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ObjectiveThis study aimed to investigate the relationship of the K-line with sagittal cervical curvature changes and surgical outcomes in patients with cervical ossification of the posterior longitudinal ligament (OPLL).MethodsWe retrospectively reviewed 84 patients with OPLL who underwent posterior cervical single-door laminoplasty. The patients were divided into a K-line-positive (+) group and a K-line-negative (−) group. Perioperative data, radiographic parameters, and clinical outcomes were compared between the two groups.ResultsOf 84 total patients, 50 patients were in the K (+) group and 29 patients were in the K (–) group. Neurological function improved in both groups after laminoplasty. The C2–7 Cobb angle, T1 slope, and C2–7 sagittal vertical axis were significantly changed in the K(−) group compared with those in the K (+) group before the operation and at the 3-month and final follow-ups.ConclusionNeurological function was recovered in both groups, and the clinical effect on the K (+) group was better than that on the K (−) group. The cervical curvature in patients with OPLL tends to be anteverted and kyphotic after laminoplasty and is an important factor in reducing the clinical effect.

Background: Most prior studieshave used conventional statistical techniquessuch asthe nomogram to examine patient prognosis and survival based on the distinct subtypes and primary locations of chondrosarcoma. Nevertheless, few studies have examined overall survival in patients with non-metastatic chondrosarcomas. We aim to develop a machine learning algorithm to evaluate 5-year survival in this cohort and transform the most accurate prediction model into an online calculator for clinical use. Methods: Between 1975 and 2018, we gathered data on patients with non-metastatic chondrosarcoma from the Surveillance, Epidemiological, and End Result databases. From these data, nine features were used to develop four machine learning models, including the boosted decision tree, support vector machine, bayes point machine, and neural network models, which were then evaluated and compared based on discrimination, calibration, and overall performance. Results: Ultimately, 1202 patients met our inclusion criteria. With a c statistic of 0.88, a calibration slope of 0.997, a calibration intercept of -0.02, and a Brier score of 0.12, the Bayes point machine performed best overall, and it was integrated into a free, publicly available software interface that can be found at https://bayesglm.shinyapps.io/non-metastatic-chondrosarcoma/. Conclusion: Although this Bayes point machine-based prediction model has not been externally validated, the online calculator can be used as a reference tool for medical staff as well as patients on survival prediction. External validation of this prediction model should be the focus of future research to improve its credibility.

Background: Chondrosarcoma is a rare type of bone tumor which more commonly found in adults range from 40 to 60 years old. Few studies has described the characteristic and prognostic factors of patients older than 60 years. This study aimed to study this feature and identify the prognostic factors based on SEER database.Methods: Thus, we collected clinicopathological data of chondrosarcoma patients in the Surveillance, Epidemiology, and End Results registry database from 1975 to 2018, and then use the Kaplan-Meier to analyze the patients’ survival. We also utilize Cox proportional hazard model to explore the prognostic factors and relevant characteristic including patients’ baseline demographics (age, race, and gender), tumor characteristics (tumor extension, histologic subtype, therapy, primary site, stage and grade.Results: After the implementation of exclusion criteria, there were 610 patients with chondrosarcoma older than 60 years. Our data showed that the incidence of chondrosarcoma is slightly higher in men than in women (52.3% vs 47.7%). In general, 90.8% of tumor had metastasized to distant sites. Meanwhile, 41.8% of tumors occurred in axial location (pelvis, spine, and ribs), 50.8% of tumors occurred in extremity (long or short bones of the upper or lower extremity), and 7.4% in other location (mandible, skull, and other atypical locations). Dedifferentiated chondrosarcoma (hazard ratio [HR] =2.553; 95% confidence interval [CI]= 1.754-3.716), grade (g2:HR:=1.299; 95% CI:=0.888-1.900, g3:HR=1.839;95% CI= 1.174-2.881, g4:HR=3.284,95%CI=2.053-5.253), distant metastasis (HR=3.264; 95% CI= (2.288-4.058), non-surgery perform (HR = 2.854; 95% CI= 2.022-4.028) were independent risk factors for 5-year overall survival.Conclusion: In conclusion, higher grade, non-surgery perform, dedifferentiated chondrosarcoma and distant metastasis indicated worse prognosis survival. Surgery can significantly improve the survival time of patients.