Pin tract infection prophylaxis and treatment

Sucralfate Prevents Pin Site Infections of External Fixators in Open Tibia Fractures

Pin site infections are the main complication of external fixators. The most common pathogens are Staphylococcus epidermidis and Staphylococcus aureus. The incidence of pin site infections ranges from 2% to 30%. Until now, no satisfactory prevention strategy exists. Therefore, we performed this study to assess the effect of a sucralfate gel 25% applied around the pins of external fixation systems in trauma patients with open tibia fractures. We prospectively studied two groups of patients with open tibia fractures treated with external fixators. In group A patients, pin site care was performed with the use of normal saline and plain dressings once a day. In group B patients, pin site care was performed with the use of sucralfate gel 25%. The incidence of pin site infections was 33.33% for patients of group A and 16.67% for patients of group B. Patients of group B showed significantly lower rate of pin site infections compared to patients of group A (p-value = 0.032). No patient experienced any complications related to the local application of the drug. Sucralfate significantly prevents pin site infections of external fixators in open tibia fractures. Therefore, it can be used as a preventive antimicrobial agent for pin site infections in patients with external fixators.

Effects of substrate topography on the regulation of human fibroblasts and capsule formation via modulating macrophage polarization

The host-material interface is critical in determining the successful integration of medical devices into human tissue. The surface topography can regulate the fibrous capsule formation around implants through macrophage polarization, but the exact mechanism remains unclear. In this study, four types of microgrooves (10 or 50 µm in groove depths and 50 or 200 µm in groove widths) were fabricated on polydimethylsiloxane (PDMS) using lithography. The microgroove surfaces were characterized using the laser scanning confocal microscopy and fourier transform infrared spectroscopy. The effect of surface topography on macrophage phenotypes and conditioned medium (CM) collected from macrophages on human foreskin fibroblast 1 (HFF-1) were investigated. The result revealed that a deeper and narrower microgroove structure means a rougher surface. Macrophages tended to adhere and aggregate on group 50-50 surface (groove depths and widths of 50 µm). THP-1 cell polarized toward both inflammatory M1 and anti-inflammatory M2 macrophages on the surface of each group. Meanwhile, CM from macrophages culture on PDMS differentially up-regulated the proliferation, migration and fibrosis of HFF-1. Among them, the group 50-50 had the strongest promoting effect. In vivo, the inflammatory response and fibrotic capsule around the implants were observed at 1 week and 4 weeks. As time passed, the inflammatory response decreased, while the capsule thickness continued to increase. The rough material surface was more inclined to develop a severe fibrotic encapsulation. In conclusion, this finding further suggested a potential immunomodulatory effect of macrophages in mediating the fibrotic response to implants and facilitated the design of biomaterial interfaces for improving tissue integration.

AO distractor and manual traction reduction techniques repair in distal tibial fractures: a comparative study

BACKGROUND

Minimally invasive plate osteosynthesis (MIPO) via percutaneous plate placement on the distal medial tibia can be performed with minimizes soft tissue injury and produces good clinical results. However, the difficulty with MIPO lies in how to achieve satisfactory fracture reduction and maintain that reduction via indirect reduction techniques to facilitate internal fixation. The purpose of this study was to compare the effects of AO distractor and manual traction reduction techniques combined with MIPO in the treatment of distal tibia fractures.

METHODS

Between January 2013 and December 2019, 58 patients with a distal tibia fracture were treated using MIPO. Patients were divided into two groups according to the indirect reduction method that was used: 26 patients were reduced with manual traction(group M), and 32 were reduced with an AO distractor (group A).Time until union and clinical outcomes including AOFAS ankle-rating score and ankle range of ankle motion at final follow-up were compared. Mean operative time, incision length, blood loss and postoperative complications were recorded via chart review. Radiographic results at final follow-up were assessed for tibial angulation and shortening by a blinded reader.

RESULTS

Mean operative time, incision length, and blood loss in group A were significantly lower than in group M(p = 0.019, 0.018 and 0.016, respectively).Radiographic evidence of bony union was seen in all cases, and mean time until union was equivalent between the two groups (p = 0.384).Skin irritation was noted in one case(3.1%) in group A and three cases(11.5%)in group M, but the symptoms were not severe and the plate was removed after bony union. There was no statistically significant difference in postoperative complications between the two groups(p = 0.461). Mean AOFAS score and range of ankle motion were equivalent between the two groups, as were varus deformity, valgus deformity, anterior angulation and posterior angulation. No patients had gross angular deformity. Mean tibial shortening was not significantly different between the two groups, and no patients had tibial shortening > 10 mm.

CONCLUSION

Both an AO distractor and manual traction reduction techniques prior to MIPO in the treatment of distal tibial fractures permit a high fracture healing rate and satisfying functional outcomes with few wound healing complications. An AO distractor is an excellent indirect reduction method that may improve operative efficiency and reduce the risk of soft tissue injury.

Microbial resistance to nanotechnologies: An important but understudied consideration using antimicrobial nanotechnologies in orthopaedic implants

Microbial resistance to current antibiotics therapies is a major cause of implant failure and adverse clinical outcomes in orthopaedic surgery. Recent developments in advanced antimicrobial nanotechnologies provide numerous opportunities to effective remove resistant bacteria and prevent resistance from occurring through unique mechanisms. With tunable physicochemical properties, nanomaterials can be designed to be bactericidal, antifouling, immunomodulating, and capable of delivering antibacterial compounds to the infection region with spatiotemporal accuracy. Despite its substantial advancement, an important, but under-explored area, is potential microbial resistance to nanomaterials and how this can impact the clinical use of antimicrobial nanotechnologies. This review aims to provide a better understanding of nanomaterial-associated microbial resistance to accelerate bench-to-bedside translations of emerging nanotechnologies for effective control of implant associated infections.

Complication of lengthening and the role of post-operative care, physical and psychological rehabilitation among fibula hemimelia

There is a clear clinical need for efficient physiotherapy and rehabilitation programs during and after bone lengthening and reconstruction for gaining the optimal effect and also prevention or treatment of lengthening side effects. Pin tract infection is the most prevalent side effect during lengthening which could be prevented and treated initially via proper wound care. Muscle contractures are typically a consequence of the generated tension on the distracted muscle. It can be managed by physiotherapy initially and surgically in later severe stages. Furthermore, it is essential to avoid muscle contracture development, which is the demonstration of the imbalanced muscle appeals on the joint to inhibit the following subluxation. The knee is the furthermost affected joint by the aforementioned problem due to the inherent lack of ligamentous and bony stability. Joint stiffness is the other possible unfavorable effect of lengthening. It happens because of extensive muscle contractures or may possibly be attributed to rigidity of the joint following the amplified pressure on the joint surface during the process of lengthening. Physiotherapy and occupational therapy including endurance and strength exercise as well as stretching play an important role during the rehabilitation periods for the prevention and also the treatment of muscle contracture and the following deformity and also joint stiffness. Likewise, the effect of mental and physical rehabilitation programs should not be overlooked.

Pin-site Infection: A Systematic Review of Prevention Strategies

Introduction

Circular frame fixation remains a key tool in the armamentarium of the limb reconstruction surgeon. One of the key drawbacks is the onset of pin-site infection (PSI). As a result of limited evidence and consensus of PSI prevention, a wide variation in practice remains.

Aim

The principal aim of this review is to synthesise primary research concerning all aspects of treatment regarded as relevant to PSI in frame constructs.

Materials and methods

Comparative studies until week 26, 2021, were included in the trial. Studies were included that concerned patients undergoing management of a musculoskeletal condition in which pin-site care is necessary for over 4 weeks.

Results

Eighteen studies over a 13-year period were captured using the search strategy. Sulphadiazine and hydrogen peroxide cleansing was found to reduce PSI, with the use of low-energy fine wires and hydroxyapatite (HA)-coated pins also associated with lower infection rate. The remainder of studies found no significant improvement across interventions.

Conclusion

There is no superiority between weekly and daily care. Low-energy pin-insertion technique had lower rates of infection. Sulphadiazine has positive results as a pin-care solution, but more research is necessary to determine the most effective care regime. Current literature is limited by absence of established definitions and by a lack of studies addressing all aspects of care relevant to PSI.

How to cite this article

Shields DW, Iliadis AD, Kelly E, et al. Pin-site Infection: A Systematic Review of Prevention Strategies. Strategies Trauma Limb Reconstr 2022;17(2):93–104.

Concepts and clinical aspects of active implants for the treatment of bone fractures

Nonunion is a complication of long bone fractures that leads to disability, morbidity and high costs. Early detection is difficult and treatment through external stimulation and revision surgery is often a lengthy process. Therefore, alternative diagnostic and therapeutic options are currently being explored, including the use of external and internal sensors. Apart from monitoring fracture stiffness and displacement directly at the fracture site, it would be desirable if an implant could also vary its stiffness and apply an intervention to promote healing, if needed. This could be achieved either by a predetermined protocol, by remote control, or even by processing data and triggering the intervention itself (self-regulated 'intelligent' or 'smart' implant). So-called active or smart materials like shape memory alloys (SMA) have opened up opportunities to build active implants. For example, implants could stimulate fracture healing by active shortening and lengthening via SMA actuator wires; by emitting pulses, waves, or electromagnetic fields. However, it remains undefined which modes of application, forces, frequencies, force directions, time durations and periods, or other stimuli such implants should ideally deliver for the best result. The present paper reviews the literature on active implants and interventions for nonunion, discusses possible mechanisms of active implants and points out where further research and development are needed to build an active implant that applies the most ideal intervention. STATEMENT OF SIGNIFICANCE: Early detection of delays during fracture healing and timely intervention are difficult due to limitations of the current diagnostic strategies. New diagnostic options are under evaluation, including the use of external and internal sensors. In addition, it would be desirable if an implant could actively facilitate healing ('Intelligent' or 'smart' implant). Implants could stimulate fracture healing via active shortening and lengthening; by emitting pulses, waves, or electromagnetic fields. No such implants exist to date, but new composite materials and alloys have opened up opportunities to build such active implants, and several groups across the globe are currently working on their development. The present paper is the first review on this topic to date.

Risk factors of pin tract infection during bone transport using unilateral external fixator in the treatment of bone defects

Background

The bone transport using the unilateral external fixator, one of the Ilizarov techniques, is widely practiced in lower limb reconstructive surgery. Pin tract infection (PTI), one of most common complication, has become the important postoperative problems which plague clinicians gradually.

Methods

A group of 130 patients who received bone transport surgery for tibia or femur defects using the unilateral external fixation (Orthofix limb reconstruction system, Verona, Italy) and met the inclusion criteria were selected for the study from 2015 to 2019. Regular pin tract care was performed twice a day, and the conditions of the pin tract were evaluated by the same observer using clinical appearance criteria. The Saw’s classification of PTI was used to assess the condition around screws. After the data were significant by the T-test or Pearson’s Chi-square test analyzed, odds ratios were calculated using logistic regression tests to describe factors associated with the diagnosis of PTI.

Results

Ninety-one males and thirty-nine females with a mean age of 43 years (range 28–58 years) were included in this cohort. 7816 observations were documented from 12 to 36 months, and 58 cases (44.6%) of PTI (thirty-nine cases in grade 1, 17 cases in grade 2, and 2 cases in grade 3). The top five risk factors were agricultural work (OR 1.86, CI 0.94–2.39), non-urban living (OR 1.75, CI 1.24–3.26), male (OR 1.71, CI 1.02–2.31), smoking (OR 1.53, CI 0.76–1.89), and diabetes (OR 1.26, CI 1.12–2.64). No long-term sequelae were observed at the latest clinical visit.

Conclusion

Occupation, gender, living environment (non-urban), smoking, and diabetes were the top five significant risk factors for PTI in the period of bone transport using unilateral external fixation. Awareness of predictable risk factors of PTI is beneficial to avoid or early detect the severe complications which can affect the effectiveness.

Gene therapy for bone healing: lessons learned and new approaches

Although gene therapy has its conceptual origins in the treatment of Mendelian disorders, it has potential applications in regenerative medicine, including bone healing. Research into the use of gene therapy for bone healing began in the 1990s. Prior to this period, the highly osteogenic proteins bone morphogenetic protein (BMP)-2 and -7 were cloned, produced in their recombinant forms and approved for clinical use. Despite their promising osteogenic properties, the clinical usefulness of recombinant BMPs is hindered by delivery problems that necessitate their application in vastly supraphysiological amounts. This generates adverse side effects, some of them severe, and raises costs; moreover, the clinical efficacy of the recombinant proteins is modest. Gene delivery offers a potential strategy for overcoming these limitations. Our research has focused on delivering a cDNA encoding human BMP-2, because the recombinant protein is Food and Drug Administration approved and there is a large body of data on its effects in people with broken bones. However, there is also a sizeable literature describing experimental results obtained with other transgenes that may directly or indirectly promote bone formation. Data from experiments in small animal models confirm that intralesional delivery of BMP-2 cDNA is able to heal defects efficiently and safely while generating transient, local BMP-2 concentrations 2-3 log orders less than those needed by recombinant BMP-2. The next challenge is to translate this information into a clinically expedient technology for bone healing. Our present research focuses on the use of genetically modified, allografted cells and chemically modified messenger RNA.

Operative choice for displaced proximal humeral fractures in adolescents with open visible physis: A comparative study of external fixator vs. Kirschner wire

BACKGROUND

For adolescents with severely displaced proximal humeral fracture (PHF), surgery is a good choice yielding excellent outcomes, and Kirchner wire (KW) is a cost-effective choice for fixation. Purpose of this study is to compare the clinical outcomes of external fixator (EF) and KW for the treatment of PHF in adolescents.

METHODS

Patients of PHF operated at our institute, from January 2008 to January 2016, were reviewed retrospectively. Demographic data, including sex, age at the time of surgery, operated side, and hardware choice, were collected from the hospital database. Preoperative radiographs were reviewed and classified according to Neer-Horwitz classification. Shoulder function was evaluated at the last follow-up using the American Shoulder and Elbow Surgeons (ASES) score. Complications, including infection, malunion, nonunion, stiffness of the shoulder joint, and failure of fixation were also recorded.

RESULTS

Thirty-five patients, including 23 males and 12 females, were included in the EF group, whereas 40 patients, including 25 males and 15 females, were included in the KW group (P = 0.867). The average age of patients in the EF group was 13.3 ± 1.7 years, and that of KW was 13.6 ± 1.8 years (P = 0.409). Patients in both groups were followed-up for at least 12 months. The operative time in the EF group (42.4 ± 11.2 min) was significantly shorter than those in the KW group (54 ± 13.6 min) (P < 0.001). The frequency of fluoroscopy in the EF group (12 ± 2.4 times) was significantly less than those in the KW group (17 ± 2.8 times (P < 0.001). The rate of open reduction was significantly higher in KW (35%) group than those in the EF group (0%) (P < 0.001). There was no case of nonunion and malunion in both groups.

CONCLUSION

External fixator is superior to Kirschner wire in the treatment of proximal humeral fractures in adolescents with shorter operative time and lower rate of open reduction with comparable clinical outcomes.

Antibiotic-Impregnated Liquid-Infused Coatings Suppress the Formation of Methicillin-Resistant Staphylococcus aureus Biofilms

Medical device-associated infections are an ongoing problem. Once an implant is infected, bacteria create a complex community on the surface known as a biofilm, protecting the bacterial cells against antibiotics and the immune system. To prevent biofilm formation, several coatings have been engineered to hinder bacterial adhesion or viability. In recent years, liquid-infused surfaces (LISs) have been shown to be effective in repelling bacteria due to the presence of a tethered liquid interface. However, local lubricant loss or temporary local displacement can lead to bacteria penetrating the lubrication layer, which can then attach to the surface, proliferate, and form a biofilm. Biofilm formation on biomedical devices can subsequently disrupt the chemistry tethering the slippery liquid interface, causing the LIS coating to fail completely. To address this concern, we developed a "fail-proof" multifunctional coating through the combination of a LIS with tethered antibiotics. The coatings were tested on a medical-grade stainless steel using contact angle, sliding angle, and Fourier transform infrared spectroscopy. The results confirm the presence of antibiotics while maintaining a stable and slippery liquid interface. The antibiotic liquid-infused surface significantly reduced biofilm formation (97% reduction compared to the control) and was tested against two strains of Staphylococcus aureus, including a methicillin-resistant strain. We also demonstrated that antibiotics remain active and reduce bacteria proliferation after subsequent coating modifications. This multifunctional approach can be applied to other biomaterials and provide not only a fail-safe but a fail-proof strategy for preventing bacteria-associated infections.

Analysis of 1430 hand fractures and identifying the 'Red Flags' for cases requiring surgery: Head: Hand Fracture Treatment

BACKGROUND

Hand fractures constitute 20% of hand injury patients who apply to emergency services. Conservative approaches are satisfactory in the majority of the cases. However, the minority group in need of surgery reaches a serious number of patients considering the frequency of these injuries. Retrospective questioning of the indications of the performed surgeries is a proper way of understanding the decisional process for surgery.

PATIENTS/METHODS

Patients treated for hand fractures were retrospectively reviewed. Patient gender, age, finger/fingers involved, soft tissue involvement, treatment method (conservative/surgery) and if operated, devices used for fixation were noted. Plain radiographs of the patient were evaluated. Descriptive statistics of these variables and the effect of each variable on the decision for surgery were analyzed.

RESULTS

The study involved 1430 fractures of 1303 patients (1016 male and 287 female). Fifth finger was the most commonly injured digit (31%). Comminuted fractures (29%) followed by transverse fractures (29%) and spiral/oblique fractures (22%) were commonly diagnosed fracture types. Thirteen percent (13%) of the study group needed tendon/nerve/vessel repairs. Male patients, cases with soft tissue involvement, second, third and fourth finger fractures, fractures involving multiple digits, fractures with an intra-articular component, fractures with dislocation more than 4 mm and angulation more than 15° had a significantly higher rate of surgery.

CONCLUSION

Less than half of the hand fractures require surgery, and conservative treatment is usually preferred. Certain variables that indicate surgical treatment were identified with our study. These findings may help to weigh the options and choose the right path in doubtful conditions.

LEVEL OF EVIDENCE

Level 4, Case-control study.

Operative Choice for Length-Unstable Femoral Shaft Fracture in School-Aged Children: Locking Plate vs. Monolateral External Fixator

BACKGROUND

Locking plate (LP) is a good choice in the treatment of length-unstable femoral shaft fracture in children. Monolateral external fixator (EF) has been reported for this condition for decades. This study aims to compare the clinical outcomes of school-aged children with length-unstable femoral shaft fracture treated with LP vs. EF.

METHODS

Patients aged 5-11 years old with length-unstable femoral shaft fractures treated at our institute from January 2014 to January 2018 were retrospectively reviewed and categorized into LP and EF groups. The preoperative data, including baseline information of the patients, radiographic parameters, and types of surgical procedure, were collected from the hospital database, and postoperative data, including complications, were collected during the follow-up visits.

RESULTS

Overall, 36 patients (average, 8.2 ± 2.1 years; male, 20; female, 16) in the LP group and 35 patients (average, 8.3 ± 2.3 years; male 20, female 15) in the EF group were included. There was significantly less operative time for EF (45.4 ± 7.8 min) compared with LP (67.8 ± 11.3 min) (P < 0.001). As for the frequency of fluoroscopy, there was a significant difference between the EF (13.9 ± 2.4) and LP (16.5 ± 3.2) groups (p < 0.001). The rate of major complications was not significantly different between these two groups. There was a significant difference between the EF group (11.2 ± 5.8 mm) and the LP group (7.5 ± 1.6 mm) group concerning limb length discrepancy (P < 0.001).

CONCLUSION

Both LP and EF produce satisfactory outcomes in school-aged children with length unstable femoral shaft fractures. External fixation remains a viable choice without the necessity of secondary surgery for hardware removal.

Reduction of pin tract infections during external fixation using cadexomer iodine

PURPOSE

Knee joint distraction (KJD) is a joint-preserving treatment for younger osteoarthritis patients. KJD has shown positive results in regular care, but the external fixation frame often caused pin tract skin infections. Therefore, the use of cadexomer iodine was included in the wound care protocol. The goal of this cross-sectional study was to evaluate whether use of this ointment reduced the number of patients with infections during KJD treatment.

METHODS

Patients treated with KJD in regular care were included if they gave consent for use of their data and completed treatment with the newest distraction device before 2020. All patients followed a wound care protocol, which since March 2019 included using cadexomer iodine ointment. The number of patients experiencing pin tract infections was compared between patients who did (March 2019-December 2019) and did not (November 2017-March 2019) use the ointment.

RESULTS

Sixty-seven patients were included; 34 patients used cadexomer iodine and 33 patients did not. Patient who did not use cadexomer iodine experienced twice as many infections (64% vs 32%;p = 0.010). There was a significant difference in the number of patients with serious infections, requiring more antibiotics than the standard 7-day oral antibiotics (30% without vs 6% with cadexomer iodine; p = 0.009).

CONCLUSIONS

The use of cadexomer iodine ointment during KJD results in a significant reduction of the number of patients experiencing pin tract infections during treatment. Use of this ointment should be considered standard protocol during KJD treatment and could be of value in general external fixator usage as well.

Early complications of preoperative external traction fixation in the staged treatment of tibial fractures: A series of 402 cases

BACKGROUND

Different external skeletal fixators have been widely used in preoperative traction of high-energy tibial fractures prior to a definitive surgical treatment. However, the early complications associated with this staged treatment for traction and soft tissue injury recovery have rarely been discussed.

AIM

To analyze the early complications associated with preoperative external traction fixation in the staged treatment of tibial fractures.

METHODS

A total of 402 patients with high-energy tibial fractures treated using preoperative external traction fixation at a Level 1 trauma center from 2014 to 2018 were enrolled in this retrospective study. Data regarding the demographic information, Tscherne soft tissue injury, fracture site, entry point placement, and duration of traction were recorded. Procedure-related complications such as movement and sensation disorder, vessel injury, discharge, infection, loosening, and iatrogenic fractures were analyzed.

RESULTS

The mean patient age was 42.5 (18-71) years, and the mean duration of traction was 7.5 (0-26) d. In total, 19 (4.7%) patients presented with procedure-related complications, including technique-associated complications in 6 patients and nursing-associated complications in 13. Differences in the incidence of complications with respect to sex, affected side, soft tissue injury classification, and fracture sites were not observed. However, the number of complications due to hammer insertion was significantly reduced than those due to drill insertions (2.9% vs 7.4%).

CONCLUSION

We found a low incidence of early complications related to the fixation. Furthermore, the complications were not significantly associated with the severity of the soft tissue injury and fracture site. Although relatively rough and more likely to cause pain, the number of complications associated with hammer insertion was significantly smaller than that of complications associated with drill insertion.

Optimum timing of conversion from DCO to definitive fixation in closed fractures of the lower limb: When and how?

INTRODUCTION

In damage control orthopaedics (DCO), fractures are initially stabilised with external fixation followed by delayed conversion to definitive internal fixation. The aim of this study is to determine whether the timing of the conversion influences the development of deep infection and fracture healing in a cohort of patients treated by DCO after a closed fracture of the lower limb. Furthermore, we wanted to evaluate whether the one-stage conversion procedure is always safe.

MATERIALS AND METHODS

A retrospective cohort study was conducted at a single level 1 trauma centre. Ninety-four cases of closed fractures of lower limb treated by DCO subsequently converted to internal fixation from 2012 to 2019 were included. Development of deep infection, superficial infection, non-union and time to union were recorded. Patients were then divided into three groups according to the timing of conversion: Group A (<7 days), Group B (7-13 days), Group C (> 14 days). Comparison between groups was performed to assess intergroup variabilty.

RESULTS

The mean number of days between DCO and conversion was 6.7±4.52 (range 1-22). We observed one case of deep infection (1.1%), one case of non-union (1.1%), four cases of superficial infection (4.3%) and mean time to union was ±1.38 months. Comparison between groups demonstrated no significant correlation between timing of conversion and development of superficial or deep infection and non-union, while it highlighted that complexity of the fracture and longer surgical time of conversion procedure were significantly higher in Group C.

CONCLUSIONS

One-stage conversion to definitive internal fixation within 22 days from DCO is a safe and feasible procedure, which does not influence the incidence of infection or non-union.