Development of Digital Twins to Optimize Trauma Surgery and Postoperative Management. A Case Study Focusing on Tibial Plateau Fracture

Background and context: Surgical procedures are evolving toward less invasive and more tailored approaches to consider the specific pathology, morphology, and life habits of a patient. However, these new surgical methods require thorough preoperative planning and an advanced understanding of biomechanical behaviors. In this sense, patient-specific modeling is developing in the form of digital twins to help personalized clinical decision-making.Purpose: This study presents a patient-specific finite element model approach, focusing on tibial plateau fractures, to enhance biomechanical knowledge to optimize surgical trauma procedures and improve decision-making in postoperative management.Study design: This is a level 5 study.Methods: We used a postoperative 3D X-ray image of a patient who suffered from depression and separation of the lateral tibial plateau. The surgeon stabilized the fracture with polymethyl methacrylate cement injection and bi-cortical screw osteosynthesis. A digital twin of the patient’s fracture was created by segmentation. From the digital twin, four stabilization methods were modeled including two screw lengths, whether or not, to inject PMMA cement. The four stabilization methods were associated with three bone healing conditions resulting in twelve scenarios. Mechanical strength, stress distribution, interfragmentary strains, and fragment kinematics were assessed by applying the maximum load during gait. Repeated fracture risks were evaluated regarding to the volume of bone with stress above the local yield strength and regarding to the interfragmentary strains.Results: Stress distribution analysis highlighted the mechanical contribution of cement injection and the favorable mechanical response of uni-cortical screw compared to bi-cortical screw. Evaluation of repeated fracture risks for this clinical case showed fracture instability for two of the twelve simulated scenarios.Conclusion: This study presents a patient-specific finite element modeling workflow to assess the biomechanical behaviors associated with different stabilization methods of tibial plateau fractures. Strength and interfragmentary strains were evaluated to quantify the mechanical effects of surgical procedures. We evaluate repeated fracture risks and provide data for postoperative management.

Hip, Vertebral, and Wrist Fracture Risks and Schizophrenia: A Nationwide Longitudinal Study

Background: Fractures are a great health issue associated with morbidity, quality of life, life span, and health care expenditure. Fractures are correlated with cardiovascular disease, type 2 diabetes mellitus, cerebrovascular disease, and some psychiatric disorders. However, representative national data are few, and longitudinal cohort studies on the association between schizophrenia and the subsequent fracture risk are scant. We designed a nationwide population-based cohort study to investigate the association of schizophrenia with hip, vertebral, and wrist fractures over a 10-year follow-up. Methods: Data of patients with schizophrenia (International Classification of Diseases, Ninth Revision, Clinical Modification code 295) and matched over January 2000–December 2009) were extracted from Taiwan National Health Insurance Research Database. A Cox proportional-hazards regression model was constructed to calculate hazard ratios (HRs) for fractures between the schizophrenia and control cohorts. Results: Of 2,028 people with schizophrenia (mean age: 36.3 years, 49.4% female), 89 (4.4%) reported newly diagnosed fractures—significantly higher than the proportion in the control population (257, 3.2%; P = 0.007). The incidences of hip (1.2%, P = 0.009) and vertebral (2.6%, P = 0.011) fractures were significantly higher in the schizophrenia cohort than in the control cohort. In Cox regression analysis, hip (adjusted HR: 1.78, 95% confidence interval [CI]: 1.08–2.93) and vertebral (adjusted HR: 1.40, 95% CI: 1.01–1.95) fracture risks were significantly higher in patients with schizophrenia. Furthermore, a sex-based subgroup analysis revealed that the risk of hip fracture remained significantly higher in female patients with schizophrenia (HR: 2.68, 95% CI: 1.32–5.44) than in female controls. On the other hand, there was no significant interaction between effects of sex and schizophrenia on the risk of fractures. Conclusions: Over a 10-year follow-up, hip and vertebral fracture risks were higher in the people with schizophrenia than in the controls. The risk of fractures in patients with schizophrenia does not differ between female and male.

Biomechanical Computed Tomography Captures Older Men at High Risk of Hip Fracture Despite Low Fracture Risk Calculation by FRAX

Background: Biomechanical computed tomography (BCT) can be applied to hip-containing CT scans to estimate femoral bone strength using finite-element analysis and to measure DXA-equivalent femoral neck (FN) BMD. Current guidelines recommend osteoporosis pharmacotherapy initiation in men with BMD T-score ≤ -2.5 or T-score between -1.0 and -2.5 with 10-year hip fracture risk ≥ 3% by FRAX.1 Estimated femoral strength by BCT is associated with incident hip fractures in men, independent of BMD,2 and can be used in conjunction with clinical risk factors for consideration of therapy initiation per the International Society of Clinical Dosimetry.3 Aim: To determine how many men are at increased risk of fractures with fragile bone strength (≤ 3500N) despite normal-to-low BMD (T-score > -2.5) and low 10-year hip fracture risk (< 3%). Methods: 625 men age ≥ 65 with hip-containing CT scans were randomly selected for BCT analysis out of 4209 scans performed from 2017 to 2019 at a single academic hospital. Scans were excluded if an intact femur was not imaged. BCT was performed for 557 men after accounting for un-processable scans. Electronic health records were retrospectively reviewed by investigators blinded to BCT results. 10-year hip fracture risks were calculated by FRAX based on available clinical data and FN BMD T-score from BCT. Chi-squared and t-test were used to investigate differences in clinical parameters between men with and without fragile bone strength. Results: The mean age was 77 (± 7.6 years), and 69% of men were white. Out of 102 men (18.3%) who met criteria for fragile bone strength by BCT, 42 (7.5%) had low FN BMD (T-score between -1.0 and -2.5) and 2 (0.4%) had normal FN BMD (T-score ≥ -1.0). The percentage of men with fragile bone strength and discrepant BMD increased with age (5.4% in age 65–74; 8.2% in age 75–84; 13.0% in age ≥ 85). The average 10-year hip fracture risk by FRAX of men with fragile bone strength was 6.5% (± 4.0%). However, 13 out of 44 men with normal-to-low BMD had 10-year hip fracture risks < 3% despite fragile bone strength presence and did not meet recommendation for osteoporosis pharmacotherapy. Examining men with normal-to-low BMD (n=493), those with fragile bone strength tended to be older, have lower BMI, and of Hispanic ethnicity compared to those with normal-to-low bone strength (p<0.05). Conclusions: Our study showed that fragile bone strength is present in older men with normal-to-low BMD, and that inclusion of 10-year hip fracture risk by FRAX may capture some, but not all, men at increased risk of hip fractures. Skeletal fragility measured by BCT may serve as additional data to assist with clinical decision making for men with osteoporosis, though further prospective research is needed. Reference: 1. Watts et al, J Clin Endocrinol Metab. 2012 Jun;97(6):1802–22. 2. Adams et al, J Bone Miner Res 2018 Jul;33(7):1291–1301. 3. Shuhart et al, J Clin Densitom. 2019 Oct-Dec;22(4):453–471.

Epi-Mucosa Fixation and Autologous Platelet-Rich Fibrin Treatment in Medication-Related Osteonecrosis of the Jaw

Medication-related osteonecrosis of the jaw (MRONJ) frequently affects patients after treatments with bisphosphonates or denosumab, especially with high doses in patients with bone osteoporosis, neoplastic metastases, or possibly anti-angiogenic treatment for cancer. The aim of this article was to show a new treatment planning for stage 2 and stage 3 MRONJ using platelet-rich fibrin (PRF) at the surgical field to enhance healing in association with a new epi-mucosal fixation technique to prevent or treat mandibular fracture. Two cases were treated by epi-mucosa fixation and autologous PRF use for prevention of mandibular fracture risks related to necrotic bone resection or a narrow fracture reduction. Both cases were successfully treated by this new technique of epi-mucosa fixation combined with autologous PRF and achieved good results and good quality of life. Ability to wear prosthesis with good mastication in the absence of side effect such as infection, plate and screw mobilization, pain, and other disabilities or extension of necrosis was reported. After surgical removal of necrotic bone, no infection was detected without any extension of the necrosis.

Fracture Risks in Patients Treated With Different Oral Anticoagulants: A Systematic Review and Meta‐Analysis

Background Evidence on the differences in fracture risk associated with non‐vitamin K antagonist oral anticoagulants (NOAC) and warfarin is inconsistent and inconclusive. We conducted a systematic review and meta‐analysis to assess the fracture risk associated with NOACs and warfarin. Methods and Results We searched PubMed, Embase, Cochrane Library, Scopus, Web of Science, and ClinicalTrials.gov from inception until May 19, 2020. We included studies presenting measurements (regardless of primary/secondary/tertiary/safety outcomes) for any fracture in both NOAC and warfarin users. Two or more reviewers independently screened relevant articles, extracted data, and performed quality assessments. Data were retrieved to synthesize the pooled relative risk (RR) of fractures associated with NOACs versus warfarin. Random‐effects models were used for data synthesis. We included 29 studies (5 cohort studies and 24 randomized controlled trials) with 388 209 patients. Patients treated with NOACs had lower risks of fracture than those treated with warfarin (pooled RR, 0.84; 95% CI, 0.77–0.91; P <0.001) with low heterogeneity ( I 2 =38.9%). NOACs were also associated with significantly lower risks of hip fracture than warfarin (pooled RR, 0.89; 95% CI, 0.81–0.98; P =0.023). A nonsignificant trend of lower vertebral fracture risk in NOAC users was also observed (pooled RR, 0.74; 95% CI, 0.54–1.01; P =0.061). Subgroup analyses for individual NOACs demonstrated that dabigatran, rivaroxaban, and apixaban were significantly associated with lower fracture risks. Furthermore, the data synthesis results from randomized controlled trials and real‐world cohort studies were quite consistent, indicating the robustness of our findings. Conclusions Compared with warfarin, NOACs are associated with lower risks of bone fracture.

65 Comparison of Frax and Qfracture in Predicting Fragility Fractures in Patients Presenting with Falls

Introduction Falls are a major risk factor for fragility fractures and patients should be appropriately assessed to reduce future fragility fracture risk. National guidelines provide recommendations on assessing fracture risk using calculators to guide therapy initiation. FRAX and QFracture are the two main calculators used, however they differ considerably in their inputs. The aim of this study was to compare the risk estimation and performance between these two frequently used calculators to help determine their appropriate utility. Methods Data from patients aged ≥70 years admitted with a fall to the Acute Medical Units at Charing Cross Hospital between 1st Dec 2018–31st March 2019 were retrospectively collected, covering all inputs required for the two risk calculators. The 10-year major osteoporotic and hip fracture risks were calculated using FRAX and QFracture and compared. The one-year major osteoporotic and hip fracture risks from QFracture were assessed against actual one-year fracture rates. Results Conclusions Risk calculators are effective tools to aid the decision of bone therapy initiation. Here we demonstrate that there is a strong correlation between the two commonly used calculators. However, in terms of absolute risk values there is a mean 8.9% difference with QFracture providing higher risks in this “fallers” group. As absolute treatment thresholds are frequently used to guide bone therapy initiation, opposing recommendations may result. Therefore, there is a need to further explore calculator performance and determine which would more accurately serve different patient groups.

How to prevent fracture of NiTi files

More certain therapeutic and significantly facilitated solution of everyday endodontic problems are provided by the introduction of NiTi rotary files in endodontic practice and their proper application. However, their widespread use has caused more and more frequent fractures and has become a significant frustrating factor that diminishes their numerous benefits. Torsional stress and cyclic fatigue are the main reasons for the occurrence of a fracture, and the frequency of NiTi file fractures is exactly proportional to the degree of bending of the canal, knowledge of the features of the file, ie. the skill and expertise of the therapist. The most dominant factor for the occurrence of fractures is the dentist who, in addition to manual dexterity, must have a good knowledge of the anatomy of various canal systems and file design in order to make the best choice for each individual case. Properly formed access cavity and knowledge of the working part of NiTi files enable maximum realization of endodontic skills, increased efficiency of intervention and reduced possibility of error during canal instrumentation. The special treatment of NiTi alloy and new solutions related to the design of the working part have significantly increased file flexibility and resistance to cyclic fatigue. Specific design (reduced number of threads, change of conicity, interruption of blade continuity), reduced engagement of file, ie. change of dynamics of movement in the canal (full rotation, reciprocal, eccentric, transaxial), as well as reduced number of processing files, have also significantly influenced the reduction of fracture risks. The aim of this paper was to analyze the most common reasons for the fracture of NiTi files and emphasize measures and factors that can increase their safe use and reduce complications during canal instrumentation.