Does Topical Vancomycin Powder Use in Fracture Surgery Change Bacteriology and Antibiotic Susceptibilities? An Analysis of the VANCO Trial.

OBJECTIVE: To determine whether intrawound vancomycin changes the bacteriology of surgical site infection pathogens and investigate the emergence of antibiotic-resistant pathogens. DESIGN: Secondary analysis of phase III, prospective, randomized clinical trial. SETTING: Thirty-six US trauma centers. PATIENT SELECTION CRITERIA: Patients who became infected after fixation of tibial plateau or pilon fracture. OUTCOME MEASURES AND COMPARISONS: Pathogen types and bacterial susceptibilities as determined from routine clinical culture in the operating room. RESULTS: Seventy-four patients were studied who were 67.5% male with a mean age of 48.6 years. A lower proportion of gram-positive cocci was observed in the vancomycin powder compared with the standard-of-care group (3.7% vs. 8.0%, P = 0.01). Methicillin-resistant Staphylococcus aureus infection incidence was comparable in both the vancomycin powder and the standard-of-care groups, but rates of methicillin-susceptible S. aureus infections were lower in the treatment group (1.4% vs. 4.8%, P = 0.01). The incidence of coagulase-negative Staphylococci and gram-negative rod infections were similar in both groups. There was no significant difference in susceptibilities between groups in rates of vancomycin-resistant enterococcus. CONCLUSIONS: Topical vancomycin powder decreases the likelihood of gram-positive infections consistent with the biologic activity of vancomycin. Fewer methicillin-susceptible S. aureus and coagulase-negative Staphylococci infections were observed in the group treated with vancomycin powder. An effect of vancomycin powder on methicillin-resistant S. aureus infection risk was not detected given the low incidence in both the intrawound vancomycin and the standard-of-care groups. There was no emergence of gram-negative rod infections or increased resistance patterns observed. Use of topical vancomycin powder does not seem to produce infections in these patients with greater antibiotic resistance than would have occurred without its use. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Open Reduction Is Associated With Greater Hazard of Early Reoperation After Internal Fixation of Displaced Femoral Neck Fractures in Adults 18-65 Years.

OBJECTIVES: To determine (1) which factors are associated with the choice to perform an open reduction and (2) by adjusting for these factors, if the choice of reduction method is associated with reoperation. DESIGN: Retrospective cohort study with radiograph and chart review. SETTING: Twelve Level 1 North American trauma centers. PATIENTS: Two hundred thirty-four adults 18-65 years of age with an isolated, displaced, OTA/AO type 31-B2 or type 31-B3 femoral neck fracture treated with internal fixation with minimum of 6-month follow-up or reoperation. Exclusion criteria were pathologic fractures, associated femoral head or shaft fractures, and primary arthroplasty. INTERVENTION: Open or closed reduction technique during internal fixation. MAIN OUTCOME: Cox proportional hazard of reoperation adjusting for propensity score for open reduction based on injury, demographic, and medical factors. Reduction quality was assessed by 3 senior orthopaedic traumatologists as "acceptable" or "unacceptable" on AP and lateral postoperative radiographs. RESULTS: Median follow-up was 1.5 years. One hundred six (45%) patients underwent open reduction. Reduction quality was not significantly affected by open versus closed approach (71% vs. 69% acceptable, P = 0.378). The propensity to receive an open reduction was associated with study center; younger age; male sex; no history of injection drug use, osteoporosis, or cerebrovascular disease; transcervical fracture location; posterior fracture comminution; and surgery within 12 hours. A total of 35 (33%) versus 28 (22%) reoperations occurred after open versus closed reduction (P = 0.056). Open reduction was associated with a 2.4-fold greater propensity-adjusted hazard of reoperation (95% confidence interval 1.3-4.4, P = 0.004). A total of 35 (15%) patients underwent subsequent total hip arthroplasty or hemiarthroplasty. CONCLUSIONS: Open reduction of displaced femoral neck fractures in nonelderly adults is associated with a greater hazard of reoperation without significantly improving reduction. Prospective randomized trials are indicated to confirm a causative effect of open versus closed reduction on outcomes after femoral neck fracture. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The biomechanical cost of variable angle locking screws.

INTRODUCTION: Variable angle (VA) locking plates in fracture fixation surgery allow screws to be fastened to the plate within a conical "locus of vectors" in order to avoid existing prostheses, joint surfaces, or poor quality bone. Clinical failures of VA constructs in which screws have rotated at the plate/screw interface have been reported raising the concern that there may be a biomechanical cost for the increased flexibility that VA provides. The objective of this study was to test the mechanical properties of one commonly used VA locking mechanism with screws placed in both nominal and off-axis trajectories and compare these against the standard locking mechanism. METHODS: VA locking screws were inserted into plates for distal femur fractures (VA Curved Condylar) at various angles (0° to 15° away from perpendicular). A control group of standard locking screws/plates was also tested. Maximum moment at the screw/plate interface and moment at two reference displacements were determined. RESULTS: VA screws locked perpendicular to the plate provided the greatest maximum moment and moment at the reference displacements when using the VA system, and demonstrated lower moments compared to standard locking screws/plates (p<0.001). Based on linear regression, there was an average decrease of approximately 0.4 Nm screw-plate interface strength for every 1° increase in screw-plate angle (p<0.001). Decreases (p<0.05) were discovered in both maximum moment and moment at the reference displacements for screws locked at 5° relative to those locked at 0°, 10° relative to 0°, and 15° relative to 10°. DISCUSSION: Standard locking systems provided greater resistance to rotational failure at the screw/plate interface than variable angle locking systems. Variable angle systems provided the greatest resistance to rotation when the screw was inserted perpendicular to the plate. As the off-axis angle increased, the resistance to rotation at the screw/plate interface decreased almost linearly. It is unknown if these differences are clinically significant in an actual fracture construct, but recent reported failures in the distal femur suggest that they might be. CONCLUSION: Surgeons should weigh the risks and benefits of VA systems and attempt to minimize the off-axis angle magnitude when VA systems are selected.

Outcome of 28 open pilon fractures with injury severity-based fixation.

INTRODUCTION: Open pilon fracture management and treatment poses a significant challenge to orthopedic surgeons. The purpose of this study was to determine patient outcomes for open pilon fractures based on wound complication and infection rates, as well as subjective outcome instruments. MATERIALS AND METHODS: This was a retrospective consecutive case series of 28 fractures with Orthopaedic Trauma Association (OTA)-type 43-B and 43-C open pilon fractures. Mean length of follow-up was 36 months and minimum of 1 year. Ten fractures were Gustilo and Anderson grade IIIB, and the remaining fractures were grades I-IIIA. Patients were initially treated with spanning external fixation and staged wound debridement followed by osteosynthesis of the articular surface. Metaphyseal fixation was by either plate fixation or Ilizarov frame. The primary outcome was the incidence of deep tissue infection requiring surgery. Secondary outcomes included the incidence of other complications (nonunion, malunion, amputation) and functional outcomes (Short Musculoskeletal Functional Assessment Questionnaire and AAOS Foot and Ankle Questionnaire). RESULTS: Four patients developed deep tissue infections, three in the internal fixation group and one in the Ilizarov group, and all were treated successfully with staged debridement. There were two delayed unions required bone grafting, and infection-free union was ultimately achieved in all fractures. Two patients underwent arthrodesis secondary to post-traumatic arthritis, while no patients experienced malunions or amputations. CONCLUSIONS: The use of staged wound debridement in conjunction with either plate fixation or Ilizarov frame achieves low rates of wound infection and stable fixation after anatomic joint reconstruction for OTA-type 43-B and 43-C open pilon fractures.

Single Nucleotide Polymorphisms in Osteogenic Genes in Atrophic Delayed Fracture-Healing: A Preliminary Investigation.

UpdateThis article was updated on September 10, 2014, because of a previous error. On page 1242, in the byline, and on page 1247, in the author addresses, the academic degree for Henry J. Donahue had previously read "MD." The degree now reads "PhD." BACKGROUND: We propose that fracture-healing potential is affected by the patient's genome. This genotype is then phenotypically expressed by the patient at the time of injury. We examined the hypothesis that patients who exhibit delayed or impaired fracture-healing may have one or more single nucleotide polymorphisms (SNPs) within a series of genes related to bone formation. METHODS: We performed a population-based, case-controlled study of delayed fracture-healing. Sixty-two adults with a long-bone fracture were identified from a surgical database. Thirty-three patients had an atrophic nonunion (delayed healing), and twenty-nine displayed normal fracture-healing. These patients underwent buccal mucosal cell harvesting. SNP genotyping was performed with use of bead array technology. One hundred and forty-four SNPs (selected from HapMap) within thirty genes associated with fracture-healing were investigated. Three SNPs did not segregate in the population and were excluded from the analysis. Eight of the remaining SNPs failed the test for Hardy-Weinberg equilibrium (p value smaller than the Bonferroni-corrected level of 0.05/141 = 0.000355) and were excluded. RESULTS: Five SNPs on four genes were found to have a p value of <0.05 in the additive genetic model. Of these five significant SNPs, three had an odds ratio (OR) of >1, indicating that the presence of the allele increased the risk of nonunion. The rs2853550 SNP, which had the largest effect (OR = 5.9, p = 0.034), was on the IL1B gene, which codes for interleukin 1 beta. The rs2297514 SNP (OR = 3.98, p = 0.015) and the rs2248814 SNP (OR = 2.27, p = 0.038) were on the NOS2 gene coding for nitric oxide synthase. The remaining two SNPs had an OR of <1, indicating that the presence of the allele may be protective against nonunion. The rs3819089 SNP (OR = 0.26, p = 0.026) was on the MMP13 gene for matrix metallopeptidase 13, and the rs270393 SNP (OR = 0.30, p = 0.015) was on the BMP6 gene for bone morphogenetic protein 6. CONCLUSIONS: Variations in the IL1B and NOS2 genes may contribute to delayed fracture-healing and warrant further investigation. CLINICAL RELEVANCE: Impaired fracture union may have genetic contributions.

Tibiofibular bone-bridging osteoplasty in transtibial amputation: case report and description of technique.

Transtibial amputation osteoplasty procedures were originally designed as a technique for achieving a functional end-bearing limb in the post-World War I era; the Ertl procedure is now often used as a reconstructive procedure for failed primary amputations. Modifications of the original periosteal sleeve-covering technique include the tibiofibular bone-bridging osteoplasty. The theoretical advantages to this procedure are highly debated among trauma surgeons. For the patient with a lower extremity injury that necessitates a transtibial amputation, there are many psychologic and physiologic factors to consider, and a persistently painful residual limb postamputation may be mentally and physically disabling. Although the advantages of these techniques may be unproven, they are fairly simple and add little additional operative time to the primary transtibial amputation. A surgeon who performs transtibial amputations should at least be aware of the osteoplasty techniques and how to perform them. The decision to use these techniques may then be made by the surgeon on a case-by-case basis, given the individual demands of the patient. This article presents a case report and outlines the use of the fibular bone-bridging osteoplasty technique in transtibial amputations.

Effect of COX-2-specific inhibition on fracture-healing in the rat femur.

BACKGROUND: Nonsteroidal anti-inflammatory medications have been shown to delay fracture-healing. COX-2-specific inhibitors such as celecoxib have recently been approved for human use. Our goal was to determine, mechanically, histologically, morphologically, and radiographically, whether COX-2-specific inhibition affects bone-healing. METHODS: A nondisplaced unilateral fracture was created in the right femur of fifty-seven adult male rats. Rats were given no drug, indomethacin (1 mg/kg/day), or celecoxib (3 mg/kg/day) daily, starting on postoperative day 1. Fractures were analyzed at four, eight, and twelve weeks after creation of the fracture. Callus and bridging bone formation was assessed radiographically. The amounts of fibrous tissue, cartilage, woven bone, and mature bone formation were determined histologically. Morphological changes were assessed to determine fibrous healing, callus formation, and bone-remodeling. Callus strength and stiffness were assessed biomechanically with three-point bending tests. RESULTS: At four weeks, only the indomethacin group showed biomechanical and radiographic evidence of delayed healing. Although femora from rats treated with celecoxib appeared to have more fibrous tissue than those from untreated rats at four and eight weeks, radiographic signs of callus formation, mechanical strength, and stiffness did not differ significantly between the groups. By twelve weeks, there were no significant differences among the three groups. CONCLUSIONS: Postoperative administration of celecoxib, a COX-2-specific inhibitor, did not delay healing as seen at twelve weeks following fracture in adult rat femora. At four and eight weeks, fibrous healing predominated in the celecoxib group as compared with the findings in the untreated group; however, mechanical strength and radiographic signs of healing were not significantly inhibited. CLINICAL RELEVANCE: Many orthopaedists rely on narcotic analgesia for postfracture and postoperative pain, despite deleterious side effects and morbidity. Traditional nonsteroidal anti-inflammatory medications have been shown to delay fracture union. This effect may be smaller with COX-2-specific inhibitors.

Percutaneous pinning of talar neck fractures.

In this article, we describe a technique for percutaneous pinning of talar neck fractures. This technique, which uses 2 partially threaded cannulated screws placed in opposite directions and parallel to each other, minimizes soft-tissue injury and blood-supply disruption and can shorten surgery. In addition, it allows for fracture compression and optimal positioning of screws, which increase the biomechanical stability of the fixation.