Clinical Efficacy of Combined Internal and External Fixation with Nanosilver Dressing and Vacuum Closure for Gustilo Type I/II Open Tibial Fractures

Summary

The combination of internal and external fixation with nanosilver-based antibacterial dressings (NSAD) and vacuum-assisted closure (VAC) technology demonstrates strong antibacterial activity, reduced healing time, high healing rates, shorter hospital stays, lower medical expenses, and decreased patient pain in the treatment of Gustilo Type I and II open tibial fractures.

Abstract

Gustilo type I and II open tibial fractures (OTFs) are associated with significant soft tissue injury and a high risk of infection, often resulting in prolonged healing and postoperative complications when treated using conventional internal or external fixation. This study introduces a clinically validated approach that integrates nanosilver antibacterial dressing (NSAD) and vacuum-assisted closure (VAC) with closed reduction and intramedullary nail fixation (CRINF) to improve wound and fracture healing outcomes. A total of 300 patients with Gustilo type I/II OTFs were enrolled and randomly assigned into three groups (n = 100 per group): Group 1 received CRINF with conventional wound care, Group 2 received CRINF with VAC, and Group 3 received CRINF with NSAD and VAC. Clinical outcomes, including infection rate, wound and fracture healing time, hospital stay, medical cost, and postoperative pain, were compared among the groups using chi-square and ANOVA tests, with significance defined as p < 0.05. Group 3 exhibited the lowest complication rate and the most favorable recovery profile, with an average wound healing time of 41 days and a fracture healing time of 7.2 months, both significantly shorter than in the control groups (p < 0.05). The wound and fracture healing rates were 97% and 94%, respectively, while patients experienced shorter hospital stays (10-15 days), lower total medical costs (~1500 yuan), and reduced pain levels. These findings demonstrate that combining NSAD and VAC with CRINF offers an effective and safe clinical protocol for managing Gustilo type I and II OTFs, substantially reducing postoperative complications and accelerating recovery.

Introduction

Open tibial fractures (OTFs) are among the most frequent long-bone injuries and usually result from high-energy trauma such as traffic accidents or falls^1,2. Because the fracture site directly communicates with the external environment, these injuries are often accompanied by severe contamination, soft-tissue loss, and a high risk of infection or nonunion^3,4. According to the Gustilo-Anderson classification, OTFs are divided into three types based on the extent of soft-tissue damage and wound contamination: Type I (minimal tissue injury and clean wound), Type II (moderate tissue damage and contamination), and Type III (severe tissue loss often with neurovascular involvement)^5,6.

Traditional management strategies -- external fixation and open internal fixation -- remain clinically important but have inherent limitations. Prolonged external fixation can lead to joint stiffness and fibrous union, whereas extensive internal exposure may prolong operative time and increase infection risk⁷. Consequently, attention has shifted toward adjunctive technologies that enhance infection control and wound healing without compromising fracture stability.

Nanosilver-based antibacterial materials have recently emerged as promising biomedical dressings owing to their broad-spectrum antimicrobial activity and tissue-regenerative potential^8,9,10. The nanosilver material used in this study exhibits a uniform microscopic structure that facilitates sustained silver ion release and stable antibacterial performance (Figure 1). Silver nanoparticles continuously release Ag⁺ ions that disrupt bacterial cell membranes, interfere with enzymatic activity, and promote fibroblast and keratinocyte proliferation^11,12. The proposed antibacterial mechanism of nanosilver-based materials is illustrated in Figure 2.

Simultaneously, vacuum-assisted closure (VAC) therapy creates a localized negative-pressure microenvironment that improves tissue perfusion, stimulates granulation tissue formation, and removes wound exudate to reduce bacterial load^13,14. The main components and functional principle of the VAC system are shown in Figure 3.

Previous studies have demonstrated the individual benefits of either VAC or silver-based dressings in treating open fractures and infected wounds, but have rarely examined their combined application in a large-scale clinical setting^15,16. Therefore, this study investigates the clinical efficacy and safety of integrating nanosilver antibacterial dressing (NSAD) and VAC with closed reduction and intramedullary fixation (CRINF) for the management of Gustilo type I and II OTFs. A schematic overview of the expected therapeutic advantages of this combined approach is presented in Figure 4. We hypothesize that this strategy will enhance antibacterial activity, accelerate soft-tissue and fracture healing, and decrease postoperative complications compared with conventional treatment.

Protocol

This clinical protocol was approved by the Ethics Committee of Hengshui People's Hospital (Approval No. 2019-2-013). All participants or their legal guardians provided written informed consent before inclusion. The study adhered to the Declaration of Helsinki and institutional guidelines for human research ethics.

Preparation of silver-carbon (Ag-C) nanocomposite
To synthesize the Ag-C nanocomposite, 3.0 g of potassium sodium tartrate was weighed precisely and placed in a 50 mL quartz crucible inside a tube furnace. The sample was heated to 400 °C at a rate of 15 °C/min and maintained for 6 h, then allowed to cool to room temperature (~25 °C). The product was transferred to a 250 mL glass beaker and dispersed in 80 mL of deionized water (resistivity ≥18 MΩ·cm) using a magnetic stirrer at 400 rpm for 10 min. The suspension was centrifuged at 10,000 x g for 10 min at 4 °C, and the brown supernatant containing carbon quantum dots (CQDs) was collected. The supernatant was concentrated to 20 mL at 80 °C under stirring, followed by the addition of 60 mL of acetone and vortex mixing for 1 min. After centrifugation at 9,500 x g for 20 min at 4 °C, the light-yellow supernatant was collected as the CQD stock solution. To prepare the Tollens reagent, 1 mL of 0.5 M AgNO₃ was mixed with 1.04 mL of ammonia water and 0.65 mL of 3 M NaOH, followed by the addition of 17.3 mL of deionized water under continuous stirring. In a three-necked flask wrapped in aluminum foil, 25 mL of CQD solution and 75 mL of deionized water were combined and stirred at 500 rpm for 5 min. The pH was adjusted to approximately 7.0 with concentrated ammonia water, after which 1 mL of Tollens reagent was added. The mixture was heated to 120 °C for 20 min under dark conditions. Upon cooling to room temperature, the yellow Ag-C solution was obtained and stored at 4 °C until use.

CAUTION: NaOH and ammonia water are corrosive and release irritant vapors. Handle all reactions in a chemical fume hood while wearing gloves, goggles, and a lab coat. Do not seal heated containers tightly to prevent pressure buildup.

Preparation of nanosilver antibacterial dressings (NSAD)
To prepare the solvent mix, 15 mL of deionized water was mixed with 200 µL of glacial acetic acid in a 100 mL glass beaker. To this, 0.1 mL of the prepared Ag-C solution (22 mg/L), 0.2 mL of glycerol, and 60 mg of poloxamer were added and dissolved completely at 50 °C with magnetic stirring. Subsequently, 0.6 g of chitosan powder was gradually incorporated to prevent clumping and stirred continuously for 30 min until homogeneous. Then, 2 mL of 1 M NaHCO₃ was added dropwise while stirring to induce mild foaming, followed by another 10 min of mixing. The total volume was adjusted to 20 mL with deionized water, and the solution was degassed ultrasonically for 5 min. The homogeneous solution was poured into a rectangular mold (14 cm x 8 cm x 0.5 cm), sealed with plastic wrap, and left to gel for 48-72 h at room temperature (20-25 °C). After gelation, the film was removed and dried in a forced-air oven at 40 °C for 12-18 h, yielding NSAD films approximately 1 mm thick. Record ambient temperature and humidity during gelation, as they influence film uniformity and tensile strength. Discard any films containing visible cracks or bubbles.

Characterization of Ag-C nanocomposite
A drop of diluted Ag-C solution was placed on a carbon-coated copper transmission electron microscopy (TEM) grid and dried under infrared light for 10 min. The samples were imaged at 100 kV under a TEM. Particle size was analyzed using ImageJ software by measuring at least 200 randomly selected particles, and data was expressed as mean ± SD.

Evaluation of antibacterial activity
Staphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 25922) were cultured in tryptone soy broth (TSB) overnight at 37 °C. The bacterial suspension was adjusted to an optical density of OD₆₀₀ = 0.1 (~1 x 10⁷ CFU/mL). Samples were divided into three groups: deionized water-treated controls, amoxicillin-treated positive controls (10 µg/mL), and Ag-C nanocomposite-treated test groups (10 µg/mL equivalent Ag content). Cultures were incubated at 37 °C and shaken at 150 rpm for 7 days. Each day, 100 µL of samples were collected, serially diluted, plated on TSB agar, and incubated for 24 h. Colony-forming units (CFUs) were counted, and inhibition rates (%) were calculated as [(N₀− N_t)/N₀] x 100. Each experiment was performed in triplicate, and results were reported as mean ± SD.

CAUTION: Handle all bacterial cultures in a biosafety level II cabinet. Autoclave all waste at 121 °C for 20 min before disposal.

Swelling behavior of the NSAD
Square NSAD samples (1 cm x 1 cm) were weighed to obtain the dry weight (W₀). Each sample was immersed in 10 mL of physiological saline at 37 °C. At 1 h, 6 h, 12 h, and 24 h, samples were removed, blotted with filter paper, and weighed (Wt). The swelling ratio (%) was calculated as [(Wt − W₀)/W₀] x 100. All measurements were performed in triplicate, and results were reported as mean ± SD.

Assembly and application of VAC combined with NSAD
The prepared NSAD film was cut to match the wound size using sterile scissors and applied directly to the wound bed. Two sterile silicone drainage tubes (1 mm wall thickness, 0.4-0.5 mm micropores) were inserted beneath the NSAD. The entire wound and 2-3 cm of surrounding intact skin were sealed with a transparent polyurethane film to ensure airtight coverage. The drainage tubes were connected to a continuous negative-pressure source maintained between -60 kPa and -80 kPa for 72 h. The seal was inspected daily, and the collected exudate was recorded for color and volume. Dressings were replaced every 3-5 days or sooner if leakage occurred. VAC therapy was discontinued once the granulation tissue fully covered the wound. Confirm complete hemostasis before sealing the wound. If active bleeding occurs, temporarily reduce negative pressure to -40 kPa. Monitor for patient discomfort, excessive pain, or device malfunction.

Waste management
All silver-containing and alkaline residues were collected in labeled waste containers for hazardous waste disposal. Alkaline solutions were neutralized to pH 7 before discharge. Biological waste was sterilized by autoclaving and disposed of according to hospital biosafety regulations.

Patients and study design
A total of 300 patients diagnosed with Gustilo type I or II open tibial fractures (OTFs) were recruited at the Department of Trauma Orthopedics, Hengshui People's Hospital, between November 2019 and November 2022. Patients were screened according to predefined inclusion and exclusion criteria. Inclusion criteria were: (1) age between 18 and 70 years; (2) confirmed Gustilo type I or II fracture based on clinical and radiological evaluation; (3) absence of major vascular or nerve injury; and (4) ability to provide informed consent and comply with postoperative follow-up. Exclusion criteria included: (1) Gustilo type III fractures; (2) severe comorbidities such as uncontrolled diabetes, peripheral vascular disease, chronic infection, or immune deficiency; (3) pathological fractures; and (4) pregnancy or coagulation disorders. Randomization was performed using a computer-generated sequence with block randomization (block size = 6). Allocation concealment was ensured using sealed opaque envelopes prepared by an independent statistician. Patients were divided evenly into three groups (n = 100 each): Group 1 received closed reduction and intramedullary nail fixation (CRINF) with conventional wound care; Group 2 received CRINF combined with vacuum-assisted closure (VAC); and Group 3 received CRINF with nanosilver antibacterial dressing (NSAD) and VAC. All procedures were performed by the same surgical team to minimize operator bias. Outcome assessors were blinded to treatment allocation when evaluating wound healing, infection, and pain scores. All patients were followed for 9 months postoperatively to assess fracture healing and functional recovery.

Treatment plan for Gustilo type I and II OTFs
Patients underwent anesthesia (general, spinal, or local) according to injury severity and medical status. After preliminary debridement, wounds were thoroughly irrigated with sterile saline and hydrogen peroxide; devitalized tissue was trimmed, and soft-tissue edges were provisionally sutured as needed. Fracture stabilization was achieved by closed reduction and intramedullary nail fixation following standard orthopedic procedures¹⁷. For Group 3, a sterile NSAD film was cut to match wound dimensions and applied to the wound bed; two silicone drains were positioned beneath the dressing. A semi-permeable polyurethane film sealed the wound plus 2-3 cm of surrounding intact skin. Airtightness and hemostasis were confirmed before suction; pin tracts (if present) were covered with sterile gauze. Continuous negative pressure was applied at -60 to -80 kPa and adjusted according to wound size and depth, with dressing replacement every 3-5 days or earlier if leakage/saturation occurred. For Groups 1 and 2, wounds were covered with sterile petrolatum gauze and changed every 48-72 h. Postoperative care included prophylactic broad-spectrum antibiotics for 3-5 days (cephalosporins or fluoroquinolones), anaerobic coverage with metronidazole when needed¹⁸, anti-inflammatory and analgesic therapy, edema control, circulation-promoting measures, and nutritional support (including protein supplementation). Patients with neurovascular involvement received neurotrophic and anti-edematous/antispasmodic agents when appropriate. Laboratory monitoring (complete blood count, erythrocyte sedimentation rate, C-reactive protein) was performed at scheduled postoperative visits to surveil infection. Rehabilitation began with isometric contractions and gentle joint motion from day 3, progressing to active range-of-motion after ~1 week as tolerated. Radiographic follow-up was obtained at approximately 1 month, 3 months, 6 months, and 9 months; graduated weight-bearing commenced once bridging callus and continuity with the tibial cortex were evident on X-ray and clinical pain allowed.

Observation indices
The main outcome measures included wound healing time, fracture healing time, wound healing rate, and fracture healing rate. Secondary outcomes included the incidence of postoperative complications (surface infection, deep infection, delayed union, fat embolism, needle-tract infection, and infected nonunion), length of hospital stay, total medical costs, and postoperative pain intensity. Pain intensity was evaluated using a Numeric Rating Scale (NRS) from 0 (no pain) to 10 (worst pain imaginable). Wound healing was defined as complete epithelialization with no exudate, while fracture healing was confirmed radiographically by bridging callus across at least three cortices. Follow-up assessments were performed at 1 month, 3 months, 6 months, and 9 months after surgery, including clinical evaluation and radiography.

Statistical analysis
Statistical analyses were performed using SPSS version 20.0. Continuous variables were tested for normality and expressed as mean ± standard deviation (SD). Differences among the three groups were analyzed using one-way ANOVA followed by Tukey's post-hoc test for multiple comparisons. Non-normally distributed data were analyzed using the Kruskal-Wallis test. Categorical variables were expressed as counts and percentages and analyzed using the chi-square (χ²) test or Fisher's exact test when appropriate. The 95% confidence intervals (CIs) were calculated for key parameters. Statistical significance was set at p < 0.05. All analyses were conducted by an independent biostatistician blinded to group allocation.

Results

Characterization of Ag-C nanocomposite
Transmission electron microscopy (TEM) revealed that the commercial nanosilver particles (NSP) exhibited an average size of 13.56 ±3.85 nm with irregular agglomeration, while the synthesized Ag-C nanocomposite showed a slightly larger average diameter of 14.38 ±4.65 nm and uniform spherical morphology (Figure 5A-F). The Ag-C particles displayed better monodispersity and smoother boundaries than NSP,...

Discussion

Gustilo type I and II open tibial fractures (OTFs) are often caused by high-energy trauma such as traffic accidents or falls, leading to extensive bone and soft-tissue injury^1,19. The communication between the fracture and the external environment facilitates bacterial invasion, resulting in high infection rates and delayed healing^20,21. Conventional treatment involving internal or external fixation alone...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
AgNO3 solution	Yarong Instrument	196305000
ammonia water	Xilong Chemical	480905
chitosan	Aladdin Biochemical Technology	428850500
commercial nanosilver particles	Aladdin Biochemical Technology	NA
deionized water	Thermo Fisher Scientific(USA)	345470250
external fixators and locking plates	Zimmered Medical Instrument	NA
glacial acetic acid solution	Dongbang Chemical Group	Mar-26
glycerol	Aladdin Biochemical Technology	036646.K7
H1850 desktop centrifuge	Xiangyi Laboratory Instrument Development	203270008
heating sleeve	Yarong Instrument	A57027
HJ-4A multi-head heating stirrer	Guohua Electric Appliance	02774-1
medical silicone drainage tubes	B. Braun Medical Inc(USA)	491288/491310
NaHCO3	Aladdin Biochemical Technology	123360250
NaOH solution	Macklin Biochemical	210-5
OTF-1200X hollow tube furnace	Kejing Technology	OTF-1200X-ALD
permeable adhesive film	3M Company(USA)	537722zd
poloxamer	Aladdin Biochemical Technology	104082
potassium sodium tartrate	Sinopharm Group	202860051
tryptone soy broth	Thermo Fisher Scientific	CM0129B
vortex mixer	Dynamic Industrial	88882010