Efficacy of personalized 3D-printed osteotomy guide in maximizing fibular utilization and minimizing graft length for reconstruction of large mandibular defect.

OBJECTIVE: The study addresses the long-standing challenge of insufficient length in vascularized fibular flaps when reconstructing large mandibular defects that require dual-barrel grafts. Employing personalized 3D-printed osteotomy guides, the study aims to optimize fibular utilization and minimize the required graft length. MATERIAL AND METHODS: Two reconstruction methods for distal bone defects were compared: a fold-down (FD) group that employed a specialized osteotomy guide for folding down a triangular bone segment, and a traditional double-barrel (DB) group. Metrics for comparison included defect and graft lengths, as well as the graft-to-defect length ratio. Postoperative quality of life was assessed using the University of Washington Quality of Life questionnaire (UW-QoL). RESULT: Both FD and DB groups achieved successful mandibular reconstruction. Despite larger defects in the FD group (117 ± 31.35 mm vs 84 ± 35.34 mm, p = 0.028), the used fibula length was not statistically longer in the FD group. The median ratio of graft-to-defect length was also lower in the FD group (1.327 vs 1.629, p = 0.024), suggesting that FD required only 82.47% of the graft length needed in the DB approach. Quality of life scores post-surgery were comparable between the groups. CONCLUSION: Personalized 3D-printed osteotomy guides enhance fibula graft efficacy for reconstructing larger mandibular defects, necessitating shorter graft lengths while preserving postoperative quality of life. CLINICAL RELEVANCE: This study confirms the utility of 3D printing technology as an effective and precise tool in orthopedic surgery, particularly for complex reconstructions like large mandibular defects. It suggests a viable alternative that could potentially revolutionize current practices in bone grafting.

Evaluation of the electrocardiogram RV5 /V6 criteria in the diagnosis of left ventricular hypertrophy in marathon runners.

To assess the value of electrocardiogram (ECG) RV5/V6 criteria for diagnosing left ventricular hypertrophy (LVH) in marathons. A total of 112 marathon runners who met the requirements for "Class A1" events certified by the Chinese Athletics Association in Changzhou City were selected, and their general clinical information was collected. ECG examinations were performed using a Fukuda FX7402 Cardimax Comprehensive Electrocardiograph Automatic Analyser, whereas routine cardiac ultrasound examinations were performed using a Philips EPIQ 7C echocardiography system. Real-time 3-dimensional echocardiography (RT-3DE) was performed to acquire 3-dimensional images of the left ventricle and to calculate the left ventricular mass index (LVMI). According to the LVMI criteria of the American Society of Echocardiography for the diagnosis of LVH, the participants were divided into an LVMI normal group (n = 96) and an LVH group (n = 16). The correlation between the ECG RV5/V6 criteria and LVH in marathon runners was analysed using multiple linear regression stratified by sex and compared with the Cornell (SV3 + RaVL), modified Cornell (SD + RaVL), Sokolow-Lyon (SV1 + RV5/V6), Peguero-Lo Presti (SD + SV4), SV1, SV3, SV4, and SD criteria. In marathon runners, the ECG parameters SV3 + RaVL, SD + RaVL, SV1 + RV5/V6, SD + SV4, SV3, SD, and RV5/V6 were able to identify LVH (all p < .05). When stratified by sex, linear regression analysis revealed that a significantly higher number of ECG RV5/V6 criteria were evident in the LVH group than in the LVMI normal group (p < .05), both with no adjustment and after initial adjustment (including age and body mass index), as well as after full adjustment (including age, body mass index, interventricular septal thickness, left ventricular end-diastolic diameter, left ventricular posterior wall thickness, and history of hypertension). Additionally, curve fitting showed that the ECG RV5/V6 values increased with increasing LVMI in marathon runners, exhibiting a nearly linear positive correlation. In conclusions, the ECG RV5/V6 criteria were correlated with LVH in marathon runners.

Modified Cornell electrocardiographic criteria in the assessment of left ventricular hypertrophy geometry of patients with essential hypertension.

To evaluate the value of modified Cornell electrocardiographic criteria in the assessment of left ventricular hypertrophy (LVH) for patients with essential hypertension. A total of 381 patients with essential hypertension diagnosed in our hospital were selected. Using the left ventricle (LV) geometric patterns classified by the American Society of Echocardiography (ASE), we examined the distribution of the modified Cornell criteria of Ravl + SD (the deepest S wave in 12-lead ECG) in different geometric patterns and analyzed the correlation of modified Cornell criteria with changes in the LV geometric patterns using multiple linear regression analysis. The distribution of modified Cornell criteria, Sokolow-Lyon criteria (RV5/V6 + SV1), and Cornell criteria (Ravl + SV3) in gender-specific hypertensive geometric patterns were significantly different (P ≤ .01 for all). The voltage of Ravl + SD in male patients showed an increase trend in the normal geometry (NG), concentric remodeling (CR), concentric hypertrophy (CH), and eccentric hypertrophy (EH) groups, and this increase trend was significantly in the unadjusted model and the adjusted model. The voltages of Ravl + SV3 and RV5/V6 + SV1 of male patients in CR, CH and RH groups showed a gradual increase trend, but the increase trend in CR group has no statistical significance compared to that in NG group (P ≥ .05). The voltages of Ravl + SD , RV5/V6 + SV1, and Ravl + SV3 in female patients in CR, CH and EH groups showed a trend of increase after decrease in the adjusted model. In conclusion, the modified Cornell criteria could dynamically reflect left ventricular hypertensive geometry of male patients.