BACKGROUND: Studies on the biomechanical properties in NUSS procedure have obtained some achievements, but the effect of scoliosis surgical correction of scoliosis on thoracic deformity remains unclear.OBJECTIVE: To explore the effect of simultaneous correction of pectus excavatum and scoliosis on thoracic deformity so as to provide reference for designing a rational orthopedic scheme.METHODS: The three-dimensional reconstruction model of the chest was established based on the CT data of the patients with pectus excavatum and scoliosis. The surgical correction of pectus excavatum and scoliosis was simulated by numerical simulation method.RESULTS AND CONCLUSION: (1) Results after correction showed that the bilateral spinous processes at T3-5 segments displaced to the left (X direction) about 1 mm, suggesting that the simultaneous correction is favorable for the correction of scoliosis. (2) Compared with the single NUSS procedure, the displacement at Y direction was increased by 13.358 mm in the simultaneous correction; meanwhile, there was significant difference in the shortest displacement between two methods.(3) In views of Von Mises stress distribution, the stress in the simultaneous correction was decreased by 24.6 MPa compared with the single Nuss procedure, indicating that the simultaneous correction can significantly reduce the Von Mises stress on the chest, which contributes to alleviate the postoperative pain. (4) Our results show that the simultaneous correction cannot only improve scoliosis, but also improve the symptoms of pectus excavatum.

Background:In patients with diffuse large B?cell lymphoma (DLBCL), central nervous system (CNS) relapse is uncom?mon but is nearly always fatal. This study aimed to determine the risk factors for CNS relapse in DLBCL patients and to evaluate the effcacy of rituximab and intrathecal chemotherapy prophylaxis for CNS relapse reduction. Methods:A total of 511 patients with newly diagnosed DLBCL treated at the Sun Yat?sen University Cancer Center between January 2003 and December 2012 were included in the study. Among these patients, 376 received R?CHOP regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) as primary treatment, and 135 received CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone) as primary treatment. Intrathe?cal chemotherapy prophylaxis (methotrexate plus cytarabine) was administered to those who were deemed at high risk for CNS relapse. In the entire cohort and in the R?CHOP set in particular, the Kaplan–Meier method coupled with the log?rank test was used for univariate analysis, and the Cox proportional hazards model was used for multivariate analysis. Differences were evaluated using a two?tailed test, andP<0.05 was considered signiifcant. Results:At a median follow?up of 46months, 25 (4.9%) patients experienced CNS relapse. There was a trend of reduced occurrence of CNS relapse in patients treated with rituximab; the 3?year cumulative CNS relapse rates were 7.1% in CHOP group and 2.7% in R?CHOP group (P=0.045). Intrathecal chemotherapy prophylaxis did not confer much beneift in terms of preventing CNS relapse. Bone involvement [hazard ratio (HR)=4.21, 95% conifdence interval (CI) 1.38–12.77], renal involvement (HR=3.85, 95% CI 1.05–14.19), alkaline phosphatase (ALP) >110U/L (HR=3.59, 95% CI 1.25–10.34), serum albumin (ALB) <35g/L (HR=3.63, 95% CI 1.25–10.51), treatment with rituxi?mab (HR=0.34, 95% CI 0.12–0.96), and a time to complete remission≤ 108days (HR=0.22, 95% CI 0.06–0.78) were independent predictive factors for CNS relapse in the entire cohort. Bone involvement (HR=4.44, 95% CI 1.08–18.35), bone marrow involvement (HR=11.70, 95% CI 2.24–60.99), and renal involvement (HR=10.83, 95% CI 2.27–51.65) were independent risk factors for CNS relapse in the R?CHOP set. Conclusions:In the present study, rituximab decreased the CNS relapse rate of DLBCL, whereas intrathecal chemo?therapy prophylaxis alone was not suffcient for preventing CNS relapse. Serum levels of ALB and ALP, and the time to complete remission were new independent predictive factors for CNS relapse in the patients with DLBCL. In the patients received R?CHOP regimen, a trend of increased CNS relapse was found to be associated with extranodal lesions.