Predictive value of bone mineral density for postoperative efficacy and factors influencing treatment outcomes in patients undergoing total hip arthroplasty: a retrospective study.

OBJECTIVE: To investigate the value of bone mineral density (BMD) in predicting postoperative efficacy in patients undergoing total hip arthroplasty (THA), and to analyze the influencing factors of short-term outcomes. PATIENTS AND METHODS: Clinical data, including general data, perioperative indicators, and postoperative follow-up information, were collected from patients undergoing THA from July 2018 to June 2020 at Jiangsu Taizhou People's Hospital for retrospective analysis. Using the Harris Hip Score (HHS) at 12 months after THA as the therapeutic effect evaluation index, the BMD levels of patients with different therapeutic effects were compared, and the correlation of BMD with therapeutic efficacy was analyzed. Furthermore, the influencing factors of postoperative efficacy were discussed by using a logistic regression model. RESULTS: The HHS scores of 194 patients undergoing THA improved markedly at postoperative month 12 compared with the preoperative values (p<0.05), with a treatment excellent and good rate of 79.90% (155/194). The BMD level varied greatly among patients with different curative effects (p<0.05). Pearson correlation analysis identified a significant positive correlation between BMD values and HHS scores in patients undergoing THA. THA patients with different body mass index (BMI), surgical approach, occult blood loss, postoperative complications, length change of the affected limb, postoperative exercise time, and BMD had statistically significant differences in the excellent and good rate of clinical efficacy (p<0.05). According to the multivariate Logistic regression analysis, BMI, surgical approach, length change of the affected limb, and BMD were independent factors influencing the postoperative excellent and good rate of efficacy in THA patients (p<0.05). CONCLUSIONS: Preoperative BMD levels are strongly correlated with postoperative efficacy improvement in patients undergoing THA. BMD is an independent influencing factor of excellent and good postoperative efficacy in patients undergoing THA, and increasing the BMD is conducive to improving outcomes in such patients.

Genetic Polymorphisms and Mutations of 30 Y-STR Loci in Chinese Han Population.

OBJECTIVES: To investigate the genetic polymorphisms and mutations of 30 Y-STR loci in Chinese Han males and to evaluate its forensic application. METHODS: The DNA extracted from blood samples of 1 005 unrelated males and 1 008 father-son pairs （1 949 individuals in all） in Chinese Han population were typed using developed 30 Y-STR loci identification system. The parameters of population genetics and the mutation rates of each locus were analysed statistically. RESULTS: A total of 983 haplotypes were found in 1 005 unrelated males from Chinese Han population, of which 963 were unique. The overall haplotype diversity （HD） and discrimination capacity （DC） were 0.999 955 and 0.978 109, respectively. Totally 340 alleles were detected on 30 Y-STR loci, the value of gene diversity （GD） ranged from 0.410 3 to 0.952 3. The GD values of 24 out of the 30 loci were over 0.6. There were 30 269 allele transfers in 1 008 father-son pairs, one mutation in 68 father-son pairs, and the mutation of three father-son pairs occurred at two loci. On 26 Y-STR loci, 74 mutations were detected in 71 father-son pairs. The average mutation rates were 2.4×10⁻³ （95% CI： 1.9×10⁻³-3.1×10⁻³ï¼‰. Seventy-three mutation events were one-step mutation （98.6%）, 1 mutation event was two-step mutation （1.4%）. CONCLUSIONS: The multiplex PCR system with 30 Y-STR loci has high genetic polymorphism and low mutation rates in Chinese Han males. Therefore, the system shows important values in Y-STR database construction and population genetic research.

[Efficiency of the Modified Ottawa ankle rules for the differential diagnosis of fracture in acute foot and ankle injury].

Objective: To evaluate the efficiency of modified Ottawa Ankle Rules (OAR) for the differential diagnosis of fractures in acute foot and ankle injuries. Methods: From October 2016 to December 2016, 272cases (135 males and 137 females) of foot and ankle injury in emergency department of Tianjin Hospital were prospective enrolled in the study.The median age was 27.5 years (7-87); left limb 155, right 117 cases; injury time ranged from 0.3 to 24 h (median 4 h). Conventional and modified OAR was applied on physical examination, subsequently radiography performed to determine the occurrence of fractures.The efficiency of the two methods were compared and analyzed. Results: Fractures were found in 100 cases (36.8%), 49 cases of ankle and 51 cases of foot fractures.With the imaging results as the standard, the sensitivity for conventional and modified OAR were 93.0% and 100%, specificity were 9.9% and 8.7%, the positive predictive value were 37.5% and 38.9%, the negative predictive value were 70.8% and 100%, the accuracy were 40.4% and 42.3%, missed diagnosis rate were 7% and 0% respectively.The sensitivity, positive likelihood ratio, positive predictive value, negative predictive value, accuracy, negative likelihood ratio and missed diagnosis ratio were better than in modified OAR compared with Conventional OAR, while the specificity was slightly lower compared to Conventional OAR.The Kappa value of modified OAR was 0.065 (P>0.05), which is better than conventional OAR.Conventional OAR can reduce 6.3% (17/272) X-ray and modified OAR decline 5.5% (15/272). Conclusion: Modified OAR significantly reduces the rate of missed diagnosis of foot fractures, but its specificity is poor. Ultrasound can be assisted to improve the specificity and reduce the number of unnecessary X-rays.