[Clinical efficacy of femoral neck screw system combined with supported hollow screw in treatment of femoral neck fractures with posterometral comminution in young and middle-aged patients].

Objective: To investigate the clinical efficacy of dynamic cross screw system (FNS) for femoral neck fractures in young and middle-aged patients with posterior medial comminution. Methods: A retrospective cohort study. Clinical data of 197 young and middle-aged patients with femoral neck fractures accompanied by posterior medial comminution treated with closed reduction FNS and internal fixation with anti-rotation cannulated screws in Beijing Luhe Hospital, Beijing Jishuitan Hospital and Beijing Tongren Hospital from October 2019 to October 2021 were analyzed retrospectively. According to different surgical methods, the patients were divided into two groups. There were 102 patients in the FNS group, included 55 males and 47 females with a mean age of (40.49±19.79) years; and there were 95 patients in the FNS plus anti-rotation hollow screw group (combined group), included 51 males and 44 females with an average age of (40.03±18.82) years. All patients were followed-up for at least 1 year after surgery. The general clinical data, surgical conditions and Harris score of the hip joint at the last follow-up of the two groups were compared. And the clinical efficacy of the two surgical schemes were evaluated and compared. After surgery, routine X-ray and CT examinations were performed to evaluate the fracture reduction and internal fixation, and the shortening of the femoral neck on the affected side was compared to that of healthy side according to the Zlowodzki method. Results: At the last follow-up, the incidence of fracture reduction loss, screw resection and coxa vara in the combined group were all significantly lower than those in the FNS group [10 (10.5%) vs 28 (27.4%), 1 (1.0%) vs 7 (6.8%) and 9 (9.4%) vs 21 (20.5%), respectively, all P<0.05]. The incidence of nonunion and necrosis of the femoral head in the combined group were both lower than those in the FNS group, but there was no significant difference between two groups (both P>0.05). The postoperative mild, moderate and severe femoral neck shortening in the combined group were all lower than those in the FNS group, and the difference were not statistically significant (all P>0.05). At the last follow-up, the Harris score in the combined group was 84.60±2.08, and it was higher than that in the FNS group (79.57±4.31), but the difference was not statistically significant (P=0.403). Conclusion: FNS plus supporting hollow screw has a good clinical effect on femoral neck fractures in young and middle-aged adults with posterior medial comminution.

The impact of COVID-19 on subthreshold depressive symptoms: a longitudinal study.

AIMS: The coronavirus disease 2019 (COVID-19) pandemic represents an unprecedented threat to mental health. Herein, we assessed the impact of COVID-19 on subthreshold depressive symptoms and identified potential mitigating factors. METHODS: Participants were from Depression Cohort in China (ChiCTR registry number 1900022145). Adults (n = 1722) with subthreshold depressive symptoms were enrolled between March and October 2019 in a 6-month, community-based interventional study that aimed to prevent clinical depression using psychoeducation. A total of 1506 participants completed the study in Shenzhen, China: 726 participants, who completed the study between March 2019 and January 2020 (i.e. before COVID-19), comprised the 'wave 1' group; 780 participants, who were enrolled before COVID-19 and completed the 6-month endpoint assessment during COVID-19, comprised 'wave 2'. Symptoms of depression, anxiety and insomnia were assessed at baseline and endpoint (i.e. 6-month follow-up) using the Patient Health Questionnaire-9 (PHQ-9), Generalised Anxiety Disorder-7 (GAD-7) and Insomnia Severity Index (ISI), respectively. Measures of resilience and regular exercise were assessed at baseline. We compared the mental health outcomes between wave 1 and wave 2 groups. We additionally investigated how mental health outcomes changed across disparate stages of the COVID-19 pandemic in China, i.e. peak (7-13 February), post-peak (14-27 February), remission plateau (28 February-present). RESULTS: COVID-19 increased the risk for three mental outcomes: (1) depression (odds ratio [OR] = 1.30, 95% confidence interval [CI]: 1.04-1.62); (2) anxiety (OR = 1.47, 95% CI: 1.16-1.88) and (3) insomnia (OR = 1.37, 95% CI: 1.07-1.77). The highest proportion of probable depression and anxiety was observed post-peak, with 52.9% and 41.4%, respectively. Greater baseline resilience scores had a protective effect on the three main outcomes (depression: OR = 0.26, 95% CI: 0.19-0.37; anxiety: OR = 1.22, 95% CI: 0.14-0.33 and insomnia: OR = 0.18, 95% CI: 0.11-0.28). Furthermore, regular physical activity mitigated the risk for depression (OR = 0.79, 95% CI: 0.79-0.99). CONCLUSIONS: The COVID-19 pandemic exerted a highly significant and negative impact on symptoms of depression, anxiety and insomnia. Mental health outcomes fluctuated as a function of the duration of the pandemic and were alleviated to some extent with the observed decline in community-based transmission. Augmenting resiliency and regular exercise provide an opportunity to mitigate the risk for mental health symptoms during this severe public health crisis.

[Genes associated with Wolbachia-induced cytoplasmic incompatibility in natural populations of Culex pipiens pallens: a preliminary study].

OBJECTIVE: To investigate the genes involved in Wolbachia-induced cytoplasmic incompatibility among three natural populations of Culex pipiens pallens in eastern China, so as to provide insights into the development of preventive and control measures for mosquito-borne diseases based on Wolbachia. METHODS: The cytoplasmic incompatibility was tested among three natural populations of C. pipiens pallens collected from Nanjing and Wuxi of Jiangsu Province and Tangkou of Shandong Province using reciprocal crosses. Wolbachia infection was detected in C. pipiens pallens using a PCR assay, and the expression of Wolbachia wsp and WD0513 genes was quantified using a fluorescent quantitative real-time PCR (qPCR) assay. RESULTS: Bidirectional compatibility was found between the natural populations of C. pipiens pallens collected from Nanjing and Wuxi of Jiangsu Province (t = 0.57 and 0.15, both P values > 0.05), while bidirectional incompatibility was seen between the natural populations of C. pipiens pallens collected from Tangkou of Shandong Province and Wuxi of Jiangsu Province (t = 63.81 and 43.51, both P values < 0.01), and between the natural populations of C. pipiens pallens collected from Nanjing of Jiangsu Province and Tangkou of Shandong Province (t = 39.62 and 43.12, both P values < 0.01). Wolbachia wsp gene was amplified in all three natural populations of C. pipiens pallens, and qPCR assay detected no significant difference in the Wolbachia wsp gene expression among the three natural populations of C. pipiens pallens (F = 2.15, P > 0.05). In addition, there was no significant difference in the WD0513 gene expression between the natural populations of C. pipiens pallens collected from Tangkou of Shandong Province and Nanjing of Jiangsu Province (q = 8.42, P < 0.05) or between the natural populations of C. pipiens pallens collected from Tangkou of Shandong Province and Wuxi of Jiangsu Province (q = 7.84, P < 0.05); however, there was a significant difference detected in the WD0513 gene expression between the natural populations of C. pipiens pallens collected from Nanjing and Wuxi of Jiangsu Province (q = 0.40, P > 0.05). CONCLUSIONS: Different Wolbachia numbers are detected in natural populations of C. pipiens pallens collected from Nanjing and Wuxi of Jiangsu Province and Tangkou of Shandong Province, and WD0513 gene may be involved in the Wolbachia-induced cytoplasmic incompatibility among three natural populations of C. pipiens pallens.

[Incidence and risk factors of ulnar nerve dysfunction after open reduction and internal fixation of humeral intercondylar fractures].

Objective: To investigate the incidence and related risk factors of ulnar nerve dysfunction after open reduction and internal fixation of humeral intercondylar fractures. Methods: A total of 168 patients who underwent open reduction and plate and screw fixation of a humeral intercondylar fracture between January 2013 and May 2017 were retrospectively analyzed. There were 85 males and 83 females, aged from 14 to 77 years with a mean age of (43±17) years. Diagnosis of ulnar neuropathy was defined as documentation of sensory and motor dysfunction of the ulnar nerve in the medical record. The explanatory (independent) variables included age, gender, injury type, AO typing, time from injury to surgery, surgery approach, plates fixation methods and whether the nerve was transposed. Univariate and multivariate analyses were performed to determine risk factors associated with postoperative ulnar nerve dysfunction. Results: Acute injury-related ulnar nerve neuropathy was diagnosed in 12(7.1%) of 168 patients. Among the other 156 patients without preoperative ulnar nerve neuropathy,the total postoperative ulnar neuropathy was found in 52 patients (33.3%), and in 26(16.7%) at the final follow-up, according to the McGowan grades system; 23(88.5%) of 26 patients were clinically graded as grade 1, and 3(11.5%) were graded as grade 2. Multivariate logistic analysis showed that triceps sparing approach (OR=2.639, P=0.039) and parallel double plate fixation (OR=3.089, P=0.046) were associated with a risk of postoperative ulnar nerve dysfunction. Conclusion: There is a substantial incidence of postoperative ulnar nerve dysfunction after open reduction and plate and screw fixation of humeral intercondylar fracture, postoperative ulnar neuropathy may occur from the time of injury through the long-term follow-up period, triceps sparing approach and parallel double plate fixation are the risk factors for ulnar neuropathy.

[Study on insecticide resistance of Culex pipiens pallens in southwest region of Shandong Province].

OBJECTIVE: To explore the sensitivity of Culex pipiens pallens to common chemical insecticides in the southwestern region of Shandong Province, so as to provide a theoretical basis for the development of reasonable and effective mosquito control measures. METHODS: The resistance of Cx. pipiens pallens larvae to 5 chemical insecticides, such as cypermethrin, deltamethrin, DDVP, propoxur, and acetofenate were tested by using the WHO biological test method in 2018, and the co-toxicity coefficients after compounding the above-mentioned insecticides were tested by using a drug compounding method. RESULTS: The resistance indexes of Cx. pipiens pallens to cypermethrin, deltamethrin, DDVP, propoxur, and acetofenate in 3 cities were 144.43-557.54, 118.17-445.33, 6.44-19.00, 2.37-8.10, and 0.88-2.98, respectively, and expect the difference between the DDVP resistances of Cx. pipiens pallens in Jining City and Heze City was not statistically significant (P > 0.05), all the other differences were statistically significant (all P < 0.05). The synergistic coefficients of cypermethrin + DDVP, cypermethrin + propoxur, DDVP + acetofenate, and propoxur + acetofenate were 199.58 - 456.95, 190.56 - 292.37, 123.32 - 319.24, and 192.31 - 367.32, respectively. The lower synergism was observed by using the mixture of DDVP + propoxur (synergistic coefficient: 99.87-108.36) . CONCLUSIONS: After decades of chemical control, Cx. pipiens pallens in the southwestern region of Shandong Province has produced different degrees of resistance to common chemical insecticides. Therefore, comprehensive control measures should be taken to control mosquito breeding and prevent the development of insecticide resistance.

[Analysis of anterolateral approach and lateral approach for the treatment of coronal shear fracture of the distal humeral].

OBJECTIVE: To treat the coronal shear fracture of the distal humeral during open reduction and internal fixation by anterolateral approach and lateral approach, and to analyze the advantage and disadvantage of each approach. METHODS: From September 2006 to July 2014, 10 patients with coronal fracture of the distal humeral were analyzed, who were all treated with Open Reduction and Internal Fixation (ORIF), 5 with anterolateral approach (group A) and 5 with lateral approach (group B). For the anterior-lateral approach, the radial nerve and brachioradialis were retracted laterally and the brachialis was retracted medially, the capsule was incised and the fracture line was exposed, usually the capitellum and the lateral part of the trochlear could be exposed clearly but the exposure was limited. For the lateral approach, the brachioradialis was retracted anteriorly, the lateral collateral ligament (LCL) was protected or released from the starting point on the lateral condyle of the humeral, the elbow could be dislocated and the capitellum and part of the trochlear could be exposed. The fractures were classified with the system of Dubberley, the complications were analyzed and the ultimate results were evaluated according to the Mayo elbow performance index (MEPI). RESULTS: For group A, 4 re-operations were performed, 2 for the irritation of the screws,1 for stiff elbow and 1 for failure of the internal fixation. One radial nerve injury happened but recovered later. The mean MEPI was 82 points. For group B, 1 failure of the internal fixation and instability of the elbow happened. The revision operation was performed for this patient. The mean MEPI was 91 points. CONCLUSION: Lateral approach is better,it gives more exposure for the joint and the radial nerve is safe, but the trochlear is difficult to be exposed, and the LCL must be protected or repaired during the operation. Anterolateral approach can be used to expose the capitellum and the radial side of the trochlear, but the radial nerve is dangerous and more complications may happen.

[A new kinematics method of determing elbow rotation axis and evaluation of its feasibility].

OBJECTIVE: To study a new positioning method of elbow external fixation rotation axis, and to evaluate its feasibility. METHODS: Four normal adult volunteers and six Sawbone elbow models were brought into this experiment. The kinematic data of five elbow flexion were collected respectively by optical positioning system. The rotation axes of the elbow joints were fitted by the least square method. The kinematic data and fitting results were visually displayed. According to the fitting results, the average moving planes and rotation axes were calculated. Thus, the rotation axes of new kinematic methods were obtained. By using standard clinical methods, the entrance and exit points of rotation axes of six Sawbone elbow models were located under X-ray. And The kirschner wires were placed as the representatives of rotation axes using traditional positioning methods. Then, the entrance point deviation, the exit point deviation and the angle deviation of two kinds of located rotation axes were compared. RESULTS: As to the four volunteers, the indicators represented circular degree and coplanarity of elbow flexion movement trajectory of each volunteer were both about 1 mm. All the distance deviations of the moving axes to the average moving rotation axes of the five volunteers were less than 3 mm. All the angle deviations of the moving axes to the average moving rotation axes of the five volunteers were less than 5°. As to the six Sawbone models, the average entrance point deviations, the average exit point deviations and the average angle deviations of two different rotation axes determined by two kinds of located methods were respectively 1.697 2 mm, 1.838 3 mm and 1.321 7°. All the deviations were very small. They were all in an acceptable range of clinical practice. CONCLUSION: The values that represent circular degree and coplanarity of volunteer's elbow single curvature movement trajectory are very small. The result shows that the elbow single curvature movement can be regarded as the approximate fixed axis movement. The new method can replace the traditional method in accuracy. It can make up the deficiency of the traditional fixed axis method.

[Treatment of the old terrible triad of the elbow without operative history].

OBJECTIVE: To introduce the surgical techniques and treating results of the old "terrible triad" of the elbow. METHODS: A retrospective analysis of 11 cases of old "terrible triad" of the elbow treated by the author from March 2009 to February 2014 were performed, with 9 males and 2 females; mean age was (31.82±8.66) years (17-45 years). The average time after injury was (6.36±2.50) weeks (4-12 weeks), with 7 cases on the left and 4 right. The combined injury included 2 cases with distal radius fractures, 1 with ankle fractures, fractures of the distal radius and the head injury (minor epidural hematoma, no surgery), and 1 with Pilon fractures and L4 fractures (fixed at local hospital). All the patients had elbow stiffness and joint dislocation, and 2 patients had symptoms of ulnar nerve. Mason classification of radial head fractures: 2 cases were type I, 5 were type II, 4 were type III. Classification of the coronoid process: Regan & Morrey: 1 was type I, 10 were type II; according to O'Driscoll classification, all the fractures were tip fracture, one was the first subtype, 10 were the second subtype. The elbow were released, the coronoid process were fixed by lasso suture combined with Kirschner wires. Radial head fractures were resected in 1 case, and replaced in 1 case, 3 cases with no treatment, 6 cases with osteotomy and 3.0 mm headless compression screw (HCS) fixation. The lateral collateral ligament complex and the common extensor tendon were repaired to the humeral lateral epicondyles, No.2 Ethibon was used in 2 cases through bone holes, and suture anchorsin the other 9 cases. All the patients were fixed by Stryker DJD II hinged external fixator to protect the bone and soft tissue. RESULTS: The average follow-up time was (38.36±21.92) months (19-77 months). All the patients had no obvious pain, instability and ulnar nerve symptoms in the last follow-up. The average elbow flexion was 134.09°±12.41° (100°-140°), average extension was -15.91°±14.46 ° (-40°-0°), range of flexion and extension was 118.18°±23.80° (70°-140°). Average pronation was 70.91°±26.63° (20°-90°), supination was 70.91°±26.63° (20°-100 °). The range of motion (ROM) of forearm rotation was 150.91°±43.00° (40°-180°). Average Mayo elbow performance score (MEPS) was 96.36±5.04 (85- 100).X-ray showed that no degenerative changes. Five patients had heterotopic ossifications, according to Hastings and Graham grading: 1 case was grade I, 3 cases were grade IIA, 1 case was IIB. CONCLUSION: The old "terrible triad" of elbow with no operative history is difficult to treat. The elbow's functions and stabilization can be recovered by thorough elbow release, repair of coronoid process and anterior capsule, radial head fractures, lateral collateral ligament and the common extensor tendon insertion, combined with hinged external fixator. Joint stiffness and heterotopic ossification are common complications.

[Effect of radiotherapy and indomethacin together in the prevention of recurrence of ectopic ossification around the elbow after resection].

OBJECTIVE: To discuss the effect of single low dose local radiotherapy and indomethacin together in the prevention of recurrence of ectopic ossification around the elbow after resection. METHODS: From Jun. 2009 to Dec. 2011, we performed excision of ectopic ossification around the elbow in 78 stiff elbows. For each case, we used both medial and lateral approaches, and we performed both anterior and posterior capsulectomies and removal of ectopic ossification. In the lateral approach, we started proximally, the lateral supracondylar ridge of the humerus was exposed from the interval between extensor carpi radialis longus (ECRL) and triceps, and then distally passed the interval between ECRL and extensor carpi radialis brevis (ECRB). With the medial approach, after releasing the ulnar nerve, the pronator teres muscle origin was reflected from the medial epicondyle, and then the common flexor-pronator tendon was split longitudinally distally and the brachalis and the anterior portion of the flexor-pronator group were dissected off the anterior humerus. If there was forearm rotation dysfunction, we used extensive lateral approach, the anconeus muscle was reflected from the ulna and the scar tissue and ectopic ossification around the proximal radioulnar joint were resected. The important structures, such as the lateral ulnar collateral ligament (LUCL) and the anterior part of the medial collateral ligament (AMCL), should be carefully protected, because they were important for the elbow stability. Anterior transposition of the ulnar nerve depended on the patients' condition. We performed low dose radiotherapy 4 hours before operation, and we used indomethacin for 6 weeks after operation. In these patients, there were 46 males and 32 females, whose age averaged (35.8±7.9) years (16-65 years). According to Hastings-Graham classification, there were 56 IIA, 5 IIB, 6 IIC and 11 III before operation. RESULTS: We followed up these patients for 26 months with an average of 24-36 months, all the patients improved their elbow function, and no recurrence of ectopic ossification appeared except for 1 patient. For this patient, his elbow function was excellent, and according to Hastings-Graham classification, his ectopic ossification was of type I. CONCLUSION: Single low dose local radiotherapy and indomethacin together are effective in the prevention of recurrence of ectopic ossification around the elbow after excision.

[Diagnosis and treatment of adult capitellar fractures].

OBJECTIVE: To discuss the diagnosis, differential diagnosis, classification methods and treatment of the capitellar fractures of the distal humerus. METHODS: In the study, 28 adult patients with the capitellar fractures were treated in Beijing Jishuitan Hospital from Sep. 2008 to Jan. 2014. There were 10 females and 18 males with an average age of 34 years (range: 14-66 years). According to Dubberley classification: IA type in 6 cases, IB type in 2 cases, IIA type in 8 cases, IIB type in 4 cases, IIIA type in 4 cases, and IIIB type in 4 cases. Sixteen patients were treated with a single Kochr approach, 1 with a lateral approach combined with a medial approach, 2 combined with anterior elbow approach and 9 combined with posterior median approach. All of the fractures were fixed with Herbert screws, 7 cases with support plates, and 4 cases with the hinged elbow external fixator. All of the patients were followed up for clinical examination and radiograph check. They were evaluated with Broberg-Morrey score system. RESULTS: The average follow-up time was 28.5 months (range 12-72 months). The average bone union time was 8 weeks. The average ulnohumeral motion was 112°(60°-150°) and forearm rotation was 145°(100°-170°). The average Broberg-Morrey score was 92.5 points (range: 62-100 points). The excellent and good rate was 91.8%. The complications of traumatic arthritis was in 2 cases and elbow stiffness was in 2 cases. CONCLUSION: Attention should be paid to the diagnosis and differential diagnosis of capitellar fractures without missing the combined injury. According to Dubberley classification, appropriate surgical approach and the internal and external fixed methods could be chosen. Early postoperative, reasonable and effective exercise is helpful to the recovery of elbow joint function.