Morphological changes in flatfoot: a 3D analysis using weight-bearing CT scans.

BACKGROUND: Flatfoot is a condition resulting from complex three-dimensional (3D) morphological changes. Most Previous studies have been constrained by using two-dimensional radiographs and non-weight-bearing conditions. The deformity in flatfoot is associated with the 3D morphology of the bone. These morphological changes affect the force line conduction of the hindfoot/midfoot/forefoot, leading to further morphological alterations. Given that a two-dimensional plane axis overlooks the 3D structural information, it is essential to measure the 3D model of the entire foot in conjunction with the definition under the standing position. This study aims to analyze the morphological changes in flatfoot using 3D measurements from weight-bearing CT (WBCT). METHOD: In this retrospective comparative our CT database was searched between 4-2021 and 3-2022. Following inclusion criteria were used: Patients were required to exhibit clinical symptoms suggestive of flatfoot, including painful swelling of the medial plantar area or abnormal gait, corroborated by clinical examination and confirmatory radiological findings on CT or MRI. Healthy participants were required to be free of any foot diseases or conditions affecting lower limb movement. After applying the exclusion criteria (Flatfoot with other foot diseases), CT scans (mean age = 20.9375, SD = 16.1) confirmed eligible for further analysis. The distance, angle in sagittal/transverse/coronal planes, and volume of the two groups were compared on reconstructed 3D models using the t-test. Logistic regression was used to identify flatfoot risk factors, which were then analyzed using receiver operating characteristic curves and nomogram. RESULT: The flatfoot group exhibited significantly lower values for calcaneofibular distance (p = 0.001), sagittal and transverse calcaneal inclination angle (p < 0.001), medial column height (p < 0.001), sagittal talonavicular coverage angle (p < 0.001), and sagittal (p < 0.001) and transverse (p = 0.015) Hibb angle. In contrast, the sagittal lateral talocalcaneal angle (p = 0.013), sagittal (p < 0.001) and transverse (p = 0.004) talocalcaneal angle, transverse talonavicular coverage angle (p < 0.001), coronal Hibb angle (p < 0.001), and sagittal (p < 0.001) and transverse (p = 0.001) Meary's angle were significantly higher in the flatfoot group. The sagittal Hibb angle (B = - 0.379, OR = 0.684) and medial column height (B = - 0.990, OR = 0.372) were identified as significant risk factors for acquiring a flatfoot. CONCLUSION: The findings validate the 3D spatial position alterations in flatfoot. These include the abduction of the forefoot and prolapse of the first metatarsal proximal, the arch collapsed, subluxation of the talonavicular joint in the midfoot, adduction and valgus of the calcaneus, adduction and plantar ward movement of the talus in the hindfoot, along with the first metatarsal's abduction and dorsiflexion in the forefoot.

High expression of TAZ/YAP promotes the progression of malignant melanoma and affects the postoperative survival of patients.

Background: YAP/TAZ have been reported to be highly expressed in malignant tumors. This research was aimed to study the expression of TAZ/YAP protein in malignant melanoma and to investigate its relationship to the clinicopathology and prognosis of patients with malignant melanoma. Methods: A total of 156 pairs of malignant melanoma tumor tissues and melanocytic nevi tissues were collected. The expression of TAZ and YAP proteins were detected by immunohistochemistry and western blotting. Relationship between TAZ/YAP and clinical data of malignant melanoma were analyzed. Results: The number of positive cells of TAZ and YAP in malignant melanoma tumor tissues was significantly higher than that in melanocytic nevi tissues, and the expression of both proteins was positively correlated with malignant melanoma (r = 0.687, P <0.01); TAZ and YAP protein expression in malignant melanoma tissue was significantly correlated with tumor thickness, invasive depth grade, lymph node metastasis and TNM stages (P <0.05), and increased with TNM staging. The expression of TAZ and YAP in patients with lymph node metastasis was significantly higher than that in non-metastatic patients (P <0.05). High expression of TAZ/YAP significantly reduced the postoperative survival rate in patients with malignant melanoma. Conclusion: TAZ/YAP is highly expressed in malignant melanoma tumor tissues. The high expression of TAZ/YAP promotes the progression of malignant melanoma and affects the postoperative survival of patients.