Purpose: Previous work demonstrated that negative pressure wound therapy (NPWT) resulted in less Pseudomonas aeruginosa than standard wet-to-dry (WTD) dressings in a complex orthopaedic wound model. Staphylococcus aureus is more clinically relevant in open fractures, and is the most prevalent bacteria in osteomyelitis. The purpose of this study is to determine if S. aureus responds similarly to P. aeruginosa when treated with NPWT. Methods: A complex musculoskeletal wound was created on the hindlimb of 20 goats and contaminated with S. aureus (lux) bacteria. The bacteria are genetically engineered to emit photons, allowing for quantification with a photon-counting camera system. The wounds were débrided and irrigated with 9 L of normal saline using gravity flow irrigation 6 hours after inoculation. Goats were assigned to two different treatment groups: a control group using WTD dressing changes and an experimental group using NPWT. The wounds were débrided and irrigated every other day for 6 days. Bacteria within the wounds were quantified both before and after each débridement. Results: There was no difference between treatment groups in amounts of bacteria in the wound at all time points (p≥0.37). Conclusion: Previous work demonstrated that NPWT resulted in a significant and clinically relevant reduction of P. aeruginosa at all time points in a similar model. We presume that NPWT was effective because it created an environment that allowed the body to ward off this “opportunistic” gram negative. However, as shown in this study, S. aureus is less affected by NPWT and persists within the wound

Introduction. Negative pressure wound therapy (NPWT) and vessel loop assisted closure are two common methods used to assist with the closure of fasciotomy wounds. This retrospective review compares these two methods using a primary outcome measurement of skin graft requirement. Methods. A retrospective search was performed to identify patients who underwent fasciotomy at our institution. Patient demographics, location of the fasciotomy, type of assisted closure, injury characteristics, need for skin graft, length of stay and evidence of infection within 90 days were recorded. Results. A total of 56 patients met the inclusion criteria. Of these, 49 underwent vessel loop closure and seven underwent NPWT assisted closure. Patients who underwent NPWT assisted closure were at higher risk for requiring skin grafting than patients who underwent vessel loop closure, with an odds ratio of 5.9 (95% confidence interval 1.11 to 31.24). There was no difference in the rate of infection or length of stay between the two groups. Demographic factors such as age, gender, fracture mechanism, location of fasciotomy and presence of open fracture were not predictive of the need for skin grafting. Conclusion. This retrospective descriptive case series demonstrates an increased risk of skin grafting in patients who underwent fasciotomy and were treated with NPWT assisted wound closure. In our series, vessel loop closure was protective against the need for skin grafting. Due to the small sample size in the NPWT group, caution should be taken when generalising these results. Further research is needed to determine if NPWT assisted closure of fasciotomy wounds truly leads to an increased requirement for skin grafting, or if the vascular injury is the main risk factor

Objectives. The period of post-operative treatment before surgical wounds are completely closed remains a key window, during which one can apply new technologies that can minimise complications. One such technology is the use of negative pressure wound therapy to manage and accelerate healing of the closed incisional wound (incisional NPWT). . Methods. We undertook a literature review of this emerging indication to identify evidence within orthopaedic surgery and other surgical disciplines. Literature that supports our current understanding of the mechanisms of action was also reviewed in detail. . Results. A total of 33 publications were identified, including nine clinical study reports from orthopaedic surgery; four from cardiothoracic surgery and 12 from studies in abdominal, plastic and vascular disciplines. Most papers (26 of 33) had been published within the past three years. Thus far two randomised controlled trials – one in orthopaedic and one in cardiothoracic surgery – show evidence of reduced incidence of wound healing complications after between three and five days of post-operative NPWT of two- and four-fold, respectively. Investigations show that reduction in haematoma and seroma, accelerated wound healing and increased clearance of oedema are significant mechanisms of action. . Conclusions. There is a rapidly emerging literature on the effect of NPWT on the closed incision. Initiated and confirmed first with a randomised controlled trial in orthopaedic trauma surgery, studies in abdominal, plastic and vascular surgery with high rates of complications have been reported recently. The evidence from single-use NPWT devices is accumulating. There are no large randomised studies yet in reconstructive joint replacement. Cite this article: Bone Joint Res 2013;2:276–84

Objectives

Wound complications are reported in up to 10% hip and knee arthroplasties and there is a proven association between wound complications and deep prosthetic infections. In this randomised controlled trial (RCT) we explore the potential benefits of a portable, single use, incisional negative pressure wound therapy dressing (iNPWTd) on wound exudate, length of stay (LOS), wound complications, dressing changes and cost-effectiveness following total hip and knee arthroplasties.

Aims. To evaluate the impact of negative pressure wound therapy (NPWT) on the odds of having deep infections and health-related quality of life (HRQoL) following open fractures. Methods. Patients from the Fluid Lavage in Open Fracture Wounds (FLOW) trial with Gustilo-Anderson grade II or III open fractures within the lower limb were included in this secondary analysis. Using mixed effects logistic regression, we assessed the impact of NPWT on deep wound infection requiring surgical intervention within 12 months post-injury. Using multilevel model analyses, we evaluated the impact of NPWT on the Physical Component Summary (PCS) of the 12-Item Short-Form Health Survey (SF-12) at 12 months post-injury. Results. After applying inverse probability treatment weighting to adjust for the influence of injury characteristics on type of dressing used, 1,322 participants were assessed. The odds of developing a deep infection requiring operative management within 12 months of initial surgery was 4.52-times higher in patients who received NPWT compared to those who received a standard wound dressing (95% confidence interval (CI) 1.84 to 11.12; p = 0.001). Overall, 1,040 participants were included in our HRQoL analysis, and those treated with NPWT had statistically significantly lower mean SF-12 PCS post-fracture (p < 0.001). These differences did not reach the minimally important difference for the SF-12 PCS. Conclusion. Our analysis found that patients treated with NPWT had higher odds of developing a deep infection requiring operative management within 12 months post-fracture. Due to possible residual confounding with the worst cases being treated with NPWT, we are unable to determine if NPWT has a negative effect or is simply a marker of worse injuries or poor access to early soft-tissue coverage. Regardless, our results suggest that the use of this treatment requires further evaluation. Cite this article: Bone Jt Open 2022;3(3):189–195

Aims. High-energy injuries can result in multiple complications, the most prevalent being infection. Vancomycin powder has been used with increasing frequency in orthopaedic trauma given its success in reducing infection following spine surgery. Additionally, large, traumatic injuries require wound coverage and management by dressings such as negative pressure wound therapy (NPWT). NPWT has been shown to decrease the ability of antibiotic cement beads to reduce infection, but its effect on antibiotic powder is not known. The goal of this study was to determine if NPWT reduces the efficacy of topically applied antibiotic powder. Methods. Complex musculoskeletal wounds were created in goats and inoculated with a strain of Staphylococcus aureus modified to emit light. Six hours after contaminating the wounds, imaging, irrigation, and debridement and treatment application were performed. Animals received either vancomycin powder with a wound pouch dressing or vancomycin powder with NPWT. Results. There were no differences in eradication of bacteria when vancomycin powder was used in combination with NPWT (4.5% of baseline) compared to vancomycin powder with a wound pouch dressing (1.7% of baseline) (p = 0.986), even though approximately 50% of the vancomycin was recovered in the NPWT exudate canister. Conclusion. The antimicrobial efficacy of the vancomycin powder was not diminished by the application of NPWT. These topical and locally applied therapies are potentially effective tools that can provide quick, simple treatments to prevent infection while providing coverage. By reducing the occurrence of infection, the recovery is shortened, leading to an overall improvement in quality of life. Cite this article: Bone Joint Res 2021;10(2):149–155

Aim. Fracture-related infection (FRI) is one of the most serious complications in orthopedic trauma surgery [1]. The role of Negative Pressure Wound Therapy (NPWT) remains controversial in the management pathway of FRI [2]. Currently, as scientific evidence is lacking, most recommendations for NPWT with respect to the treatment of FRI are based on expert opinion [3]. The aim of this study was to assess the influence of NPWT and its duration on recurrence of infection in operatively treated FRI patients. Methods. This is a retrospective cohort study based on the FRI database of three Level 1 Trauma Centres. To be included, patients had to be at least 16 years of age and needed to be surgically treated for FRI between January 1. st. 2015 and September 1. st. 2020. Included patients were subdivided in either the NPWT group, or in the control group, when no NPWT had been applied. To avoid confounding, patients were excluded if they (also) underwent NPWT prior to the FRI diagnosis. The relation between the duration of NPWT during FRI treatment and the recurrence rate of infection was analyzed using a multivariable logistic regression model. Results. 99 patients were included in the NPWT group with a mean age of 51.4 ± 17.0 years. Most patients were male (n = 66). Tibia/fibula was the most common FRI location (n = 68). The median duration of NPWT was 18.0 (IQR 15.8) days. Overall, 28 patients (28.3%) developed a recurrent FRI. In the control group (n = 164), 19 patients (11.6%) developed a recurrent FRI (p = 0.001, 95% CI [0.174 – 0.635]). There were no significant differences in baseline characteristics between the recurrence and non-recurrence category in NPWT group. The duration of NPWT was associated with a higher risk of re-infections (p = 0.013, OR 1.036, 95% CI [1.008 – 1.066]). Conclusion. The application of NPWT is associated with a two-and-a-half-fold increased risk of recurrence in patients with soft tissue defects due to FRI. Also, the duration of NWPT is an independent risk factor for recurrence. Therefore, NPWT should be used with caution in the treatment of orthopedic trauma patients with FRI. It is advised to consider its use only as a short-term necessity to bridge the period until definitive wound closure can be established and to keep this interval as short as possible

Aims. The primary objective of this study was to compare the postoperative infection rate between negative pressure wound therapy (NPWT) and conventional dressings for closed incisions following soft-tissue sarcoma (STS) surgery. Secondary objectives were to compare rates of adverse wound events and functional scores. Methods. In this prospective, single-centre, randomized controlled trial (RCT), patients were randomized to either NPWT or conventional sterile occlusive dressings. A total of 17 patients, with a mean age of 54 years (21 to 81), were successfully recruited and none were lost to follow-up. Wound reviews were undertaken to identify any surgical site infection (SSI) or adverse wound events within 30 days. The Toronto Extremity Salvage Score (TESS) and Musculoskeletal Tumor Society (MSTS) score were recorded as patient-reported outcome measures (PROMs). Results. There were two out of seven patients in the control group (28.6%), and two out of ten patients in the intervention group (20%) who were diagnosed with a SSI (p > 0.999), while one additional adverse wound event was identified in the control group (p = 0.593). No significant differences in PROMs were identified between the groups at either 30 days (TESS, p = 0.987; MSTS, p = 0.951) or six-month (TESS, p = 0.400) follow-up. However, neoadjuvant radiotherapy was significantly associated with a SSI within 30 days of surgery, across all patients (p = 0.029). The mean preoperative modified Glasgow Prognostic Score (mGPS) was also significantly higher among patients who developed a postoperative adverse wound event (p = 0.028), including a SSI (p = 0.008), across both groups. Conclusion. This is the first RCT comparing NPWT with conventional dressings following musculoskeletal tumour surgery. Postoperative wound complications are common in this group of patients and we observed an overall SSI rate of 23.5%. We propose proceeding to a multicentre trial, which will help more clearly define the role of closed incision NPWT in STS surgery. Cite this article: Bone Jt Open 2021;2(12):1049–1056

Negative pressure wound therapy (NPWT) is commonly used to manage severe open fracture wounds. The recently completed X randomized controlled trial (RCT) evaluated the effect of NPWT versus standard wound management on 12-month disability and rate of deep infection among patients with severe open fractures of the lower limb and reported no differences. Using data from the Y trial of open fracture patients, we aimed to evaluate the impact of NPWT on the odds of having deep infections and health-related quality of life (HRQL). Our analyses included participants from the Y trial who had Gustilo II and III lower extremity fractures. To adjust for the influence of injury characteristics on type of dressing received, a propensity score was developed from the dataset. A one-to-one matching algorithm was then used to pair patients with a similar propensity for NPWT. Mixed effects logistic regression was used to evaluate the association between type of wound dressing and development of a deep infection requiring operative management (dependent variable) in the matched cohort. Gustilo type, irrigation solution, fracture location, mechanism of injury, and degree of contamination were included as adjustment variables. To determine any differences in HRQL between the NPWT and standard wound dressing groups, we conducted two multi-level models with three levels (centre, patient, and time) and included Short Form-12 (SF-12) Physical Health Component (PCS) and SF-12 Mental Health Component (MCS) as dependent variables. Gustilo type, irrigation solution, fracture location, mechanism of injury, degree of contamination, and pre-injury SF-12 scores were included as adjustment variables. All tests were 2-tailed with alpha=0.05. After applying propensity score-matching to adjust for the influence of injury characteristics on type of dressing used, there were 270 matched pairs of patients available for comparison. The odds of developing a deep infection requiring operative management within 12 months of initial surgery was 4.22 times higher in patients who received NPWT compared to those who did not receive NPWT (Odds Ratio (OR) 4.22, 95% Confidence Interval (CI) 2.26–7.87. 1,329 participants were included in our HRQL analysis and those treated with NPWT had significantly lower SF-12 PCS at all follow-up visits (6w, 3m, 6m, 12m) post fracture (p=0.01). Participants treated with NPWT had significantly lower SF-12 MCS at 6-weeks post-fracture (p=0.03). Unlike the X trial, our analysis found that patients treated with NPWT had higher odds of developing a deep infection requiring operative management and that being treated with NPWT was associated with lower physical quality of life in the 12 months post-fracture. While there may have been other potential adjustment variables not controlled for in this analysis, our results suggest that the use of this treatment should be re-evaluated

Aims. The aims of this study were to report the outcomes of patients with a complex fracture of the lower limb in the five years after they took part in the Wound Healing in Surgery for Trauma (WHIST) trial. Methods. The WHIST trial compared negative pressure wound therapy (NPWT) dressings with standard dressings applied at the end of the first operation for patients undergoing internal fixation of a complex fracture of the lower limb. Complex fractures included periarticular fractures and open fractures when the wound could be closed primarily at the end of the first debridement. A total of 1,548 patients aged ≥ 16 years completed the initial follow-up, six months after injury. In this study we report the pre-planned analysis of outcome data up to five years. Patients reported their Disability Rating Index (DRI) (0 to 100, in which 100 = total disability), and health-related quality of life, chronic pain scores and neuropathic pain scores annually, using a self-reported questionnaire. Complications, including further surgery related to the fracture, were also recorded. Results. A total of 1,015 of the original patients (66%) provided at least one set of outcome data during the five years of follow-up. There was no evidence of a difference in patient-reported disability between the two groups at five years (NPWT group mean DRI 30.0 (SD 26.5), standard dressing group mean DRI 31.5 (SD 28.8), adjusted difference -0.86 (95% CI -4.14 to 2.40; p = 0.609). There was also no evidence of a difference in the complication rates at this time. Conclusion. We found no evidence of a difference in disability ratings between NPWT compared with standard wound dressings in the five years following the surgical treatment of a complex fracture of the lower limb. Patients in both groups reported high levels of persistent disability and reduced quality of life, with little evidence of improvement during this time. Cite this article: Bone Joint J 2024;106-B(8):858–864

Abstract. Objective. In this systematic review we aim to compare wound complication rates from Negative Pressure Wound Therapy (NPWT) to dry sterile surgical dressings in primary and revision total knee arthroplasty (TKA). Methods. A search was performed using PubMed, Embase, Science Direct, and Cochrane Library. Eligible studies included those investigating the use of NPWT in primary and revision TKA. Exclusion criteria included studies investigating NPWT not related to primary or revision TKA; studies in which data relating to NPWT was not accessible; missing data; without an available full text, or not well reported. We also excluded studies with poor scientific methodology. All publications were limited to the English language. Abstracts, case reports, conference presentations, and reviews were excluded. Welch independent sample t-test was used for the statistical analysis. Results. Our review identified 11 studies evaluating 1,414 patients. Of the 1,181 primary TKA patients analysed (NPWT = 416, surgical dressing = 765), the overall wound complication rates in patients receiving NPWT ranged from 0% – 63% (Median 7.30%, SD ± 21.44) This is in comparison to complication rates of 2.8% – 19% (Median 6.50%, SD ± 6.59) in the dry dressing group. The difference in complication rates between the two groups was not statistically significant (p =0.337). In the revision TKA cohort of 279 patients (NPWT group = 128, dry dressing group = 151), the overall wound complication rates in the NPWT group ranged between 6.7% – 12% (Median 9.80%, SD ± 2.32) vs 23.8% – 30% (Median 26.95%, SD ± 2.53) in the dry dressing group. This difference was statistically significant (p<0.001). Conclusion. NPWT dressing demonstrated statistically significant reduction in wound complication rates when used in revision TKA but not primary TKA when compared to dry sterile dressings. This is probably due to higher wound related risks encountered with revision TKA surgery compared to primary TKA surgery. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Abstract. Objective. In this systematic review we aim to analyse the economical impact of using Negative Pressure Wound Therapy (NPWT) in primary total knee arthroplasty (TKA). Methods. Four medical electronic databases were searched. Eligible studies included those investigating the costs of NPWT in primary TKA. Exclusion criteria included studies investigating cost of NPWT not related to primary TKA. We also excluded studies with poor scientific methodology. We retrieved and analysed data on dressing costs and hospital length of stay (LOS). Results. Three studies (359 patients) reported on dressing and associated health care costs, and two further studies (330 patients) reported on hospital LOS in primary TKA. The cost of NPWT ranged between £125 and £196; with an average cost of £155, compared to £23 for the regular surgical dressing. The hospital LOS in NWPT patients ranged from 1.9 – 3.8 days, while LOS in patients managed with regular surgical dressing ranged between 2.3 – 4.7 days. The hospital LOS accounted for delayed discharge due to wound complications. Any extended LOS secondary to medical comorbidities or for other reasons were not included here. Conclusion. Our pooled analysis found a decrease in hospital LOS from wound related problems when using NWPT instead of regular dressings after accounting for other variables responsible for LOS. If the mean cost of overnight inpatient hospital stay for elective TKA is estimated as £275, the range of overnight admission cost for one TKA patient would be £522 - £1045 when NPWT dressing is used, and £632.5 - £1292 when using regular dressings. The cost savings from reduced LOS amounts to £110 - £247 per patient when NPWT is used. We hypothesize that in primary TKA patients with high risk of wound related problems that may delay discharge from hospital, there may be an overall cost saving when using NWPT dressings. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Aim. Negative-pressure wound therapy (NPWT) is often propagated as treatment option for fracture-related infection (FRI). After surgical debridement and repeated NPWT dressing changes, the wounds are often closed by free flaps. Sometimes even healing by secondary intention seems an alternative. Recently, concerns have been raised on the long-term use of NPWT as it could be related to bacterial overgrowth and possible re-infection. The purpose of this study was to conduct a retrospective evaluation of the influence of long-term NPWT on tissue culture results and outcome in FRI patients. Method. Between January 1. st. , 2015 and December 31st, 2018, a total of 852 patients were treated with NPWT for different indications on the Department of Trauma Surgery. Inclusion criteria for this study were patients with a closed fracture, stabilized with osteosynthetic fixation and complicated with a confirmed FRI according to the FRI consensus definition. Patients were included when they received at least three NPWT dressing changes in the operating room. Exclusion criteria were patients younger than 18 years, or the absence of cultures results from dressing changes. Results. During the study period 23 patients met the inclusion criteria. According to the tripartite classification of Willenegger and Roth, one patient had an early, 14 a delayed and 8 patients a late onset FRI. Overall, 139 NPWT dressing applications were performed, with an average amount of six per patient. In 14 patients (61%) and 57 dressing changes (41%), at least 2 tissue cultures showed the same pathogen or at least one, in case of highly virulent organisms (e.g. S. aureus) during a single dressing exchange. Coagulase-negative staphylococci were present in 33% of the cases, followed by Enterococcus spp. (21%), S. aureus (16%), non-fermentative gram negative bacilli (14%) and Enterobacteriaceae (7%). Furthermore, 17 exchanges showed polymicrobial growth. Five patients had repeatedly significant growth of the same pathogen despite adequate antimicrobial therapy, within this group one patient was immunocompromised. Conclusions. In a large amount of patients (61%), a significant number of positive culture results could be acquired, even in the presence of adequate local and systemic antimicrobial therapy. The clinical relevance of these results remains unclear. This said, it seems important to limit the duration of NPWT as prolonged treatment could increase bacterial overgrowth and possible (re-)infection. Therefore, a rapid definitive soft tissue coverage should be encouraged. Future larger prospective clinical trials are required

Introduction. Over the past decade, the use of negative pressure wound therapy (NPWT) devices has increased and expanded to include a wide variety of patients. However, the safety and efficacy of NPWT over skin in open fractures is still unknown. The purpose of this study was to evaluate the complication rate and outcome of open fractures treated by NPWT over closed wounds or flaps. Materials and methods. We performed a retrospective review of prospectively collected data of 10 patients, with an average age of 37.9 years old, who underwent NPWT over surgically closed wounds or random pattern cutaneous flaps in open fractures. All wounds were debrided and closed, and NPWT was applied over the skin sequentially in emergency operations. Results. The open fracture sites were lower leg (6), foot and ankle (3), and knee (1). The reasons for applying NPWT were the expectation of improved viability of local flaps in 4, impossibility of airtight skin approximation in 3, high risk for wound healing problems due to swelling in 2, and securing of degloved skin in 1. The mean duration of NPWT was 11.3 days. There were 3 skin macerations under foam, however, no flap or degloved skin necrosis occurred. All the fractures eventually united, and there were no deep infections. Discussion and Conclusion. While skin macerations were sometimes seen, they did not affect the overall outcome. NPWT over the skin in open fractures is effective in preventing infection even in high-risk wounds

Purpose of the study: This was a retrospective analysis of patients with bone loss subsequent to an open leg fracture. Negative pressure therapy was applied in 42 cases over a period of 47 months. Material and method: Our strategy was designed around the goal of secondary rather than emergency cover, after preparation of the wound bed with NPWT. The time from the first surgical care to NPWT was 23.38 days on average. Mean duration of NPWT was 21.19 days. Results: After NPWT, gain in wound surface was 18.09% on average. The gain was nil for 52.38% of the patients, positive for 47.62% and exceptional for 4.76%. 100% of the wounds analysed developed a regular border which prepared a bed for a graft or flap without decreasing the depth of the wound. NPWT enabled all patients to reach the set objective: directed healing in 19%, skin graft in 48%, flap in 33%. The objective were achieved for 66% of patients, exceeded, partially achieved for 14% and not reached for 10%. Discussion: We conclude that NPWT is an excellent way to wait for slow healing after cleaning. It stimulates formation of a granulation tissue, favours the development of regular borders, and cleans the wound before definitive surgical treatment. Thus whether achieved with a flap, a graft or directed healing, the final cover is thus minimised. NPWT can also reduce the risk of infection during the initial phase since the wound is drained and outside contamination is limited by the air-tight dressing. Cost remains a limitation even though certain studies have found equivalent cost with conventional dressings, often related to use of lower cost “homemade” dressings

Aims: A previous study demonstrated that negative pressure wound therapy (NPWT) increases tissue pressure. This conflicts with the understanding that these dressings increase perfusion. This randomised case control study investigates the effects that circumferential NPWT has on perfusion in humans and how different suction pressures influence this. Methods: Ten healthy volunteers were recruited into the study and sequentially randomised to receive suction pressures of either −400 mmHg or −125 mmHg. With both hands placed in circumferential NPWT dressings, suction was only applied to one hand. Perfusion of both hands was then analysed simultaneously using radioisotope perfusion imaging. After allowing one week for complete excretion and decay of the isotope, an identical experiment was done on the same volunteers’, this time using the contralateral hand as the test hand. A total of 20 scans were carried out. Data were analysed using the Wilcoxon and Mann-Whitney tests. Results: In the hands that received suction pressures of −400 mmHg, there was a highly significant mean reduction in perfusion of 40% (SD 11.5%, p< 0.0005). In the hands that received suction pressures of −125 mmHg there was also a highly significant mean reduction in perfusion (mean 17%, SD 8.9%, p< 0.0005). The reduction in perfusion of the group undergoing NPWT at −400 mmHg was significantly greater than the group undergoing NPWT at −125 mmHg (p< 0.015). Conclusion: Tissue perfusion beneath circumferential NPWT dressings is significantly reduced when suction is applied, regardless of whether suction pressures of −125 mmHg or −400 mmHg are utilised. There is a significantly greater reduction in perfusion at suction pressures of −400 mmHg, compared to −125 mmHg. This implies that circumferential NPWT should be used with extreme caution, if at all, on tissues with compromised perfusion. This finding represents a paradigm shift in our understanding of the mechanism of action of NPWT

Since its approval by the FDA two decades ago, Negative Pressure Wound Therapy (NPWT) has become a valuable asset in the management of open fractures with significant soft tissue damage as those seen in high velocity gunshot injuries. These lesions are often associated with grossly contaminated wounds and require a prompt and effective approach. Wound dehiscence and surgical site infection are two of the most common post-operative complications, with poor results when treated with standard gauze dresses. NPTW comes as a legitimate resource promoting secondary intention healing through increased granulation and improved tissue perfusion, as well as continuous local wound drainage preventing bacterial growth and further infection. Recent evidence-based guidelines are still limited for use of NPWT in the treatment of Gustilo-Anderson type IIIB open fractures and there are few cases in literature reporting the management of upper extremity injuries. We present and discuss a successful case of a type IIIB open humeral fracture wound treated with NPWT. A 38-years-old male was admitted to the Emergency Room with a type IIIB open humeral fracture as a result of a gunshot with extensive soft tissue damage. IV antibiotic therapy was promptly started followed by surgical stabilization by intramedullary nailing with primary wound closure. The patient presented an early surgical site infection with wound dehiscence requiring secondary debridement with poor subsequent healing and deficient soft tissue coverage. After ineffective 28 days of standard gauze dresses we started NPWT. NPTW was applied using foam coverage over the dehiscence area with visible results after 13 days and complete granulation of the skin defect by the 28th day. The wound healed completely after 14 weeks of NPWT. The fracture evolved into a painless pseudarthrosis revealing an excellent functional recovery and an acceptable aesthetic result. NPTW is a valuable, effective, and well tolerated resource in the treatment of open fractures with extensive soft tissue damage such as Gustilo-Anderson type IIIB fractures. It should be considered not just as a salvage procedure but as well as a primary option especially in grossly contaminated wounds. No benefits in any form have been received from a commercial party

Aims: Previous work at this institution has demonstrated that perfusion beneath circumferential negative pressure wound therapy (NPWT) is decreased, which conflicts with most studies on NPWT and perfusion. This study investigates perfusion beneath non-circumferential NPWT in humans and also discusses the potential methodology flaw common to all previous research in this field. Methods: Tests were conducted on both lower limbs of six volunteers (N=12). Volunteers were sequentially randomised into two groups, which would receive different suction pressures (−400 mmHg and −125 mmHg). A doughnut shaped NPWT dressing was placed over the shin of each leg. The central hole allowed for measurement of the transcutaneous partial pressure of oxygen (tcpO2), an indirect measure of perfusion. Readings were taken every five minutes throughout the experiment. After acquiring readings for 15 minutes to establish a baseline, suction was switched on and readings were taken for another 15 minutes. Suction was then disconnected and readings were taken for 15 minutes. Suction was then reapplied and the sequence was repeated. Data were analysed using the Wilcoxon and Mann-Whitney tests. Results: On applying suction pressures of −400 mmHg, there was a significant reduction of the tcpO2 (mean reduction 7.35 mmHg, SD 7.4, p< 0.0005). At −125 mmHg, there was also a significant reduction of the tcpO2 (mean reduction 5.10 mmHg, SD 7.4, p< 0.0005). Although there was a tendency for greater reductions in the −400 mmHg group this was not significantly different to the −125 mmHg group (p=0.07). Conclusion: NPWT reduces tissue perfusion, with higher suction pressure resulting in greater reductions in perfusion. Studies on perfusion using laser Doppler, which report findings contrary to these, may be flawed due to the measuring technique of this device. The compressive forces of NPWT are likely to result in false increased readings on application of suction when using the laser Doppler. This represents a paradigm shift in our understanding of NWPT and that these dressings should be used with caution on tissues with compromised perfusion

Aim. Negative pressure wound treatment (NPWT) has been widely adopted in the management of septic wound complications or prophylactically after large surgeries. Recent publications have indicated the necessity of further investigations to support the use of NPWT with more evidences. Therefore, the purpose of this pilot-study was to investigate the efficacy of VAC-assisted dressing systems in the treatment of septic trauma cases. Method. We analysed data of 16 retrospective cases following traumas and septic soft tissue surgeries around the hip and knee. The collected data consisted of bacterial cultures, inflammatory markers (WBC, CRP/HCRP) and body temperature, taken periodically during treatment. Also recorded were the time periods the vacuum pump was used during treatment. To increase the number of measurements and to facilitate subsequent data analysis, the measurements were interpolated to regularly sampled curves with a sampling rate of one day. We used cross-plots and linear regression analysis to investigate trends in the data: 1) while the vacuum pump was switched on and 2) while it was switched off. Results. The analysis shows that the average WBC and CRP/HCRP values decline in the first days after initiation of the VAC treatment. WBC values decline in the first four days of VAC treatment (linear regression, R. 2. =0.960). CRP/HCRP values decline in the first thirteen days (linear regression, R. 2. =0.952). No meaningful trends were observed in body temperature measurements. Importantly, there is a trend for an increase of WBC and CRP/HCRP, following the 4. th. and 14. th. days, respectively. These findings suggest that the prolonged use of VAC treatment may result in secondary relapses. Conclusions. Our results indicate a marked decrease of inflammatory markers during the first two weeks, confirming the efficacy of NPWT in the management of septic wounds after traumas. Importantly, our analyses also show a periodic relapse with the prolonged use of NPWT. However, further studies are needed with a larger, standardized population to confirm these findings

Introduction. Hip and knee replacements are predictable orthopaedic procedure with excellent clinical outcomes. Discharging or leaking wounds affect length of hospital stay, affect bed planning and predispose to superficial and potentially deep wound infection. Predictable wound healing therefore remains the first hurdle. This trial aims to study the effectiveness of portable disposable incisional negative pressure wound therapy (NPWT) dressings in hip and knee replacements. This trial aims to study the effectiveness of portable disposable incisional negative pressure wound dressings in hip and knee replacements and the impact on wound healing, length of stay and wound complications. Patients/Materials & Methods. Following ethical approval 110 patients each were randomised to ‘Control group’ and ‘Study group’. Patients in control group received traditional dressings and those in study group received an incisional NPWT (PICO) manufactured by Smith & Nephew. Post operatively, state of the wound, level of wound exudate, length of hospital stay and complications were documented. Results. The average length of stay for control group was 4.72 ± 0.69 (Mean ± SEM) and for the study group 3.79±0.19 (mean ± SEM. Eight percent of the control group patients had wound related complications as opposed to 2% complications in the study group. The mechanical and device related issues in the study group accounted to 10%. Discussion. There is little evidence as to whether wound dressing choices affect wound healing in incisional wounds. There is good evidence for negative pressure wound therapy (NPWT) in complex, open and chronic wounds; however the concept of application of NPWT to routine incisional wounds is novel. Advances such as disposable and portable negative devices have made this option attractive in elective surgery. Conclusion. Our study shows that its application in routine primary hip and knee replacement can improve wound healing, facilitate early and predictable discharge from the hospital and reduce post discharge complications. This is particularly true for high risk wounds such as patients with BMI of >35 and is cost effective