Is obesity protective against wound healing complications in pilon surgery? Soft tissue envelope and pilon fractures in the obese

-A machine learning model to predict surgical site infection after surgery of lower extremity fractures

PURPOSE

This study aimed to develop machine learning algorithms for identifying predictive factors associated with the risk of postoperative surgical site infection in patients with lower extremity fractures.

METHODS

A machine learning analysis was conducted on a dataset comprising 1,579 patients who underwent surgical fixation for lower extremity fractures to create a predictive model for risk stratification of postoperative surgical site infection. We evaluated different clinical and demographic variables to train four machine learning models (neural networks, boosted generalised linear model, naïve bayes, and penalised discriminant analysis). Performance was measured by the area under the curve score, Youdon's index and Brier score. A multivariate adaptive regression splines (MARS) was used to optimise predictor selection.

RESULTS

The final model consisted of five predictors. (1) Operating room time, (2) ankle region, (3) open injury, (4) body mass index, and (5) age. The best-performing machine learning algorithm demonstrated a promising predictive performance, with an area under the ROC curve, Youdon's index, and Brier score of 77.8%, 62.5%, and 5.1%-5.6%, respectively.

CONCLUSION

The proposed predictive model not only assists surgeons in determining high-risk factors for surgical site infections but also empowers patients to closely monitor these factors and take proactive measures to prevent complications. Furthermore, by considering the identified predictors, this model can serve as a reference for implementing preventive measures and reducing postoperative complications, ultimately enhancing patient outcomes. However, further investigations involving larger datasets and external validations are required to confirm the reliability and applicability of our model.

Minimally Invasive Reduction and Fixation Techniques of Pilon Fractures Based on the Preoperative CT Findings

Tibial plafond fractures are often associated with significant articular cartilage and soft tissue damage. The presence of co-morbidities has been associated with an increased risk of surgical site complications. With improved in surgical techniques and implants, complication rates have declined; however, the overall prognosis often remains poor. The aims of this study were to evaluate the results of innovative minimally invasive reduction and fixation techniques in tibial plafond fractures based on a CT classification and to compare the difference between short and long-term outcomes. Based on preoperative CT findings, fractures were classified into varus, valgus, anterior, posterior, and neutral types. The minimally invasive reduction and fixation techniques depend on type of fracture, size and location of the intraarticular fragments, and degree of comminution of the extra-articular component. Ninety-one pilon fractures (90 patients) underwent minimally invasive reduction and fixation, of which 7 fractures (7.69%), required open reduction because of intraoperative failure to achieve anatomic reduction. Of the 84 fractures that underwent successful minimally invasive reduction and fixation reported, 35 fractures (41.7%) with excellent outcomes, 40 fractures (47.6%) with good outcomes, 6 fractures (7,1%) with fair outcomes, and 3 fractures (3.6%) had poor outcomes for the long-term American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score (follow-up ≥ 60 months). These results prove that minimally invasive treatment is an effective and durable treatment option for intra-articular pilon fractures. We encourage future clinical studies to further refine minimally invasive techniques for pilon fractures to improve outcomes.

The Effect of an Abnormal BMI on Orthopaedic Trauma Patients: A Systematic Review and Meta-Analysis

Aims: The aim of this systemic review is to identify the complications that arise in operating on orthopaedic trauma patients with an abnormal body mass index (BMI). Materials and Methods: Systematic literature search using a combination of MESH subject headings and free text searching of Medline, Embase, SCOPUS and Cochrane databases in August 2019. Any orthopaedic injury requiring surgery was included. Papers were reviewed and quality assessed by two independent reviewers to select for inclusion. Where sufficiently homogenous, meta-analysis was performed. Results: A total of 26 articles (379,333 patients) were selected for inclusion. All complications were more common in those with a high BMI (>30). The odds ratio (OR) for high BMI patients sustaining post-operative complication of any type was 2.32 with a 23% overall complication rate in the BMI > 30 group, vs. 14% in the normal BMI group (p < 0.05). The OR for mortality was 3.5. The OR for infection was 2.28. The OR for non-union in tibial fractures was 2.57. Thrombotic events were also more likely in the obese group. Low BMI (<18.5) was associated with a higher risk of cardiac complications than either those with a normal or high BMI (OR 1.56). Conclusion: Almost all complications are more common in trauma patients with a raised BMI. This should be made clear during the consent process, and strategies developed to reduce these risks where possible. Unlike in elective surgery, BMI is a non-modifiable risk factor in the trauma context, but an awareness of the complications should inform clinicians and patients alike. Underweight patients have a higher risk of developing cardiac complications than either high or normal BMI patient groups, but as few studies exist, further research into this group is recommended.

Minimal Invasive Fixation Can Decrease Infection Rates in Diabetic and Obese Patients With Severe Ankle Fracture and Syndesmotic Injury

BACKGROUND

Ankle fractures involving syndesmosis disruption cause severely unstable joint conditions. Traditional invasive operations put certain patient groups at an increased risk of infection. There is limited literature discussing the outcomes of minimally invasive fixation of severe ankle fractures including syndesmotic injury, as clinicians may be tempted to treat these difficult cases with open reduction internal fixation (ORIF).

METHODS

A retrospective case-control study was conducted on patients treated at a level one trauma center. Patients were divided into 2 groups based on presence of diabetes and/or obesity (body mass index ≥30.0 kg/m²). Those with either comorbidity were defined as high infection risk patients and placed in a comorbidity group. Patients were further divided into subgroups based on the operation's invasiveness; either traditional ORIF or percutaneous cannulated screw fixation.

RESULTS

Comorbid patients (N = 67) were more likely to sustain Weber C fractures compared to noncomorbid patients (N = 43) (59.70% to 37.21%, P = .019). Additionally, patients receiving minimally invasive fixation procedures experienced fewer infections than those receiving ORIF (0 vs 11 incidences, P = .01), without effect on union rates, fracture reduction, pain, need for revision surgery, or time to full weightbearing.

CONCLUSIONS

Diabetic and obese patients are at an increased risk of experiencing severe ankle fractures. The use of minimally invasive fixation methods can reduce the risk of postoperative infection without sacrificing other surgical outcomes, even with fractures involving syndesmotic injury.

LEVELS OF EVIDENCE

Therapeutic, Level III: Retrospective comparative study.

Obesity in the Polytrauma Patient

The rates of obesity continue to increase in the United States and the overall impact of obesity on health care spending and patient outcomes after trauma is considerable. The unique physiology of the obese places them at higher risk for complications, including infection, failure of fixation, nonunion, multiorgan failure, and death. These physiologic differences and overall patient size can make orthopedic care in obese patients with trauma more difficult, but appropriate initial resuscitation, careful preoperative planning, meticulous surgical technique, diligent postoperative medical management, and specialized rehabilitation give these patients their best opportunity for a good outcome.

Effect of BMI on outcomes of surgical treatment for tibial plateau fractures: A comparative retrospective case series study

PURPOSE

Tibia plateau fracture (TPF) treatment aims at achieving a stable, aligned, mobile, painless knee and preventing post-traumatic osteoarthritis. To achieve this goal, surgeons consider criteria such as patients' characteristics, severity, risk of complications, fracture displacement/depression, degree of soft tissue injury. However, body mass index (BMI) is not considered as a risk factor in literature. Our study was conducted to find out any possible correlation between BMI and functional scores or radiological score separately.

METHODS

Retrospective analysis of case series between 2011 and 2014 was done on the database of a tertiary hospital in Istanbul. There were 67 TPF patients (54 males, 13 females) in the study. Relationship between BMI and functional knee scores or radiological score was compared statistically. Closed fractures with both high-energy and low-energy injury were included in the study. Patients with open fracture, multi-trauma presence, meniscus and/or ligamentous injury, increased co-morbidity, inadequate records (25 cases in all) were excluded. Surgery type, Schatzker classification, injury side, trauma energy, and gender were considered as possible risk factors. Binary regression analysis was done for possible factors affecting functional knee scores and radiologic score.

RESULTS

Model summary calculations were done as Nagelkerke R² test for Knee Society score, Lysholm knee score, and Ahlback and Rydberg radiologic scores, which were 0.648, 0.831, and 0.327 respectively. Homer-Lemeshow test values were 0.976, 0.998, and 0.362, respectively. There is negative correlation between BMI and both knee function scores. There is no correlation between BMI and radiologic score.

CONCLUSION

An increase in BMI has a negative effect on functional knee scores after surgical treatment of TPFs. Therefore, BMI should be considered as a risk factor for surgical treatment of TPFs.

American College of Foot and Ankle Surgeons® Clinical Consensus Statement: Perioperative Management

A wide range of factors contribute to the complexity of the management plan for an individual patient, and it is the surgeon's responsibility to consider the clinical variables and to guide the patient through the perioperative period. In an effort to address a number of important variables, the American College of Foot and Ankle Surgeons convened a panel of experts to derive a clinical consensus statement to address selected issues associated with the perioperative management of foot and ankle surgical patients.

Risk factors of deep infection in operatively treated pilon fractures (AO/OTA: 43)

BACKGROUND/AIMS

The purpose of this study is to evaluate risk factors of deep infection following pilon fractures.

METHODS

This investigation was performed after gathering a six-year retrospective database from a single academic trauma center.

RESULTS

These include an overall incidence of deep infection of 16.1% (57/355). Deep infection was diagnosed at an average of 88 days (±64 days) from initial injury with a range of 10-281 days. Development of deep infection occurred in 23.2% (33/142) of open fractures, vs 11.3% (24/213) of closed fractures.

CONCLUSION

Open fractures, hypertension and male gender were associated with an increased risk of developing deep infection. In addition, even optimal surgical management may not significantly modify rates of deep surgical site infection.

The impact of glycosylated hemoglobin and diabetes mellitus on wound-healing complications and infection after foot and ankle surgery

BACKGROUND

The relationship between hyperglycemia and adverse outcomes after surgery has been widely documented. Long-term glucose control has been recognized as a risk factor for postoperative complications. In the foot and ankle literature, long-term glycemic control as a potential perioperative risk factor is not well studied. Our goal was to investigate whether hemoglobin A1c (HbA1c) level was independently associated with postoperative complications in a retrospective cohort study.

METHODS

Three hundred twenty-two patients with a diagnosis of diabetes mellitus were enrolled in the study to assess risk factors associated with postoperative foot and ankle surgery complications.

RESULTS

Bivariate analyses showed that HbA1c level and having at least one comorbidity were associated with postoperative infections. However, after adjusting for other covariates, the only significant factor was HbA1c level, with each increment of 1% increasing the odds of infection by a factor of 1.59 (95% confidence interval [CI], 1.28-1.99). For postoperative wound-healing complications, bivariate analyses showed that body mass index, having at least one comorbidity, and HbA1c level were significant factors. After adjusting for other covariates, the only significant factors for developing postoperative wound complications were having at least one comorbidity (odds ratio, 2.03; 95% CI, 1.22-3.37) and HbA1c level (each 1% increment) (odds ratio, 1.25; 95% CI, 1.02-1.53).

CONCLUSIONS

In this retrospective study, HbA1c level had the strongest association with postoperative foot and ankle surgery complications in patients with diabetes.

Effect of variable body mass on plantar foot pressure and off-loading device efficacy

An increasing body of evidence has implicated obesity as having a negative effect on the development, treatment, and outcome of lower extremity pathologic entities, including diabetic foot disease. The objective of the present study was to increase the body of knowledge with respect to the effects of obesity on foot function. Specifically, we attempted to (1) describe the relationship between an increasing body mass index (BMI) on plantar foot pressures during gait, and (2) evaluate the efficacy of commonly prescribed off-loading devices with an increasing BMI. A repeated measures design was used to compare the peak plantar foot pressures under multiple test conditions, with the volunteers acting as their own controls. The primary outcome measure was the mean peak plantar pressure in the heel, midfoot, forefoot, and first metatarsal, and the 2 variables were modification of patient weight (from "normal" BMI to "overweight," "obese," and "morbidly obese") and footwear (from an athletic sneaker to a surgical shoe, controlled ankle motion walker, and total contact cast). Statistically significant increases in the peak plantar pressures were observed with increasing volunteer BMI weight class, regardless of the off-loading device used. The present investigation has provided unique and specific data with respect to the changes that occur in the peak plantar pressures with variable BMIs across different anatomic levels and with commonly used off-loading devices. From our results, we have concluded that although the plantar pressures increase with increasing weight, it appears that at least some reduction in pressure can be achieved with an off-loading device, most effectively with the total contact cast, regardless of the patient's BMI.

Can foot and ankle surgeons accurately estimate patient body mass index?

The body mass index (BMI) is an objective patient finding that has been established to have a negative effect on the development and outcomes of podiatric pathologic entities and interventions. The objective of the present investigation was to assess the ability of podiatric physicians to estimate the patient BMI from clinical and radiographic observation. For the clinical estimation of the patient BMI, podiatric specialists across 3 levels of experience (i.e., students, residents, and practicing clinicians) performed 294 estimations on 72 patients in 3 clinical situations (standing, sitting in a treatment chair, and lying in a hospital bed). It was more common to inaccurately estimate the patient BMI (77.9%) than it was to correctly estimate it (22.1%), with underestimations being the most common error (48.3%). The estimations were particularly inaccurate when the patients were in the common clinical situation of sitting in a treatment chair or lying in a hospital bed and with patients actually classified as obese. For the radiographic estimation of patient BMI, 150 consecutive lateral ankle radiographs were analyzed, with the ratio of the overlying soft tissue diameter to the underlying bone diameter calculated and compared. Positive, but weak, relationships were observed with these ratios. From these data, we have concluded that podiatric practitioners should perform an actual calculation of the patient BMI during the patient examination and medical decision-making process to fully appreciate the potential risks inherent to the treatment of obese patients.

Periarticular tibial fracture treatment in the obese population

Lambotte's 7 steps of fracture treatment have stood the test of time. Incision, preparation of the bone ends, reduction, temporary fixation, permanent fixation, closure, and dressing are modified to suit the needs of each fracture and each patient. One specific patient characteristic, obesity, has provided complex challenges in fracture care. This article reviews the challenges of obesity as they relate to the 7 steps of lower extremity periarticular fracture care. Specifically, helpful modifications to these 7 steps are provided for the treatment of tibial plateau fractures and tibial plafond fractures. As there is little published evidence with respect to the treatment of these injuries in the obese population, the suggestions that are provided are based on the extrapolation from published evidence of fracture care in other areas in patients with obesity, logic, and personal experience with fracture care in patients with obesity.