The value of digital 3D models in evaluating surgical outcomes using the uninjured contralateral acetabulum after acetabular fracture repair.

BACKGROUND: Currently, assessment of acetabular fracture reduction is mainly performed by evaluating 2D slices of 3D CT scans. This subjective method can potentially be improved by using 3D models and objective analysis tools. In order to evaluate the potential value of digital 3D reconstructed models in the assessment of acetabular fracture reduction, 3D reconstructions of the fractured acetabulum were compared to the mirrored healthy contralateral side for both the pre-, and post-surgical setting. METHODS: Thirteen patients with one-sided acetabular fractures were included in the study. All patients received a pre-, and postoperative CT scan. The similarity between the healthy acetabulum and the contralateral fractured acetabulum was determined by two observers for both the pre-, and postoperative setting by completing the following four steps; (1) mirroring of the fractured acetabulum, (2) initial manual alignment of this mirrored 3D model to the contralateral version, (3) surface-based matching (iterative closest point registration) using the acetabular cartilage surface, and (4) calculating the surface distances between affected and healthy acetabular 3D models. Descriptive statistics showed the surface distance between pre-, and post-surgical reduction, as well as the interobserver variability. RESULTS: A total of 13 patients with an acetabular fracture were included; 11 males and 2 females with a mean ± SD age of 55.6 ± 14.7 years. Digital mirroring of the fractured acetabula to the healthy acetabula was successful for both preoperative and postoperative situations in all patients. The median distance between both fractured and mirrored healthy contralateral acetabula was significantly larger (p<0.01) for the preoperative group (2.21 mm (interquartile range (IQR): 1.30 mm)) compared to the postoperative group (0.93 mm (IQR: 0.59 mm)). The median distance deviation was not significantly different (p = 0.96) between observers. CONCLUSIONS: The results of comparing 3D model of fractured acetabula with the contra-lateral healthy acetabula before, and after surgical repair indicate that this method can be a suitable tool to objectively assess acetabular fracture reduction. Further research is needed to confirm the usefulness to predict future arthrosis after surgical repair.

Are 3D-printed Models of Tibial Plateau Fractures a Useful Addition to Understanding Fractures for Junior Surgeons?

BACKGROUND: Tibial plateau fractures are often complex, and they can be challenging to treat. Classifying fractures is often part of the treatment process, but intra- and interobserver reliability of fracture classification systems often is inadequate to the task, and classifications that lack reliability can mislead providers and result in harm to patients. Three-dimensionally (3D)-printed models might help in this regard, but whether that is the case for the classification of tibial plateau fractures, and whether the utility of such models might vary by the experience of the individual classifying the fractures, is unknown. QUESTIONS/PURPOSES: (1) Does the overall interobserver agreement improve when fractures are classified with 3D-printed models compared with conventional radiology? (2) Does interobserver agreement vary among attending and consultant trauma surgeons, senior surgical residents, and junior surgical residents? (3) Do surgeons' and surgical residents' confidence and accuracy improve when tibial plateau fractures are classified with an additional 3D model compared with conventional radiology? METHODS: Between 2012 and 2020, 113 patients with tibial plateau fractures were treated at a Level 1 trauma center. Forty-four patients were excluded based on the presence of bone diseases (such as osteoporosis) and the absence of a CT scan. To increase the chance to detect an improvement or deterioration and to prevent observers from losing focus during the classification, we decided to include 40 patients with tibial plateau fractures. Nine trauma surgeons, eight senior surgical residents, and eight junior surgical residents-none of whom underwent any study-specific pretraining-classified these fractures according to three often-used classification systems (Schatzker, OA/OTA, and the Luo three-column concept), with and without 3D-printed models, and they indicated their overall confidence on a 10-point Likert scale, with 0 meaning not confident at all and 10 absolutely certainty. To set the gold standard, a panel of three experienced trauma surgeons who had special expertise in knee surgery and 10 years to 25 years of experience in practice also classified the fractures until consensus was reached. The Fleiss kappa was used to determine interobserver agreement for fracture classification. Differences in confidence in assessing fractures with and without the 3D-printed model were compared using a paired t-test. Accuracy was calculated by comparing the participants' observations with the gold standard. RESULTS: The overall interobserver agreement improved minimally for fracture classification according to two of three classification systems (Schatzker: κconv = 0.514 versus κ3Dprint = 0.539; p = 0.005; AO/OTA:κconv = 0.359 versus κ3Dprint = 0.372; p = 0.03). However, none of the classification systems, even when used by our most experienced group of trauma surgeons, achieved more than moderate interobserver agreement, meaning that a large proportion of fractures were misclassified by at least one observer. Overall, there was no improvement in self-assessed confidence in classifying fractures or accuracy with 3D-printed models; confidence was high (about 7 points on a 10-point scale) as rated by all observers, despite moderate or worse accuracy and interobserver agreement. CONCLUSION: Although 3D-printed models minimally improved the overall interobserver agreement for two of three classification systems, none of the classification systems achieved more than moderate interobserver agreement. This suggests that even with 3D-printed models, many fractures would be misclassified, which could result in misleading communication, inaccurate prognostic assessments, unclear research, and incorrect treatment choices. Therefore, we cannot recommend the use of 3D-printed models in practice and research for classification of tibial plateau fractures. LEVEL OF EVIDENCE: Level III, diagnostic study.

Strength testing of low-cost 3D-printed transtibial prosthetic socket.

Measurement and production of traditional prosthetic sockets are time-consuming, labor-intensive, and highly dependent on the personnel involved. An alternative way to make prostheses is using computer-aided design (CAD) and computer-aided manufacturing (CAM). Fused Filament Fabrication (FFF) may be an alternative to make low-cost prosthetic sockets. This study investigates the tensile properties of potential printing materials suitable for FFF according to ISO527 (Standard Test Method for Tensile Properties of Plastics). To ensure that FFF-printed sockets are safe for patient usage, the structural integrity of the 3D-printed prosthesis will be investigated according to ISO10328 (International Standard Structural Testing of Lower Limb Prostheses). Tough PLA was the most suitable print material according to ISO 527 testing. The Tough PLA printed socket completed 2.27 million cycles and a static test target value of 4025 N. Future research remains necessary to continue testing new potential materials, improve print settings, and improve the socket design for the production of FFF-printed transtibial prosthetic sockets. FFF using Tough PLA can be used to create transtibial prostheses that almost comply with the International Standard for Structural Testing of Lower Limb Prostheses.

3D-printed prostheses in developing countries: A systematic review.

BACKGROUND: According to the World Health Organization, only 5%-15% of people in lower-income countries have access to prostheses. This is largely due to low availability of materials and high costs of prostheses. 3D-printing techniques have become easily accessible and can offer functional patient-specific components at relatively low costs, reducing or bypassing the current manufacturing and postprocessing steps. However, it is not yet clear how 3D-printing can provide a sustainable solution to the low availability of limb prostheses for patients with amputations in lower-income countries. OBJECTIVE: To evaluate 3D-printing for the production of limb prostheses in lower-income countries and lower-middle-income countries (LLMICs). STUDY DESIGN: Systematic Review. METHODS: Literature searches, completed in April 2020, were performed in PubMed, Embase, Web of Science, and Cochrane Library. The search results were independently screened and reviewed by four reviewers. Only studies that examined interventions using prostheses in LLMICs for patients with limb amputations were selected for data extraction and synthesis. The web was also searched using Google for projects that did not publish in a scientific journal. RESULTS: Eighteen studies were included. Results were reported regarding country of use, cost and weight, 3D-printing technology, satisfaction, and failure rate. CONCLUSION: Low material costs, aesthetic appearance, and the possibility of personalized fitting make 3D-printed prostheses a potential solution for patients with limb amputations in LLMICs. However, the lack of (homogeneous) data shows the need for more published (scientific) research to enable a broader availability of knowledge about 3D-printed prostheses for LLMICs.

Comparison of segmentation software packages for in-hospital 3D print workflow.

Purpose: In-hospital three-dimensional (3D) printing of patient-specific pathologies is increasingly being used in daily care. However, the efficiency of the current conversion from image to print is often obstructed due to limitations associated with segmentation software. Therefore, there is a need for comparison of several clinically available tools. A comparative study has been conducted to compare segmentation performance of Philips IntelliSpace Portal® (PISP), Mimics Innovation Suite (MIS), and DICOM to PRINT® (D2P). Approach: These tools were compared with respect to segmentation time and 3D mesh quality. The dataset consisted of three computed tomography (CT)-scans of acetabular fractures (ACs), three CT-scans of tibia plateau fractures (TPs), and three CTA-scans of abdominal aortic aneurysms (AAAs). Independent-samples t -tests were performed to compare the measured segmentation times. Furthermore, 3D mesh quality was assessed and compared according to representativeness and usability for the surgeon. Results: Statistically significant differences in segmentation time were found between PISP and MIS with respect to the segmentation of ACs ( p = < 0.001 ) and AAAs ( p = 0.031 ). Furthermore, statistically significant differences in segmentation time were found between PISP and D2P for segmentations of AAAs ( p = 0.008 ). There were no statistically significant differences in segmentation time for TPs. The accumulated mesh quality scores were highest for segmentations performed in MIS, followed by D2P. Conclusion: Based on segmentation time and mesh quality, MIS and D2P are capable of enhancing the in-hospital 3D print workflow. However, they should be integrated with the picture archiving and communication system to truly improve the workflow. In addition, these software packages are not open source and additional costs must be incurred.

People with amputations in rural Sierra Leone: the impact of 3D-printed prostheses.

We report the case of a man with a transhumeral amputation in a rural area of Sierra Leone. The patient had fractured his humerus during a football match. Due to lack of transportation and medical centres nearby, the patient was seen by a traditional healer. Although the traditional healer expected the fractured bone to heal within 3 days, the open fracture became infected. This finally resulted in a transhumeral amputation. The patient began to have a lack of self-confidence and felt excluded from society. He could not afford a conventionally fabricated prosthesis. Fourteen years later, the patient received a lightweight three-dimensional-printed arm prosthesis developed at the Masanga Hospital. The patient was very satisfied because the prosthesis met his criteria of aesthetics and functionality. His story highlights the socioeconomic hardship of being a person with an amputation in Sierra Leone and the need for affordable technological solutions.

Pioneering low-cost 3D-printed transtibial prosthetics to serve a rural population in Sierra Leone - an observational cohort study.

BACKGROUND: There is a huge unmet global need for affordable prostheses. Amputations often happen in Sierra Leone due to serious infections, complex wounds, traffic accidents and delayed patient presentation to the hospital. However, purchasing a prosthesis is still beyond reach for most Sierra Leonean amputees. METHOD: We applied computer-aided design (CAD) and computer-aided manufacturing (CAM) to produce low-cost transtibial prosthetic sockets. In February and March 2020, eight participants received a 3D printed transtibial prosthesis in the village of Masanga in Tonkolili district, Sierra Leone. Research was performed using questionnaires to investigate the use, participants' satisfaction, and possible complications related to the prostheses. Questionnaires were conducted prior to production of the prosthesis and five to six weeks after fitting the prosthesis. A personal short-term goal was set by the participants. FINDINGS: Competitively priced and fully functional prostheses were produced locally. After six weeks, all participants were still wearing the prosthesis and six of the eight participants reached their personal rehabilitation goals. Using their prostheses, all participants were no longer in need of their crutches. INTERPRETATION: We have come a step closer to the production of low-cost prostheses for low-and middle-income countries (LMICs). The goal of our project is to perform long-term follow-up and to refine our concept of 3D printed prostheses for LMICs to provide practical solutions for a global health need unmet to date. FUNDING: € 15,000 was collected during a crowdfunding campaign in collaboration with the Dutch Albert Schweitzer Fund. Internship allowance for MvdS was obtained from the University of Twente. 3D-scanner, 3D-printer, and printing material were donated by Ultimaker BV and Shining 3D.

The value of 3D reconstructions in determining post-operative reduction in acetabular fractures: a pilot study.

BACKGROUND: In patients with acetabular fractures, the reconstructed three-dimensional (3D) model of the contralateral acetabulum could be used as a mirrored template for the anatomical configuration of the affected joint. This has not been validated. OBJECTIVE: To investigate whether the right and left acetabula, as reconstructed 3D models, are valid mirrored duplicates that can be used as a reference model for the contralateral side. METHODS: CT scans of twenty patients with unaffected acetabula were used. The symmetry of the generated 3D models was evaluated through: (1) mirroring of the acetabulum; (2) initial rough matching; (3) automatic optimisation of the matching via surface-based matching; (4) calculation of distances between surfaces by evaluating the Euclidean (straight-line) error distance between the closest points between left and right. The percentages of surface points of the left and right acetabulum with a distance smaller than 0.5, 1.0, 1.5 and 2.0 mm were calculated and evaluated, in relation to Matta's criteria, for acetabular fracture reductions. RESULTS: The mean distance deviation was less than 0.75 mm in all 40 comparisons. The calculated distances in 90.7% of the surface points of the left and right acetabulum were below the tolerance threshold of 1.0 mm, based on Matta's anatomical reduction criteria, and 98.7% of the surface points scored below Matta's imperfect tolerance threshold of 2.0 mm. CONCLUSION: This study demonstrates 3D reconstructed models of healthy left and right acetabula are highly similar and could potentially be used as mirrored duplicates. The next step will be to investigate these results in patients with reduced acetabular fractures.

Improving Lives in Three Dimensions: The Feasibility of 3D Printing for Creating Personalized Medical Aids in a Rural Area of Sierra Leone.

The aim of this feasibility study was to investigate how a 3D printer could be put to its best use in a resource-limited healthcare setting. We have examined whether a 3D printer can contribute to making prostheses, braces, or splints for patients who underwent major limb amputation because of complex wounds, for example, due to burns and subsequent scarring, accidents, conflicts, or congenital abnormalities. During a 3-month period, we investigated the benefits of customized, 3D-printed arm prostheses, splints, and braces in Sierra Leone. Using a handheld 3D scanner and a 3D printer, patient-specific medical aids were designed, manufactured, and tested. Questionnaires regarding patient satisfaction and the functionality of the prostheses were used for a short-term follow-up. Four esthetic prostheses were designed: two prostheses of the hand, one of the forearm, and one of the entire arm. Follow-ups were conducted after 3 to 4 weeks to investigate the quality of the prostheses and to complete a patient questionnaire. Even though the prostheses primarily fulfill esthetic needs, they also exhibit some degree of functionality. In addition, four splints for hands and arms were made to prevent scar contractures after skin transplantation. Finally, a brace for a young boy with kyphoscoliosis was manufactured. The boy has accepted the brace and will be followed up in the months to come. Long-term follow-up is required to prove the sustainability of the 3D-printed brace and prosthetic arms. Further research into how to sustain and refine this project is underway.

What is the value of 3D virtual reality in understanding acetabular fractures?

BACKGROUND: Acetabular fractures are difficult to classify owing to the complex three-dimensional (3D) anatomy of the pelvis. 3D printing helps to understand and reliably classify acetabular fracture types. 3D-virtual reality (VR) may have comparable benefits. Our hypothesis is that 3D-VR is equivalent to 3D printing in understanding acetabular fracture patterns. METHODS: A total of 27 observers of various experience levels from several hospitals were requested to classify twenty 3D printed and VR models according to the Judet-Letournel classification. Additionally, surgeons were asked to state their preferred surgical approach and patient positioning. Time to classify each fracture type was recorded. The cases were randomized to rule out a learning curve. Inter-observer agreement was analyzed using Fleiss' kappa statistics (κ). RESULTS: Inter-observer agreements varied by observer group and type of model used to classify the fracture: medical students: 3D print (κ = 0.61), VR (κ = 0.41); junior surgical residents: 3D print (0.51) VR (0.54); senior surgical residents: 3D print (0.66) VR (0.52); junior surgeons: 3D print (0.56), VR (0.43); senior surgeons: 3D print (κ = 0.59), VR (κ = 0.42). Using 3D printed models, there was more agreement on the surgical approach (junior surgeons κ = 0.23, senior surgeons κ = 0.31) when compared with VR (junior surgeons κ = 0.17, senior surgeons 0.25). No difference was found in time used to classify these fractures between 3D printing and VR for all groups (P = 1.000). CONCLUSIONS: The Judet-Letournel acetabular classification stays difficult to interpret; only moderate kappa agreements were found. We found 3D-VR inferior to 3D printing in classifying acetabular fractures. Furthermore, the current 3D-VR technology is still not practical for intra-operative use.

Differences in the Majeed Pelvic Score Between Injured and Uninjured Patients.

OBJECTIVES: To investigate the differences in the Majeed Pelvic Score (MPS) between injured and uninjured patients. Discriminative power and applicability of the MPS in elderly are also investigated, and a norm score for the MPS in the Netherlands is provided. DESIGN: Cross-sectional cohort study. SETTING: Urban level 1 trauma center. PATIENTS/PARTICIPANTS: One hundred ninety-five patients with pelvic ring disruptions; 101 61A, 67 61B, and 27 61C (OTA/AO classification; 6%, 27%, and 82% surgically treated, respectively); mean follow-up 29 months (range 6-61); 554 adults from the Longitudinal Internet Studies for the Social Sciences panel (control group). Participants were divided into 2 age groups: <65 and ≥65 years (respectively, maximum MPS: 100 and 80 points). MAIN OUTCOME MEASUREMENTS: Majeed Pelvic Score. RESULTS: Patients <65 years of age (81.6) scored lower on the MPS when compared with the control group (88.3, P < 0.001). Patients ≥65 years of age (68.1) scored lower on the MPS when compared with the control group (72.0, P = 0.006). In the <65 group, the patient group scored worse on the sexual function, work, and standing dimensions (P < 0.001). In the ≥65 group, the patient group scored worse on the dimensions sitting (P = 0.03) and standing (P < 0.001) and better on the dimension pain (P = 0.001). CONCLUSIONS: Compared with the general population, patients with pelvic ring disruption in both age groups perceived some health problems in almost all MPS domains. The MPS discriminates well enough to provide information about the mobility of elderly patients. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Validation study of 3D-printed anatomical models using 2 PLA printers for preoperative planning in trauma surgery, a human cadaver study.

INTRODUCTION: 3D printing contributes to a better understanding of the surgical approach, reduction and fixation of complex fractures. It is unclear how a 3D-printed model relates to a human bone. The accuracy of 3D-printed models is important to pre-bend plates and fit of surgical guides. We conduct a validation study in which we compare human cadavers with 3D-printed models to test the accuracy of 3D printing. METHODS: Nine specimens were scanned, volume rendered into 3D reconstructions and saved as STL data. All models were in a ratio of 1:1 printed on the Ultimaker 3 and Makerbot Replicator Z18. Two independent observers measured all distances between the K-wires on the human cadavers, 2DCT, 3D reconstruction, Meshlab and both printers. A paired Samples T test was used to compare the measurements between the different modalities. RESULTS: The least decrease in average distance in millimetres was seen in "the 3D printed pelvis 1", - 0.3 and - 0.8% on respectively the Ultimaker and Makerbot when compared with cadaver Pelvis (1) The 3D model of "Hand 2" showed the most decrease, - 2.5 and - 3.2% on the Ultimaker and Makerbot when compared with cadaver hand (2) Most significant differences in measurements were found in the conversion from 3D file into a 3D print and between the cadaver and 3D-printed model from the Makerbot. CONCLUSION: Our 3D printing process results in accurate models suitable for preoperative workup. The Ultimaker 3 is slightly more accurate than the Makerbot Replicator Z18. We advise that medical professionals should perform a study that tests the accuracy of their 3D printing process before using the 3D-printed models in medical practice.

3D printing for corrective osteotomy of malunited distal radius fractures: a low-cost workflow.

After a severe trauma, a 16-year-old female patient sustained multiple injuries, including a distal radius fracture of the left arm. This distal radius fracture eventually developed into a malunion. In this case, we demonstrate our preoperative low-cost workup for three-dimensional (3D) planned and assisted corrective osteotomy of a malunited distal radius fracture using an in-hospital 3D printer.

Necrotising fasciitis: a ticking time bomb?

Necrotising fasciitis (NF) is a destructive bacterial infection and has often been described in media reports as a 'flesh-eating disease', which if diagnosed late is associated with worse outcome. Unfortunately, diagnosing NF is difficult due to the similar presentation of NF compared with other types of skin and soft tissue infections. The early presentation of NF only shows tenderness, swelling, erythema and warm skin. Moreover, NF is normally accompanied with aberrant laboratory findings, mainly elevated C reactive protein (CRP) levels. In this case report we evaluate the diagnostic process of a patient with NF without aberrant infection parameters; both normal levels of CRP and white blood cell count were seen.

[A man with a painful sternum]. / Een man met een pijnlijk sternum na een auto-ongeluk.

We present a case of a 81-year-old man with blunt chest trauma after a car accident. Trauma screening at the emergency department showed multiple rib fractures and a fractured sternum. We made the diagnosis floating sternum. Cardiac contusion may occur after chest-wall trauma, but was not present in this case.

Nonunion of the pisiform bone in a 9-year-old boy.

An isolated fracture of the pisiform bone is a rare condition, especially in children. The fracture may be missed in the emergency department because of the complex anatomy of the carpal region. Early diagnosis and treatment are, however, important for the functional outcome of the patient, since untreated dislocated carpal fractures may result in nonunion. We report one case of a 9-year-old boy with an unrecognized fracture of the pisiform bone who underwent a pisiformectomy 10 months after injury due to a nonunion of the pisiform bone. Good results were obtained and the wrist did not show any functional impairment.

Snowboarders' ankle.

In this case study we report a fracture of the lateral process of the talus (LPF) in a snowboarder. The fracture is frequently overlooked initially, due to subtle clinical and radiological findings and a low incidence rate. However, LPF are associated with significant morbidity when missed. To address this, we report one case of a patient with a LPF and provide a review of the available literature.

[Pelvic injuries caused by bucking horses]. / Bekkenletsel door bokkende paarden.

We report on 3 male patients aged 57, 47, and 53, who each sustained an unstable straddle injury during low-energy pelvic trauma while horseback riding. All 3 patients were haemodynamically stable; radiography revealed diastasis of the pubic symphysis in each case. In two patients, the sacroiliac joints were intact but the third patient showed widening of the right sacroiliac joint. In this patient, the pelvis was initially fixated with osteosynthesis screws and dynamic compression plates; however, arthrodesis of the right sacroiliac joint was performed due to its non-union one year after the injury. Fractures of the pelvic ring are relatively rare and are typically associated with high-energy trauma. Immediate surgical treatment is necessary for patients with fractures of the pelvic ring for the stabilisation of haemorrhagic shock, identification of soft-tissue injuries and fixation of the pelvis.