BACKGROUND:Integrated Traditional Chinese and Western Medicine minimaly invasive treatment for halux valgus based on wrapped curtain method with “8”-shaped bandage and sub toe pad external fixation has been used for a long time in the clinic. This method abandons the internal implant fixationandexternal plaster fixation. After surgery, patients could take care of themselves. However, theactivity of the broken end may cause fracture nonunion, which once aroused scholars’ question. Recently, with the continuous improvement of foot biomechanics research, foot finite element model and applications become a reality.
OBJECTIVE:To evaluate thestability of osteotomy after the operation of wrapped curtain method with“8”-shaped bandage and sub toe pad external fixation on the basis of static finite element method.
METHODS:A young female volunteer with halux valgus was selected, whose body weight was 58 kg, and right foot halux abductor valgus angle was 24°; intermetatarsal angle was 13°; proximal articulator set angle was 7°; distal articulator set angle was 7°. CT was used to scan the right foot. ABAQUS software was applied to establish a finite element model of right foot halux valgus bone, and model of the first metatarsal neck minimaly invasive osteotomy was simulated based on wrapped curtain method with external fixation. Von Mises stress and displacement at the osteotomy endwere calculated.
RESULTS AND CONCLUSION:(1) The maximum stress was 0.067 MPa without external fixation, and the maximum stress was 1.258 MPa with the external fixation. Stress was mainly distributed in the outer edge of the osteotomy. (2) The maximum absolute displacement was 0.363 mm without external fixation, and the maximum absolute displacement was 0.716 mm with external fixation. The two largest displacements were both in the Z-axis direction. Statistical analysis confirmed that the four nodes absolute displacement and stress were significantly different (P< 0.01). (3) The maximum relative displacement was 0.101 mm. The maximum relative displacement was 0.046 mm with external fixation. The maximum relative displacement without external fixation was-0.102 mm and occurred in the Z-axis. The maximum relative displacement with external fixation was 0.110 mm and occurred in the Y-axis. (4) One-way analysis of variance confirmed that the four nodes relative displacements were not statisticaly significant in X-axisand Y-axis (P> 0.05). The four nodes relative displacements were statisticaly significant in Z-axis (P< 0.05). (5) These findings suggest that the external fixation based on wrapped curtain method after halux valgus surgery could effectively reduce osteotomy displacement. The moderate stress and elastic fixation are conducive to fracture healing.

Patients with cancer are at increased risk of severe infections. From a cohort including 3060 patients with confirmed COVID-19, 109 (3.4%) cancer patients were included in this study. Among them, 23 (21.1%) patients died in the hospital. Cancer patients, especially those with hematological malignancies (41.6%), urinary carcinoma (35.7%), malignancies of the digestive system (33.3%), gynecological malignancies (20%), and lung cancer (14.3%), had a much higher mortality than patients without cancer. A total of 19 (17.4%) cancer patients were infected in the hospital. The clinical characteristics of deceased cancer patients were compared with those of recovered cancer patients. Multivariate Cox regression analysis indicated that a Nutritional Risk Screening (NRS2002) score ⩾ 3 (adjusted hazard ratio (HR) 11.00; 95% confidence interval (CI) 4.60-26.32; P < 0.001), high-risk type (adjusted HR 18.81; 95% CI 4.21-83.93; P < 0.001), tumor stage IV (adjusted HR 4.26; 95% CI 2.34-7.75; P < 0.001), and recent adjuvant therapy (< 1 month) (adjusted HR 3.16; 95% CI 1.75-5.70; P < 0.01) were independent risk factors for in-hospital death after adjusting for age, comorbidities, D-dimer, and lymphocyte count. In conclusion, cancer patients showed a higher risk of COVID-19 infection with a poorer prognosis than patients without cancer. Cancer patients with high-risk tumor, NRS2002 score ⩾ 3, advanced tumor stage, and recent adjuvant therapy (< 1 month) may have high risk of mortality.
COVID-19 ; Hospital Mortality ; Humans ; Neoplasms ; Prognosis ; Retrospective Studies ; Risk Factors ; SARS-CoV-2