Arthroscopic Treatment for Femoroacetabular Impingement Syndrome in Adolescents: A Systematic Review and Meta-Analysis.

OBJECTIVE: The objective of this review was to analyze the effect of arthroscopic surgery for femoroacetabular impingement syndrome (FAI) in adolescents and factors that may influence the revision rate. DESIGN: Systematic review and meta-analysis. SETTING: PubMed, Scopus, Cochrane Library, EMBASE, and MEDLINE were searched from their earliest records to May 2021. PATIENTS: Adolescents who underwent primary arthroscopic treatment for FAI. INTERVENTIONS: Hip arthroscopic treatment. MAIN OUTCOME MEASURES: Patient-reported outcomes (PROs), alpha angle, revision rates, and the rate of complications. RESULTS: A total of 832 hips in 753 patients were included in this study. All PROs improved significantly. The modified Harris Hip Score pooled mean difference was 24.99 (95% CI, 22.88-27.10, P < 0.0001, I2 = 19.9%), Hip Outcome Score (HOS)-Sports-Specific Subscale was 35.88 (95% CI, 33.07-38.68, P < 0.0001, I2 = 0%), HOS-Activities of Daily Living was 23.53 (95% CI, 21.21-25.85, P < 0.0001, I2 = 0%), and the Nonarthritic Hip Score was 22.34 (95% CI, 18.40-26.28, P < 0.0001, I2 = 40.9%). The visual analog scale for pain decreased by 40.39 (44.39-36.40, P < 0.0001, I2 = 0%). The alpha angle decreased by 22.0 degrees from 62.9 degrees to 40.9 degrees after arthroscopic surgery. The rate of complication and revision surgery was 1.2% (10/832) and 3.4% (28/832), respectively, with high postoperative patient satisfaction. CONCLUSIONS: All PROs significantly improved after surgery, with a low rate of complications and reoperation. High postoperative patient satisfaction was also reported.

[The Optics and Magnetic Properties of Cr Doped ZnO Thin Films].

The precursor solution is sent to the ultrasonic nozzle directly through a needle tube to prepare Zn1-xCrxO (x=0, 0.01, 0.03 and 0.05)films on quartz substratesby ultrasonic spray method. The structures, optical and magnetic properties of the films were measured by X-ray diffracmeter(XRD), scanning electron microscope(SEM), fluorescence spectrometer, ultraviolet-visible light detector, vibrating sample magnetometer (VSM) and so on. The experimental results indicate that, the undopedZnO thin films exhibit the hexagonal wurtzite crystalline structure with a preferential orientation of (002); the Cr doping restrains the preferred orientation of C axis; the average grain sizes of the samples increase withCr doping, and thesize attains the maximum(31.4 nm) when x=3%. The SEMimages show that the Zn1-xCrxO (x=0, 0.01, 0.03 and 0.05) films are grain-like particles. And it exhibits a long strip shape when x=5%. Moreover, the doping of Cr makes the photoluminescence (PL) spectra of Zn1-xCrxO films change evidently. The undoped sample shows an ultraviolet emission peak at 378 nm as well as a defect related green peak at around 550 nm. However, for the doping samples, there is only a wide range of emission peak from 350 to 550 nm. By gaussian fitting，it is found that VZn, Zni and V-Zn defects exist in the Cr doping films, and VZn is largest when x=3%. The band gap increases with the doping of Cr, and reaches the maximum when x=3%. The doping of Cr hasthe band gap of the samples increase, and the band gapreachs themaximum(3.37 eV) when x=3%. Magnetic measured results show that threedoping samples Zn1-xCrxO(x=1%, 3% and 5%) are ferromagnetic at room temperature, and the magnetization of Zn1-xCrxO (x=3%) is the largest, which is corresponding to the most VZn defect. The experimental results also prove the the oretical prediction that the substitutive Cr in the oxidation state of +3 and the neutral Zn vacancy in the ZnO∶Cr sample are the most favorable defect complex to maintain a high stability of ferromagnetic order.