Surgical Site Infection Rate in Sutured Versus Stapled Wound Closure After Orthopedic Limb Surgeries: A Prospective Cohort Study

Abstract

Objectives: Surgical site infection (SSI) is a demanding post-surgical complication. SSI has been linked to significant morbidity, mortality, and rising healthcare expenditure. Staples and sutures are the most utilized methods in orthopedic skin closure. The aim of this study was to compare the rate of SSI in sutured versus stapled wound closure after orthopedic limb surgeries. Methods: A prospective cohort study was conducted between September 2019 and March 2021. Patient demographics, method of wound closure, and potential risk factors associated with SSI were recorded. A multivariate logistic regression analysis was performed to identify independent risk factors associated with SSI. Results: A total of 775 patients were included. Eighteen patients (2.3%) acquired an SSI. 3.5% of the staples group and 1.1% of the suture group contracted an SSI (p = 0.028, univariate analysis). Length of hospital stay (LOS) was significantly higher in the staples group (p < 0.001). Use of antibiotics (AOR 5.938; 95%CI 1.693–20.820), LOS (AOR: 1.047, 95% CI:1.013–1.083), and duration of antibiotic prophylaxis (AOR:1.076, 95% CI: 1.010–1.147) were independent risk factors of SSI. Conclusions: The use of staples was associated with longer hospital stays. Use of antibiotics, prolonged hospital stays, and extended antibiotic prophylaxis were independent risk factors for SSI. These findings suggest that the choice of closure method may impact hospital stay, which could influence SSI risk.

1. Introduction

Surgical site infection (SSI) is a demanding clinical complication. SSI has been linked to significant mortality, morbidity, and rising healthcare expenditure, regardless of continuous efforts to limit its occurrence and improvements in infection control guidelines [1,2]. According to the Centers for Disease Control and Prevention (CDC), SSI is defined as the manifestation of a superficial or deep incision site infection within 30 days of surgery or by one year when implants are used [3]. In the United States, postoperative SSIs cost $3.5 billion to $10 billion annually [4,5]. Orthopedic SSIs account for 20% of all hospital-acquired nosocomial infections [6]. Postoperative orthopedic SSIs expanded healthcare expenditures up to 300% as a result of the extended length of hospital stays (LOS) [7]. Several factors play a role in minimizing SSI risk, including proper ventilation of the surgical environment, aseptic equipment, maintenance of aseptic conditions for both patient and surgical staff, antibiotic prophylaxis, surgical technique, and surgeon skill. Even with these precautions and with emerging innovations such as smart sensor-enabled dressings for real-time wound monitoring [8], the choice of skin closure technique remains a critical factor in preventing postoperative SSIs [6].

The aim of surgical wound closure is the promotion of aesthetic and quick healing via the re-approximation of incision edges. Staples or sutures are the most utilized methods in orthopedic skin closure. The biological response to these closure methods can differ. Sutures may induce localized trauma from needle passage, disrupting the extracellular matrix and epithelium and potentially prolonging inflammation, which can affect early wound healing. In contrast, staples may cause broader tissue compression and local ischemia, which can exacerbate tissue exposure–related damage and lead to sequelae such as delayed healing or hypertrophic scarring [9]. Conventional sutures are known to be the most precise; however, staples have been shown to be faster and more convenient for managing linear cuts [10,11]. Rapid closure, cosmetically acceptable appearance, reduced wound dehiscence, and infections are the goals of using either one of the two techniques [12]. Studies comparing infection rates of skin staples and sutures in orthopedic surgery showed controversy, and the literature has yet to reach a consensus proving the superiority of one method of skin closure [13]. Some studies documented a significantly higher risk of developing a wound infection with staples [12]. Others suggested that sutures are associated with greater chances of SSI but are less costly [14]. Moreover, some even reported no differences in the complication rates between staples and sutures and concluded that the choice of method depends solely on the surgeon’s preference [13]. Previous studies suffered from several limitations, including the collection of underpowered, retrospective data [12].

To our knowledge, no studies have been conducted to compare the wound complication frequency between the two methods in Saudi Arabia. The aim of this study was to compare the acute SSI frequency in sutured versus stapled wound closure after orthopedic limb surgeries. This study should contribute to the available databases to reach a Saudi guideline for implementing the proper skin closure technique in orthopedic surgery.

2. Materials and Methods

2.1. Ethical Approval

Approval from the Institutional Review Board (IRB) ethical committee was obtained before the commencement of data collection (ID number SP19/111/J, approved 18 May 2019). Confidentiality of the data was maintained by ensuring the names of participants were anonymized. The study was carried out in accordance with the codes of ethics outlined by the Declaration of Helsinki.

2.2. Study Population

The patients included in this study were all subjects 18 years or older who underwent orthopedic limb surgeries, admitted electively or under trauma. The inclusion criteria were determined so as to allow only groups where both methods of closure could be equally chosen. The exclusion criteria included patients with dirty wounds at initial presentation, open fractures, active infection at the site, pregnant females, known cases of nickel allergy, and immunocompromised patients diagnosed with HIV or patients who had received chemotherapy or radiation therapy treatments. In particular, patients with nickel allergies were excluded due to the use of metal staples, which may trigger allergic reactions and affect wound healing. Immunocompromised patients were excluded due to their higher baseline SSI risk regardless of closure method, which could confound the evaluation of closure technique.

2.3. Study Design

This study was conducted in Jeddah, Saudi Arabia, from September 2019 to March 2021. It was conducted at a tertiary care center with around 10 fellowship-trained orthopedic surgeons who had extensive experience performing nearly 160 upper and lower limb surgeries per month. The two compared methods of wound closure were metallic staples and subcuticular Vicryl sutures. An observational prospective cohort design was implemented to fulfill the aim of the study. The study was performed prospectively to avoid the consequences of handling missing data. The choice of wound closure method was based solely on the surgeons’ discretion. Furthermore, the choice of antimicrobial prophylaxis, the number of doses, and their duration were also based on the surgeon’s preference and experience. Post-operative assessment of the rate of SSIs was performed within 30 days, which was defined as the primary outcome of the study. Subsequent visits were scheduled for those with SSI or wounds indicating possible SSI. SSIs were classified as per the CDC’s classification of superficial and deep. Diagnosis was based on clinical evaluation by the treating team, and wound swab cultures were obtained when indicated to support the diagnosis.

Study subjects were recruited from the operating room list. Basic demographic data, such as age, gender, BMI, and medical comorbidities, were collected from the patients’ electronic medical records. A consecutive sampling technique was utilized until the target sample size was achieved.

2.4. Sample Size

Using the data from previous studies, considering that the rate of SSIs was 0.9% and 4% in the suture and staple groups, respectively, and using a power of 0.8 and an alpha level of 0.05, the estimated sample size was calculated to be 387 per group, i.e., 774 for the entire study. OpenEpi for cohort studies was used to calculate the sample size.

2.5. Data Collection

The data collection sheet included age, gender, BMI, type of admission (i.e., elective or trauma), and Length of Stay (LOS). Moreover, patients were assessed for several risk factors possibly affecting the incidence of incisional SSIs, including smoking, Diabetes Mellitus (DM), renal failure, the specific use of medications and steroids, known previous colonization, and antibiotic prophylaxis administration, including the total duration. Length of surgery was obtained as well. The occurrence of wound dehiscence and discharge was also assessed. In addition, the most frequently reported infection-causing microorganisms were identified in this study. Data entry was accomplished by using Microsoft Excel.

2.6. Statistical Analysis

Statistical Package for the Social Sciences (SPSS) v.27 software was used to analyze the data. Continuous data were presented in means and standard deviations or medians and quartiles, depending on the distribution. Categorical data were presented in numbers and percentages, as indicated. Comparison of these variables was performed by using a two-sample t-test or a Mann–Whitney U test for continuous data, as appropriate, and a Chi-square test for categorical data. A statistical significance cutoff of p < 0.05 was used. Logistic regression was used to model the association between the type of wound closure and the likelihood of developing SSIs, with the odds ratio and its 95% confidence interval being a measure of this association. Variables that reached a significance level of p < 0.05 in the univariate analysis and important confounders were entered as independent variables in a multivariate regression model to obtain adjusted effects and assess the risk factors for SSIs.

3. Results

A total of 2111 patients were enrolled to undergo orthopedic limb surgeries between September 2019 and March 2021. After applying the study’s inclusion and exclusion criteria and excluding cases with incomplete surgical notes lacking documentation of the wound closure method, 775 patients were included in the final analysis. Of these, staples were used in 404 patients (52.1%) and sutures in 371 patients (47.9%). Males accounted for around 61% of all cases.

Operative patient characteristics were compared between patients who received staples and those who received sutures for surgical wound closure and are summarized in

Table 1. Operative patient characteristics in different methods of wound closure.

	Staples (N = 404)	Sutures (N = 371)	p-Value
Median age in years (IQR)	59 (34–67)	37 (28–53)	<0.001
Gender
Male, N (%)	226 (55.9)	235 (63.3)	0.036
Median BMI in kg/m2 (IQR)	30.1 (25.7–35.0)	28.0 (24.0–32.7)	<0.001
Smoking, N (%)	47 (11.6)	65 (17.5)	0.020
Medical Comorbidity
Diabetes, N (%)	124 (30.7)	68 (18.3)	<0.001
Renal Failure, N (%)	15 (3.7)	6 (1.6)	0.073
Medications
Steroids, N (%)	26 (6.4)	25 (6.7)	0.865
NSAIDs, N (%)	222 (55.0)	123 (34.5)	<0.001
Antibiotics, N (%)	76 (18.8)	54 (14.6)	0.113
Anticoagulants, N (%)	215 (53.2)	90 (24.3)	<0.001
Admission type
Elective, N (%)	326 (80.7)	279 (75.2)	0.065
Trauma, N (%)	78 (19.3)	92 (24.8)
Median length of surgery in minutes (IQR)	180 (120–180)	120 (90–180)	<0.001
Antibiotic prophylaxis measures
Prophylaxis use, N (%)	366 (90.6)	316 (85.2)	0.020
Preoperative prophylaxis, N (%)	260 (64.5)	169 (46.0)	<0.001
Intraoperative prophylaxis, N (%)	252 (62.4)	194 (52.7)	0.007
Postoperative prophylaxis, N (%)	354 (87.6)	282 (76.6)	<0.001
Median duration of prophylaxis in days (IQR)	1 (4–9)	4.5 (1–7)	<0.001
Prophylactic medications
Cefazolin, N (%)	107 (27.8)	93 (26.9)	0.782
Cefuroxime, N (%)	27 (7.0)	63 (18.2)	<0.001
Cefazolin + Cefuroxime, N (%)	139 (36.1)	151 (43.6)	0.038
Cefazolin + Other, N (%)	42 (10.9)	11 (3.2)	<0.001
Other, N (%)	70 (18.2)	28 (8.1)	<0.001
Surgery type
Removal of pin/screw/wire/rod/plate/nail, N (%)	29 (7.2)	44 (11.9)	0.026
Total Knee Arthroplasty, N (%)	159 (39.4)	19 (5.1)	<0.001
Repair of ligament or tendon, N (%)	48 (11.9)	27 (7.3)	0.030
Open reduction with internal fixation, N (%)	66 (16.3)	64 (17.3)	0.734
Osteotomy, N (%)	4 (1.0)	17 (4.6)	0.002
Closed reduction, N (%)	23 (5.7)	9 (2.4)	0.022
Arthroscopy, N (%)	6 (1.5)	45 (12.1)	<0.001
Excision of lesion/biopsy, N (%)	11 (2.7)	41 (11.1)	<0.001
Other, N (%)	58 (14.4)	105 (28.3)	<0.001
Time of surgery
AM, N (%)	240 (59.9)	180 (49.3)	0.003
PM, N (%)	161 (40.1)	185 (50.7)
Previous colonization, N (%)	9 (2.2)	11 (3.0)	0.518

AM, morning; BMI, body mass index; NSAID, nonsteroidal anti-inflammatory drug; PM, afternoon.

. Staples were more frequently used in older patients, while sutures were more frequently used in male patients. Staples were used more frequently in patients with diabetes, higher BMI, and those using non-steroidal anti-inflammatory drugs (NSAIDs) or anticoagulants, whereas sutures were more frequently used in smokers.

Staple use tended to be more frequent with longer operation time. Prophylactic antibiotics were prescribed more often in the staples group, but when prescribed in the sutures group, they were given for longer durations. The choice of wound closure varied by surgery type, with staples commonly used in total knee arthroplasties. Additionally, the timing of surgery influenced the closure method, possibly reflecting differences in surgery scheduling and efficiency, as staples allow faster closure, while sutures are preferred in more complex trauma cases.

Clinical outcomes are shown in

Table 2. Clinical outcomes in different methods of wound closure.

	Staples (N= 404)	Sutures (N= 371)	p-Value
SSI, N (%)	14 (3.5)	4 (1.1)	0.028
SSI type a
Superficial, N (%)	9 (69.2)	3 (100)	0.267
Deep, N (%)	4 (30.8)	0 (0)
Wound discharge, N (%)	18 (4.5)	4 (1.1)	0.005
Wound dehiscence, N (%)	2 (0.5)	2 (0.5)	0.932
Median length of stay in nights (IQR)	5 (2–7)	1 (0–3)	<0.001

SSI, surgical site infection. ^a SSI type was undocumented in 2 patients with confirmed SSI.

. Over the study period, a total of 18 patients (2.3%) contracted an SSI, with a higher rate observed in the staples group. Although the SSI type did not differ significantly between closure methods, wounds closed with staples showed increased wound discharge. LOS was notably longer for patients with staple closure compared to sutures (5 days vs. 1 day).

Logistic regression analysis was performed to identify the risk factors associated with SSIs (

Table 3. Risk factors associated with SSI.

	SSI (N = 18)	No SSI (N = 757)	p-Value
Median age in years (IQR)	59 (45.3–65.0)	47 (30.0–63.0)	0.177
Gender
Male, N (%)	6 (33.3)	455 (60.1)	0.002
Female, N (%)	12 (66.7)	302 (39.9)
Median BMI in kg/m2 (IQR)	33.1 (30.9–39.0)	29 (24.6–33.9)	0.001
Smoking, N (%)	4 (22.2)	108 (14.3)	0.343
Medical Comorbidity
Diabetes, N (%)	7 (38.9)	185 (24.4)	0.160
Renal Failure, N (%)	0 (0.0)	21 (2.8)	0.474
Medications
Steroids, N (%)	1 (5.6)	50 (6.6)	0.859
NSAIDs, N (%)	11 (61.1)	339 (44.8)	0.169
Antibiotics, N (%)	10 (55.6)	120 (15.9)	<0.001
Anticoagulants, N (%)	13 (72.2)	292 (33.4)	0.004
Admission type
Elective, N (%)	13 (72.2)	592 (78.2)	0.544
Trauma, N (%)	5 (27.8)	165 (21.8)
Median length of surgery in minutes (IQR)	180 (165–240)	150 (120–180)	0.012
Antibiotic prophylaxis measures
Prophylaxis use, N (%)	17 (94.4)	665 (87.8)	0.395
Preoperative prophylaxis, N (%)	13 (72.2)	416 (55.3)	0.154
Intraoperative prophylaxis, N (%)	12 (66.7)	434 (57.6)	0.439
Postoperative prophylaxis, N (%)	15 (83.3)	621 (82.4)	0.915
Median duration of prophylaxis in days (IQR)	10 (3–17)	5 (2–7)	0.030
Prophylactic medications
Cefazolin, N (%)	4 (22.2)	196 (27.5)	0.621
Cefuroxime, N (%)	0 (0)	90 (12.6)	0.107
Cefazolin + Cefuroxime, N (%)	7 (38.9)	283 (39.7)	0.945
Cefazolin + Other, N (%)	2 (11.1)	51 (7.2)	0.522
Other, N (%)	5 (27.8)	93 (13.0)	0.108
Surgery type
Removal of pin/screw/wire/rod/plate/nail, N (%)	0 (0)	73 (9.6)	0.166
Total Knee Arthroplasty, N (%)	9 (50.0)	169 (22.3)	0.006
Repair of ligament or tendon, N (%)	0 (0)	75 (9.9)	0.160
Open reduction with internal fixation, N (%)	4 (22.2)	126 (16.6)	0.531
Osteotomy, N (%)	0 (0)	21 (2.8)	0.474
Closed reduction, N (%)	1 (5.6)	31 (4.1)	0.758
Arthroscopy, N (%)	0 (0)	51 (6.7)	0.255
Excision of lesion/biopsy, N (%)	0 (0)	52 (6.9)	0.250
Other, N (%)	4 (22.2)	159 (21.0)	0.900
Time of Surgery
AM, N (%)	11 (61.1)	409 (54.7)	0.588
PM, N (%)	7 (38.9)	339 (45.3)
Previous colonization, N (%)	1 (5.6)	19 (2.5)	0.421
Closure Technique
Staples, N (%)	14 (77.8)	390 (51.5)	0.028
Sutures, N (%)	4 (22.2)	367 (48.5)
Median length of stay in nights (IQR)	6 (4.8–33)	3 (0–6)	<0.001

AM, morning; SSI, surgical site infection; BMI, body mass index; NSAID, nonsteroidal anti-inflammatory drug; PM, afternoon.

). A significant association was found between SSI and the following factors in the univariate analysis: female gender, BMI, use of antibiotics, use of anticoagulants, length of surgery, duration of antibiotic prophylaxis, total knee arthroplasty, closure technique, and LOS.

Variables that were significant in the univariate analysis, together with known risk factors to cause SSIs, were entered as covariates in a multivariate analysis model and are shown in

Table 4. Independent predictors of SSI (N = 775).

	SSI %	No SSI %	Adjusted OR (95% CI)	p-Value
Gender				0.531
Female	66.7	39.9	0.654 (0.173–2.472)
Male	33.3	60.1
Diabetes				0.541
No	61.1	75.6	1.468 (0.429–5.032)
Yes	38.9	24.4
Steroids				0.523
Yes	5.6	6.6	0.482 (0.052–4.507)
No	94.4	93.4
Closure technique				0.928
Staples	77.8	51.5	1.075 (0.222–5.198)
Sutures	22.2	48.5
Admission type				0.811
Elective	72.2	78.2	1.251 (0.199–7.844)
Trauma	27.8	21.8
BMI			1.062 (0.999–1.129)	0.054
Duration of antibiotic prophylaxis			1.076 (1.010–1.147)	0.023
Length of surgery			1.004 (0.996–1.011)	0.321
Length of stay			1.047 (1.013–1.083)	0.007
Anticoagulants			1.069 (0.242–4.732)	0.930
Antibiotics			5.938 (1.693–20.820)	0.005
Total knee arthroplasty			0.414 (0.079–2.172)	0.297

SSI, surgical site infection; OR, odds ratio; CI, confidence interval.

. After adjustment of potential confounders, it became evident that the odds of SSI were significantly higher in patients with increased LOS, use of antibiotics, and longer duration of antibiotic prophylaxis. The type of wound closure used, however, did not influence the odds of SSI. There was no difference in the odds of SSI with any of the other covariates.

Organisms isolated from infection sites are presented in

Table 5. Organisms isolated from infection site fluid or tissue.

	N (%)
Culture-negative	8 (44.44)
Acinetobacter baumannii a	1 (8.33)
Corynebacterium	1 (8.33)
Citrobacter koseri a,b	1 (8.33)
Enterobacter cloacae a,b	1 (8.33)
Enterococcus faecalis	1 (8.33)
Klebsiella pneumoniae b,c	2 (16.67)
Methicillin-Resistant Staphylococcus Aureus (MRSA)	2 (16.67)
Pseudomonas aeruginosa	2 (16.67)
Rhizopus	1 (8.33)

^a Multidrug-resistant (MDR) isolate. ^b Citrobacter koseri, Enterobacter cloacae, and Klebsiella pneumoniae were isolated from the wound of one subject. ^c One isolate was multidrug resistant.

. The causative organisms were found to be highly variable between patients who developed SSIs. Nearly half of the cases produced culture-negative swabs, while the remainder were mainly caused by gram-negative bacilli, Methicillin-Resistant Staphylococcus Aureus (MRSA), or other less common pathogens. Among the SSIs in the sutures group, identified organisms included MRSA, Corynebacterium, and a combined isolate of Citrobacter koseri, Enterobacter cloacae, and Klebsiella pneumoniae, with one case yielding no growth, while the remaining infections occurred in the staples group.

4. Discussion

In this prospective cohort study, it was found that while unadjusted analysis suggested a higher SSI rate with staples compared to sutures, this was not significant after adjusting for confounders. However, staple use was associated with longer hospital stays. Additionally, use of antibiotics, longer hospital stay, and extended antibiotic prophylaxis were identified as independent risk factors for SSI.

The results in the literature concerning the occurrence of SSI in sutured versus stapled wound closure remain a topic of controversy [15]. It is crucial, therefore, to identify well-designed, high-quality studies with an acceptable sample size. A large randomized controlled trial (RCT) was published in 2020 in which the staple group was demonstrably associated with a nearly three times greater risk of SSI [16]. Through a systematic review and meta-analysis by Krishnan et al., 2019 [17], they assessed whether the use of staples or sutures after orthopedic surgery influenced SSI and described no difference between sutures and staples in terms of SSI when the analysis was limited to RCTs with a low risk of bias. However, when a subgroup analysis was conducted based on anatomic site, hip surgeries showed a higher risk of SSI in patients randomized to staples compared to those who received sutures for skin closure [17]. In addition, in a systematic review and meta-analysis specifically examining elective knee and hip arthroplasty, Kui et al., 2022 found that wound closure with staples was associated with a higher risk of SSI compared to sutures [18]. On the other hand, a study evaluating skin closure with surgical staples in ankle fractures reported that staples provided a safe and reliable method without increased infection rates, highlighting the potential variation in outcomes based on anatomical site and surgery type [19]. One chart review of primary joint arthroplasties also reported a lower rate of complications in the staple group when compared to the suture group [14]. The above study was limited by a retrospective design and an underpowered sample with significant differences in the distribution of groups allocated to different methods of wound closure.

Few studies compared LOS for patients who underwent orthopedic surgeries with wounds closed by sutures versus staples. Moreover, most of the studies that reported LOS had an insignificant statistical difference between the two closure techniques [6,7,15]. In this study, a significant difference favoring sutures over staples was demonstrated; however, this difference may reflect that staples were more frequently utilized in surgeries requiring longer hospital stays, such as knee arthroplasties, rather than a causal effect of the closure method itself. This was similar to the results of a study performed by Rui et al., 2017 [20], in which a remarkable difference in LOS was found (p < 0.001), and LOS averaged 6 days and 12 days for the sutures group vs. the staples group, respectively [20]. Furthermore, a systematic review and meta-analysis concluded that, though statistically insignificant, there is a marginal advantage of LOS with the use of sutures [21].

This study’s results showed that increased LOS, use of antibiotics, and duration of antibiotic prophylaxis were independent risk factors for acquiring SSI. Post-operative SSI attributed to prolonged LOS is well documented in several studies in the literature [22,23]. It is likely that longer hospitalization predisposes patients to greater exposure to hospital-acquired and multidrug-resistant (MDR) pathogens. This is evident by the high incidence of resistant organisms isolated from infected wounds in this study population. The risk can be mitigated by reducing the length of pre-surgical hospital stay in elective surgeries and limiting admission to the same day of the surgery rather than the day prior, as suggested by Herruzo-Cabrera et al., 2004, and Triantafyllopoulos et al., 2015 [22,24].

This study also demonstrated significantly higher odds of SSI with the use of antibiotics and a longer antibiotic prophylaxis duration. Most of the literature recommends against an extended antibiotic prophylaxis duration since continuation of antibiotic prophylaxis showed no additional benefit in reducing the incidence of SSI [22,25,26]. For instance, in a meta-analysis including both clinical trials and observational studies assessing the rate of SSI post total joint arthroplasty, no difference in SSI rate was found among the groups who received short (≤24 h) vs. prolonged (>24 h) courses of antibiotic prophylaxis postoperatively [27]. Similarly, S. M. Isaac 2016 demonstrated that a short course of antibiotics prophylaxis is as effective as a long course in infection prophylaxis in adults with open tibial fractures [28]. In addition to showing no benefit, unnecessary prolonged exposure to antibiotics carries several dire risks. One main concern is the development of antimicrobial resistance. The World Health Organization (WHO) has recognized antimicrobial resistance as one of the major threats to global health [29]. Another issue associated with excessive use of antibiotics is the potential to cause opportunistic infections, as demonstrated by this study’s findings. W. J. Gillespie and colleagues 2010 examined the effect of a single vs. multiple doses of prophylactic antibiotics on the incidence of SSI and other hospital-acquired infections in patients undergoing surgical management of proximal femur or other closed long bone fractures. Despite the beneficial effect of both strategies on the incidence of deep SSI, the single-dose prophylaxis significantly reduced the rate of urinary and respiratory tract infections, while this was not demonstrated in the multiple-dose regimen [30]. Despite these findings, the continuation of antibiotic prophylaxis for several days after surgery is still commonly practiced worldwide [31]. This warrants strengthening awareness among surgeons and anesthetists and prioritizing stewardship efforts.

Increased BMI is of particular importance in orthopedics, with a growing body of evidence reporting the association of obesity with SSIs [23,24,32,33]. In a nationwide prospective study in England, the risk of SSI increased linearly with increasing BMI in patients undergoing knee replacement surgery [33]. Besides its direct effect on SSIs, obesity was reported to be significantly associated with a longer median inpatient stay [34]. A multifactorial mechanism is thought to contribute to the risk of infection in obesity [35]. On one hand, obesity was found to affect tissue oxygenation, leading to hypoxia and impairment of wound healing [36]. On the other hand, obesity often results in prolonged operative time and local tissue trauma [34,37]. In addition, the relation of obesity to multiple chronic comorbidities linked to surgical infections, such as diabetes, is well-established [32]. Moreover, antibiotics show different pharmacokinetics in obese patients when compared to non-obese patients [38]. Therefore, obese patients require higher doses of prophylactic antibiotics to achieve adequate serum levels. Although significant preoperative modification of body weight may be difficult, obese patients should be counseled and informed of the potential increase in infection risk prior to surgery.

Diabetes, length of surgery, gender, steroid use, and anticoagulation were not independent predictors of SSIs in this study. Although diabetes has been a positive predictor of SSIs in most studies investigating independent risk factors of SSIs, no association was found in this study [7,32,39,40]. Previous data reported that the risk of SSI increases by 2.5% for every additional 30 min in surgical time. Lengthy surgeries carry a higher risk of tissue ischemia and exposure to airborne pathogens. Hence, long surgeries have been considered a predictor of SSIs in some studies [40]. Like multiple other studies, no gender association towards higher SSI rate was found in this study [32,40]. Few studies investigated the regular use of steroidal medications and their relation to SSIs. A study by Kawata et al., 2018 concluded that regular use of steroids was an independent risk factor after anterior cruciate ligament reconstruction [41]. The use of anticoagulants in orthopedic surgeries is common. Preoperative heparinization was an independent risk factor for SSI in a study limited to knee arthroplasties [42].

Data regarding the microbiological profile of orthopedic SSIs is available but remains variable across regions and healthcare settings. In studies by Mardanpour et al., 2017, Al-Mulhim et al., 2014, Herruzo-Cabrera et al., 2004, and Elifranji et al., 2022, Gram-positive pathogens represented the vast majority of the isolated pathogens [22,43,44,45]. Unlike these reports, the most identified infective organisms in this study were Gram-negative pathogens, with most of the isolates falling under hospital-acquired or MDR classes. This could be due to the increased LOS and continuation of antibiotics in those patients, in particular. Similar findings have been reported in a study on SSIs following orthopedic surgeries in a tertiary care hospital in India, where Gram-negative organisms constituted the majority of isolates, with Klebsiella pneumoniae being the most prevalent pathogen [46].

Major limitations of this study include a lack of homogeneity of the population and the fact that many of the variables were not controlled for. In particular, the choice of wound closure method was based on the surgeon’s discretion, which may introduce selection bias due to surgeon-specific practices and preferences, potentially affecting SSI outcomes and contributing to residual confounding. Additionally, assessors were not blinded to the closure technique, which may introduce detection bias when evaluating SSI outcomes. The observational nature of the study and lack of randomization may have overestimated the findings because of these confounders. Furthermore, although the LOS was longer in the staples group, which is a known risk factor for SSI, our data did not include the precise timing of infection onset relative to surgery or discharge. Therefore, we could not determine whether prolonged length of stay was a cause or consequence of infection, limiting the ability to conduct time-to-event analyses. The prospective study design, however, was chosen to offset some of the drawbacks of observational designs and record much data that would not usually be documented in patients’ records. The enormous sample size can help in overcoming this limitation, enable this study to contribute to the available data, and possibly alter clinical decisions.

5. Conclusions

While the univariate analysis identified a higher observed rate of SSIs with the use of staples compared to sutures, this association was not significant after adjusting for confounding variables. However, the closure of wounds with staples was associated with a significant increase in LOS. This study also identified increased use of antibiotics, prolonged LOS, and prolonged use of antibiotic prophylaxis as independent risk factors for increased SSI. This study’s results may have been limited by the observational study design and the lack of control of many potential confounders. However, its findings should urge orthopedic surgeons to ponder the choice of closure technique, which might have an impact on the duration of hospital stay that may, in turn, lead to an increased risk of SSI. In addition, the implementation of strict antibiotic use hospital policies and stewardship programs is of crucial importance. Future research comparing this relationship in upper versus lower limb surgeries in large clinical trials is recommended.