RESUMO
The Allan variance (AVAR) is widely used to measure the stability of experimental time series. Specifically, AVAR is commonly used in space applications such as monitoring the clocks of the global navigation satellite systems (GNSSs). In these applications, the experimental data present some peculiar aspects which are not generally encountered when the measurements are carried out in a laboratory. Space clocks' data can in fact present outliers, jumps, and missing values, which corrupt the clock characterization. Therefore, an efficient preprocessing is fundamental to ensure a proper data analysis and improve the stability estimation performed with the AVAR or other similar variances. In this work, we propose a preprocessing algorithm and its implementation in a robust software code (in MATLAB language) able to deal with time series of experimental data affected by nonstationarities and missing data; our method is properly detecting and removing anomalous behaviors, hence making the subsequent stability analysis more reliable.
RESUMO
BACKGROUND: The purpose of this retrospective case control study was to assess the outcome of K-wire osteosynthesis of a varus displaced proximal humeral fracture in patients over 65 years old, compared to a control group treated nonoperatively. METHODS: The patient cohort was taken from our database in the period 2003-2007. After data extraction, the patients were re-examined and scored by the Constant score (CS), modified Constant score (MCS), and the QuickDASH score. The control group was carefully selected and matched to the surgical one for age, type of fracture, and degree of displacement. Minimum follow-up was 12 months, with a mean of 30 months in the surgery group, and 27 months in the nonoperative group. RESULTS: K-wire osteosynthesis in our series yielded consistently good results in older patients who sustained an A2.2 proximal humeral fracture, with an average MCS of 88 points and a QuickDASH score of 15. The surgery group had a statistically significant higher CS and modified Constant score at follow-up than did the conservatively treated group (p = .03). CONCLUSION: Operative treatment of varus displaced proximal humerus fractures treated with K-wire osteosynthesis yields good results that are superior to those treated nonoperatively. LEVEL OF EVIDENCE: Level 3; Case control study, treatment study.
