Incisional Negative Pressure Wound Therapy Use on Orthopaedic Lower Extremity Trauma: An Updated Systematic Global Review

Abstract

Background: Advancements in surgical wound management have led to improved healing and reduced complications. Incisional negative pressure wound therapy (iNPWT) is a technique that applies sub-atmospheric pressure to closed surgical wounds, enhancing blood flow, minimizing edema, and promoting tissue repair. Initially developed for chronic wounds, its use has expanded across multiple surgical specialties, including orthopaedic trauma surgery, to reduce complications such as dehiscence, infection, and prolonged healing. While traditional wound care relies on standard closure methods with simple dressings, iNPWT offers additional mechanical support and may lower the risk of deep surgical site infections (SSIs). This review examines the current evidence on iNPWT’s role in preventing SSIs following surgery for lower extremity fractures to guide clinical decision-making and improve patient outcomes. Methods: A systematic search through PubMed and MEDLINE utilizing our inclusion and exclusion criteria yielded seven randomized controlled trials and randomized prospective cohort studies that were subsequently analyzed to determine iNPWT effectiveness. Results: Of the seven studies, five showed a decreased SSI rate compared to standard wound dressing, with the other two exhibiting an increased infection rate. Conclusions: This review critically examines existing literature on iNPWT, analyzing level I and II studies on deep SSI rates in traumatic fractures. The evidence remains inconclusive on whether iNPWT offers a significant advantage over standard wound dressings, highlighting the need for further research to clarify its efficacy and clinical application.

1. Introduction

Management of surgical wounds has evolved significantly over the past few decades, contributing to improved patient outcomes and reduced rates of complications [1]. Negative pressure wound therapy on primary closed incisional wounds (iNPWT) is a treatment modality employed by clinicians that involves the application of sub-atmospheric pressure to create a vacuum that is believed to have multifactorial benefits on healing. Although popularized in the early 1990s, the basic mechanism of action of negative pressure wound therapy can be traced back to the Roman Empire, where suction therapy was often used to reduce complications secondary to battle wounds [2]. In the modern era, iNPWT was originally reserved for chronic, complex wounds such as diabetic ulcers and pressure sores. It has since evolved to provide more precise pressure control, stronger seals to the wound, and increased portability, resulting in faster healing and reduced complications [3]. These advancements have contributed to the broader use of iNPWT in various specialties such as cardiothoracic, orthopaedic, and general surgery [3]. Though “iNPWT” is sometimes used interchangeably with “wound vac therapy” due to a similar mechanism, it is worth highlighting that wound vac therapy usually pertains to open wounds that were not closed with suture or staples, unlike iNPWT.

Traditionally, primary closed incisional wounds are managed with simple sutures or staples followed by standard postoperative care such as absorbent foam dressings, gauze and elastic bandages, casting, or splinting. However, there is growing interest in iNPWT to enhance healing and minimize postoperative morbidity through its ability to promote blood flow, reduce edema, and improve tissue granulation at the primary wound site [3]. Furthermore, the employment of iNPWT is thought to enhance mechanical forces that support tissue approximation, improve oxygenation, and stimulate cellular growth and regeneration [3]. iNPWT is also postulated to reduce the rate of deep SSIs, partially due to its ability to reduce the production of inflammatory exudates, although this precise mechanism remains unknown.

The following paper reviews the current literature surrounding the use of iNPWT to reduce SSIs while stratifying the evidence according to fracture type in lower extremity trauma. By having a stronger understanding of the effects of iNPWT and its applicability, clinicians will be better equipped to selectively employ this method of wound therapy and may be able to reduce patient morbidity, length of hospital stay, infections, and wound dehiscence.

2. Indications and Use of iNPWT

iNPWT is most widely employed in the treatment of closed incisional wounds that carry high risk for surgical site infection due to patient comorbidities, mechanism of injury, and wound type. The top 25 of these risk factors were investigated by a 2017 multidisciplinary consensus article to recommend indications for iNPWT in various surgical fields like orthopaedic, plastic, cardiothoracic, vascular, and general surgery. These comorbidities include but are not limited to, diabetes mellitus, obesity, advanced age, prolonged operative time, reoperation, patient American Society of Anesthesiologists (ASA) of ≥3, chronic obstructive pulmonary disease (COPD), peripheral vascular disease, emergency operations, and non-healing wounds [4]. In the acute setting, iNPWT is used to facilitate closure of wounds at high risk of infection, with high tissue tension, or severe swelling that renders primary closure unfeasible. Acute wounds that commonly present with these complications include open fractures, large lacerations, and burns requiring skin grafting. These wounds are highly prone to infection [1], thus, wound debridement is often necessary before the application of iNPWT. iNPWT is also commonly used in wound dehiscence, due to previous failure of primary closure. In addition, iNPWT promotes increased healing rates after the revision of primary closure [3].

High-risk fractures seen in acute trauma may have incisions that are difficult to close or are in suboptimal anatomical positions, therefore, iNPWT can be used. iNPWT dressings can be applied over skin grafts, reducing the risk of infection and reducing the length of hospital stay when compared to conventional skin graft dressings [3]. Management of chronic wounds, including those secondary to venous or arterial insufficiency, diabetes, or high pressures, has also increasingly been treated with iNPWT. In orthopaedic surgeries, iNPWT is commonly used to manage surgical incisions and reduce infections, hematomas, seromas, and dehiscence [5]. In inpatient orthopaedic settings, traditional iNPWT devices are typically larger, electrically powered systems that require a constant power source, limiting patient mobility. In contrast, outpatient settings often utilize portable, lightweight, single-use iNPWT systems, such as Prevena™ and PICO™, which enhance patient mobility and comfort [6]. By managing exudate and reducing bacterial contamination, iNPWT aims to enhance wound healing and support patient recovery, although clinical outcomes may vary based on patient and surgical factors [5].

Despite the utility of iNPWT for high-risk patients, there are absolute and relative contraindications to its use. For example, iNPWT should be avoided in the presence of necrotic tissue with eschars, active osteomyelitis, non-enteric fistulas, in wounds with active malignancy, exposed neuro-vasculature, exposed anastomotic sites, and exposed organs [7]. Additionally, some iNPWT dressings contain metallic parts which may pose problems in diagnostic tools such as MRI or life-saving measures like defibrillation and must be removed before these interventions and procedures [5].

The application of iNPWT involves several key steps. It begins with postoperative preparation, where the incision site is cleaned and assessed to ensure that there are no exposed vessels or nerves. The foam dressing is then centrally placed over the incision, ensuring that the whole incision is covered. Fixation strips are applied over the foam to secure and maintain an airtight seal. Once the pump is connected to the dressing with a tube connected to a port that is in contact with the foam, negative pressure is initiated, typically at −125 mmHg, which has been shown to effectively promote granulation tissue formation and enhance blood supply to the wound area [7]. Regular monitoring is essential to check for leaks, dressing saturation, or blockages. Usually, if a leak is detected, the machine alerts the user, which allows for immediate troubleshooting to address the leak properly. Dressings are changed when saturated or at least once every seven days. Therapy is discontinued when minimal fluid collection is observed for at least 12 h, indicating sufficient wound healing [5,8] (Figure 1).

The proposed mechanisms by which iNPWT may enhance wound healing include the reduction of lateral tension on the wound edges, which may help prevent dehiscence and promote wound approximation [9]. Negative pressure is also believed to assist in the removal of exudate, potentially reducing bacterial contamination and lowering the risk of SSIs. Additionally, negative pressure is thought to stimulate blood flow and angiogenesis, providing oxygen and nutrients to the healing tissue [10]. Lastly, it has been hypothesized that iNPWT reduces localized edema, enhancing nutrient delivery and reducing pain and inflammation [11].

3. Materials and Methods

This systematic review was conducted following the Joanna Briggs Institute (JBI) methodology and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews.

3.1. Review Question

Our research question was the following: “Does incisional negative pressure wound therapy (iNPWT) reduce the incidence of postoperative surgical site infections (SSIs) in lower extremity orthopaedic trauma surgeries compared to standard wound dressings?”.

3.2. Eligibility Criteria

The clinical studies qualified for inclusion if they met the following population, concept, and context (PCC) criteria. Population (P): Studies were included if they involved participants of any age or gender who underwent orthopaedic trauma surgery. Concept (C): Included studies directly compared iNPWT to standard wound dressings, assessing outcomes such as SSI rates, wound healing complications, and the need for reoperation. Only studies reporting clinical measures of deep SSI rates, wound dehiscence, or related postoperative complications in the context of lower extremity traumatic orthopaedic fractures were considered. Context (C): Eligible studies were randomized controlled trials (RCTs) with a follow-up period of at least 30 days. Only human studies published in English between January 2009 and February 2025 were included.

3.3. Exclusion Criteria

Studies were excluded if they did not meet the PCC criteria, lacked comparative data between iNPWT and standard wound care, or were observational without a randomized control design. Additionally, animal studies, case reports, and studies focusing solely on chronic wounds or non-orthopaedic surgical procedures were excluded.

3.4. Search Strategy

To find relevant studies for inclusion, a comprehensive search strategy was employed. This strategy was conducted across two databases to ensure a thorough examination of the literature. PubMed and MEDLINE were searched using a combination of MeSH terms and keywords from January 2009 to February 2025, limiting the search to papers published between January 2009 and February 2025.

3.5. Study Selection Process

After filtering for human clinical trials published from 2009 to 2025 written in English, 52 articles were identified through this search method. After removing duplicates, 28 articles remained and were subsequently screened by reading the titles and abstracts. Of these 28, 21 articles were excluded for not meeting the inclusion criteria. This systematic review assessed and included the full text of the final seven articles. The assessment of inclusion for the selected studies involved two processes. First, we screened study titles and reviewed the abstracts. Then, we assessed the full text. This process was conducted individually by two authors, with any disagreements being resolved by a third. The process adheres to the PRISMA 2020 guidelines for transparency and reliability.

3.6. Data Extraction and Data Synthesis

This review’s data were extracted using a form based on the JBI tool to encapsulate key details such as authorship, publication year, study design, patient characteristics, outcomes, interventions, and other relevant data. Subsequently, descriptive analyses of these data were conducted (Figure 2).

4. Outcomes and Results

A total of seven studies were included in this review (

Table 1. Study Characteristics and Demographics.

Study	Study Type	Level of Evidence	Fracture Type	Sex (M/F)	Mean Age (years)	Avg BMI (kg/m2)	Follow-Up Duration
Stannard et al. (2009) [12]	Prospective Randomized Study	Level II	Severe Open Fractures	39 M/19	N/A	N/A	12 months
Stannard et al. (2012) [13]	Multicenter RCT	Level I	High-Risk Lower Extremity Fractures	161/88	N/A	N/A	12 months
Crist et al. (2017) [14]	Prospective Randomized Trial	Level II	Acetabular Fractures	47/16	43.7	30.4	Fracture Union
WOLLF RCT (2018) [15]	Multicenter RCT	Level I	Open Lower Limb Fractures	342/118	42.5	N/A	12 months
Canton et al. (2020) [16]	Prospective Randomized Study	Level II	Ankle & Distal Tibia Fractures	22/43	66	26	Postoperative
WHIST RCT (2020) [17]	Multicenter RCT	Level I	Major Trauma to Lower Limb	965/583	49.8	26.5 ± 5.9	6–12 months
WHISH RCT (2021) [18]	Multicenter RCT	Level I	Hip Fractures	134/328	85	N/A	30–90 days

). Four of the seven studies were randomized controlled studies, with the other three being prospective studies. A total of 2913 patients were included in these studies. Total patients, sex, mean age, level of evidence, fracture type, and follow-up duration were evaluated (Table 1). Additionally, the summarized results, infection rate for both iNPWT and standard dressing, primary outcome, strengths and weaknesses, and JBI score were also evaluated (

Table 2. Analysis Of Study Results.

Study	Sample Size	Infection Rate—Standard Dressings (%)	Infection Rate—iNPWT/NPWT (%)	Primary Outcome	Key Findings	Strengths & Weaknesses	JBI Critical Appraisal
Stannard et al. (2009) [12]	58	28.0	5.4	Total infection rate (acute and delayed) post-severe open fractures	This study on severe open fractures found significantly lower infection rates with iNPWT (5.4%) versus control (28%), p = 0.024. The relative risk ratio was 0.199, indicating iNPWT patients were one-fifth as likely to develop infections. For tibial fractures, infection rates were 8% with iNPWT and 36% in the control group. The iNPWT group had no acute infections and 2 delayed infections (5.4%), while the control group had 2 acute (8%) and 5 delayed infections (20%).	Strengths: RCT with long follow-up, robust NPWT comparison, and reduced deep infections. Weaknesses: Small, unblinded, single-center study with potential selection bias.	9/13
Stannard et al. (2012) [13]	249	18.9	9.9	Infection and wound dehiscence rate post high-risk fractures	This larger study on high-risk lower extremity fractures reported infection rates of 9.9% with iNPWT versus 18.9% in the control group (p = 0.049). For closed fractures, rates were 9% (iNPWT) vs. 19% (control), p < 0.05. By fracture type, infections in iNPWT vs. control were Calcaneus (5 vs. 8), Pilon (2 vs. 5), and Tibial plateau (7 vs. 10). Control patients were 1.9 times more likely to develop an infection than those treated with iNPWT.	Strengths: Multicenter RCT, reduced dehiscence/infections, comprehensive high-risk fracture analysis. Weaknesses: No blinding, selection bias, fracture heterogeneity, industry funding.	11/13
Crist et al. (2017) [14]	71	6.1	15.2	Deep infection rate following acetabular ORIF	This study on acetabular fractures found higher infection rates with iNPWT: 15.2% (iNPWT) vs. 6.1% (control), though not statistically significant (p = 0.25). Patients in the iNPWT group were 2.77 times more likely to develop an infection. All deep infections in this study involved posterior wall or column fractures.	Strengths: RCT targeting high-risk acetabular fractures with clear criteria and strong methodology. Weaknesses: No infection difference, unblinded, small size, gender bias, limited generalizability.	9/13
WOLLF RCT (2018) [15]	460	7.1	8.1	Functional outcomes using DRI, Deep SSI infections.	The WOLLF trial on open lower limb fractures assessed functional outcomes via the Disability Rating Index (DRI) at 12 months, finding no significant difference between NPWT (45.5, SD 28.0) and standard dressings (42.4, SD 24.2); mean difference −3.9 (95% CI −8.9 to 1.2; p = 0.132). Deep SSI rates at 30 days were 7.1% (16/226) for NPWT and 8.1% (19/234) for standard dressings, with no statistical comparison reported.	Strengths: Large multicenter RCT with strong randomization, follow-up, and clear outcomes. Weaknesses: No blinding, possible assessment bias, no clinical benefit, high cost.	11/13
Canton et al. (2020) [16]	65	10.2	0	Wound healing complications (minor and major) in ankle/distal tibia fractures	Overall, 29.2% of patients had complications, most commonly surgical wound dehiscence (24.6%), wound edge necrosis (13.8%), and surgical site infection (6.2%). Although not statistically significant, the iNPWT group had fewer minor complications (6.3% vs. 30.6%) and no infections (0% vs. 10.2%) compared to the conventional dressing group.	Strengths: Prospective cohort of high-risk ankle/tibia fractures showing reduced minor complications with iNPWT. Weaknesses: Small, unblinded, non-randomized, selection bias, no difference in primary outcome.	8/13
WHIST RCT (2020) [17]	1548	6.7(30 Days) 13.2(90 Days)	5.8 (30 Days) 11.4(90 Days)	Deep SSI at 30 and 90 days post-surgery	No significant difference in deep SSI rates was found between NPWT and standard dressings. At 30 days, rates were 5.8% (45/770) for NPWT vs. 6.7% (50/749) for standard dressings (OR 0.87, 95% CI 0.57–1.33; p = 0.52), and at 90 days, 11.4% (72/629) vs. 13.2% (78/590), respectively (OR 0.84, 95% CI 0.59–1.19; p = 0.32). No difference in health-related quality of life was observed.	Strengths: Large, multicenter study with high follow-up and economic analysis. Weaknesses: No blinding, no outcome difference, high cost, limited generalizability.	11/13
WHISH RCT (2021) [18]	462	6.4(30 days) 6.4(90 days)	1.9(30 days) 2.3(90 days)	Deep SSI rate at 30 and 90 days	The WHISH feasibility trial on elderly hip fracture patients showed a trend toward lower deep SSI rates with NPWT. At 30 days, rates were 1.9% (4/214) for NPWT vs. 6.4% (14/218) for standard dressings (risk ratio 0.29; 95% CI 0.10–0.85). At 90 days, rates were 2.3% vs. 6.4%, respectively, though no statistical significance was reported. As a feasibility study, WHISH was not powered for definitive conclusions.	Strengths: Robust multicenter RCT with clear outcomes and strong recruitment. Weaknesses: Small sample, unblinded, short follow-up, limited global applicability.	10/13

).

The WHIST trial, involving 1548 adult patients with lower limb fractures associated with major trauma, reported 30-day deep SSI rates of 5.8% (45/770) in the iNPWT group versus 6.7% (50/749) in the standard dressing group (OR 0.87, 95% CI 0.57–1.33; p = 0.52). At 90 days, the corresponding rates were 11.4% (72/629) for NPWT and 13.2% (78/590) for standard dressings (OR 0.84, 95% CI 0.59–1.19; p = 0.32). Notably, the overall 30-day deep SSI rate was 6.3% (95/1519), lower than the 15% anticipated in the sample size calculation [17]. Focusing on 460 patients with open lower limb fractures, the WOLLF trial found the total 30-day deep SSI rates to be 7.6% (35/460), with the iNPWT group boasting 7.1% (16/226) and 8.1% (19/234) in the standard dressing group. The estimated odds ratio was 1.18 (95% CI 0.59 to 2.37 in favor of iNPWT but this was not statistically significant (p = 0.638). These findings contradict smaller studies conducted by Stannard et al. in 2009 and 2012, providing no evidence that iNPWT results in a reduction of deep surgical site infection as opposed to standard dressing [12,13]. In contrast, the WHISH feasibility trial, which included 462 elderly patients undergoing hip fracture surgery, showed lower infection rates and a trend favoring iNPWT. At 30 days, deep SSI rates were 1.9% (4/214) for iNPWT versus 6.4% (14/218) for standard dressings (risk ratio 0.29; 95% CI 0.10–0.85). At 90 days, infection rates were 2.3% (5/214) in the iNPWT group and 6.4% (14/218) in the standard dressing group, with an overall 30-day deep SSI rate of 4.2% (18/432; 95% CI 2.7–6.5) [18].

Stannard et al. reported significantly lower overall infection rates with iNPWT among patients with severe open fractures: 5.4% (2/37 fractures) in the iNPWT group versus 28% (7/25 fractures) in the control group (p = 0.024). The relative risk (RR) was 0.199, indicating that patients treated with iNPWT were only one-fifth as likely to develop an infection [12]. A larger study by Stannard et al. in 2012, involving 249 patients with 263 high-risk lower extremity fractures, showed similar results. The overall infection rate was 9.9% (14/141 fractures) in the iNPWT group compared to 18.9% (23/122 fractures) in the control group (p = 0.049). In this study, the relative risk of developing an infection was 1.9 times higher in the control group compared to those treated with iNPWT [13].

Canton et al. reported that 29.2% of patients experienced complications, with surgical wound dehiscence being the most common (24.6%), followed by wound edge necrosis (13.8%) and surgical site infection (6.2%). While not statistically significant (p = 0.565), the iNPWT group showed a notably lower rate of minor complications (6.3%) compared to the conventional dressing group (30.6%). The infection rate was 0% in the iNPWT group versus 10.2% in the conventional dressing group [16]. By contrast, Crist et al. found higher infection rates in the iNPWT group (15.2%, 5/33 patients) than in the control group (6.1%, 2/33 patients) for acetabular fractures. Although not statistically significant (p = 0.25), patients in the iNPWT cohort were 2.77 times more likely to develop a deep infection [14].

Finally, when considering only closed fractures, Stannard in 2012, reported infection rates of 9% (12/133 fractures) in the iNPWT group versus 19% (23/121 fractures) in the control group (p < 0.05), demonstrating a statistically significant benefit of iNPWT for closed fractures [13].

Subgroup Analysis by Fracture Type

In the WHIST trial, which included 1548 adult patients with lower limb fractures associated with major trauma, over 80% of the open fractures involved the tibia; however, specific infection rates for tibial fractures were not reported [17]. Femur fractures were noted as the second most common, followed closely by foot fractures, yet no detailed infection data were provided for these types. The WHISH trial focused exclusively on hip fractures in patients over 65 and reported a 30-day deep SSI rate of 4.2% (18/432, 95% CI 2.7–6.5). Notably, the 30-day deep SSI rate in the iNPWT group was 1.9% (4/214) compared to 6.4% (14/218) in the standard dressing group. By contrast, the WOLLF trial investigated open lower limb fractures, finding 30-day deep SSI rates of 7.1% (16/226) in the iNPWT group and 8.1% (19/234) in the control group, but without a further breakdown by fracture location. None of these trials provided a comprehensive subgroup analysis of infection by fracture type, making direct comparisons challenging and suggesting only a potential difference between hip fractures and other lower limb fractures [15].

Several studies, however, offer more targeted information about iNPWT. Stannard in 2009, reported significantly lower infection rates for severe open fractures with iNPWT (5.4%) than with standard dressings (28%; p = 0.024) [12]. Stannard in 2012, observed overall infection rates of 9.9% (iNPWT) versus 18.9% (control; p = 0.049) among 263 high-risk lower extremity fractures. A breakdown by fracture site in that study included infection counts for the calcaneus (5 vs. 8), pilon (2 vs. 5), and tibial plateau (7 vs. 10), favoring iNPWT [13]. An earlier report by Stannard in 2009, specifically on tibial fractures, demonstrated infection rates of 8% (iNPWT) versus 36% (control) [12]. Research focusing on ankle and distal tibia fractures also reflects these positive trends: Canton found deep infection rates of 0% (iNPWT) versus 10.2% (control; p = 0.565) [16]. In contrast, Crist noted higher rates of infection in patients with acetabular fractures treated with iNPWT (15.2% vs. 6.1% in the control group, p = 0.25) [14].

5. Discussion

5.1. Surgical Site Infection Rates

There is available evidence to suggest that the implementation of iNPWT reduces the rate of SSIs. Findings from Stannard in 2009 showed that there was a statistically significant difference in the rate of total infections between the two groups (p = 0.024), and that patients in the iNPWT group were one-fifth as likely to obtain an SSI compared to the standard dressing group [12]. Considering the differences in infection rates between groups were 5.4% versus 28% in the control group, this result has clinical importance as it shows a dramatic reduction in infection rate when using iNPWT. Furthermore, they found that bacterial clearance was greater in the iNPWT group, with 8% colonization compared to 20% of control wounds colonized. While this was found to be not significant, it can provide further support indicating that iNPWT leads to decreased SSIs. With improved bacterial clearance from the wound, patients undergoing iNPWT have a minimized risk of infection. Similarly, a second study conducted by Stannard in 2012 found a statistically significant difference between the groups regarding the total number of infections, with the iNPWT group performing better. It was found that patients in the control group were 1.9 times more likely to experience an infection compared to the iNPWT group [13]. This is also clinically significant as there was a large reduction in the number of patients who experienced an SSI, 9.9% versus 18.9%. This study supports the previous findings from 2009 showing that iNPWT is effective at reducing infection in more severe trauma cases and acute infection prevention, as well. Both articles highlight the potential for use as a prophylactic strategy for high-risk trauma fractures, while also bringing up the factor of time as a possible way to measure effectiveness.

Other studies demonstrate results that have favorable trends to support the use of iNPWT, although not significant. In Canton’s study, it was determined that there were no statistically significant differences between the two groups for complications, but the incidence of minor complications was lower in the iNPWT group (6.3%) compared to standard dressing (30.6%) [16]. The small sample size may have limited the power; however, this finding indicates that iNPWT may lead to a lowered risk of minor complications when powered correctly. Similarly, the differences between SSI and surgical wound dehiscence rates both exemplified that iNPWT may be a better option, despite not being statistically significant. Considering this study population was composed of those with comorbidities, it may be concluded that iNPWT is associated with a lower rate of minor complications in patients with risk factors for infection. Similarly, Stannard in 2009 found significant findings regarding SSI and wound dehiscence rates for patients with risk factors in favor of iNPWT, providing further evidence that it is a tolerable and efficacious option to promote wound healing in this population [12]. The WHISH trial provided valuable insights into the potential benefits of iNPWT in elderly surgical patients, which found a significant reduction in deep SSIs among patients treated with iNPWT following surgery for hip fractures (95% CI, 2.7–6.5%) [18]. Although significant, the WHISH trial is a feasibility trial and only suggests the possibility of a clinically meaningful reduction in SSI rates in a larger population, rather than providing true evidence of efficacy. Nonetheless, given that hip fractures are highly prevalent in the elderly population and given the severity of SSIs as a postoperative complication, the results of the study highlight iNPWT as a potential therapeutic option for these patients.

Multiple studies did not find a statistically significant relationship between iNPWT and SSIs. Crist had seven total patients who experienced a deep infection, two from the standard dressing group and five from the iNPWT group, demonstrating that iNPWT does not reduce SSIs [14]. Though not statistically significant, it was even found that patients in the iNPWT group were 2.77 times more likely to develop a deep infection (p = 0.25). However, the iNPWT group was composed of a higher proportion of males, which has been proposed as a risk factor for postoperative SSIs in the literature [19]. Although this may have contributed, the mechanism regarding the increased rate of infection in the iNPWT group is unclear. A limited sample size represents a clear limitation of this study that can impact power, ultimately affecting whether a significant difference can be detected. In contrast, the WOLLF and WHIST trials were sufficiently powered and yet saw no difference in rates of deep SSIs between an iNPWT group and standard dressing group [15,17]. Variability in surgical techniques and postoperative wound care practices across multiple centers could have influenced outcomes, reducing the trials’ abilities to detect a true effect. Furthermore, adherence to iNPWT protocols and variations in its application might have introduced inconsistencies in treatment effects. Length of time therapy was applied, differences in device settings, or improper sealing of the wound dressings may have affected the studies’ outcomes. For the WHIST trial specifically, infection rates were in part determined by tissue viability analysts who evaluated photographs of the incisions [17]. Due to the quality of the photos and being limited to one point in time in a two-dimensional image, reported infection rates may have been partially inaccurate. Lastly, while both studies were well-powered, the expected difference between groups may have been overestimated, and a larger sample size or longer follow-up could have been necessary to detect a more subtle effect. These articles suggest that while iNPWT may offer benefits in certain contexts, its universal effectiveness for surgical wound healing remains uncertain.

5.2. Patient Satisfaction and Health-Related Quality of Life

Health-related quality of life (HRQoL) and patient satisfaction (PS) are influenced by multiple factors beyond wound healing, including pain management, rehabilitation, and psychological well-being. While patient satisfaction in the Crist study was not directly studied, it can be assumed that prolonged hospital stays, whether consisting of time spent in ICU, or overall length of stay, can impact patient satisfaction. This study found a statistically significant increase in ICU duration for patients with deep infections (p = 0.02). Since the ICU length of stay was found to be around 7.3 days for the control group versus 2.3 days for the iNPWT group, a reduction of 5 days is clinically significant as it can lead to further cost savings and increased patient satisfaction [14]. Therefore, it can be concluded that interventions that can impact the rate of infection, such as iNPWT, can also indirectly impact patient satisfaction by prolonging or shortening hospital stay. This is further supported by the hospital length of stay being 9.8 days versus 13.4, although not statistically significant, it is meaningful in the clinical setting. For the 2009 Stannard study, data were collected pertaining to physical component scores (PCSs) and mental component scores (MCSs). While there were no differences for the MCS, there was a significant difference in the PCS at three, six-, and nine-months post-op, with p-values of 0.013, 0.049, and 0.005, respectively [12]. Since PCS is representative of a patient’s health as it relates to their quality of life, it can be concluded that patients in the iNPWT group had higher scores with an increased quality of life, potentially due to fewer postoperative complications such as infection. Interestingly, the study also found that the PCS score at nine months was higher than expected compared to a score considered normal quality of life, contrasting heavily with the control group, with scores that were 50% less than that. This provides additional evidence of the clinical significance of the use of iNPWT, as these patients specifically experienced less interference of physical ailments, such as SSI, on their lives, evident by their higher scores compared to both the control group as well as a standard population. This supports the use of iNPWT as a way of not only reducing the risk of SSI but also serving to improve patient satisfaction in both an acute and long-term manner.

WOLLF and WHIST trials did not find a significant change in PS or HRQoL scores between groups [15,17]. The WOLLF trial measured HR-QoL using EuroQoL-5 Dimensions (EQ-5D) utility score (quality of life health status from “perfect health” to “death”), EQ-5 Dimensions Visual Analog Scale (EQ-5D VAS) (health status from “worst imaginable to best imaginable”), and SF-12 scores with MCS and PCS components in preoperative period, immediate postoperative period, and at three, six, nine, and twelve months post-op. Though both groups showed improvements in HRQoL over time as they recovered from surgery, there was no meaningful difference in reported pain, mobility, self-care, usual activities, or overall well-being. While both groups improved in physical health following surgery, though never achieving pre-injury scores, neither saw a positive trend in mental health scores [15]. Thus, it may take longer, beyond one year post-injury, for mental health to recover. The WHIST trial utilized EQ-5D and EQ-5D VAS scores as well, but included DN4 and Patient Observer Scar and Assessment Scale (POSAS) to assess chronic pain and wound healing, respectively. Results also demonstrated no significant changes in these criteria [17]. Thus, findings from the WOLFF and WHIST trials suggest that iNPWT did not provide additional benefits in terms of reducing pain, improving function, or enhancing overall recovery experiences. Potential reasons for this include the fact that wound complications and deep infections were similarly distributed between groups, meaning neither cohort experienced a disproportionate burden of complications that could negatively impact HRQoL. Additionally, psychological and functional recovery may be more strongly influenced by fracture severity, rehabilitation protocols, and individual patient factors rather than wound management strategies alone [20,21]. Since iNPWT primarily targets wound healing, its lack of effect on HRQoL suggests that broader recovery factors played a more significant role in patient-reported outcomes. While deep SSIs were the primary focus, wound healing complications, rehospitalization rates, and HRQoL were not the main endpoints, leaving gaps in the understanding of iNPWT’s full impact on patient recovery. A longer follow-up period might have provided a more comprehensive evaluation of iNPWT’s potential benefits beyond initial infection rates. Given that HRQoL is highly subjective, differences in patient expectations, baseline health status, and post-operative support systems may have contributed to the absence of a clear benefit for iNPWT in this domain.

5.3. Fracture Type

Fracture types were variable throughout these studies, but all were in the lower extremity. The Gustilo–Anderson (G&A) classification is a widely used system for categorizing open fractures based on the severity of soft tissue damage, contamination, and fracture pattern. It consists of three main types: I, II, and III. Type I fractures are simple fractures with minimal comminution or contamination, associated with a wound less than one centimeter, and little to no soft tissue damage. Type II fractures are associated with a wound greater than one centimeter, moderate contamination and comminution, but are still without extensive soft tissue damage. Type III is further subdivided into IIIA (adequate soft tissue coverage), IIIB (extensive soft tissue loss requiring reconstruction), and IIIC (vascular injury requiring repair). This classification helps guide treatment decisions, surgical management, and infection risk assessment in orthopaedic trauma cases. Higher Gustilo types have significantly increased infection rates and poor wound healing. Specifically, Type IIIB and IIIC fractures have infection rates ranging from 20 to 50% in the literature, making severe open fractures an important target for intervention [22].

The WOLLF trial looked exclusively at open fractures of the lower extremity, with most of the fractures (over 80%) being in the tibia, and the majority of the patient population being young men in their twenties. The remaining 30 percent of the population that were women were most commonly in their seventies [15]. This correlates with the suggestion that young men are more likely to suffer from high-energy, traumatic injuries associated with open fractures, while older women are more likely to endure lower-energy, closed fractures related to an osteoporotic state. This bimodal distribution of fracture energy is commonly known in the field of orthopaedic trauma [23,24]. The WHIST trial did not comment on the type of fracture but rather took note of the specific bone involved and laterality of the wound. Tibia/fibula (575 total, 37.2% overall) and femur (271 total, 37.1% overall) fractures made up the majority of injury types [17]. No further data on SSI rates subgroup analyses were observed when stratifying by specific fracture type in either of these trials.

Stannard in 2009 looked at more complex fractures, but overall fracture type within this study was variable. Following the G&A classification, all heavily contaminated type II, IIIA, IIIB, and IIIC fractures were included [12]. Due to the difficult nature of diaphyseal tibial fractures, this group was studied independently. Of the five total infections within this group, four came from standard dressing, while one came from iNPWT, with an incidence of 36% versus 8%. The nature of severe open fractures leads to them being more prone to infection. Since these fracture types are more extensive, the results that iNPWT lowered the rate of infection are promising that this therapy may be better suited for this specific indication.

In the Canton study, it was concluded that there were no statistically significant differences in the ability of iNPWT to decrease SSI, but the differences in fracture distribution between the standard and iNPWT groups pose a question in making this conclusion. The authors discuss how tri-malleolar ankle fracture-dislocation patterns are known to have more complications concerning wound healing, which could make this specific fracture pattern more difficult to heal in a postoperative setting [16]. This could potentially impact the results of the study by placing the iNPWT-treated group at a disadvantage from the start, since it was found that this group consisted of a significantly higher amount of this specific fracture pattern compared to the standard dressing group, p = 0.034. Otherwise, separating the outcomes based on the type of fracture did not reveal any significant differences in the rate of complications.

In the 2012 Stannard study, the fractures included were calcaneus, pilon, and tibial plateau, all of which are linked to increased infection in a postoperative setting. Calcaneus fractures had a higher incidence of infection, however, iNPWT was most preventative in this fracture type as well [13]. While this study was not specifically trying to associate the use of iNPWT with a fracture type, this intervention showed encouraging results for all three. Further, fracture type could be categorized based on open or closed, and since there were three patients in the control group with open fractures versus seven in the iNPWT group, overall findings were analyzed both with and without this specific subgroup. Total delayed infections in the iNPWT group were reduced compared to the control group when excluding open fractures [13], suggesting that both open and closed fractures benefited from the iNPWT intervention. Crist et al. looked primarily at acetabular fractures requiring open reduction internal fixation (ORIF), another fracture type known to be at higher risk of infection. The higher rate of deep SSI in the iNPWT group in this study underscores the importance of further research to better ascertain the type of fractures that have the most effective results with iNPWT.

5.4. Comorbid Conditions

Certain comorbidities, such as obesity, smoking, and diabetes mellitus, significantly impact wound healing after orthopaedic trauma surgery, increasing the risk of postoperative complications [25,26]. Aberrant vascularization, chronic inflammatory states, and weakened immune response are hallmarks of these processes and likely explain this increased risk [27,28].

In 2009, Stannard proposed a stratified approach, recommending that patients with at least one comorbidity receive iNPWT instead of standard wound dressings—a strategy later supported by the Wang 2019 meta-analysis [29]. The iNPWT group contained a higher number of patients who smoked, and even with this imbalance, still achieved a significant reduction in SSI rates. It is reasonable to conclude that the use of iNPWT is beneficial in high-risk populations, potentially mitigating the increased rate of infection associated with this specific population. Given these findings, iNPWT may offer particular benefits for high-risk patients, potentially reducing complications and improving overall recovery outcomes [4].

In the Canton study, a part of the inclusion criteria was that patients needed to have at least one risk factor commonly associated with poor wound healing, including obesity, diabetes mellitus, and smoking status. The authors further discussed that historically, the rate of SSIs and complications is higher in patients with these specific comorbidities. However, in this study, there were no significant differences found regarding the incidence of developing wound complications based on risk factors for the patients [16]. Similarly, the 2012 Stannard study monitored smoking and diabetic status. There were similar numbers of smokers per group, and more diabetics in the iNPWT group (11 vs. 4). While this was not significantly different, it can still highlight the advantage of iNPWT, as this group had better results, even though the composition leaned more toward diabetics [13].

The Crist study showed conflicting results regarding comorbidities. It was found that of those patients who had an SSI, it was less likely that they were older than 65 (OR: 0.47, p = 0.61) [14]. This is an unexpected finding as old age is usually associated with worse wound healing. For patients who had a BMI over 35, they had a higher likelihood of getting an SSI (OR: 2.65), more consistent with what is expected, as obesity is considered a risk factor that can impede wound healing; however, neither of these was significant. The 2009 Stannard study made note of patients who were either smokers or diabetic and found no differences between the two groups concerning risk factors that affect wound healing [12].

The WOLLF, WHISH, and WHIST trials did not perform subgroup analyses of SSI rates in patients with reported risk factors for wound healing, though the distribution of patients with diabetes mellitus, regular smoking habits, and greater alcohol use per week in all trials was distributed evenly between groups [15,17,18]. In the WHIST trial, there was a greater percentage of diabetes mellitus in the standard dressing group vs. the iNPWT group (11.1% vs. 8.0%, respectively).

None of the studies in this review commented on other comorbid conditions that affect wound healing, including peripheral artery disease, cardiovascular disease, immunosuppressed state, or autoimmune diseases. This may be an important confounding variable affecting infection rates throughout all studies. Failing to account for these factors also has important clinical implications, as failure to tailor postoperative wound care strategies based on individual risk profiles can result in ineffective infection prevention, longer hospital stays, and potential need for revision surgeries. Therefore, comprehensive risk assessment and optimization strategies are critical to minimizing SSIs and improving overall surgical outcomes. However, given the low rates of SSIs overall, it is unclear how much of an effect this would have on outcomes.

5.5. Cost-Effectiveness

Balancing cost-effectiveness and quality care is essential to maintain financial sustainability while delivering optimal patient outcomes. High-cost interventions that do not provide significant clinical benefits can strain hospital budgets, leading to resource shortages, staffing challenges, and increased healthcare disparities [30]. Cost-conscious decision-making, such as choosing evidence-based, cost-effective treatments and preventive measures, helps institutions reduce unnecessary expenses, lower readmission rates, and optimize healthcare delivery. Thus, it is critical to determine whether there is an economic advantage to iNPWT by either reducing cost or improving outcomes.

The Stannard study from 2012 called attention to the economic feasibility of iNPWT implementation. The cost to use iNPWT was found to be less than $500 [12] and considering patients in this group were ready for discharge earlier, the cost savings associated with a shortened hospital stay more than balanced out the cost to use it. Furthermore, the anticipated cost of treating an infection would be much more than what it takes to supply the iNPWT. These findings provide insight into the practicality of the incorporation of this therapy, so far showing an overall cost saving. Similarly, while the Canton study did not explicitly look at the economics associated with iNPWT; it cites a study conducted by Mullins et. al, showing overall cost savings around $5338 for infections and $1586 for wound dehiscence when using iNPWT [16,31]. Both studies support the use of iNPWT in terms of cost-effectiveness.

The WOLLF trial’s cost-effectiveness analysis was through the National Health Service (NHS) and Personal Social Services (PSS) perspectives in the United Kingdom for twelve months postoperatively. NHS data include all healthcare-related costs covered by the government, such as hospital stays, surgeries, medications, and follow-up care. PSS information includes extra care services that might be needed, such as rehabilitation, home care, and support for patients recovering from surgery. Their analysis revealed that iNPWT incurred higher average costs (£678) and provided only a marginal increase in Quality-Adjusted Life Years (QALYs) (0.002) compared to standard dressings [15]. The probability of iNPWT being cost-effective did not surpass 27%, even when varying the willingness-to-pay thresholds. The initial patient stay mean costs were £1223 higher in the iNPWT group (p = 0.030), but otherwise, there were no statistically significant differences in costs between the trial arms in any cost category. These findings suggest that iNPWT is unlikely to be a cost-effective strategy for improving outcomes in this patient population. The WHIST trial involved a similar analysis using the NHS and PSS perspective but only evaluated up to the six-month postoperative mark. The incremental cost of using standard dressings instead of iNPWT over six months was £2037 per patient (95% CI: £349 to £3724) [17]. Only 0.005 QALYs were gained (95% CI: −0.018 to 0.028), further reinforcing that there was no meaningful improvement in patient-reported health outcomes with iNPWT use. The probability of iNPWT being cost-effective at a standard UK threshold of £20,000 per QALY was even lower than the WOLLF trial at 1.9%, making it highly unlikely to be a worthwhile investment. Since iNPWT did not significantly reduce SSIs or improve healing, the extra cost may not be justified for routine use in lower limb fracture surgeries [17]. It is also worth noting that both the WOLLF and WHIST trials were conducted in the U.K., where the NHS often covers costs associated with iNPWT and hospital stays overall. Patients in the U.S. are more likely to pay for the same expenses out-of-pocket, depending on insurance coverage, meaning iNPWT may be even less cost-effective if applied to the U.S. healthcare system. Spending money on more costly interventions that do not yield significant benefits unnecessarily diverts funds from other critical areas, such as patient care, staffing, and essential medical supplies. Overall, there may not be sufficient evidence to support implementing iNPWT as it relates to cost-effectiveness.

5.6. Limitations

There are several limitations to this review. As stated earlier, four of the seven included trials were multicenter studies and may have unreported differences in wound care technique, length of time therapy was applied, differences in device settings, or improper sealing of the wound dressings. Trials focused on a variety of outcomes, which limited our ability to draw definitive conclusions about the results. Studies also had varying definitions of “surgical site infection”, with some using the CDC criteria and others using a vaguer terminology. Per the CDC, a superficial SSI is defined as an infection occurring within 30 days of surgery and involving only the skin or subcutaneous tissue of the incision. It is diagnosed based on purulent drainage, positive cultures, localized infection symptoms (pain, redness, swelling, or heat) with incision reopening, or a physician’s diagnosis of a superficial SSI. In contrast, deep SSIs, according to the CDC, are infections occurring within 30 days of surgery (or within 1 year if an implant is placed) and involve the deep soft tissues, like fascia and muscle. They are diagnosed based on purulent drainage, deep incision dehiscence with signs of infection, an abscess detected through imaging or reoperation, or a physician’s diagnosis of a deep SSI [32]. This is in comparison to Crist et al., which more loosely defined superficial SSIs as drainage plus one or more signs of infection, and deep SSIs as “those that require operative debridement [14]”. Heterogeneity in these measures likely over- or underestimates true SSI rates in the studies’ populations. Additionally, the quality of the included studies varies, with some exhibiting methodological limitations such as small sample sizes, lack of blinding to either treatment, or incomplete outcome reporting, which may introduce biases. Our search was also limited to the English language, introducing a potential language bias. Despite these limitations, this review provides valuable insight into the current literature surrounding the efficacy of iNPWT and brings attention to key areas for future research.

5.7. Focus for Future Studies

This review highlights the need for larger, well-designed randomized controlled trials to determine whether iNPWT is effective in reducing postoperative complications following orthopaedic trauma surgery. Specifically, studies should focus on whether iNPWT should be reserved for specific fracture types or certain high-risk patients. While iNPWT appears promising for open fractures and elderly hip fracture patients, its role in closed fractures and certain anatomical sites remains unclear. Though patient satisfaction, quality of life, and economic feasibility were assessed in some of these studies, the evidence to support iNPWT as a superior intervention in these areas is lacking. Standardization in defining SSIs should also be employed to accurately assess true infection rates between groups.

6. Conclusions

The current evidence from randomized controlled trials focusing on SSI rates following surgery for traumatic fractures provides questionable evidence on whether iNPWT is more effective than standard wound dressing. Many factors, such as fracture type, location, and severity, seem to play a role in these varying rates. While there are level I and II studies that demonstrate promising results in reducing SSIs, there are also level I studies that did not show a reduction. High variability in selection criteria, subgroup analyses, fracture type, and overall rates of SSIs between studies may have impacted the ability to detect true significance. Despite conflicting results surrounding the efficacy of iNPWT, it is both safe and tolerable for patients, with some evidence to suggest increased patient satisfaction in the postoperative setting. Furthermore, based on studies conducted in the United States, it is economically practical to use iNPWT, especially in circumstances where SSIs are prevented. Further research is needed to clarify the relationship between iNPWT and SSIs and to identify specific patient populations that would benefit the most from iNPWT. This manuscript has a grade of recommendation of IIb and conclusions of evidence of B, as per the GRADE system.