Transverse patella fracture fixation: A cadaveric biomechanical comparison of cannulated screws and anterior tension band versus low-profile, multiplanar mesh plating.

INTRODUCTION: Multiplanar mesh plating of patella fractures has become more popular in recent years. It was the goal of this study to compare the biomechanical stability of cannulated screw with anterior tension band to multiplanar mesh plating for fixation of transverse patella fractures in cadaver specimens. MATERIALS AND METHODS: Eight matched pairs of fresh frozen cadaveric knees were obtained and soft tissues dissected leaving the extensor mechanism, joint capsule, and retinaculum intact. Transverse fractures were created at the mid-portion of the patella. For each pair, one specimen was repaired using cannulated screws with anterior tension band, and the second was repaired using multiplanar mesh plating. Each specimen underwent cyclic extension loading with loads increasing by 1.1 kg after every 50 cycles. Interfragmentary displacement was measured at the end of each interval at both 5° and 45° of knee flexion angle, with fixation failure defined by >2 mm displacement. RESULTS: The specimens fixed with multiplanar mesh plating survived more cycles and higher loads than the specimens fixed with cannulated screws with anterior tension band (p = 0.011 comparing survival plots). After 150 cycles of extension loading, 3 of 8 of the specimens fixed with screws/tension band had failed, whereas none of the mesh plated specimens had failed. After 400 cycles, 7 of 8 of the screws/tension band had failed, whereas half of the mesh plated specimens had failed. CONCLUSIONS: While a more technically challenging and expensive technique, mesh plating for patella fractures appears to offer greater durability than traditional cannulated screw with tension banding.

Mechanics of dynamic compression plate application in fracture fixation.

BACKGROUND: Dynamic compression plating is a fundamental type of bone fracture fixation used to generate interfragmentary compression. The goal of this study was to investigate the mechanics of the surgical application of these plates, specifically how plate prebend, screw location, fracture gap, and applied torque influence the resulting compressive pressures. METHODS: Synthetic bones with transverse fractures were fixed with locking compression plates. One side of the fracture was fixed with locking screws. On the other side of the fracture, a nonlocking screw was inserted eccentrically to induce interfragmentary compression. A pressure mapping sensor within the fracture gap was used to record the resulting pressure distribution. Plate prebends of 0 mm, 1.5 mm, and 3 mm were tested. Three locations of the eccentric screw, four levels of screw torque, and two initial fracture gap conditions also were tested. FINDINGS: With increasing plate prebend, fracture compression pressures shifted significantly toward the far cortex; however, compression force decreased (P < 0.05). The 1.5 mm prebend plate resulted in the greatest contact area. Increasing screw torque generally resulted in greater fracture compression force. The introduction of a 1 mm fracture gap at the far cortex prior to dynamic compression resulted in little or no fracture compression. INTERPRETATION: The model showed that increasing plate prebend results in an increasing shift of fracture compression pressures toward the far cortex; however, this is accompanied by decreases in compressive force. Initial fracture gaps at the far cortex can result in little or no compression.

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.

The VANCO Trial Findings Are Generalizable to a North American Trauma Registry.

OBJECTIVES: To estimate the generalizability of treatment effects observed in the VANCO trial to a broader population of patients with tibial plateau or pilon fractures. METHODS: Design and Setting: Clinical trial data from 36 United States trauma centers and Trauma Quality Programs registry data from more than 875 Level I-III trauma centers in the United States and Canada.Patient Selection Criteria: Patients enrolled in the VANCO trial treated with intrawound vancomycin powder from January 2015 to June 2017 and 31,924 VANCO-eligible TQP patients admitted in 2019 with tibial plateau and pilon fractures.Outcome Measure and Comparisons: Deep surgical site infection and gram-positive deep surgical site infection estimated in the TQP sample weighed by the inverse probability of trial participation. RESULTS: The 980 patients in the VANCO trial were highly representative of 31,924 TQP VANCO-eligible patients (Tipton generalizability index 0.96). It was estimated that intrawound vancomycin powder reduced the odds of deep surgical infection by odds ratio (OR) = 0.46 (95% confidence interval [CI] 0.25-0.86) and gram-positive deep surgical infection by OR = 0.39 (95% CI, 0.18-0.84) within the TQP sample of VANCO-eligible patients. For reference, the trial average treatment effects for deep surgical infection and gram-positive deep surgical infection were OR = 0.60 (95% CI, 0.37-0.98) and OR = 0.44 (95% CI, 0.23-0.80), respectively. CONCLUSIONS: This generalizability analysis found that the inferences of the VANCO trial generalize and might even underestimate the effects of intrawound vancomycin powder when observed in a wider population of patients with tibial plateau and pilon fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Hospitalization for computer-assisted hexapod ring fixation application - analyses of patient variability, peri-operative complications, hospital costs, and discharge status.

BACKGROUND: Computer-assisted hexapod ring fixation systems (HRF) are used for multiple conditions and in very diverse patient populations. This study analyzes perioperative outcomes following HRF application based on patient etiology and clinical presentation. METHODS: Data from patients in the Premier Hospital Billing Database between 2007-2019 undergoing HRF application were analyzed for the duration of patients' hospitalizations. Patients were grouped based on etiology: acquired deformity, arthrosis, congenital deformity, deep infection, infected nonunion, fracture, nonunion, and other post-operative complications. Demographics, comorbidities, operating room time (ORT), length of stay (LOS), peri-operative complications, and hospital costs were estimated using generalized linear models. Logistic regression evaluated factors associated with peri-operative complications. RESULTS: One thousand eight hundred eighteen patients (average age: 46.9, standard deviation (SD) (19.6) - 38.9% female) were included in the study, and included 72% fracture cases, 9.6% deep infection, 10.2% deformity (acquired: 5.9%, congenital: 4.3%), 4.2% nonunions, 2% arthrosis and 1.4% other sequelas from prior fractures. Comorbidities varied across diagnosis categories and age, 40% adults and 86% pediatric had no comorbidities. Pediatric cases mostly suffered from obesity (16.1%) and pulmonary disease (10.7%). Complicated diabetes was present in 45.9% of arthropathy and 34.3% of deep infection patients. ORT, LOS and inflation-adjusted hospital costs for all patients averaged 277.7 min (95% Confidence interval (CI): 265.1-290.3), 7.07 days (95% CI: 6.6-7.5) and $41,507 (95%CI: $39,728-$43,285), respectively, but were highest in patients with deep infection (ORT: 369 min (95%CI: $321.0-$433.8); LOS: 14.4 days (95%CI: $13.7-$15.1); Cost: $54,666 (95%CI: $47,960-$63,553)). The probability of having an intraoperative complication averaged 35% (95%CI: 28%-43%) in adult patients with deep infection vs 7% (95%CI: 2%-20%) in pediatric cases treated for congenital deformity. The risk for intraoperative complications was mostly associated with preexisting comorbidities, an Elixhauser > 5 was the most predictive risk factor for complications (odds ratios: 4.53 (95%CI: 1.71-12.00, p = 0.002). CONCLUSIONS: There is important heterogeneity among HRF patients. Adults with HRF for fracture, deep infection and arthrosis are at far greater risk for peri-operative complications vs. patients with deformity, especially pediatric deformity cases, mostly due to existing comorbidities and age. Device-specific HRF clinical studies cannot be generalized beyond their exact patient population.

Two-year clinical and economic burden, risk and outcomes following application of software-assisted hexapod ring fixation systems.

BACKGROUND: Multiplanar external fixation systems that employ software-assisted deformity correction consist of rings connected by angled struts, defined as hexapod ring fixators (HRF). Costs and outcomes associated with the application of HRFs are not well documented. This study was designed to provide a nationwide baseline understanding of the clinical presentation, risks, outcomes and payer costs, and healthcare resource utilization (HCU) of patients requiring application of an HRF, from the day of, and up to 2 years, post-application. METHODS: Patients with HRF application ("index") between 2007 and 2019 within the IBM Marketscan® Commercial Claims database were identified and categorized based on diagnosis: acquired deformity, arthropathy, congenital deformity, deep infection, nonunion, fracture, and other post-operative fracture sequelae. Demographics, comorbidities at index, complications post-index, HCU, and payments were analyzed. Payments were estimated using a generalized linear model and were adjusted for inflation to the 2020 consumer price index. Rates of deep infection and amputation were estimated up to 2 years post-index using Poisson regressions, and risk factors for each were estimated using logistic regression models. RESULTS: Six hundred ninety-five patients were included in our study (including 219 fractures, 168 congenital deformities, 68 deep infections, 103 acquired deformities). Comorbidities at index were significantly different across groups: less than 2% pediatrics vs 18% adults had 3 or more comorbidities, < 1% pediatric vs 29% adults had diabetes. Index payments ranged from $39,250-$75,350, with 12-months post-index payments ranging from $14,350 to $43,108. The duration of the HRF application ranged from 96 days to 174 days. Amputation was observed in patients with deep infection (8.9, 95% confidence interval (CI): 3.2-23.9%), nonunion (5.0, 95%CI: 1.6-15.4%) or fracture (2.7, 95%CI: 0.9-7.6%) at index. Complicated diabetes was the main predictor for deep infection (odds ratio (OR): 5.14, 95%CI: 2.50-10.54) and amputation (OR: 5.26, 95%CI: 1.79-15.51). CONCLUSIONS: Findings from this longitudinal analysis demonstrate the significant heterogeneity in patients treated with HRF, and the wide range in treatment intensity, payments, and outcomes. Risks for deep infection and amputation were primarily linked to the presence of complicated diabetes at the time of HRF application, suggesting a need for careful management of comorbid chronic conditions in patients requiring HRF for orthopedic care.

Virtual Simulation for Interactive Visualization of 3D Fracture Fixation Biomechanics.

INTRODUCTION: In the surgical fixation of fractures, proper biomechanical stability is key in preventing clinical complications including poor fracture healing, residual deformity, loss of fixation, or implant failure. Stability is largely influenced by treatment decisions made by the surgeon. The interplay of surgeon-controlled variables and their effect on the three-dimensional (3D) biomechanics of a fracture fixation construct are often not intuitive, and current training methods do not facilitate a deep understanding of these interactions. METHODS: A simulation software interface, FracSim, was developed. FracSim is built on a large precomputed library of finite element simulations. The software allows a surgeon to make adjustments to a virtual fracture fixation construct/weight-bearing plan and immediately visualize how these changes affect 3D biomechanics, including implant stress and fracture gap strain, important for clinical success. Twenty-one orthopaedic residents completed an instructor-led educational session with FracSim focused on bridge plating. Subjects completed pretests and posttests of knowledge of biomechanical concepts and a questionnaire. RESULTS: Subjects scored a mean of 5.6/10 on the pretest of biomechanical knowledge. Senior residents scored better than junior residents (P = 0.04). After the educational session with FracSim, residents improved their test scores to a mean of 8.0/10, with a significant improvement (P < 0.001). Questionnaire scores indicated that subjects believed that FracSim had realistic implants, constructs, and motions and that training with FracSim was purposeful, desirable, efficient, fun, and useful for enhancing the understanding of fracture fixation biomechanics. DISCUSSION: This new type of simulation software enables interactive visualization of 3D fracture fixation biomechanics. Limitations of this study include lack of a control group undergoing traditional education and lack of a delayed posttest to assess retention. FracSim may provide an effective and engaging way to promote a deeper understanding of biomechanical concepts in the orthopaedic learner.

Smith-Petersen Versus Watson-Jones Approach Does Not Affect Quality of Open Reduction of Femoral Neck Fracture.

OBJECTIVE: To compare immediate quality of open reduction of femoral neck fractures by alternative surgical approaches. DESIGN: Retrospective cohort study. SETTING: Twelve Level 1 North American trauma centers. PATIENTS: Eighty adults 18-65 years of age with isolated, displaced, OTA/AO type 31-B2 or -B3 femoral neck fractures treated with internal fixation. INTERVENTION: Thirty-two modified Smith-Petersen anterior approaches versus 48 Watson-Jones anterolateral approaches for open reduction performed by fellowship-trained orthopaedic trauma surgeons. MAIN OUTCOME: Reduction quality as assessed by 3 senior orthopaedic traumatologists as "acceptable" or "unacceptable" on AP and lateral postoperative radiographs. RESULTS: No difference was observed in the rate of acceptable reduction by modified Smith-Petersen (81%) versus Watson-Jones (81%) approach (risk difference null, 95% confidence interval -17.4% to 17.4%, P = 1.00) with 90.4% panel agreement (Fleiss' weighted κ = 0.63, P < 0.01). Stratified analyses did not identify a significant difference in the rate of acceptable reduction between approaches when stratified by Pauwels angle, basicervical or transcervical fracture location, or posterior comminution. The Smith-Petersen approach afforded a better reduction when preoperative skeletal traction was not applied (RR = 1.67 [95% CI 1.10-2.52] vs. RR = 0.87 [95% CI 0.70-1.08], P = 0.006). CONCLUSIONS: No difference was observed in the quality of open reduction of displaced femoral neck fractures in young adults when a Watson-Jones anterolateral approach versus a modified Smith-Petersen anterior approach was performed by orthopaedic trauma surgeons. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Finite Element Analysis of Fracture Fixation.

PURPOSE OF REVIEW: Fracture fixation aims to provide stability and promote healing, but remains challenging in unstable and osteoporotic fractures with increased risk of construct failure and nonunion. The first part of this article reviews the clinical motivation behind finite element analysis of fracture fixation, its strengths and weaknesses, how models are developed and validated, and how outputs are typically interpreted. The second part reviews recent modeling studies of the femur and proximal humerus, areas with particular relevance to fragility fractures. RECENT FINDINGS: There is some consensus in the literature around how certain modeling aspects are pragmatically formulated, including bone and implant geometries, meshing, material properties, interactions, and loads and boundary conditions. Studies most often focus on predicted implant stress, bone strain surrounding screws, or interfragmentary displacements. However, most models are not rigorously validated. With refined modeling methods, improved validation efforts, and large-scale systematic analyses, finite element analysis is poised to advance the understanding of fracture fixation failure, enable optimization of implant designs, and improve surgical guidance.

Surgical management of angulated femoral intramedullary nails associated with closed fractures: A systematic review of the literature.

BACKGROUND: Femoral nail bending is a rare complication of intramedullary (IM) fixation of femoral diaphyseal fractures. Published literature regarding this injury pattern has thus far been limited to case reports or case series, thus no universally accepted surgical treatment strategy has been developed. METHODS: A systematic review was conducted using the Pubmed/MEDLINE and Scopus/EMBASE databases. A standardized template was used to extract data including author, year of publication, patient demographics, degree of angulation, mechanism of injury, time since initial procedure to reinjury, surgical treatment, and clinical outcomes. A case report from our institution was described as well. RESULTS: 27 cases in 25 reports were included in the qualitative analysis. All of the patients were males, and the ages ranged from 17 to 66 (mean age = 27.8). The degree of deformity ranged from 18 to 85° (mean 35.6), most commonly in a varus or apex anterior orientation. The nail deformities were corrected via one of six general surgical techniques: full transection of the nail, partial sectioning and manual straightening, limited corticotomy or longitudinal bone window, straightening with the assistance of a plate and reduction clamps, closed manipulation, or extraction without the need for manipulation. The fractures were then most commonly treated with revision IM nail. CONCLUSIONS: The bent IM nail is a rare and challenging injury to treat. No one technique has been identified as "the gold standard" and each case must be approached with its unique characteristics in mind.

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.

Parametric Finite Element Analysis of Intramedullary Nail Fixation of Proximal Femur Fractures.

Proximal femur fracture fixation with intramedullary nailing relies on stability at the fracture site and integrity of the fixation construct to achieve union. The biomechanics that dictate fracture site stability and implant stress depend on fracture type as well as implant features such as nail length, nail diameter, presence of distal fixation screws, and material composition of the implant. When deciding how to fix a fracture, surgeons have choices in these implant-related design variables. This study models all combinations of a range of implant variables for nine standard AO/OTA proximal femur fractures using finite element analysis. Under simulated maximum load during gait, the maximum stress in the implant and screws as well as interfragmentary motions at the fracture site in the axial and shear directions were computed. The results were separated by fracture type to show the influence of each design variable on measured biomechanical outcomes. Filling the reamed canal with the largest fitting nail diameter reduced axial and shear interfragmentary motion for all fracture types. Nail length was less predictive of shear interfragmentary motion for most simulated fracture types than other construct variables. Furthermore, gapping at the fracture site predisposed the construct to higher implant stresses and larger interfragmentary motions. Clinical significance: Biomechanical outcomes from this computational study can aid in surgical decision-making for optimizing hip fracture fixation with IM nailing. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2358-2366, 2019.

Finite Element-Derived Surrogate Models of Locked Plate Fracture Fixation Biomechanics.

Internal fixation of bone fractures using plates and screws involves many choices-implant type, material, sizes, and geometric configuration-made by the surgeon. These decisions can be important for providing adequate stability to promote healing and prevent implant mechanical failure. The purpose of this study was to develop mathematical models of the relationships between fracture fixation construct parameters and resulting 3D biomechanics, based on parametric computer simulations. Finite element models of hundreds of different locked plate fixation constructs for midshaft diaphyseal fractures were systematically assembled using custom algorithms, and axial, torsional, and bending loadings were simulated. Multivariate regression was used to fit response surface polynomial equations relating fixation design parameters to outputs including maximum implant stresses, axial and shear strain at the fracture site, and construct stiffness. Surrogate models with as little as three regressors showed good fitting (R 2 = 0.62-0.97). Inner working length was the strongest predictor of maximum plate and screw stresses, and a variety of quadratic and interaction terms influenced resulting biomechanics. The framework presented in this study can be applied to additional types of bone fractures to provide clinicians and implant designers with clinical insight, surgical optimization, and a comprehensive mathematical description of biomechanics.

Percutaneous Sacroiliac Screw Technique.

Remembering that preoperative planning, surgical indications, and fracture reduction are paramount for this procedure, presented here is our technique for performing percutaneous sacroiliac screws, both transiliac-transsacral and sacral style. A combination of video, still pictures, and fluoroscopy images will guide the viewer through the process we routinely use highlighting specific details. Patient positioning and intraoperative fluoroscopy imaging are critical to a successful procedure. Although inlet and outlet films remain important, we find the procedure best started on the lateral sacral view to reduce the need for start site, trajectory, and imaging position changes during the case. A cannulated pig sticker (drill guide) used with long drill tip guide wires provide improved manual control to both finding a good start site and directing the trajectory. For patient safety, sacral anatomy and safe zones are discussed as well. Using these technical points will help make this a successful procedure.

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.