Pin Site Complications Associated With Computer-Assisted Navigation in Hip and Knee Arthroplasty.

BACKGROUND: There has been a great increase in the use of navigation technology in joint arthroplasty. In most types of navigation-assisted surgery, several temporary navigation pins are placed in the patient. Goals of this study are (1) to identify complications and (2) risk factors associated with placement of these pins. METHODS: This is a retrospective cohort study of all navigation-assisted hip and knee arthroplasty performed a single institution over a 3-year period. Records were reviewed and outcome measures were tabulated in a database. Complications included in the database were pin site infection, deep prosthetic joint infection, neurologic injury, vascular injury, and fracture through a pin site. RESULTS: A total of 3136 pin sites in 839 patients were included in the study. Five pin site complications were reported with a complication rate of 0.16% per pin site and 0.60% per patient. The complications-per-procedure were slightly higher for unicondylar knee arthroplasty (0.64%) compared with patellofemoral arthroplasty (0%) and total hip arthroplasty (0.46%), but not statistically significant. There were three infections, one neuropraxia, and one suture abscess. No periprosthetic fractures through a pin site were reported. All complications were resolved with nonoperative treatment. The infections required oral antibiotics, and were associated with transcortical drilling in two cases and juxtacortical drilling in the third. CONCLUSION: Pins required for navigation-assisted arthroplasty have a low complication rate. Transcortical or juxtacortical drilling may be a risk factor for pin site infection; future studies should be directed at quantifying this effect.

Staphylococcal persistence due to biofilm formation in synovial fluid containing prophylactic cefazolin.

Antibiotic prophylaxis is standard for patients undergoing surgical procedures, yet despite the wide use of antibiotics, breakthrough infections still occur. In the setting of total joint arthroplasty, such infections can be devastating. Recent findings have shown that synovial fluid causes marked staphylococcal aggregation, which can confer antibiotic insensitivity. We therefore asked in this study whether clinical samples of synovial fluid that contain preoperative prophylactic antibiotics can successfully eradicate a bacterial challenge by pertinent bacterial species. This study demonstrates that preoperative prophylaxis with cefazolin results in high antibiotic levels. Furthermore, we show that even with antibiotic concentrations that far exceed the expected bactericidal levels, Staphylococcus aureus bacteria added to the synovial fluid samples are not eradicated and are able to colonize model implant surfaces, i.e., titanium pins. Based on these studies, we suggest that current prophylactic antibiotic choices, despite high penetration into the synovial fluid, may need to be reexamined.

A rabbit humerus model of plating and nailing osteosynthesis with and without Staphylococcus aureus osteomyelitis.

The local mechanical environment at a fracture is known to influence biological factors such as callus formation, immune cell recruitment and susceptibility to infection. Infection models incorporating a fracture are therefore required to evaluate prevention and treatment of infection after osteosynthesis. The aim of this study was to create humane, standardised and repeatable preclinical models of implant-related bone infection after osteosynthesis in the rabbit humerus. Custom-designed interlocked intramedullary nails and commercially available locking plates were subjected to biomechanical evaluation in cadaveric rabbit humeri; a 10-week in vivo healing study; a dose response study with Staphylococcus aureus over 4 weeks; and finally, a long-term infection of 10 weeks in the plate model.Outcome measures included biomechanical testing, radiography, histology, haematology and quantitative bacteriology. Both implants offered similar biomechanical stability in cadaveric bones, and when applied in the in vivo study, resulted in complete radiographic and histological healing and osteotomy closure within 10-weeks. As expected in the infection study, higher bacterial doses led to an increasing infection rate. In both infected groups, there was a complete lack of osteotomy closure at 4 weeks. C-reactive protein (CRP), lymphocyte: granulocyte ratio and weight loss were increased in infected animals receiving IM nails in comparison with non-inoculated equivalents, although this was less evident in the plate group. In the 10-week infection group, healing does not occur in the plated rabbits. We have successfully developed a rabbit model that is suitable for further studies, particularly those looking into preventative strategies for post-traumatic implant-related osteomyelitis.

The calcium phosphate matrix of FGF-2-apatite composite layers contributes to their biological effects.

The purpose of the present study was to fabricate fibroblast growth factor (FGF)-2-apatite composite layers on titanium (Ti) pins in one step at 25 °C using a supersaturated calcium phosphate (CaP) solution, and to evaluate the physicochemical characteristics and biological effects of the coated Ti pins compared with coated Ti pins fabricated at 37 °C. Ti pins were immersed in a supersaturated CaP solution containing 0.5, 1.0, or 2.0 µg/mL FGF-2 at 25 °C for 24 h (25F0.5, 25F1.0, and 25F2.0) or containing 4.0 µg/mL FGF-2 at 37 °C for 48 h (37F4.0). Except for the 25F0.5, the chemical compositions and the mitogenic activity levels of FGF-2 of the composite layers formed by these two methods were similar, except for the Ca/P molar ratio, which was markedly smaller at 25 °C (1.55-1.56±0.01-0.02, p=0.0008-0.0045) than at 37 °C (1.67±0.11). Thus, either the apatite was less mature or the amount of amorphous calcium phosphate was higher in the composite layer formed at 25 °C. In vivo, the pin tract infection rate by visual inspection for 37F4.0 (45%) was lower than that for 25F1.0 (80%, p=0.0213), and the rate of osteomyelitis for 37F4.0 (35%) was lower than that for 25F0.5 (75%, p=0.0341). The extraction torque for 37F4.0 (0.276±0.117 Nm) was higher than that for 25F0.5 (0.192±0.117 Nm, p=0.0142) and that for 25F1.0 (0.176±0.133 Nm, p=0.0079). The invasion rate of S. aureus for 37F4.0 (35%) was lower than that for 25F0.5 (75%, p=0.0110). On the whole, the FGF-2-apatite composite layer formed at 25 °C tended to be less effective at improving fixation strength in the bone-pin interface and resisting pin tract infections. These results suggest that the chemistry of the calcium phosphate matrix that embeds FGF-2, in addition to FGF-2 content and activity, has a significant impact on composite infection resistance and fixation strength.

Remission rate of implant-related infections following revision surgery after fractures.

PURPOSE: In contrast to a large amount of epidemiological data regarding the incidence of implant infections after fracture management, surprisingly few have been published concerning the success of their treatment. METHODS: This was a single-centre cohort study at Geneva University Hospitals from 2000 to 2012 investigating the remission rates of orthopaedic implant infections after fracture repair and associated variables. RESULTS: A total of 139 episodes were included: There were 51 women (37%) and 28 immunosuppressed (20%) patients with a median age and American Society of Anaesthesiologists (ASA) score of 51 years and 2 points, respectively. The infected implants were plates (n = 75, 54 %), nails (24, 17%), wires (20), screws (10), cerclage cables or wires (3), hip screws (4) or material for spondylodesis (3). A pathogen was identified in 135 (97%) cases, including Staphylococcus aureus (73, 52%), coagulase-negative staphylococci (20), streptococci (7) and 19 Gram-negative rods. All patients underwent antibiotic treatment, and 128 (92%) remained in remission at a median follow-up time of 2.6 years (range one to 13 years). In multivariate logistic regression analysis, the plate infections were significantly associated with lower remission rates [65/75, 87%, odds ratio (OR) 0.1, 95% confidence interval (CI) 0.01-0.90]. No associations were found for gender, age, immune status, ASA score, additional surgical interventions (OR 0.4, 95% CI 0.1-4.1) or duration of antibiotic treatment (OR 1.0, 95% CI 0.98-1.01). CONCLUSIONS: Among all infected and removed orthopaedic implants, plates were associated with slightly lower remission rates, while the overall treatment success exceeded 90%. The duration of antibiotic therapy did not alter the outcome.

Murine immune response to a chronic Staphylococcus aureus biofilm infection.

Staphylococcus aureus has reemerged as an important human pathogen in recent decades. Although many infections caused by this microbial species persist through a biofilm mode of growth, little is known about how the host's adaptive immune system responds to these biofilm infections. In this study, S. aureus cells adhered to pins in culture and were subsequently inserted into the tibiae of C57BL/6 mice, with an infecting dose of 2 × 105 CFU. This model was utilized to determine local cytokine levels, antibody (Ab) function, and T cell populations at multiple time points throughout infection. Like human hosts, S. aureus implant infection was chronic and remained localized in 100% of C57BL/6 mice at a consistent level of approximately 10(7) CFU/gram bone tissue after day 7. This infection persisted locally for >49 days and was recalcitrant to clearance by the host immune response and antimicrobial therapy. Local inflammatory cytokines of the Th1 (interleukin-2 [IL-2], IL-12 p70, tumor necrosis factor alpha [TNF-α], and IL-1ß) and Th17 (IL-6 and IL-17) responses were upregulated throughout the infection, except IL-12 p70, which dwindled late in the infection. In addition, Th1 Ab subtypes against a biofilm antigen (SA0486) were upregulated early in the infection, while Th2 Abs and anti-inflammatory regulatory T cells (Tregs) were not upregulated until later. These results indicate that early Th1 and Th17 inflammatory responses and downregulated Th2 and Treg responses occur during the development of a chronic biofilm implant infection. This unrestrained inflammatory response may cause tissue damage, thereby enabling S. aureus to attach and thrive in a biofilm mode of growth.

Thermal damage and tracker-pin track infection in computer-navigated total knee arthroplasty.

Choice of pins, drills, and drilling technique can result in heat generation leading to thermal necrosis of bone. This has been reported frequently in internal as well as in external fixation. This publication is the first report of a patient having osteomyelitis of the proximal tibia due to thermal necrosis following tracker pin placement in computer-navigated total knee arthroplasty.

Infectious pin complication rates in halo vest fixators using ceramic versus metallic pins.

STUDY DESIGN: Retrospective review of database patients. OBJECTIVE: To compare infectious pin complication rates utilizing ceramic pins, an emerging technology, with a large database of complications in halo's using metallic pins. SUMMARY OF BACKGROUND DATA: The halo/vest fixator remains a useful modality of treatment for cervical spine trauma but has been described as having a high incidence of complications, foremost pin-related complications. Ceramic pins and vest modifications have been introduced under the premise of (1) decreasing pin-tract infections compared with metallic pins manufactured from stainless steel or titanium and with the advent of 3T MRI, (2) decreasing brain MRI artifact, and (3) lowering MRI intolerance owing to material overheating. MATERIAL AND METHODS: We retrospectively reviewed a prospectively collected patient data set of the Harborview Medical Center spine trauma registry. A historic control group exclusively utilizing metallic halo pins over a 10-year period was compared with patients who were treated with halo's exclusively utilizing ceramic pins over a recent 14-month period. Complications investigated included aseptic, loosening, and infections graded on a novel 3-tier system adapted from external fixation in long bone and periarticular trauma. Inclusion criteria were the patients with traumatic cervical spine injuries treated with a halo for a period of at least 14 days. RESULTS: Forty-four patients were available for analysis in the ceramic pin group versus 263 in the metallic pin group. Overall pin complications amounted to 40.9% ceramic (C) versus 21.7% metal (M) pins (P<0.05), aseptic loosening rates 13.7% (C) compared with 8.3% (M), and pin site infections 27.3% (C) compared with 13.3% (M) (P<0.05). A grading system for halo pin tract infections was developed. In assessing overall complications and infections specifically, ceramic pins seemed to be associated with a higher incidence of adverse events or complications compared with titanium pins. CONCLUSION: Despite the imbalance of size of our cohort groups, there seems to be a strong trend toward the newer ceramic pin technology not meeting expected minimum performance standards set by the earlier metallic material. Causes for the higher failure rate likely lay in the necessary changes made to the halo vest and specifically the pin design owing to the inherent mechanical property limitations of MRI compatible materials.

External fixation of unstable pelvic fractures: a systematic review and meta-analysis.

BACKGROUND: Unstable pelvic fractures are typically caused by high-impact trauma. Early stabilization is required to prevent further neurological or visceral injury, haemorrhage, reduce pain, infection and long-term deformity and disability. The aim was to review the optimal external fixation techniques and management for unstable pelvic fractures. METHODS: A total of 28 studies were identified from the initial database search. Seventeen studies met our inclusion criteria - eight prospective cohorts, four retrospective cohorts and five in vitro studies. This equated to 539 patients and 38 cadaveric (in vitro) models. RESULTS: Type B and double vertical fractures have less re-displacement (43.7% and 68.2% <5 mm, respectively) than Type C fractures (55.7% >15 mm) regardless of pin placement. Greater than 50% experience a complication with the most common being pin site infection (36%) and a trend towards increased infection with increasing pins was seen. Most can be managed with antibiotics alone (93%). A minimum time of 6-8 weeks in frame was required for definitive management of all fractures. CONCLUSION: This review supports the use of supra-acetabular pins over iliac crest pins to decrease re-displacement, the least number of pins for the shortest amount of time and the largest size pin where possible. Type B fractures will generally have a better outcome than Type C fractures. Definitive management in a frame should be at least 8 weeks. Further studies directly comparing iliac crest and supra-acetabular pin placement are recommended.

Is the proximity of external fixator pins to eventual definitive fixation implants related to the risk of deep infection in the staged management of tibial pilon fractures?

INTRODUCTION: In the staged management of tibial pilon fractures, overlap between definitive internal fixation and external fixation pin sites has been investigated as a risk factor for infection with equivocal conclusions. Our aim was to determine if overlap or proximity of definitive internal fixation to external fixation pin sites influences the risk of deep infection. PATIENTS AND METHODS: We reviewed 280 AO/OTA 43B or 43C type distal tibia fractures in 277 patients at two level-one trauma centers. Patients underwent staged management using early temporizing external fixation followed by definitive open reduction and plate fixation. Primary outcome was the association between pin site overlap and the development of deep infection. Secondary outcome was the relationship between development of deep infection and the distance from pin site to definitive fixation. RESULTS: The average duration between external fixation and definitive internal fixation was 14 days. 24% of fractures developed deep infection requiring surgical intervention. There was no association between pin site overlap and the development of deep infection (p = 0.18). There was no relationship between infection and the distance between proximal plate extent and pin site (p = 0.13). DISCUSSION: We identified no association between pin site overlap and the development of deep infection. We suggest that temporizing external fixation pins should be placed so as to obtain optimal stability of the construct with lesser emphasis on aiming to be absolutely outside the zone of future fixation. LEVEL OF EVIDENCE: Level III Therapeutic Retrospective Comparative study.

Studies of photokilling of bacteria using titanium dioxide nanoparticles.

Metal pins used to apply skeletal traction or external fixation devices protruding through skin are susceptible to the increased incidence of pin site infection. In this work, we tried to establish the photokilling effects of titanium dioxide (TiO2) nanoparticles on an orthopedic implant with an in vitro study. In these photocatalytic experiments, aqueous TiO2 was added to the tested microorganism. The time effect of TiO2 photoactivation was evaluated, and the loss of viability of five different bacteria suspensions (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus hirae, and Bacteroides fragilis) was examined by the viable count procedure. The bactericidal effect of TiO2 nanoparticle-coated metal plates was also tested. The ultraviolet (UV) dosage used in this experiment did not affect the viability of bacteria, and all bacteria survived well in the absence of TiO2 nanoparticles. The survival curve of microorganisms in the presence of TiO2 nanoparticles showed that nearly complete killing was achieved after 50 min of UV illumination. The formation of bacterial colonies above the TiO2 nanoparticle-coated metal plates also decreased significantly. In this study, we clearly demonstrated the bactericidal effects of titanium dioxide nanoparticles. In the presence of UV light, the titanium dioxide nanoparticles can be applicable to medical facilities where the potential for infection should be controlled.

Penetration of a selected antibiotic and antiseptic into a biofilm formed on orthopedic steel implants.

BACKGROUND: The aim of the study was to determine the impact of octenidine hydrochloride and gentamicin on bacterial survival and reduction of biofilms formed on orthopaedic metal implants. MATERIAL AND METHODS: We studied metal orthopaedic components (screws, nails, fragments of wires used in Ilizarov devices) and a bone sequester. The presence and intensity of biofilm formation on the medical biomaterials was determined using the method of Richards et al. by visual evaluation of 2,3,5-triphenyl tetrazolium chloride (TTC) reduction by viable bacteria. The presence and structure of the biofilm on the components of the Ilizarov device, screws and bone sequester was also studied by electron microscopy. Bacterial survival in the biofilm following exposure to the antibiotic and antiseptic was studied by CLSI microdilution method in microtitre plates using TTC. Results. Most of the 16 strains (S. aureus, S. epidermidis, E. coli, Enterobacter) isolated from orthopaedic implants were able to form a biofilm. Established biofilms were resistant to gentamicin and octenidine hydrochloride but demonstrated greater susceptibility to octenidine. CONCLUSIONS: The results of the study indicate that octenidine hydrochloride is more effective than gentamicin in the treatment of infections associated with the formation of a biofilm on orthopaedic implants.

Antimicrobial and bone-forming activity of a copper coated implant in a rabbit model.

Current strategies in implant technology are directed to generate bioactive implants that are capable to activate the regenerative potential of the surrounding tissue. On the other hand, implant-related infections are a common problem in orthopaedic trauma patients. To meet both challenges, i.e. to generate a bone implant with regenerative and antimicrobial characteristics, we tested the use of copper coated nails for surgical fixation in a rabbit model. Copper acetate was galvanically deposited with a copper load of 1 µg/mm2 onto a porous oxide layer of Ti6Al4V nails, which were used for the fixation of a tibia fracture, inoculated with bacteria. After implantation of the nail the concentration of copper ions did not increase in blood which indicates that copper released from the implant was locally restricted to the fracture site. After four weeks, analyses of the extracted implants revealed a distinct antimicrobial effect of copper, because copper completely prevented both a weak adhesion and firm attachment of biofilm-forming bacteria on the titanium implant. To evaluate fracture healing, radiographic examination demonstrated an increased callus index in animals with copper coated nails. This result indicates a stimulated bone formation by releasing copper ions. We conclude that the use of implants with a defined load of copper ions enables both prevention of bacterial infection and the stimulation of regenerative processes.

Bacteriological aspects of chronic osteoarticular infections in adults: the influence of the osteosynthesis material.

BACKGROUND: The aim of this study is to establish the bacterial epidemiology of chronic osteoarticular infections in adults, to study the susceptibility of the isolated strains to antibiotics and to demonstrate the influence of osteosynthesis material thereon. PATIENTS AND METHODS: This is a retrospective study of 78 months, from January 2006 to June 2012, providing bacteriological samples from patients with osteitis and osteoarthritis in the Mohammed V military teaching hospital of Rabat. Isolation and identification of bacteria were made by bacteriological classical techniques. The antimicrobial susceptibility testing of the isolates was performed by disk diffusion agar method, as recommended by the Committee of the susceptibility of the French Society for Microbiology (CA-SFM). RESULTS: We collected 234 cases, 53% (n = 124) of patients without osteosynthesis material (group A) and 47% (n = 110) patients with osteosynthesis material (group B).We isolated 371 bacteria which 51.49 (n = 191) in group A and 48.51% (n = 180) in group B. Gram-positive cocci were the most frequent (n = 234), followed by the Gram-negative bacilli (n = 114) and the Gram-positive bacilli (n = 19). Our study shows that the rate of resistance to antibiotics in strains obtained from patients with osteosynthesis material is higher compared to those obtained from patients without osteosynthesis material. CONCLUSIONS: Chronic OA infection in adults is difficult to diagnose and treat. Its good management must be multidisciplinary.

A simple practical protocol for care of metal-skin interface of external fixation.

Patients treated with external fixation for limb reconsturciton or fracture stabilization equire regular and prolongedperiod of pin-tract care involving frequent visits to clinic and dressing traditionally carried out by trained nurses or medical assistants. A simple method of do-it-yourself dressing was introduced in our institution and this study was undertaken to evaluate the effectiveness of the protocol. Sixty patients (40 trauma-related problems and 20 congenital or developmental disorders) were enrolled into the study. Following application of external fixation, the patients and/or their caretakers were taught on how to do pin-site dressing using normal saline or drinking water as cleansing solution on daily basis. Patients were discharged on the second or third post-operative day and were followed-up every two weeks for an average 182 days (range 66 to 379 days) with special attention on identifying pin-tract infection. A simple grading system for pin-tract infections was proposed. Of 40 patients with trauma-related problems. 65% were post-traumatic infections. There were 788 metal-skin interfaces (239 half-pin fixations and 549 tensioned wire fixations. A total 143 metal-skin interface infections (18.1%) involving half-pin sites (41.3%) and tensioned wire sites (58.7%) was noted. Majority were grade I infections (79.7%), 18.8% grade II and only 1.4% grade III. Most infections (81%)were caused by Staphylococcus aureus. Grade I infections were successfully treated with frequent dressing, grade II by adjunctive oral antibiotic but grade III infections required removal of fixator. All eventually healed. Do yourself non-sterile dressing of metal-skin interfaces is a cost-effective method of pin-site care with a low infection rate. The infections were sucessfully treated using guidelines according to the proposed classification of pin-tract infections.

Silver ion doped ceramic nano-powder coated nails prevent infection in open fractures: In vivo study.

BACKGROUND: Despite improvement in operative techniques and antibiotic therapy, septic complications still occur in open fractures. We developed silver ion containing ceramic nano powder for implant coating to provide not only biocompatibility but also antibacterial activity to the orthopaedic implants. QUESTIONS/PURPOSES: We hypothesised silver ion doped calcium phosphate based ceramic nano-powder coated titanium nails may prevents bacterial colonisation and infection in open fractures as compared with uncoated nails. METHODS: 33 rabbits divided into three groups. In the first group uncoated, in the second group hydroxyapatite coated, and in the third group silver doped hydroxyapatite coated titanium nails were inserted left femurs of animals from knee regions with retrograde fashion. Before implantation of nails 50 µl solution containing 10(6)CFU/ml methicillin resistance Staphylococcus aureus (MRSA) injected intramedullary canal. Rabbits were monitored for 10 weeks. Blood was taken from rabbits before surgery and on 2nd, 6th and 10th weeks. Blood was analysed for biochemical parameters, blood count, C-reactive protein and silver levels. At the end of the 10 weeks animals were sacrificed and rods were extracted in a sterile fashion. Swab cultures were taken from intramedullary canal. Bacteria on titanium rods were counted. Liver, heart, spleen, kidney and central nervous tissues samples were taken for determining silver levels. Histopathological evaluation of bone surrounding implants was also performed. RESULTS: No significant difference was detected between the groups from hematologic, biochemical, and toxicological aspect. Microbiological results showed that less bacterial growth was detected with the use of silver doped ceramic coated implants compared to the other two groups (p=0.003). Accumulation of silver was not detected. No cellular inflammation was observed around the silver coated prostheses. No toxic effect of silver on bone cells was seen. CONCLUSION: Silver ion doped calcium phosphate based ceramic nano powder coating to orthopaedic implants may prevents bacterial colonisation and infection in open fractures compared with those for implants without any coating.

In vivo bactericidal efficacy of farnesol on Ti6Al4V implants. / Eficacia bactericida in vivo del farnesol sobre implantes de Ti6Al4V.

OBJECTIVE: To evaluate the in vivo anti-staphylococcal bactericidal activity of farnesol on Ti6Al4V surfaces. MATERIAL AND METHODS: An experimental model of infection in biomaterials was developed by inoculation of Staphylococcus aureus ATCC 29213 into the canal of both femurs of 15 Wistar rats. A Ti6Al4V pin impregnated with 30mM of farnesol was inserted into study femur, and a Ti6Al4V control was inserted into the control femur. To evaluate the bactericidal efficacy, a comparison was made between the median of the colony forming units recovered after inoculation in the study group and the control group for different times of euthanasia and inoculum size. RESULTS: The median expressed as Log10 CFU counts obtained with farnesol titanium pin was 4.26, and in control group, it was 4.86, which was statistically significant (P=.001) on applying the Student t test for related samples. The median reduction obtained in farnesol pins relative to the control was 74%. CONCLUSIONS: Treatment with farnesol 30mM on Ti6Al4V pins appears to decrease the rate of colonisation by Staphylococcus aureus.

Evaluation of effectiveness of 10% polyvinylpyrrolidone-iodine solution against infections in wire and pin holes for Ilizarov external fixators.

CONTEXT AND OBJECTIVE: Superficial infection at wire and pin insertions in the skin is a frequent disorder among patients utilizing the Ilizarov method. The objective of this study was to evaluate the effectiveness of daily topical application of 10% polyvinylpyrrolidone-iodine solution against infections of the holes for Kirschner wires and Schanz pins among patients using Ilizarov external fixators, in comparison with cleaning these holes only with 0.9% sterile physiological saline solution. DESIGN AND SETTING: Controlled randomized clinical trial, in the Orthopedics and Traumatology Outpatient Clinic, Hospital São Paulo, and Orthopedics and Traumatology Center of Jundiaí. METHODS: 30 patients were treated using the Ilizarov technique: 15 were instructed to apply 0.9% physiological saline dressing on the wire and pin insertions and 15 to apply 0.9% physiological saline plus 10% polyvinylpyrrolidone-iodine. Patients were evaluated at outpatient return visits for identification of signs and symptoms of superficial infection at wire and pin insertion sites. Samples were collected from cases of purulent exudate secretion, for culturing and clinical tests. RESULTS: The chi-squared and Fischer exact tests were applied, but no statistically significant association between the intervention of topical polyvinylpyrrolidone-iodine solution and the prevention of infections at wire and pin insertions could be found. CONCLUSIONS: Topical 10% polyvinylpyrrolidone-iodine solution applied daily to Kirschner wire and Schanz pin insertions did not reduce the incidence of superficial infection at these holes, in comparison with mechanical removal of dirt using 0.9% physiological saline solution.

Seasonal Temperature and Pin Site Care Regimen Affect the Incidence of Pin Site Infection in Pediatric Supracondylar Humeral Fractures.

Pin site infection is a common complication after fracture fixation and bone lengthening, and daily pin site care is recommended. Weather is a strong environmental factor of infection, but few articles studied the issue of weather and pin site infection. We performed a prospective comparative study of 61 children with supracondylar humeral fractures treated by closed reduction and percutaneous pinning. The patients were divided into high-temperature season or low-temperature season by the months they received surgery. The patients within each season were further allocated to 2 groups by the different postoperative pin site care methods of daily care or noncare. The infection rate per patient was significantly higher in the high-temperature season compared to low-temperature season (45% versus 19%, P = 0.045). In the high-temperature season, the infection rate per patient was significantly higher in the daily care group versus the noncare group (70% versus 20%, P = 0.001). In the low-temperature season, the infection rate per patient was not significantly different in the daily care group versus the noncare group (10% versus 27.3%, P = 0.33). We recommend that careful monitoring of infection signs, rather than pin site cleaning, would be appropriate in the treatment of pediatric supracondylar humeral fractures, especially during the summer months.

A controlled antibiotic release system to prevent orthopedic-implant associated infections: An in vitro study.

A new device for local delivery of antibiotics is presented, with potential use as a drug-eluting fixation pin for orthopedic applications. The implant consists of a stainless steel hollow tubular reservoir packed with the desired antibiotic. Release takes place through several orifices previously drilled in the reservoir wall, a process that does not compromise the mechanical properties required for the implant. Depending on the antibiotic chosen and the number of orifices, the release profile can be tailored from a rapid release of the load (ca. 20h) to a combination of rapid initial release and slower, sustained release for a longer period of time (ca. 200h). An excellent bactericidal action is obtained, with 4-log reductions achieved in as little as 2h, and total bacterial eradication in 8h using 6-pinholed implants filled with cefazolin.