With the increasing number of patients receiving fracture internal fixation,the number of patients with infection after fracture internal fixation (IAFIF) has gradually increased.IAFIF has severe consequences for the patients,not only increasing the financial burden,but also causing pain to the patient and family members.The diagnosis and treatment of IAFIF are relatively difficult,and there are few systematic etiological studies,so IAFIF has drawn much attetion from orthopedic surgeons.The authors summarize the clinical manifestations,etiological characteristics,research progress of IAFIF diagnosis and treatment,to provide reference for clinical practices.

Objective To investigate the efficacy of anti-infective reconstituted bone xenograft (ARBX) combined with external fixation in the treatment of adult infective nonunion of humeral shaft.Methods A retrospective case series study was conducted to analyze the clinical data of 18 patients with infected nonunion of humeral shaft admitted to Xijing Hospital of Air Force Military Medical University from January 2014 to December 2016.There were 10 males and eight females,aged 19-62 years [(36.9 ± 11.8)years].According to Umiarov classification of infective nonunion,there were 11 patients with type Ⅲ and seven with type Ⅳ.All patients were treated with anti-infective reconstituted bone xenograft (ARBX) combined with external fixation.The number of operations,bone healing time,bone healing rate,infection control rate,postoperative weight bearing time,the time of external fixation removal,postoperative complications,erythrocyte sedimentation rate (ESR),and C-reactive protein (CRP) before and after operation were recorded.Fracture healing and functional recovery were evaluated using the Johner-Wruch lower limb function score.Results The patients were followed up for 12-30 months [(21.3 ±5.6)months].The operation was performed for (1.4 ±0.9) times,with time of bone healing for (16.6 ± 5.8)months,bone healing rate of 83％ (15/18),and infection control rate of 94％ (17/18).The postoperative weight bearing time in 15 patients who obtained bone healing was (3.3 ± 1.5)months after operation,and the external fixation removal time was (18.5 ± 4.2) months after operation.There were three patients with nonunion after operation including one with infection recurrence.Five patients were found with nail tract infection.ESR and CRP at postoperative 3 months [(13.1 ± 8.4)mm/h and (5.6 ± 4.6)mg/L] were significantly lower than those before operation [(47.3 ± 19.2)mm/h and (23.4 ± 7.4) mg/L] (P ＜ 0.05).According to Johner-Wruch lower limb function scores,the results were excellent in nine patients,good in four,fair in one,and poor in four,with excellent and good rate of 72％.Conclusion ARBX combined with External fixation can effectively treat infective nonunion of humeral shaft,improve bone healing rate,and promote function recovery.

Objective To compare the effectiveness of expandable intramedullary nail(EIMN) versus locked compression plate (LCP) in the treatment of humeral shaft fractures of AO types A and B.Methods The clinical data were retrospectively analyzed and compared of the 44 humeral shaft fractures which had been treated between May 2012 and February 2016.There were 26 men and 18 women,from 23 to 66 years of age (average,41.5 years).By AO classification,22 cases were type 12-A and 22 type 12-B.EINM was used in 22 patients with an average age of 41.3 ± 1 1.7 years and LCP in 22 ones with an average age of 41.6 ± 10.3 years.The 2 groups were compared in terms of intraoperative blood loss,operative time,hospital stay,union time,union rate,Constant and Mayo scores at the final follow-ups,and complications as well.Results The 2 groups were compatible without significant differences in the preoperative demographic data (P ＞ 0.05).All the 44 patients were followed up for 10 to 18 months (average,12 months).The intraoperative blood loss (76.4 ± 18.66 mL),operative time (69.1 ± 13.2 min),incision length (5.8 ± 1.5 cm) and union time (13.2 ± 8.4 w) in the EIMN group were significantly better than those in the LCP group (138.6 ± 39.4 mL,96.4 ± 14.2 min,8.5 ± 1.4 cm and 18.4 ± 6.6 w,respectively) (P ＜ 0.05).There was also a significant difference between the 2 groups in the total complication rate[18.2％ (4/22) versus 50.0％ (11/22)] (P ＜0.05).No deep infection or should pain was observed in either group.Conclusions Inthe treatment of humeral shaft fractures of AO types 42-A and 42-B,compared with LCP,EIMN may have advantages of less intraoperative blood loss,operative time,union time and complications.The 2 methods are similar in hospital stay and final functional recovery of the should joint.

Objective To investigate the clinical effect of Gamma 3 intramedullary nails for the treatment of unstable intertrochanteric fractures in the elderly. Methods A total of 36 elderly patients (aged over 70 years)with unstable intertrochanteric fractures (Evans type Ⅲ or above)treated with Gamma 3 intramedullary nails from January 2013 to December 2016 were followed up and analyzed. Results All patients were followed up for 6 to 12 months ,with an average of (9.4 ± 2.6) months. The fractures were healed in all patients ,and the healing time was between 10 and 18 weeks , with an average of 14 weeks. A mild type of coxa varus was found in 2 cases. According to the Harris hip score ,the curative effect was excellent in 24 cases ,good in 7 cases ,fair in 3 cases and poor in 2 cases. The excellent and good rate was 86.1% . Conclusions The gamma 3 intramedullary nail is an outstanding internal fixation tool for the treatment of unstable intertrochanteric fractures in the elderly ,with such advantages as minimal trauma ,short operation time ,firm fixation and few postoperative complications.

Objective To compare the function recovery of multiple injuries combined with floating knee joint injury and simple knee joint injury,and to analyze the risk factors.Methods A retrospective case control study was conducted to analyze the clinical data of 41 patients with multiple injuries combined with Blake and McBryde Ⅱ A floating knee injury admitted to Xijing Hospital of Air Force Medical University from June 2011 to June 2017.There were 26 males and 15 females,aged 18-76 years,with an average of 34.5 years.There were 25 patients with simple knee joint injury and and 16 patients with multi-joint combined injury involving knee joint and ipsilateral hip joint or ankle joint injury.Surgical fixation was performed in different parts by external fixation,intramedullary nail and plate screw fixation.According to the Kalstr(o)m and Olerud functional evaluation criteria,the excellent and good rate of postoperative functional recovery was compared between the two groups.The surgical fixation methods of the two groups were compared.Logistic regression analysis was performed on the influencing factors of functional recovery.Results The patients were followed up for 1-7 years,with an average of 3 years.The excellent and good rate of overall functional recovery in the two groups was 68％,and the rate was 84％ in simple knee injury group and 44％ in multi-joint combined injury group (P ＜ 0.01).There was no significant difference in the ratio of intramedullary nail and plate screw fixation between the two groups (P ＞ 0.05),while the proportion of the external fixation in the multi-joint combined injury group [31％ (5/16)] was significantly higher than that in the simple knee joint injury group [16％ (4/25)] (P ＜ 0.05).Logistic regression analysis showed that the rate of external fixation was an independent factor affecting the postoperative function (OR =0.15,P ＜ 0.01).Conclusions The postoperative function in multi-joint injury patients is poorer than in the single joint injury patients.The higher rate of using external fixation in multi-joint injury patients is a risk factor.For Blake and McBryde Ⅱ A floating knee injury combined with multi-joint injury,less external fixation should be used,so as to improve the postoperative function.

Objective To observe the incidence,clinical characteristics,related factors,adverse events during hospitalization and short-term prognosis of postprandial hypotension (PPH) in elderly patients with coronary heart disease.Methods One hundred and sixty-eight elderly patients with coronary heart disease hospitalized in the Department of Cardiology,Second Hospital of Hebei Medical University from January 2014 to January 2015 were selected as the research subjects.They were monitored by 24 h ambulatory blood pressure monitoring.According to the diagnostic criteria of PPH,they were divided into postprandial hypotension group (PPH group) 34 cases and non-postprandial hypotension group (NPPH group) 134 cases.The clinical characteristics,risk factors related to PPH,occurrence of adverse events and prognosis of all-cause death,cardiovascular and cerebrovascular adverse events were compared between the two groups.Results Among 168 elderly patients with coronary heart disease,thirty-four patients had PPH,and the incidence rate was 20.2％ (34/168).The average systolic blood pressure before meals in PPH group was (139.8± 18.6) mmHg (1 mmHg =0.133 kPa).The proportion of taking calcium antagonists was 50.0％ (17/34) higher than that in NPPH group (127.4± 13.2) mmHg,27.6％ (37/134).The difference between the two groups was statistically significant (t =6.463,x2=6.232,P＜ 0.05).PPH was higher in breakfast and dinner than in lunch;the higher the basal systolic blood pressure level,the higher the incidence of PPH.Logistic regression analysis showed that the basal systolic blood pressure level and age were positively correlated with the occurrence of PPH (r =0.301,r =0.208,P＜ 0.05).Follow-up for 26 months showed that the incidence of all-cause death and cerebrovascular events in PPH group was higher than that in NPPH group (x2 =5.800,11.560,P＜ 0.05).Conclusion The incidence of PPH in elderly patients with coronary heart disease during hospitalization is 20.2％.Breakfast and dinner at three meals are prone to PPH.Older age and high systolic blood pressure level will increase the incidence of PPH.PPH will increase the incidence of mid-term all-cause death and cerebrovascular events.

In causal inference, the concept of temporality (or directionality) has not been fully clarified. Starting from causal thinking, this paper divides the time axis in nature into three time domains and two time points by the occurrence timings of both a real cause and a real effect. This has anchored that causal inference can only be realized in the third domain. The measured temporalities can be divided into five types: cross-first-to-third-domain longitudinal (or experimental temporalities), cross-second-to-third-domain longitudinal, within-domain longitudinal, within-domain reversely longitudinal, and within-domain transversal (or observational temporalities). This new classification encompasses all measurement strategies, either for first or multiple measurements, or timely and delayed measurements. Except that the actual measurement for the cause occurs either before its occurrence (only in experiment) or within the second domain, all other measurements are similar to the act of historical reconstruction or "archaeology" , where the importance of measured temporalities may be inferior to the accuracy of the measurements. From the point of view that research design should integrate bias design, this new classification for measured temporalities based on the time axis in Nature, which has a clear meaning and helps to judge the possible biases in the observation methods, provides a basis for correct causal inferences.