be available with allograft bone. The advancement of 3D printing technology has allowed for the use of custom designed implants for foot and ankle surgery. This study reports on the radiographic and functional outcomes of a case series of patients treated with patient-specific 3D printed titanium implants. Methods: Seven consecutive patients who were treated with custom designed 3D printed implant cages for severe bone loss, deformity correction, and arthrodesis procedures were included in this study. A minimum of 1-year follow-up was required. No patients were lost to follow-up. Patients completed preoperative and most recent follow-up VAS for pain, FAAM, and SF-36 outcomes questionnaires. All patients had post-operative radiographs and CT scans to assess bony incorporation. Results: The mean age of these patients was 54.6 (35-73 years of age). The mean follow-up of these seven patients was 17.1 months (range 12 to 31). Radiographic fusion with cage ingrowth and integration occurred in all seven patients verified by CT scan. There was statistically significant improvement in all functional outcome score measures (VAS for pain, FAAM, and SF-36). All patients returned were satisfied with surgery. There were no failures. Case examples are demonstrated in Figure 1. Conclusion: This cohort of patients demonstrated the successful use of custom 3D printed implants to treat complex large bony defects, deformities and arthrodesis procedures of the lower extremity. These implants offer the surgeon a patient specific approach to treat both pain and deformity that is not necessarily available with allograft bone.

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Use of Patient-Specific 3D-Printed Titanium Implants for Complex Foot and Ankle Limb Salvage, Deformity Correction, and Arthrodesis Procedures

Foot & Ankle International ◽

10.1177/1071100718770133 ◽

2018 ◽

Vol 39 (8) ◽

pp. 916-921 ◽

Cited By ~ 27

Author(s):

Travis J. Dekker ◽

John R. Steele ◽

Andrew E. Federer ◽

Kamran S. Hamid ◽

Samuel B. Adams

Keyword(s):

Clinical Success ◽

Case Series ◽

Deformity Correction ◽

Clinical Success Rate ◽

Titanium Implants ◽

Patient Specific ◽

Foot And Ankle ◽

Level Of Evidence ◽

3D Printed

Background: The advancement of 3D printing technology has allowed for the use of custom-designed implants for difficult-to-treat foot and ankle pathologies. This study reports on the radiographic and functional outcomes of a case series of patients treated with patient-specific 3D-printed titanium implants. Methods: Fifteen consecutive patients treated with custom-designed 3D-printed implant cages for severe bone loss, deformity correction, and/or arthrodesis procedures were included in this study. A minimum of 1 year of clinical and radiographic follow-up was required. No patients were lost to follow-up. Patients completed a visual analog scale for pain, the Foot and Ankle Ability Measure Activities of Daily Living score, and the American Orthopaedic Foot & Ankle Society Score outcomes questionnaires preoperatively and at most recent follow-up. All patients had postoperative radiographs and computed tomography (CT) scans to assess bony incorporation. The mean age was 53.3 years (range, 22-74 years) with a mean follow-up of 22 months (range, 12-48 months) for these 15 patients. Results: Radiographic fusion verified by CT scan occurred in 13 of 15 patients. There was significant improvement in pain and all functional outcome score measures. All patients who went on to fusion were satisfied with their surgery. There were 2 failures, consisting of 1 infection and 1 nonunion, with an overall clinical success rate of 87%. Conclusion: These patients demonstrated the successful use of patient-specific 3D-printed titanium implants to treat complex large bony defects, deformities, and arthrodesis procedures. These implants offer surgeons a novel and promising approach to treat both lower extremity pain and deformity that is not always available with current techniques. Level of Evidence: Level IV, retrospective case series.

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Three-Dimensional-Printed Patient-Specific Osteotomy Guides, Repositioning Guides and Titanium Plates for Acute Correction of Antebrachial Limb Deformities in Dogs

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.1055/s-0040-1709702 ◽

2020 ◽

Author(s):

Darren R. Carwardine ◽

Mark J. Gosling ◽

Neil J. Burton ◽

Ffion L. O'Malley ◽

Kevin J. Parsons

Keyword(s):

Kirschner Wire ◽

Three Dimensional ◽

Case Series ◽

Deformity Correction ◽

Patient Specific ◽

Kirschner Wire Fixation ◽

Limb Deformities ◽

Acute Correction ◽

3D Printed

Abstract Objectives The aim of this study was to describe the use of patient-specific three-dimensional (3D)-printed osteotomy guides, repositioning guides and custom-printed titanium plates for acute correction of antebrachial limb deformities in four dogs. Methods Retrospective review of antebrachial limb deformities in small breed chondrodystrophic dogs that were surgically corrected using a closing wedge ostectomy of the radius at a predetermined site using patient-specific osteotomy guides. Reduction was achieved without the need for intraoperative measurements using patient-specific 3D-printed repositioning guides secured and manipulated using temporary Kirschner wire fixation. The ostectomy of the radius was stabilized with a patient-specific 3D-printed titanium plate. Results All limbs were corrected to within 3.5 degrees (standard deviation [SD]: 1 degree) and 7.5 degrees (SD: 3 degrees) of the pre-planned deformity correction in the frontal and sagittal planes, respectively. No complications were encountered. Owners completed a canine orthopaedic index survey at a median postoperative follow-up time of 19 months. Surgery eliminated the main presenting complaint of buckling over of the manus in all cases. Clinical Significance The 3D-printed osteotomy repositioning guides and titanium plates facilitated accurate acute correction of antebrachial deformities in this case series. The methodology described simplifies intraoperative surgical decision-making on limb position with good clinical outcomes seen in a small number of clinical cases.

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Complicated Postoperative Flat Back Deformity Correction With the Aid of Virtual and 3D Printed Anatomical Models: Case Report

Frontiers in Surgery ◽

10.3389/fsurg.2021.662919 ◽

2021 ◽

Vol 8 ◽

Author(s):

Jennifer Fayad ◽

Mate Turbucz ◽

Benjamin Hajnal ◽

Ferenc Bereczki ◽

Marton Bartos ◽

...

Keyword(s):

Case Report ◽

Physical Model ◽

Similarity Index ◽

Deformity Correction ◽

Vertical Axis ◽

Pedicle Subtraction Osteotomy ◽

Patient Specific ◽

Sagittal Vertical Axis ◽

Number Of Patients ◽

3D Printed

Introduction: The number of patients with iatrogenic spinal deformities is increasing due to the increase in instrumented spinal surgeries globally. Correcting a deformity could be challenging due to the complex anatomical and geometrical irregularities caused by previous surgeries and spine degeneration. Virtual and 3D printed models have the potential to illuminate the unique and complex anatomical-geometrical problems found in these patients.Case Presentation: We present a case report with 6-months follow-up (FU) of a 71 year old female patient with severe sagittal and coronal malalignment due to repetitive discectomy, decompression, laminectomy, and stabilization surgeries over the last 39 years. The patient suffered from severe low back pain (VAS = 9, ODI = 80). Deformity correction by performing asymmetric 3-column pedicle subtraction osteotomy (PSO) and stabilization were decided as the required surgical treatment. To better understand the complex anatomical condition, a patient-specific virtual geometry was defined by segmentation based on the preoperative CT. The geometrical accuracy was tested using the Dice Similarity Index (DSI). A complex 3D virtual plan was created for the surgery from the segmented geometry in addition to a 3D printed model.Discussion: The segmentation process provided a highly accurate geometry (L1 to S2) with a DSI value of 0.92. The virtual model was shared in the internal clinical database in 3DPDF format. The printed physical model was used in the preoperative planning phase, patient education/communication and during the surgery. The surgery was performed successfully, and no complications were registered. The measured change in the sagittal vertical axis was 7 cm, in the coronal plane the distance between the C7 plumb line and the central sacral vertical line was reduced by 4 cm. A 30° correction was achieved for the lumbar lordosis due to the PSO at the L4 vertebra. The patient ODI was reduced to 20 points at the 6-months FU.Conclusions: The printed physical model was considered advantageous by the surgical team in the pre-surgical phase and during the surgery as well. The model was able to simplify the geometrical problems and potentially improve the outcome of the surgery by preventing complications and reducing surgical time.

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Computed Tomography-Based Patient-Specific Instrumentation Loses Accuracy with Significant Varus Preoperative Misalignment

The Journal of Knee Surgery ◽

10.1055/s-0040-1716381 ◽

2020 ◽

Author(s):

Vicente Jesús León-Muñoz ◽

Mirian López-López ◽

Alonso José Lisón-Almagro ◽

Francisco Martínez-Martínez ◽

Fernando Santonja-Medina

Keyword(s):

Computed Tomography ◽

Deformity Correction ◽

Patient Specific ◽

Control Group ◽

X Rays ◽

Varus Alignment ◽

Patient Specific Instrumentation ◽

Conventional Instrumentation ◽

The Mean ◽

Valgus Alignment

AbstractPatient-specific instrumentation (PSI) has been introduced to simplify and make total knee arthroplasty (TKA) surgery more precise, effective, and efficient. We performed this study to determine whether the postoperative coronal alignment is related to preoperative deformity when computed tomography (CT)-based PSI is used for TKA surgery, and how the PSI approach compares with deformity correction obtained with conventional instrumentation. We analyzed pre-and post-operative full length standing hip-knee-ankle (HKA) X-rays of the lower limb in both groups using a convention > 180 degrees for valgus alignment and < 180 degrees for varus alignment. For the PSI group, the mean (± SD) pre-operative HKA angle was 172.09 degrees varus (± 6.69 degrees) with a maximum varus alignment of 21.5 degrees (HKA 158.5) and a maximum valgus alignment of 14.0 degrees. The mean post-operative HKA was 179.43 degrees varus (± 2.32 degrees) with a maximum varus alignment of seven degrees and a maximum valgus alignment of six degrees. There has been a weak correlation among the values of the pre- and postoperative HKA angle. The adjusted odds ratio (aOR) of postoperative alignment outside the range of 180 ± 3 degrees was significantly higher with a preoperative varus misalignment of 15 degrees or more (aOR: 4.18; 95% confidence interval: 1.35–12.96; p = 0.013). In the control group (conventional instrumentation), this loss of accuracy occurs with preoperative misalignment of 10 degrees. Preoperative misalignment below 15 degrees appears to present minimal influence on postoperative alignment when a CT-based PSI system is used. The CT-based PSI tends to lose accuracy with preoperative varus misalignment over 15 degrees.

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Lower limb deformity correction with a simple non-surgical technique

Minerva Ortopedica e Traumatologica ◽

10.23736/s0394-3410.19.03953-5 ◽

2019 ◽

Vol 70 (4) ◽

Author(s):

Marianna Faggiani ◽

Selena Desayeux ◽

Giovanni Martino ◽

Eraclite Petruccelli ◽

Alessandro Aprato ◽

...

Keyword(s):

Surgical Technique ◽

Lower Limb ◽

Deformity Correction ◽

Limb Deformity

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Quality Control in 3D Printing: Accuracy Analysis of 3D-Printed Models of Patient-Specific Anatomy

Materials ◽

10.3390/ma14041021 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1021

Author(s):

Bernhard Dorweiler ◽

Pia Elisabeth Baqué ◽

Rayan Chaban ◽

Ahmed Ghazy ◽

Oroa Salem

Keyword(s):

Wall Thickness ◽

Large Scale ◽

Fused Deposition Modeling ◽

Vascular Anatomy ◽

3D Models ◽

Patient Specific ◽

Stl File ◽

Fused Deposition ◽

3D Printed ◽

The Mean

As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original STL file using dedicated 3D engineering software. The mean wall thickness for the large-scale aortic models was 2.11 µm (+5%), and 1.26 µm (+0.8%) for the coronary models, resulting in an overall mean wall thickness of +5% for all 35 3D models when compared to the original STL file. The mean surface deviation was found to be +120 µm for all models, with +100 µm for the aortic and +180 µm for the coronary 3D models, respectively. Both printing technologies were found to conform with the currently set standards of accuracy (<1 mm), demonstrating that accurate 3D models of large and small vessel anatomy can be generated by both FDM and PolyJet printing technology using rigid and flexible polymers.

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Total Meniscus Reconstruction Using a Polymeric Hybrid-Scaffold: Combined with 3D-Printed Biomimetic Framework and Micro-Particle

Polymers ◽

10.3390/polym13121910 ◽

2021 ◽

Vol 13 (12) ◽

pp. 1910

Author(s):

Hun-Jin Jeong ◽

Se-Won Lee ◽

Myoung Wha Hong ◽

Young Yul Kim ◽

Kyoung Duck Seo ◽

...

Keyword(s):

Shape Matching ◽

Femoral Condyle ◽

Immunohistochemical Analysis ◽

Cartilage Degeneration ◽

Patient Specific ◽

Hybrid Scaffold ◽

Meniscus Tissue ◽

Cell Source ◽

3D Printed ◽

Meniscus Regeneration

The meniscus has poor intrinsic regenerative capability, and its injury inevitably leads to articular cartilage degeneration. Although there are commercialized off-the-shelf alternatives to achieve total meniscus regeneration, each has its own shortcomings such as individualized size matching issues and inappropriate mechanical properties. We manufactured a polycaprolactone-based patient-specific designed framework via a Computed Tomography scan images and 3D-printing technique. Then, we completed the hybrid-scaffold by combining the 3D-printed framework and mixture micro-size composite which consists of polycaprolactone and sodium chloride to create a cell-friendly microenvironment. Based on this hybrid-scaffold with an autograft cell source (fibrochondrocyte), we assessed mechanical and histological results using the rabbit total meniscectomy model. At postoperative 12-week, hybrid-scaffold achieved neo-meniscus tissue formation, and its shape was maintained without rupture or break away from the knee joint. Histological and immunohistochemical analysis results showed obvious ingrowth of the fibroblast-like cells and chondrocyte cells as well as mature lacunae that were embedded in the extracellular matrix. Hybrid-scaffolding resulted in superior shape matching as compared to original meniscus tissue. Histological analysis showed evidence of extensive neo-meniscus cell ingrowth. Additionally, the hybrid-scaffold did not induce osteoarthritis on the femoral condyle surface. The 3D-printed hybrid-scaffold may provide a promising approach that can be applied to those who received total meniscal resection, using patient-specific design and autogenous cell source.

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Design, Fabrication, and Accuracy of a Novel Noncovering Lock-Mechanism Bilateral Patient-Specific Drill Guide Template for Nondeformed and Deformed Thoracic Spines

HSS Journal ® ◽

10.1177/1556331621996331 ◽

2021 ◽

pp. 155633162199633

Author(s):

Mehran Ashouri-Sanjani ◽

Shima Mohammadi-Moghadam ◽

Parisa Azimi ◽

Navid Arjmand

Keyword(s):

Thoracic Spine ◽

Sagittal Plane ◽

Ct Scanning ◽

Entry Point ◽

In Vivo Studies ◽

Patient Specific ◽

Plane Angle ◽

Severe Scoliosis ◽

3D Printed

Background: Pedicle screw (PS) placement has been widely used in fusion surgeries on the thoracic spine. Achieving cost-effective yet accurate placements through nonradiation techniques remains challenging. Questions/Purposes: Novel noncovering lock-mechanism bilateral vertebra-specific drill guides for PS placement were designed/fabricated, and their accuracy for both nondeformed and deformed thoracic spines was tested. Methods: One nondeformed and 1 severe scoliosis human thoracic spine underwent computed tomographic (CT) scanning, and 2 identical proportions of each were 3-dimensional (3D) printed. Pedicle-specific optimal (no perforation) drilling trajectories were determined on the CT images based on the entry point/orientation/diameter/length of each PS. Vertebra-specific templates were designed and 3D printed, assuring minimal yet firm contacts with the vertebrae through a noncovering lock mechanism. One model of each patient was drilled using the freehand and one using the template guides (96 pedicle drillings). Postoperative CT scans from the models with the inserted PSs were obtained and superimposed on the preoperative planned models to evaluate deviations of the PSs. Results: All templates fitted their corresponding vertebra during the simulated operations. As compared with the freehand approach, PS placement deviations from their preplanned positions were significantly reduced: for the nonscoliosis model, from 2.4 to 0.9 mm for the entry point, 5.0° to 3.3° for the transverse plane angle, 7.1° to 2.2° for the sagittal plane angle, and 8.5° to 4.1° for the 3D angle, improving the success rate from 71.7% to 93.5%. Conclusions: These guides are valuable, as the accurate PS trajectory could be customized preoperatively to match the patients’ unique anatomy. In vivo studies will be required to validate this approach.

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