G Model
JINJ-6572; No. of Pages 3 Injury, Int. J. Care Injured xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Injury journal homepage: www.elsevier.com/locate/injury
Technical Note
3D Printed models of distal radius fractures Nicola Bizzotto a,*, Ivan Tami b, Andrea Tami c, Adrian Spiegel c, Denis Romani d, Massimo Corain e, Roberto Adani e, Bruno Magnan d a
Dolomiti Sportclinic, Via Purger 181, 39046 Ortisei/St. Ulrich, Bolzano/Bozen, Italy Centro manoegomito, Clinica Ars Medica, Gravesano, Lugano Switzerland c Medartis AG, Basel, Switzerland d Department of Orhopaedic Surgery, Azienda Ospedaliera Universitaria Integrata, Verona, Italy e Hand Surgery Department, Azienda Ospedaliera Universitaria Integrata, Verona, Italy b
A R T I C L E I N F O
Article history: Accepted 13 January 2016
Introduction 3D printing, also known as additive manufacturing or ‘‘rapid prototyping’’, is a low cost technology that uses a 3D computer representation to create solid objects from a feedstock material. In the literature studies report that 3D printed models for orthopedic conditions can improve surgeons’ evaluation of patient-specific anatomy and pathology by way of tactile and visual experience [1–4]. However, it has not been analysed yet how far models may support the surgeon by selecting the most adequate surgical procedure, and which effect they may have on patient’s understanding (and in some cases on their approval) of the surgical procedure they will undergo. In this paper, we present our initial experience preparing and using 3D printed models of the bony anatomy of distal radius fractures and we describe their effect on surgical planning and patient information. Materials and methods From November 2014 to June 2015, 40 patients were enrolled at our clinics. Selected patients were affected with a distal radius
* Corresponding author. E-mail addresses: [email protected] (N. Bizzotto), [email protected] (I. Tami), [email protected] (A. Tami), [email protected] (A. Spiegel), [email protected] (D. Romani), [email protected] (M. Corain), [email protected] (R. Adani), [email protected] (B. Magnan).
fracture (AO classification, 23-A/B/C) eligible for surgery because of presence of displacement, dislocation of fragments and instability. A CT scan with a thickness of 0.625 mm was performed in all cases to study the fracture pattern. The obtained sections (DICOM files) were uploaded into OsiriX Viewer Software (Pixmeo, Geneva, Switzerland), rendered to a ‘‘surface-model’’ of the fractured radius and finally exported to a ‘‘stereolithography’’ file (STL-file), which is widely used for rapid prototyping. This file was analysed and prepared for printing with dedicated 3D software (Mesh Lab http:// meshlab.sourceforge.net). A 3D-printing system Stratasys uPrint SE (Stratasys Ltd 7665 Commerce Way, Eden Prairie MN 55344 USA) was used to obtain the prototype. The 1:1 realistic model was constructed with acrylonitrile butadiene styrene material (ABS). After 3–4 h from the CT scan (Fig. 1) the model was ready. The printed fractured bone was evaluated by the surgeons and used for preoperative planning and selection of surgical approach and selection and placement of osteosynthesis hardware; specifically, ideal screw location and orientation was evaluated (Fig. 2). 3D prints were then used to illustrate fracture morphology and surgical technique to the patient. A simple questionnaire (Table 1) was used to obtain feedback from surgeons and patients regarding the use of the models. All patients were operated with modified Henry volar approach under local anaesthesia.
Results Patients reported an enthusiastic general appreciation about the use of this new technology in our hospitals. There was a substantial improvement in comprehension of the fracture before and after seeing the 3D printed models (average of +3 points on the grading scale) (Fig. 3). Both compliance and confidence in the surgeons appeared improved. Surgeons rated the use of models most beneficial for articular fractures (+2 points%) with articular gaps or steps of 2 mm, or with a multi-fragmentary pattern was evident. For simple and methaphyseal fractures the models did not improve any parameter in either group.
http://dx.doi.org/10.1016/j.injury.2016.01.013 0020–1383/ß 2016 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Bizzotto N, et al. 3D Printed models of distal radius fractures. Injury (2016), http://dx.doi.org/10.1016/ j.injury.2016.01.013
G Model
JINJ-6572; No. of Pages 3 N. Bizzotto et al. / Injury, Int. J. Care Injured xxx (2016) xxx–xxx
2
Fig. 1. Multi-planar reconstruction (i.e. axial, sagittal, coronal views) and 3D volume rendering (A) of a distal radius fracture. 3D printed model (B).
While surgical planning was not changed after checking the 3D printed models, the plates selected during pre-operative planning fitted perfectly during the operation. Discussion The addition of 2D and 3D CT scan to radiographs led to improved diagnosis of fracture line comminution and involvement of the articular surface, articular gaps or steps. A 1:1 3D printed model provides an additional tactile and visual experience, increasing the appreciation of articular surface gaps of 2 mm with severe displacement of bony fragments.
The accuracy of the 3D print is dependent on the technical capabilities of the machine; commercial 3D printer have an accuracy of 0.1 mm [1], which is unlikely to have a major effect on accuracy given the fact that DICOMs were processed with 0.625 mm slice thickness. Generally we noticed some inaccuracy on details and displacements of 1 mm or less because of digital post-processing performed on the 3D data (surface rendering algorithms and smoothing filters); this has also been described in the literature [5]. Guitton et al. reported in a study that the addition of models led to significantly improved agreement on treatment modalities compared to 3DCT alone (p = 0.046). However, using a model did not affect other factors [6], due also to the fact that
Fig. 2. Surgical planning the day before operation: plate fitting and checking of ideal screw location and orientation on 3D printed model.
Please cite this article in press as: Bizzotto N, et al. 3D Printed models of distal radius fractures. Injury (2016), http://dx.doi.org/10.1016/ j.injury.2016.01.013
G Model
JINJ-6572; No. of Pages 3 N. Bizzotto et al. / Injury, Int. J. Care Injured xxx (2016) xxx–xxx Table 1 Questionnaire for patients and surgeons. Questions For the patient 1. Have you seen a 3D printed model of any of your body parts before? 2. How well could you understand the gravity of your fracture based on computer images and surgeon’s explanation? 3. How well could you understand the gravity of your fracture after seeing the 3D printed model? 4. How important/critical was it to see a physical model of your fracture and the implant that would be used for the osteosynthesis? 5. Would you suggest to other patients to request a 3D printed model of their fracture before the surgery? For the surgeon 1. How complex was the diagnosis of the articular damage (comminution and amount of fragments) based only on computer images? 2. How complex was the diagnosis of the articular damage (comminution and amount of fragments) after seeing the 3D printed model? 3. Did the availability of the 3D printed model influence your pre-operative surgical plan? 4. Did the 3D printed model influence implant’s selection? 5. Would you use 3D printed models for other fractures and would you suggest their use to any of your colleagues?
Answers Y/N 1 to 10
1 to 10 1 to 10
Y/N
1 to 10
1 to 10
Y/N Y/N Y/N
3
images were usually rated retrospectively, i.e. after surgery. While in our study we did not notice any change on surgical decisions, evaluation of lesion and fracture displacement were generally improved. Additionally, the possibility to pre-operatively select the ideal plate was appreciated by surgeons, saved time during surgery (1 min) and reduced sterilization costs. Considering the general trend to reduce health care cost and the increasing trend to sterile-packaged single-use kits for specific standard surgeries, 3D printing may open additional opportunities [7]. Further studies with more patients should be conducted in the future to quantify the benefit and cost reduction in regard to OR time and expenses for sterilization. Recommendations regarding the use of this technology should be based on both diagnostic performance characteristics and clinical impact. Conclusions Three-dimensional printed models are an innovative method to facilitate tangible pre-operative evaluation of the fracture pattern, help planning the surgical procedure and improve patient’s compliance through better understanding. Funding Medartis (Basel, Switzerland) covered the costs of the 3D Printed models. Conflict of interest None. References
Fig. 3. Graphical representation of patients’ and surgeons’ feedback regarding the availability of 3D printed models (see Table 1 with questionnaire).
[1] Tam MD, Laycock SD, Bell D, Chojnowski A. 3-D printout of a DICOM file to aid surgical planning in a 6 year old patient with a large scapular osteochondroma complicating congenital diaphyseal aclasia. Journal of Radiology Case Reports 2012;6:31–7. [2] Wu XB, Wang JQ, Zhao CP, Sun X, Shi Y, Zhang ZA, et al. Printed threedimensional anatomic templates for virtual preoperative planning before reconstruction of old pelvic injuries: initial results. Chinese Medical Journal 2015;128:477–82. [3] Esses SJ, Berman P, Bloom AI, Sosna J. Clinical applications of physical 3D models derived from MDCT data and created by rapid prototyping. AJR American Journal of Roentgenology 2011;196:W683–8. [4] Bizzotto N, Sandri A, Regis D, Romani D, Tami I, Magnan B. Three-dimensional printing of bone fractures: a new tangible realistic way for preoperative planning and education. Surgical Innovation 2015;22:548–51. [5] Huotilainen E, Jaanimets R, Valasek J, Marcian P, Salmi M, Tuomi J, et al. Inaccuracies in additive manufactured medical skull models caused by the DICOM to STL conversion process. Journal of Cranio-Maxillo-Facial Surgery: Official Publication of the European Association for Cranio-Maxillo-Facial Surgery 2014;42:e259–65. [6] Guitton TG, Brouwer K, Lindenhovius AL, Dyer G, Zurakowski D, Mudgal CS, et al. Diagnostic accuracy of two-dimensional and three-dimensional imaging and modeling of radial head fractures. Journal of Hand and Microsurgery 2014;6:13–7. [7] Chung KJ, Hong do Y, Kim YT, Yang I, Park YW, Kim HN. Preshaping plates for minimally invasive fixation of calcaneal fractures using a real-size 3D-printed model as a preoperative and intraoperative tool. Foot & Ankle International 2014;35:1231–6.
Please cite this article in press as: Bizzotto N, et al. 3D Printed models of distal radius fractures. Injury (2016), http://dx.doi.org/10.1016/ j.injury.2016.01.013
JINJ-6572; No. of Pages 3 Injury, Int. J. Care Injured xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Injury journal homepage: www.elsevier.com/locate/injury
Technical Note
3D Printed models of distal radius fractures Nicola Bizzotto a,*, Ivan Tami b, Andrea Tami c, Adrian Spiegel c, Denis Romani d, Massimo Corain e, Roberto Adani e, Bruno Magnan d a
Dolomiti Sportclinic, Via Purger 181, 39046 Ortisei/St. Ulrich, Bolzano/Bozen, Italy Centro manoegomito, Clinica Ars Medica, Gravesano, Lugano Switzerland c Medartis AG, Basel, Switzerland d Department of Orhopaedic Surgery, Azienda Ospedaliera Universitaria Integrata, Verona, Italy e Hand Surgery Department, Azienda Ospedaliera Universitaria Integrata, Verona, Italy b
A R T I C L E I N F O
Article history: Accepted 13 January 2016
Introduction 3D printing, also known as additive manufacturing or ‘‘rapid prototyping’’, is a low cost technology that uses a 3D computer representation to create solid objects from a feedstock material. In the literature studies report that 3D printed models for orthopedic conditions can improve surgeons’ evaluation of patient-specific anatomy and pathology by way of tactile and visual experience [1–4]. However, it has not been analysed yet how far models may support the surgeon by selecting the most adequate surgical procedure, and which effect they may have on patient’s understanding (and in some cases on their approval) of the surgical procedure they will undergo. In this paper, we present our initial experience preparing and using 3D printed models of the bony anatomy of distal radius fractures and we describe their effect on surgical planning and patient information. Materials and methods From November 2014 to June 2015, 40 patients were enrolled at our clinics. Selected patients were affected with a distal radius
* Corresponding author. E-mail addresses: [email protected] (N. Bizzotto), [email protected] (I. Tami), [email protected] (A. Tami), [email protected] (A. Spiegel), [email protected] (D. Romani), [email protected] (M. Corain), [email protected] (R. Adani), [email protected] (B. Magnan).
fracture (AO classification, 23-A/B/C) eligible for surgery because of presence of displacement, dislocation of fragments and instability. A CT scan with a thickness of 0.625 mm was performed in all cases to study the fracture pattern. The obtained sections (DICOM files) were uploaded into OsiriX Viewer Software (Pixmeo, Geneva, Switzerland), rendered to a ‘‘surface-model’’ of the fractured radius and finally exported to a ‘‘stereolithography’’ file (STL-file), which is widely used for rapid prototyping. This file was analysed and prepared for printing with dedicated 3D software (Mesh Lab http:// meshlab.sourceforge.net). A 3D-printing system Stratasys uPrint SE (Stratasys Ltd 7665 Commerce Way, Eden Prairie MN 55344 USA) was used to obtain the prototype. The 1:1 realistic model was constructed with acrylonitrile butadiene styrene material (ABS). After 3–4 h from the CT scan (Fig. 1) the model was ready. The printed fractured bone was evaluated by the surgeons and used for preoperative planning and selection of surgical approach and selection and placement of osteosynthesis hardware; specifically, ideal screw location and orientation was evaluated (Fig. 2). 3D prints were then used to illustrate fracture morphology and surgical technique to the patient. A simple questionnaire (Table 1) was used to obtain feedback from surgeons and patients regarding the use of the models. All patients were operated with modified Henry volar approach under local anaesthesia.
Results Patients reported an enthusiastic general appreciation about the use of this new technology in our hospitals. There was a substantial improvement in comprehension of the fracture before and after seeing the 3D printed models (average of +3 points on the grading scale) (Fig. 3). Both compliance and confidence in the surgeons appeared improved. Surgeons rated the use of models most beneficial for articular fractures (+2 points%) with articular gaps or steps of 2 mm, or with a multi-fragmentary pattern was evident. For simple and methaphyseal fractures the models did not improve any parameter in either group.
http://dx.doi.org/10.1016/j.injury.2016.01.013 0020–1383/ß 2016 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Bizzotto N, et al. 3D Printed models of distal radius fractures. Injury (2016), http://dx.doi.org/10.1016/ j.injury.2016.01.013
G Model
JINJ-6572; No. of Pages 3 N. Bizzotto et al. / Injury, Int. J. Care Injured xxx (2016) xxx–xxx
2
Fig. 1. Multi-planar reconstruction (i.e. axial, sagittal, coronal views) and 3D volume rendering (A) of a distal radius fracture. 3D printed model (B).
While surgical planning was not changed after checking the 3D printed models, the plates selected during pre-operative planning fitted perfectly during the operation. Discussion The addition of 2D and 3D CT scan to radiographs led to improved diagnosis of fracture line comminution and involvement of the articular surface, articular gaps or steps. A 1:1 3D printed model provides an additional tactile and visual experience, increasing the appreciation of articular surface gaps of 2 mm with severe displacement of bony fragments.
The accuracy of the 3D print is dependent on the technical capabilities of the machine; commercial 3D printer have an accuracy of 0.1 mm [1], which is unlikely to have a major effect on accuracy given the fact that DICOMs were processed with 0.625 mm slice thickness. Generally we noticed some inaccuracy on details and displacements of 1 mm or less because of digital post-processing performed on the 3D data (surface rendering algorithms and smoothing filters); this has also been described in the literature [5]. Guitton et al. reported in a study that the addition of models led to significantly improved agreement on treatment modalities compared to 3DCT alone (p = 0.046). However, using a model did not affect other factors [6], due also to the fact that
Fig. 2. Surgical planning the day before operation: plate fitting and checking of ideal screw location and orientation on 3D printed model.
Please cite this article in press as: Bizzotto N, et al. 3D Printed models of distal radius fractures. Injury (2016), http://dx.doi.org/10.1016/ j.injury.2016.01.013
G Model
JINJ-6572; No. of Pages 3 N. Bizzotto et al. / Injury, Int. J. Care Injured xxx (2016) xxx–xxx Table 1 Questionnaire for patients and surgeons. Questions For the patient 1. Have you seen a 3D printed model of any of your body parts before? 2. How well could you understand the gravity of your fracture based on computer images and surgeon’s explanation? 3. How well could you understand the gravity of your fracture after seeing the 3D printed model? 4. How important/critical was it to see a physical model of your fracture and the implant that would be used for the osteosynthesis? 5. Would you suggest to other patients to request a 3D printed model of their fracture before the surgery? For the surgeon 1. How complex was the diagnosis of the articular damage (comminution and amount of fragments) based only on computer images? 2. How complex was the diagnosis of the articular damage (comminution and amount of fragments) after seeing the 3D printed model? 3. Did the availability of the 3D printed model influence your pre-operative surgical plan? 4. Did the 3D printed model influence implant’s selection? 5. Would you use 3D printed models for other fractures and would you suggest their use to any of your colleagues?
Answers Y/N 1 to 10
1 to 10 1 to 10
Y/N
1 to 10
1 to 10
Y/N Y/N Y/N
3
images were usually rated retrospectively, i.e. after surgery. While in our study we did not notice any change on surgical decisions, evaluation of lesion and fracture displacement were generally improved. Additionally, the possibility to pre-operatively select the ideal plate was appreciated by surgeons, saved time during surgery (1 min) and reduced sterilization costs. Considering the general trend to reduce health care cost and the increasing trend to sterile-packaged single-use kits for specific standard surgeries, 3D printing may open additional opportunities [7]. Further studies with more patients should be conducted in the future to quantify the benefit and cost reduction in regard to OR time and expenses for sterilization. Recommendations regarding the use of this technology should be based on both diagnostic performance characteristics and clinical impact. Conclusions Three-dimensional printed models are an innovative method to facilitate tangible pre-operative evaluation of the fracture pattern, help planning the surgical procedure and improve patient’s compliance through better understanding. Funding Medartis (Basel, Switzerland) covered the costs of the 3D Printed models. Conflict of interest None. References
Fig. 3. Graphical representation of patients’ and surgeons’ feedback regarding the availability of 3D printed models (see Table 1 with questionnaire).
[1] Tam MD, Laycock SD, Bell D, Chojnowski A. 3-D printout of a DICOM file to aid surgical planning in a 6 year old patient with a large scapular osteochondroma complicating congenital diaphyseal aclasia. Journal of Radiology Case Reports 2012;6:31–7. [2] Wu XB, Wang JQ, Zhao CP, Sun X, Shi Y, Zhang ZA, et al. Printed threedimensional anatomic templates for virtual preoperative planning before reconstruction of old pelvic injuries: initial results. Chinese Medical Journal 2015;128:477–82. [3] Esses SJ, Berman P, Bloom AI, Sosna J. Clinical applications of physical 3D models derived from MDCT data and created by rapid prototyping. AJR American Journal of Roentgenology 2011;196:W683–8. [4] Bizzotto N, Sandri A, Regis D, Romani D, Tami I, Magnan B. Three-dimensional printing of bone fractures: a new tangible realistic way for preoperative planning and education. Surgical Innovation 2015;22:548–51. [5] Huotilainen E, Jaanimets R, Valasek J, Marcian P, Salmi M, Tuomi J, et al. Inaccuracies in additive manufactured medical skull models caused by the DICOM to STL conversion process. Journal of Cranio-Maxillo-Facial Surgery: Official Publication of the European Association for Cranio-Maxillo-Facial Surgery 2014;42:e259–65. [6] Guitton TG, Brouwer K, Lindenhovius AL, Dyer G, Zurakowski D, Mudgal CS, et al. Diagnostic accuracy of two-dimensional and three-dimensional imaging and modeling of radial head fractures. Journal of Hand and Microsurgery 2014;6:13–7. [7] Chung KJ, Hong do Y, Kim YT, Yang I, Park YW, Kim HN. Preshaping plates for minimally invasive fixation of calcaneal fractures using a real-size 3D-printed model as a preoperative and intraoperative tool. Foot & Ankle International 2014;35:1231–6.
Please cite this article in press as: Bizzotto N, et al. 3D Printed models of distal radius fractures. Injury (2016), http://dx.doi.org/10.1016/ j.injury.2016.01.013
