Prosthetic Accuracy Depends on the Design of Patient-Specific Instrumentation: Results of a Retrospective Study Using Three-Dimensional Imaging

2020 ◽  
Author(s):  
Kazumasa Yamamura ◽  
Fumiaki Inori ◽  
Sadahiko Konishi
Keyword(s):  
Sagittal Plane ◽  
Three Dimensional ◽  
Computer Software ◽  
Patient Specific ◽  
Ct Image ◽  
3D Ct ◽  
Patient Specific Instrumentation ◽  
Prosthetic Alignment ◽  
Before And After ◽  
Preoperative Plan

AbstractTo determine accuracy of patient-specific instrumentation (PSI), the preoperative three-dimensional (3D) plan should be superimposed on the postoperative 3D image to compare prosthetic alignment. We aimed to compare prosthetic alignment on a preoperative 3D computed tomography (CT) plan and postoperative 3D-CT image, and evaluate the accuracy of PSI during total knee arthroplasty (TKA). Thirty consecutive knees (30 patients) who underwent TKA using PSI were retrospectively evaluated. The preoperative plan was prepared using 3D CT acquisitions of the hip, knee, and ankle joints. The postoperative 3D CT image obtained 1 week after surgery was superimposed onto the preoperative 3D plan using computer software. Differences in prosthetic alignment between the preoperative and postoperative images were measured using six parameters: coronal, sagittal, and axial alignments of femoral and tibial prostheses. Differences in prosthetic alignment greater than 3 degrees were considered outliers. Two observers performed all measurements. All parameters were repeatedly measured over a 4-week interval. This measurement method's intraobserver and interobserver reliabilities were more than 0.81 (very good). For the femoral and tibial prostheses, absolute differences between the preoperative and postoperative 3D CT images were significantly larger in the sagittal than in the coronal and axial planes (p < 0.001). The outlier rate for the sagittal alignment of femoral and tibial prostheses was significantly higher than that for the alignment of coronal and axial planes (p < 0.001). However, there were no significant differences in the range of motion (ROM) before and after TKA when comparing cases with and without outliers in the sagittal plane. Even though the present study did not reveal any issues with the ROM that depended on the presence of an outlier, accurate verification of prosthetic alignment for individual PSI models may be necessary because the designs, referenced images, and accuracy are different in each model.

Preoperative three-dimensional computer planning for reverse total shoulder arthroplasty and bone grafting for severe glenoid deformity

2020 ◽  
pp. 175857322090890
Author(s):  
Robert Z Tashjian ◽  
Lindsay Beck ◽  
Irene Stertz ◽  
Peter N Chalmers
Keyword(s):  
Shoulder Arthroplasty ◽  
Bone Grafting ◽  
Total Shoulder Arthroplasty ◽  
Three Dimensional ◽  
Reverse Total Shoulder Arthroplasty ◽  
Patient Specific ◽  
Computer Assisted ◽  
Patient Specific Instrumentation ◽  
Reverse Total Shoulder ◽  
Glenoid Erosion

Background Computer assisted planning without patient specific instrumentation may be utilized to guide reverse total shoulder arthroplasty baseplate placement. The purpose of this study was to determine the difference between planned and achieved inclination and retroversion correction with three-dimensional preoperative computer assisted planning in reverse total shoulder arthroplasty without patient specific instrumentation with bone grafting for severe glenoid erosion. Methods Preoperative three-dimensional computer assisted planning without patient specific instrumentation was performed on 15 patients undergoing primary reverse total shoulder arthroplasty with glenoid bone grafting for severe glenoid erosion. On preoperative and immediate postoperative computed tomography slices, two-dimensional retroversion and inclination were measured. Preoperative three-dimensional baseline retroversion and inclination and planned postoperative three-dimensional retroversion and inclination were measured. Planned and achieved version and inclination changes were compared. Results The planned and achieved retroversion corrections were 18° and 12°, respectively (p < 0.001). The planned and achieved inclination corrections were 11° and 11°, respectively (p = 0.803). Conclusions Three-dimensional computer assisted planning without patient specific instrumentation in the setting of reverse total shoulder arthroplasty with severe glenoid erosion requiring bone grafting can accurately guide baseplate placement. All cases in which failure to correct retroversion or inclination within 10° of planning occurred in patients with severe erosion (B3 or E3 glenoids), therefore patient specific guides may be warranted in these cases to improve accuracy of implantation. Level of evidence Level IV, retrospective case series.

scholarly journals Use of three-dimensional technology for complications of upper limb fracture treatment

2019 ◽  
Vol 4 (6) ◽  
pp. 302-312 ◽  
Author(s):  
Maartje Michielsen ◽  
Annemieke Van Haver ◽  
Matthias Vanhees ◽  
Roger van Riet ◽  
Frederik Verstreken
Keyword(s):  
Upper Limb ◽  
Three Dimensional ◽  
Computer Software ◽  
Operation Time ◽  
Cost Benefit ◽  
Added Value ◽  
Patient Specific ◽  
Technical Developments ◽  
Key Factor ◽  
Patient Specific Instruments

In malunion cases, restoration of anatomy is a key factor in obtaining a good functional outcome, but this can be technically very challenging. Three-dimensional printed bone models can further improve understanding of the malunion pattern. The use of three-dimensional (3D) computer planning, and the assembly of patient-specific instruments and implants, especially in complex deformities of the upper limb, allow accurate correction while reducing operation time, blood loss volume and radiation exposure during surgery. One of the major disadvantages of the 3D technique is the additional cost because it requires specific computer software, a dedicated clinical engineer, and a 3D printer. Further technical developments and clinical investigations are necessary to better define the added value and cost/benefit relationship of 3D in the treatment of complex fractures, non-unions, and malunions. Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180074

Estimation of [177Lu]PSMA-617 tumor uptake based on voxel-wise 3D Monte Carlo tumor dosimetry in patients with metastasized castration resistant prostate cancer

2020 ◽  
Vol 59 (05) ◽  
pp. 365-374
Author(s):  
Theresa Ida Götz ◽  
Elmar Wolfgang Lang ◽  
Olaf Prante ◽  
Michael Cordes ◽  
Torsten Kuwert ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Monte Carlo ◽  
Three Dimensional ◽  
Absorbed Dose ◽  
Whole Body ◽  
Patient Specific ◽  
Average Dose ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Before And After

Abstract Objective Patients with advanced prostate cancer are suitable candidates for [177Lu]PSMA-617 therapy. Integrated SPECT/CT systems have the potential to improve the accuracy of patient-specific tumor dosimetry. We present a novel patient-specific Monte Carlo based voxel-wise dosimetry approach to determine organ and total tumor doses (TTD). Methods 13 patients with histologically confirmed metastasized castration-resistant prostate cancer were treated with a total of 18 cycles of [177Lu]PSMA-617 therapy. In each patient, dosimetry was performed after the first cycle of [177Lu]PSMA-617 therapy. Regions of interest were defined manually on the SPECT/CT images for the kidneys, spleen and all 295 PSMA-positive tumor lesions in the field of view. The absorbed dose to normal organs and to all tumor lesions were calculated by a three dimensional dosimetry method based on Monte Carlo Simulations. Results The average dose values yielded the following results: 2.59 ± 0.63 Gy (1.67–3.92 Gy) for the kidneys, 0.79 ± 0.46 Gy (0.31–1.90 Gy) for the spleen and 11.00 ± 11.97 Gy (1.28–49.10 Gy) for all tracer-positive tumor lesions. A trend towards higher TTD was observed in patients with Gleason Scores > 8 compared to Gleason Scores ≤ 8 and in lymph node metastases compared to bone metastases. A significant correlation was determined between the serum-PSA level before RLT and the TTD (r = –0.57, p < 0.05), as well as between the TTD with the percentage change of serum-PSA levels before and after therapy was observed (r = –0.57, p < 0.05). Patients with higher total tumor volumes of PSMA-positive lesions demonstrated significantly lower kidney average dose values (r = –0.58, p < 0.05). Conclusion The presented novel Monte Carlo based voxel-wise dosimetry calculates a patient specific whole-body dose distribution, thus taking into account individual anatomies and tissue compositions showing promising results for the estimation of radiation doses of normal organs and PSMA-positive tumor lesions.

scholarly journals Three-dimensional Analysis of the Talocrural Joint Axis

2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0003
Author(s):  
Christian Plaass ◽  
Leif Claassen ◽  
Christina Stukenborg-Colsman ◽  
Daiwei Yao ◽  
Kiriakos Daniilidis ◽  
...  
Keyword(s):  
Sagittal Plane ◽  
Articular Surface ◽  
Three Dimensional ◽  
Frontal Plane ◽  
High Standard ◽  
Patient Specific ◽  
Rotational Axis ◽  
Talocrural Joint ◽  
Joint Axis

Category: Ankle Introduction/Purpose: The total ankle replacement (TAR) is increasingly used in cases of severe ankle arthritis. Although the knowledge about joint kinematics is crucial for designing and positioning of TAR there is no consensus about the talocrural joint axis. The aim of the present study was the determination of the kinematic rotational axis of the talocrural joint as an orientation for prosthesis positioning. Methods: We analyzed 96 CT-scans of full cadaver caucasien legs. With the software Mimic, 3-Matic (both Materialize) and GOM inspect we generated three-dimensional reconstruction models of the talus and a best fitting cone orientated to the talar articular surface. The kinematic rotational axis was defined to be the axis of this cone. Results: The determination of the kinematic rotational axis showed a high inter- and intrarater reliability. The kinematic rotational axis of the talocrural joint is orientated from lateral-distal to medial-proximal (84.9° ± 8.5 compared to mechanical tibial axis in frontal plane), from dorsal-proximal to anterior-distal (93.1° ± 42.3 compared to mechanical tibial axis in sagittal plane) and from dorsal-lateral to anterior-medial (169.0° ± 6.7 compared to mechanical tibial axis in axial plane). A high standard deviation especially in the sagittal plane was noteworthy. Conclusion: With the present study we present a new reproducable single-axis model of the talocrural joint. Our data showed relevant interindividual variations. The consideration of these variations might support the development of patient-specific TAR implantation techniques.

The influence of selected manual techniques on the relative length of lower limbs in children with postural defects – a pilot study

2018 ◽  
Vol 1 (2) ◽  
pp. 21-27
Author(s):  
Mirosław KAPICA ◽  
Agnieszka JANKOWICZ-SZYMAŃSKA ◽  
Teresa GNIEWEK ◽  
Radosław RAŹNIEWSKI ◽  
Andrzej ŻYTKOWSKI ◽  
...  
Keyword(s):  
Sagittal Plane ◽  
Three Dimensional ◽  
Relative Length ◽  
Lower Limbs ◽  
School Age Children ◽  
Leg Length ◽  
Therapeutic Tool ◽  
Before And After ◽  
Postural Abnormalities ◽  
Selection Of

Introduction: One of the very important indicators used in the treatment of postural defects is the relative symmetry of the lower limbs. The selection of a safe and effective therapeutic tool is not an easy task and is particularly important in children. The authors of the experiment have decided to check the effectiveness of two manual techniques, that minimally interfere with patient's tissues. The objective of this study was to evaluate the influence of selected manual procedures: the Ackerman's second phenomenon and mobilization of the sacroiliac joint to hyperextension (Kowtun's grip) on the relative length of the lower limbs in a school-age children. Materials and methods: 70 children aged 8-12 participated in the study. All of them were diagnosed with postural abnormalities: spine defects in the sagittal plane, three-dimensional asymmetry of the torso, knee and / or foot defects and asymmetry of the length of the lower limbs. Qualification of children for a particular group with a postural defects was based on the concept of Sastre Fernandez. In each patient, the manual procedure in order to compensate the leg length, was applied once. In 28 children the applied procedure was the Ackerman's second phenomenon and in 42 it was the Kowtun's grip. The relative length of t h e l o w e r l i m b s w a s m e a s u r e d immediately before and after the manual procedure. Results: The executed experiment indicates the effectiveness of the Ackerman's second phenomenon in compensating the asymmetry of the length of the lower limbs in children with posture defects. The effect of Kovtun's mobilization is less clear. Conclusions: Manual procedure change the relative length of the lower limbs in children with postural defects. The Ackerman's second phenomenon in an effective and yet gentle and safe manual tool that can be used in children in order to compensate the relative length of the lower limbs. The effect of the Kowtun's treatment requires further research.

scholarly journals Patient-specific instrumentation improved three-dimensional accuracy in total knee arthroplasty: a comparative radiographic analysis of 1257 total knee arthroplasties

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Leo Pauzenberger ◽  
Martin Munz ◽  
Georg Brandl ◽  
Julia K. Frank ◽  
Philipp R. Heuberer ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Three Dimensional ◽  
Mobile Bearing ◽  
Patient Specific ◽  
Limb Alignment ◽  
Patient Specific Instrumentation ◽  
Conventional Instrumentation ◽  
Total Knee

Abstract Background The purpose of this study was to compare restoration of mechanical limb alignment and three-dimensional component-positioning between conventional and patient-specific instrumentation in total knee arthroplasty. Methods Radiographic data of patients undergoing mobile-bearing total knee arthroplasty (n = 1257), using either conventional (n = 442) or patient-specific instrumentation (n = 812), were analyzed. To evaluate accuracy of axis restoration and 3D-component-positioning between conventional and patient-specific instrumentation, absolute deviations from the targeted neutral mechanical limb alignment and planned implant positions were determined. Measurements were performed on standardized coronal long-leg and sagittal knee radiographs. CT-scans were evaluated for accuracy of axial femoral implant rotation. Outliers were defined as deviations from the targeted neutral mechanical axis of > ± 3° or from the intraoperative component-positioning goals of > ± 2°. Deviations greater than ± 5° from set targets were considered to be severe outliers. Results Deviations from a neutral mechanical axis (conventional instrumentation: 2.3°± 1.7° vs. patient-specific instrumentation: 1.7°± 1.2°; p < 0.001) and numbers of outliers (conventional instrumentation: 25.8% vs. patient-specific instrumentation: 10.1%; p < 0.001) were significantly lower in the patient-specific instrumentation group. Significantly lower mean deviations and less outliers were detected regarding 3D-component-positioning in the patient-specific instrumentation compared to the conventional instrumentation group (all p < 0.05). Conclusions Patient-specific instrumentation prevented from severe limb malalignment and component-positioning outliers (> ± 5° deviation). Use of patient-specific instrumentation proved to be superior to conventional instrumentation in achieving more accurate limb alignment and 3D-component positioning, particularly regarding femoral component rotation. Furthermore, the use of patient-specific instrumentation successfully prevented severe (> 5° deviation) outliers.

scholarly journals Advances and innovations in total hip arthroplasty

SICOT-J ◽  
2021 ◽  
Vol 7 ◽  
pp. 26
Author(s):  
Andreas Fontalis ◽  
Jean-Alain Epinette ◽  
Martin Thaler ◽  
Luigi Zagra ◽  
Vikas Khanduja ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Three Dimensional ◽  
Young Patients ◽  
Cost Effective ◽  
Patient Specific ◽  
Three Dimensional Printing ◽  
Total Hip ◽  
Patient Specific Instrumentation ◽  
Dimensional Printing

Total hip arthroplasty (THA) has been quoted as one of the most successful and cost-effective procedures in Orthopaedics. The last decade has seen an exponential rise in the number of THAs performed globally and a sharp increase in the percentage of young patients hoping to improve their quality of life and return to physically demanding activities. Hence, it is imperative to review the various applications of technology in total hip arthroplasty for improving outcomes. The development of state-of-the-art robotic technology has enabled more reproducible and accurate acetabular positioning, while long-term data are needed to assess its cost-effectiveness. This opinion piece aims to outline and present the advances and innovations in total hip arthroplasty, from virtual reality and three-dimensional printing to patient-specific instrumentation and dual mobility bearings. This illustrates and reflects the debate that will be at the centre of hip surgery for the next decade.

scholarly journals Intraoperative Manufacturing of Patient-Specific Instrumentation for Shoulder Arthroplasty: A Novel Mechatronic Approach

2016 ◽  
Vol 01 (04) ◽  
pp. 1650005
Author(s):  
A. Darwood ◽  
R. Secoli ◽  
S. A. Bowyer ◽  
A. Leibinger ◽  
R. Richards ◽  
...  
Keyword(s):  
New Technology ◽  
Three Dimensional ◽  
Patient Specific ◽  
Orthopaedic Implant ◽  
Patient Specific Instrumentation ◽  
Additional Manufacturing ◽  
Standard Geometry ◽  
Manual Group ◽  
3D Printed ◽  
Placement Accuracy

Optimal orthopaedic implant placement is a major contributing factor to the long term success of all common joint arthroplasty procedures. Devices such as three-dimensional (3D) printed, bespoke guides and orthopaedic robots are extensively described in the literature and have been shown to enhance prosthesis placement accuracy. These technologies, however, have significant drawbacks, such as logistical and temporal inefficiency, high cost, cumbersome nature and difficult theatre integration. A new technology for the rapid intraoperative production of patient-specific instrumentation, which overcomes many of the disadvantages of existing technologies, is presented here. The technology comprises a reusable table side machine, bespoke software and a disposable element comprising a region of standard geometry and a body of moldable material. Anatomical data from computed tomography (CT) scans of 10 human scapulae was collected and, in each case, the optimal glenoid guidewire position was digitally planned and recorded. The achieved accuracy compared to the pre-operative bespoke plan was measured in all glenoids, from both a conventional group and a guided group (GG). The technology was successfully able to intraoperatively produce sterile, patient-specific guides according to a pre-operative plan in 5[Formula: see text]min, with no additional manufacturing required prior to surgery. Additionally, the average guidewire placement accuracy was [Formula: see text][Formula: see text]mm and 6.82[Formula: see text] in the manual group, and [Formula: see text][Formula: see text]mm and [Formula: see text] in the guided group, also demonstrating a statistically significant improvement.

Computational Modeling of the Patient-Specific Femoral Head before and after the Treatment

2014 ◽  
Vol 998-999 ◽  
pp. 214-218
Author(s):  
Yu Qian Mei ◽  
Chao Lu ◽  
Hai Jun He ◽  
Wei Heng Chen ◽  
Duan Duan Chen
Keyword(s):  
Femoral Head ◽  
Drug Treatment ◽  
Cancellous Bone ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
Femoral Head Necrosis ◽  
Patient Specific ◽  
Before And After ◽  
Cortical Shell ◽  
Three Dimensional Models

In femoral head necrosis, the cortical shell of the femoral head collapses and buckles into the cancellous bone. The purpose of this study is to explore the biomechanical characteristics of the femoral head and the necrosis region by comparing the results before and after drug treatment. In this paper, we study two patient cases with femoral head necrosis disease and establish the corresponding computational three-dimensional models. The results show that the deformation of the femur decreases slightly after the treatment, the equivalent stress distributes more evenly, and the stress magnitude reduces. The results also reveal that the volume of the necrosis in the femoral head decreases after treatment, the overall necrosis presents relatively lower equivalent stress, and the area with the relatively high equivalent stress is smaller comparing to the necrosis in femoral head before treatment.

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