ACS is a recognized consequence of both upper and lower limb fractures and is known to occur more often following fractures of the lower extremity, particularly the tibia [2, 24]. ALCS, one of the most severe complications after lower extremity fractures, is a clinical condition caused by trauma or other factors that result in bleeding, edema, or worsened limb perfusion [4]. Delayed treatment may result in irreversible nerve and muscle damage, and even death [5]. Therefore, early identification and subsequent fasciotomy are essential to preventing its serious complications. Nowadays, fasciotomy is an effective treatment for ALCS, which can reduce pressure and restore blood flow to the affected compartment, improving the patient's prognosis significantly [4, 25]. It is widely accepted that performing an unnecessary fasciotomy is preferable to failing to recognize compartment syndrome due to the increased risk of myonecrosis and functional loss associated with untreated ALCS. However, increasing fasciotomies may lead to several adverse outcomes, including SSI, bleeding, DVT, and muscle herniation [6–8].
SSI, one of the most frequent complications after surgery, can cause sepsis, reduce the viability of the injured limb and then lead to widespread organ failure, as well as account for 34.3% of all adverse events associated with surgery [13, 14]. Deformities and pains caused by infections will significantly affect patients' quality of life. Due to SSI's high prevalence and poor prognosis, we believe it is essential to investigate its risk factors and implement preventative measures.
As far as we know, this is the first study focusing on risk factors that might have affected the rate of SSI in patients with ALCS who had experienced a fasciotomy. In the present research, the SSI rate was 20.8% (26 of 125). Based on our results, several predictors of SSI were identified using univariate analysis, including BMI, NEU, GLOB, GLU, TCO2, patients with open fractures, and patients with a smoking history. According to logistic regression analysis, BMI levels, open fractures, and smoking history were associated with an elevated risk of SSI. ROC curve analysis revealed that the cut-off value for BMI to predict SSI was 24.69 kg/m2. In addition, the most accurate diagnosis was made when BMI, smoking history, and open fractures were all taken together.
In our research, patients with open fractures had an increased incidence of SSI. We also observed that patients with open fractures had a 3.174-fold increased incidence of SSI compared to those with closed fractures. Previously, we thought that the pressure inside the fascial compartment seemed to be released due to the appearance of skin cracks, and therefore the risk of ALCS was reduced. However, recent retrospective studies suggested that a skin laceration would not reduce the pressure inside the compartments. Obey et al. even discovered that open fractures were a risk factor for ACS [26]. A meta-analysis reviewed 51 articles covering 2,980 open and 7,893 closed fractures [27]. They discovered that infection rates were 4.2% for closed fractures and 10.6% for open ones. In addition, Ryan et al. and Li et al. all believed that open fractures represented an independent risk factor for SSI [28, 29], which was consistent with our study. In their research, when compared to closed fractures, open fractures increased the prevalence of SSI by roughly 4.53-fold and 1.99-fold, respectively. The increased infection incidence in patients with open fractures may result from damage to the adjacent soft tissues and the entry of environmental contaminants that may interact with the fracture site. Furthermore, to maintain a healthy soft-tissue envelope, patients may have been subjected to repeated debridement; as a result, preoperative waiting time and surgery time would inevitably be extended. In a retrospective study, Abdo Bachoura et al. found that multiple surgical procedures doubled the incidence of surgical site infection [30]. Our findings demonstrated that open fractures continued to pose significant challenges for physicians. Therefore, improving the level of care for patients with open injuries, closely observing the changes in their condition, and the rational application of antibiotics are crucial measures to reduce SSI.
Smoking is a well-known risk factor for SSI after tibial plateau fracture surgery [28] and general spine surgery [31]. However, no research has been able to establish an association between smoking and SSI after fasciotomy. This is the first study to show that smoking is a risk factor for SSI following fasciotomy (OR = 4.185). Our study found that smoking history was an independent risk factor for SSI after fasciotomy. Compared to non-smokers, the infection incidence among smokers remained very high, and our results demonstrated that smoking increased the risk of SSI by up to 4.185-fold. Blair et al. [32] found that the influence of smoking on nonunion and infection following fasciotomy cannot be ignored. Li et al. [28] also demonstrated that smoking was an independent predictor of SSI. In a retrospective database review, Ryan et al. [29] found that smoking was associated with elevated infection rates in patients with upper extremity fractures. All of the above studies were consistent with our results. This may be because smoking, even in small amounts, may significantly impact a patient's prognosis via various mechanisms, including vasoconstriction, local tissue hypoxia, and compromising the reparative processes of wound healing and neutrophil defense against microorganisms. Quitting smoking helped reduce the incidence of SSI prior to surgery. Thomsen et al. found that patients who gave up smoking before surgery nearly halved their risk of postoperative complications compared to those who smoked [33]. Therefore, at the time of hospitalization, surgeons should proactively inform patients about the advantages of quitting smoking and encourage them to take action to quit tobacco.
A higher BMI is becoming a typical comorbidity for patients requiring orthopedic surgery, which significantly affects healthcare system resources. In our study, the level of BMI was significantly higher in the SSI group compared with the non-SSI group. It has been previously shown in the orthopedic trauma literature that higher BMI levels is associated with higher infection rates [34, 35]. In a retrospective multicenter study, Liu et al. [36] found that BMI was independently related to SSI after geriatric hip fracture surgery. In a meta-analysis, Abdallah et al. [37] discovered that a higher BMI was associated with an increased risk of SSI following spine surgery. The above findings were in line with our study. Higher BMI patients had thicker subcutaneous fat, necessitating higher retraction pressures and increasing the likelihood of dead space formation at wound closure [38]. These factors could result in increased tissue necrosis and inadequate vascular perfusion, which inhibit neutrophils' oxidative killing of bacteria and cause wound infection [39]. However, Brophy et al. [40] found that the level of BMI was not connected with the incidence of infection after anterior cruciate ligament (ACL) replacement, which was inconsistent with our study. This may be related to the fact that the subcutaneous fat around the knee joint was minimal and hence did not exhibit substantial alterations with changes in BMI. Furthermore, the severity of the ACL injury and the incision length were much less than those of ALCS, resulting in a lower chance of infection. As a result, a referral to a nutritionist, bariatric surgeon, or exercise counselor may be necessary prior to fasciotomy.
NEU was generally considered an SSI risk factor [41–43]. In this study's univariate analysis, the difference in NEU between the SSI and non-SSI groups was statistically significant; however, the multivariate analysis failed to identify NEU as an SSI predictor. This was probably related to the small number of ALCS patients who had fasciotomy in these two hospitals during the last decade. Besides, in the univariate analysis, we discovered that the SSI group had a higher level of GLU than the non-SSI group. Cheadle et al. also found that diabetes was an independent risk factor for SSI. Regarding diabetes, however, we found no difference between the two groups [44]. Although there was a difference in GLU levels between the groups, there was no change in the prevalence of diabetes, which might be because ALCS patients are much younger than participants in earlier studies. Patients who are younger have a lesser likelihood of getting serious health conditions such as diabetes and cardiovascular disease, which were considered risk factors for SSI in previous research but did not manifest similarly in ours [45].
Despite the fact that this is the first study to investigate SSI risk factors in ALCS patients following fasciotomies, several limitations should be acknowledged. First, since this research was retrospective, certain potential variables that may be connected to SSI, such as types of antibiotics, were only partially available. Second, we were unable to include every confounding factor, as with any other multivariate study, and residual confounding still presents a problem. Third, patient-specific variables (such as smoking, drinking, and medical comorbidities) were mostly based on the patient's self-report and were only as reliable as the patient's understanding of their medical issues. Fourth, the sample size of this study was relatively small. A larger sample size and clinical study were required.
In conclusion, our study revealed that BMI, smoking history, and open fractures were independent predictors of SSI. The cut-off value for BMI in the ROC curve to predict SSI was discovered to be 24.69 kg/m2. Our findings allowed us to provide an individualized assessment of the risk of SSI in ALCS patients after fasciotomy, allowing for prompt targeted therapy.