Risk prediction model for deep surgical site infection (DSSI) following open reduction and internal fixation of displaced intra-articular calcaneal fracture

Adverse effect of smoking on surgical site infection following ankle and calcaneal fracture fixation: a meta-analysis

Purpose

Studies have reported conflicting findings on the relationship between smoking and surgical site infection (SSI) post fixation for ankle and calcaneal fractures. This meta-analysis explored the effect of smoking on SSI incidence following open reduction and internal fixation (ORIF) of these fractures.

Methods

Full-text studies on smoking's influence on post-ORIF SSI rates for closed ankle and calcaneal fractures were sourced from the PubMed, Embase, and Cochrane databases, with no consideration given to language or publication date. Study quality was appraised using the Newcastle-Ottawa Scale. Odds ratios (OR) and the corresponding 95% CIs were determined using random-effects models. This meta-analysis adhered to the PRISMA guidelines and was registered with PROSPERO (CRD42023429372).

Results

The analysis incorporated data from 16 cohort and case-control studies, totaling 41 944 subjects, 9984 of whom were smokers, with 956 SSI cases. Results indicated smokers faced a higher SSI risk (OR: 1.62; 95% CI: 1.32-1.97, P < 0.0001) post ORIF, with low heterogeneity (I 2 = 26%). Smoking was identified as a significant deep SSI risk factor (OR: 2.09; 95% CI: 1.42-3.09; P = 0.0002; I 2 = 31%). However, the subgroup analysis revealed no association between smoking and superficial SSI (OR: 1.05; 95% CI: 0.82-1.33; P = 0.70; I 2 = 0%).

Conclusion

Smoking is associated with increased SSI risk after ORIF for closed ankle and calcaneus fractures. Although no clear link was found between superficial SSI and smoking, the data underscore the negative influence of smoking on deep SSI incidence.

Risk factors for surgical site infection after closed proximal humerus fractures

Proximal humerus fractures are common in clinical practice, and there are relatively a few studies on postoperative incision infections of such fractures. The purpose of this study was to explore the risk factors for surgical site infection (SSI) after internal fixation in patients with closed proximal humerus fractures. Patients with closed proximal humerus fractures who underwent surgery from January 2016 to January 2022 were retrospectively analysed. Cases with superficial or deep infections within 3 months after surgery were in the infection group and the remaining cases were in the non-infection group. The types of pathogenic bacteria in the infection group were analysed. The potential risk factors for SSI in all patients were recorded: (1) patient-related factors: gender, age, body mass index (BMI), smoking, comorbidities; (2) trauma-related factors: mechanism of injury, Injury Severity Score, visual analogue scale, fracture type, soft tissue condition and combined dislocation; (3) laboratory-related indexes: haemoglobin, albumin; (4) surgery-related factors: time from injury to surgery, American Society of Anesthesiologists anaesthesia classification, surgical time, fixation mode, intraoperative blood loss, suture method, bone graft and postoperative drainage. The risk factors for the occurrence of SSI were analysed using univariate analysis and multivariate logistic regression. The incidence of SSI was 15.7%. The most common bacterium in the infection group was Staphylococcus aureus. High BMI (p = 0.033), smoking (p = 0.030), an increase in mean time from injury to definitive surgery (p = 0.013), and prolonged surgical time (p = 0.044) were independent risk factors for the development of SSI after closed proximal humeral fractures. In patients with closed proximal humerus fractures, weight loss, perioperative smoking cessation, avoidance of delayed surgery, and shorter surgical time may be beneficial in reducing the incidence of SSI.

Prevalence of surgical site infection and risk factors in patients after knee surgery: A systematic review and meta-analysis

The present systematic review and meta-analysis aimed to determine the prevalence of surgical site infection (SSI) and risk factors in patients after knee surgery. A comprehensive and systematic search was carried out across various international electronic databases, including Scopus, PubMed and Web of Science, as well as Persian electronic databases like Iranmedex and the Scientific Information Database (SID). This search involved the utilization of keywords derived from Medical Subject Headings, such as 'Prevalence', 'Surgical wound infection', 'Surgical site infection' and 'Orthopaedics', spanning from the earliest records up to 1 October 2023. To assess the quality of the included studies, the Appraisal tool for Cross-Sectional Studies (AXIS tool) was utilized. The study encompassed a combined participant pool of 11 028 individuals who underwent knee surgery across seven selected studies. The collective prevalence of SSI in patients who underwent knee surgery, as reported in the seven included studies, was determined to be 3.0% (95% CI: 1.2% to 7.5%; I2  = 96.612%; p < 0.001). The combined prevalence of SSI in patients with DM, as reported in six studies, was 5.1% (95% CI: 1.7% to 14.5%; I2  = 79.054%; p < 0.001). Similarly, the pooled prevalence of SSI in patients with HTN, drawn from four studies, was 1.8% (95% CI: 0.7% to 4.5%; I2  = 63.996%; p = 0.040). Additionally, the collective prevalence of SSI in patients with a history of tobacco use, based on findings from six studies, was 4.8% (95% CI: 1.4% to 15.2%; I2  = 93.358%; p < 0.001). Subgroup analysis was conducted within six studies, categorizing them by two countries, namely China and the USA. These analyses revealed that the prevalence of SSI following knee surgery was 3.0% in China and 2.0% in the USA. It is noteworthy that variations in SSI prevalence across different studies may be attributed to a multitude of factors, particularly varying risk factors among patient populations. To address this issue and mitigate the impact of SSI on knee surgery patients, it is advisable to develop tailored interventions.

Prevalence of surgical site infection and risk factors in patients after foot and ankle surgery: A systematic review and meta-analysis

The present systematic review and meta-analysis aimed to determine the prevalence of surgical site infection (SSI) and related factors in patients after foot and ankle surgery. A comprehensive, systematic search was conducted in different international electronic databases, such as Scopus, PubMed, Web of Science and Persian electronic databases such as Iranmedex and Scientific Information Database (SID) using keywords extracted from Medical Subject Headings such as 'Prevalence', 'Surgical wound infection', 'Surgical site infection' and 'Orthopaedics' from the earliest to 1 June 2023. The appraisal tool for cross-sectional studies (AXIS tool) evaluates the quality of the included studies. A total of 10 447 patients undergoing foot and ankle surgery participated in nine studies. The pooled prevalence of SSI in patients who underwent foot and ankle surgery was reported in nine studies was 4.2% (95% CI: 2.4%-7.2%; I2  = 96.793%; p < 0.001). The odds ratio of SSI prevalence in men was higher than that of women and was significant (OR: 1.335; 95% CI: 1.106-1.612; Z = 3.009; p = 0.003). The pooled prevalence of SSI in patients with hindfoot fracture sites reported in five studies was 4.9% (95% CI: 2.6%-8.9%; I2  = 90.768%; p < 0.001). The pooled prevalence of SSI in patients with diabetes mellitus (DM) reported in six studies was 9.1% (95% CI: 5.6%-14.6%; I2  = 73.957%; p = 0.002). The pooled prevalence of SSI in patients with hypertension (HTN) reported in five studies was 5.5% (95% CI: 2.5%-11.6%; I2  = 91.346%; p < 0.001). The pooled prevalence of SSI in patients with tobacco use reported in eight studies was 6.6% (95% CI: 4.1%-10.4%; I2  = 85.379%; p < 0.001). In general, the existing differences in the prevalence of SSI after foot and ankle surgery in different studies can be based on different risk factors such as comorbidities and gender. Therefore, it is suggested to design appropriate interventions to reduce SSI in these patients.

Using multiple indicators to predict the risk of surgical site infection after ORIF of tibia fractures: a machine learning based study

Objective

Surgical site infection (SSI) are a serious complication that can occur after open reduction and internal fixation (ORIF) of tibial fractures, leading to severe consequences. This study aimed to develop a machine learning (ML)-based predictive model to screen high-risk patients of SSI following ORIF of tibial fractures, thereby aiding in personalized prevention and treatment.

Methods

Patients who underwent ORIF of tibial fractures between January 2018 and October 2022 at the Department of Emergency Trauma Surgery at Ganzhou People's Hospital were retrospectively included. The demographic characteristics, surgery-related variables and laboratory indicators of patients were collected in the inpatient electronic medical records. Ten different machine learning algorithms were employed to develop the prediction model, and the performance of the models was evaluated to select the best predictive model. Ten-fold cross validation for the training set and ROC curves for the test set were used to evaluate model performance. The decision curve and calibration curve analysis were used to verify the clinical value of the model, and the relative importance of features in the model was analyzed.

Results

A total of 351 patients who underwent ORIF of tibia fractures were included in this study, among whom 51 (14.53%) had SSI and 300 (85.47%) did not. Of the patients with SSI, 15 cases were of deep infection, and 36 cases were of superficial infection. Given the initial parameters, the ET, LR and RF are the top three algorithms with excellent performance. Ten-fold cross-validation on the training set and ROC curves on the test set revealed that the ET model had the best performance, with AUC values of 0.853 and 0.866, respectively. The decision curve analysis and calibration curves also showed that the ET model had the best clinical utility. Finally, the performance of the ET model was further tested, and the relative importance of features in the model was analyzed.

Conclusion

In this study, we constructed a multivariate prediction model for SSI after ORIF of tibial fracture through ML, and the strength of this study was the use of multiple indicators to establish an infection prediction model, which can better reflect the real situation of patients, and the model show great clinical prediction performance.

Neutrophil-lymphocyte ratio as a predictive marker for postoperative infectious complications: A systematic review and meta-analysis

Objective

Postoperative infection is a common but costly complication. The neutrophil-lymphocyte ratio is a promising marker for the identification of postsurgical infectious events. We aimed to perform this meta-analysis to assessed the accuracy of the neutrophil-lymphocyte ratio for the prediction of postsurgical infection.

Methods

We searched PubMed, Embase, Web of Science, and Cochrane Library without language restriction from their inceptions to April 2022, and checked reference lists of included studies. Studies were included if they assessed predictive accuracy of neutrophil-lymphocyte ratio for postsurgical infection. We estimated its predictive value and explored the source of heterogeneity. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool was used to assess methodological quality and the Deeks' test to evaluate publication bias. The bivariate model and hierarchical summary receiver operating characteristic (HSROC) curve were used for meta-analysis and generated a summary receiver operating characteristic space (ROC) curve.

Results

Our search returned 379 reports, of which 12 fulfilled the inclusion criteria, accounting for 4375 cases. The bivariate analysis yielded a pooled sensitivity of 0.77 (95%C.I.: 0.65-0.85) and specificity of 0.78 (95%C.I.: 0.67-0.86). Pooled positive LR and negative LR were 3.48 (95%C.I.: 2.26-5.36) and 0.30 (95%C.I.: 0.20-0.46), respectively. A negative LR of 0.30 reduces the post-test probability to 2% for a negative test result. The area under of receiver operating characteristic curve was 0.84 (95%C.I.: 0.80-0.87). Subgroups comparisons revealed difference by study design, surgical site, presentence of implant, time of sampling, type of infection event and prevalence of infection. The Deeks' test showed no publication bias. The sensitivity analysis showed no study affected the robustness of combined results.

Conclusions

Low-certainty evidence suggests that the neutrophil-lymphocyte ratio is a helpful marker for predicting postoperative infectious complication. The negative predictive value of the neutrophil-lymphocyte ratio enables for reliable exclusion of postoperative infection.Trial registrationPROSPERO registration number CRD42022321197. Registered on 27 April 2022.

Clinical outcomes following treatment of deep surgical site infection after fixation of calcaneal fractures: A retrospective case-control study

INTRODUCTION

Deep surgical site infection (SSI) may be a complication of open reduction and internal fixation (ORIF) of calcaneal fractures. This study aimed to describe the characteristics of patients with deep SSI following ORIF of calcaneal fractures via extensile lateral approach (ELA). We compared clinical outcomes of these patients, with a minimum follow-up of one year after successful treatment of deep SSI with a matched control group.

METHODS

In this retrospective case-control study, demographic data, fracture characteristics, bacterial pathogens, medical treatments and surgical approaches were collected, also the outcome was evaluated by the visual analog scale (VAS) for pain, foot function index (FFI) and AOFAS ankle-hindfoot score. The differences in Böhler and Gissane's angles between infected and contralateral feet were measured. By matching a control group of uninfected cases, clinical outcomes were compared between 2 groups using the Mann-Whitney U test.

RESULTS

Among 331 calcaneus fractures in 308 patients (mean age, 38.0 ± 13.1; male/female ratio, 5.5), 21 had deep SSI (6.3 %). There were 16 (76.2 %) males and 5 (23.8 %) females with a mean age of 35.1 ± 11.7 years. Thirteen (61.9 %) patients had unilateral fractures. The most common Sanders Type was found to be type II. The most frequent type of detected microorganisms was Staphylococcus species. Intravenous antibiotic therapy, mostly clindamycin, imipenem and vancomycin, based on the microbiological results, was prescribed with a mean±SD duration of 28.1 ± 16.5 days. The mean number of surgical debridements was 1.8 ± 1.3. Implants needed to be removed in 16 (76.2 %) cases. Antibiotic-impregnated bone cement was applied in three (14.3 %) cases. The clinical outcomes of 15 cases (follow up, 35.5 ± 13.8; range, 12.6-64.5 months) were 4.1 ± 2.0, 16.7 ± 12.3 and 77.5 ± 20.8 for VAS for pain, FFI % and AOFAS ankle-hindfoot score, respectively. Comparing with the control group (VAS for pain, 2.3 ± 2.7; FFI %, 12.2 ± 16.6, and AOFAS, 84.6 ± 18.0), only VAS pain was statistically lower in this group (p-value: 0.012). The differences in Böhler and Gissane's angles between both feet of infected cases were - 14.3 ± 17.9 and - 7.7 ± 22.5 (worse in the infected side), respectively.

CONCLUSION

Proper on-time approaches to deep infection following ORIF of calcaneal fractures may lead to acceptable clinical and functional outcomes. Sometimes aggressive approaches with intravenous antibiotic therapy, multiple sessions of surgical debridement, removal of implants and antibiotic impregnated cement are necessary to eradicate deep infection.

LEVEL OF EVIDENCE

Level III.

Global research trends and hotspots in calcaneal fracture: A bibliometric analysis (2000-2021)

Background

Calcaneal fracture is common and carries high morbidity and disability. Its treatment is therefore of vital concern. Many topics concerning calcaneal fracture remain controversial, and the subject has not yet been well-researched. We aim to analyze and illustrate the trends in development, overall knowledge structure, "hotspots," and research frontiers on the topic of calcaneal fracture.

Methods

Literature relating to calcaneal fracture published between 2000 and 2021 was retrieved from Science Citation Index Expanded (SCIE) database of the Web of Science. Three bibliometric tools (Bibliometrix, CiteSpace, and VOSviewer software) were used for analysis and the generation of knowledge maps. Annual trends in publication counts and the relative contributions of different countries, regions, institutions, authors, and journals, as well as keyword clusters, "hot topics," and research frontiers, were analyzed.

Results

A total of 1,687 publications were included in the analysis. The number of calcaneal fracture articles published worldwide each year was highest in 2019, with a total of 128 articles. The United States has made the greatest contribution to the field, with the largest number of publications and the highest H-index. Foot & Ankle International was the most productive journal, publishing a total of 167 articles on calcaneal fracture during the study period. Hebei Medical University of China and the University of California, San Francisco were the most prolific institutions. Professors T. Schepers, S. Rammelt, H. Zwipp, and Y. Z. Zhang have made remarkable contributions to the field. However, the degree of collaboration between researchers and among institutions was relatively low, and took place mainly in Europe and the Americas. All relevant keywords could be categorized into three clusters: studies of internal fixation, studies of fractures, and studies of osteoporosis. A trend of balanced and diversified development could be seen within these clusters. Keywords with ongoing "citation bursts," such as sinus tarsi approach, wound complications, minimally invasive technique, extensile lateral approach, surgical treatment, and plate, may continue to be research "hotspots" in the near future.

Conclusion

Based on current global trends, the number of publications on calcaneal fracture will continue to increase. Topics such as minimally invasive techniques and complications have become important hotspots of research. We recommend enhancing international communication and collaboration for future research in this field.

Risk factors for deep surgical site infection following surgically treated peri-ankle fractures: a case-control study based on propensity score matching

AIMS

This study aims to identify the risk factors for deep surgical site infection (DSSI) following surgically treated peri-ankle fractures.

METHODS

We performed a retrospective case-control study using the propensity score matching (PSM) method in 1:2 ratio, based on the 6 baseline variables, including age, gender, living area, insurance type, fracture location and surgical date. Data on patients who underwent surgical treatment of peri-ankle fractures were collected by inquiring their hospitalization medical records and operative records, as well as the laboratory reports. Conditional logistic regression analysis was performed to identify the risk factors for DSSI.

RESULTS

A total of 2147 patients were eligibly included and 74 had a DSSI, indicating an incidence rate of 3.4%. After PSM, 70 cases of DSSI and 140 controls without DSSI were matched, constituting the study cohort. The univariate analyses showed significant differences between groups in terms of history of any surgery, time to operation, surgical wound classification, smoking, alcohol drinking, RBC count, hemoglobin concentration and hematocrit (%). The conditional logistic regression analysis showed time to operation of < 4 or > 9 (vs 4-9 days); unclean wound, current smoking, high-energy injury mechanism and lower hematocrit were independent risk factors for DSSI.

CONCLUSIONS

Timely modification of smoking and hematocrit (%), and limiting operation within a rational time frame for an optimized soft tissue condition, may provide potential clinical benefits for SSI prevention.

Development of a nomogram to predict surgical site infection after closed comminuted calcaneal fracture

Background

Compared with open comminuted calcaneal fractures, less emphasis is placed on postoperative surgical site infection (SSI) of closed comminuted calcaneal fractures. This study aimed to identify the risk factors associated with SSI and build a nomogram model to visualize the risk factors for postoperative SSI.

Methods

We retrospectively collected patients with closed comminuted calcaneal fractures from the Second Affiliated Hospital of Wenzhou Medical University database from 2017 to 2020. Risk factors were identified by logistics regression analysis, and the predictive value of risk factors was evaluated by ROC (receiver operating characteristic curve). Besides, the final risk factors were incorporated into R4.1.2 software to establish a visual nomogram prediction model.

Results

The high-fall injury, operative time, prealbumin, aspartate aminotransferase (AST), and cystatin-C were independent predictors of SSI in calcaneal fracture patients, with OR values of 5.565 (95%CI 2.220–13.951), 1.044 (95%CI 1.023–1.064), 0.988 (95%CI 0.980–0.995), 1.035 (95%CI 1.004–1.067) and 0.010 (95%CI 0.001–0.185) (P_s < 0.05). Furthermore, ROC curve analysis showed that the AUC values of high-fall injury, operation time, prealbumin, AST, cystatin-C, and their composite indicator for predicting SSI were 0.680 (95%CI 0.593–0.766), 0.756 (95%CI 0.672–939), 0.331 (95%CI 0.243–0.419), 0.605 (95%CI 0.512–0.698), 0.319 (95%CI 0.226–0.413) and 0.860 (95%CI 0.794–0.926), respectively (P_s < 0.05). Moreover, the accuracy of the nomogram to predict SSI risk was 0.860.

Conclusions

Our study findings suggest that clinicians should pay more attention to the preoperative prealbumin, AST, cystatin C, high-fall injury, and operative time for patients with closed comminuting calcaneal fractures to avoid the occurrence of postoperative SSI. Furthermore, our established nomogram to assess the risk of SSI in calcaneal fracture patients yielded good accuracy and can assist clinicians in taking appropriate measures to prevent SSI.

A nomogram for predicting post-operative wound complications after open reduction and internal fixation for calcaneal fractures

The purpose of our study was to determine the risk factors for post-operative wound complications (PWCs) after open reduction and internal fixation (ORIF) for calcaneal fracture and establish a nomogram prediction model. We retrospectively analysed the clinical data of patients who suffered from calcaneal fractures and had been surgically treated for ORIF in our institution between January 2010 and January 2020. Perioperative information was obtained through the electronic medical record system, univariate and multivariate analyses were performed to determine the risk factors of PWCs, and a nomogram model was constructed to predict the risk of PWCs. The predictive performance and consistency of the model were evaluated by the Hosmer -Lemeshow (H-L) test and the calibration curve. In total, 444 patients were enrolled in our study. Multivariate analysis results showed that smoking, limb swelling, angle of incision, and CRP were independent risk factors for skin necrosis. The AUC value for skin necrosis risk was 0.982 (95%CI 0.97-0.99). The H-L test revealed that the normogram prediction model had good calibration ability (P = .957). Finally, we found a correlation between PWCs and smoking, limb swelling, angle of incision, and CRP after ORIF for calcaneal fracture patients. Our nomogram prediction model might be helpful for clinicians to identify high-risk patients, as interventions could be taken early to reduce the incidence of PWCs.