Risk Factors of Failure in 228 Periprosthetic Distal Femur Fractures: A Multicenter Study.

OBJECTIVES: To identify risk factors of reoperation to promote union or to address deep surgical-site infection (DSSI) in periprosthetic distal femur fractures treated with lateral distal femoral locking plates (LDFLPs). DESIGN: Multicenter retrospective cohort study. SETTING: Ten level-I trauma centers. PATIENT SELECTION CRITERIA: Patients with Orthopaedic Trauma Association/Association of Osteosynthesis (OTA/AO) 33A or 33C periprosthetic distal femur fractures who underwent surgical fixation between January 2012 and December 2019 exclusively using LDFLPs were eligible for inclusion. Patients with pathologic fractures or with follow-up less than 3 months without an outcome event (unplanned reoperation to promote union or for deep surgical infection) before this time point were excluded. Fracture fixation constructs used medial plates, intramedullary nails, or hybrid fixation constructs were excluded from analysis. OUTCOME MEASURES AND COMPARISONS: To examine the influence of patient demographics, injury characteristics, and features of the fracture fixation construct on the occurrence of unplanned reoperation to promote union or to address a DSSI. RESULTS: There was an 8.3% rate (19/228) of unplanned reoperation to promote union. Predictive factors for the need for reoperation to promote union included increasing body mass index (odds ratio [OR] = 1.09; 95% confidence interval [CI]: 1.02-1.16; P = 0.01), increasing number of screws in the distal fracture segment (OR = 1.73; 95% CI: 1.06-2.95; P = 0.03), and decreasing proportion of proximal segment screws that are locking (OR = 0.17; 95% CI: 0.03-0.70; P = 0.02) There was a 4.8% rate (11/228) of reoperation to address DSSI. There were no statistically significant predictive factors identified as risk factors of the need for reoperation to address DSSI ( P > 0.05). CONCLUSIONS: 8.3% of periprosthetic distal femur fractures treated at 10 centers with LDFLPs underwent unplanned reoperation to promote union. Increasing patient body mass index and increasing number of screws in the distal fracture segment were found to be predictive factors, whereas increased locking screws in the proximal segment were found to be protective. 4.8% of patients in this cohort underwent reoperation to address DSSI. LEVEL OF EVIDENCE: Level III. See Instructions for Authors for a complete description of levels of evidence.

Skin Antisepsis before Surgical Fixation of Extremity Fractures.

BACKGROUND: Studies evaluating surgical-site infection have had conflicting results with respect to the use of alcohol solutions containing iodine povacrylex or chlorhexidine gluconate as skin antisepsis before surgery to repair a fractured limb (i.e., an extremity fracture). METHODS: In a cluster-randomized, crossover trial at 25 hospitals in the United States and Canada, we randomly assigned hospitals to use a solution of 0.7% iodine povacrylex in 74% isopropyl alcohol (iodine group) or 2% chlorhexidine gluconate in 70% isopropyl alcohol (chlorhexidine group) as preoperative antisepsis for surgical procedures to repair extremity fractures. Every 2 months, the hospitals alternated interventions. Separate populations of patients with either open or closed fractures were enrolled and included in the analysis. The primary outcome was surgical-site infection, which included superficial incisional infection within 30 days or deep incisional or organ-space infection within 90 days. The secondary outcome was unplanned reoperation for fracture-healing complications. RESULTS: A total of 6785 patients with a closed fracture and 1700 patients with an open fracture were included in the trial. In the closed-fracture population, surgical-site infection occurred in 77 patients (2.4%) in the iodine group and in 108 patients (3.3%) in the chlorhexidine group (odds ratio, 0.74; 95% confidence interval [CI], 0.55 to 1.00; P = 0.049). In the open-fracture population, surgical-site infection occurred in 54 patients (6.5%) in the iodine group and in 60 patients (7.3%) in the chlorhexidine group (odd ratio, 0.86; 95% CI, 0.58 to 1.27; P = 0.45). The frequencies of unplanned reoperation, 1-year outcomes, and serious adverse events were similar in the two groups. CONCLUSIONS: Among patients with closed extremity fractures, skin antisepsis with iodine povacrylex in alcohol resulted in fewer surgical-site infections than antisepsis with chlorhexidine gluconate in alcohol. In patients with open fractures, the results were similar in the two groups. (Funded by the Patient-Centered Outcomes Research Institute and the Canadian Institutes of Health Research; PREPARE ClinicalTrials.gov number, NCT03523962.).

Technical Factors Contributing to Nonunion in Supracondylar Distal Femur Fractures Treated With Lateral Locked Plating: A Risk-Stratified Analysis.

OBJECTIVE: To identify technical factors associated with nonunion after operative treatment with lateral locked plating. DESIGN: Retrospective cohort study. SETTING: Ten Level I trauma centers. PATIENT SELECTION CRITERIA: Adult patients with supracondylar distal femur fractures (OTA/AO type 33A or C) treated with lateral locked plating from 2010 through 2019. OUTCOME MEASURES AND COMPARISONS: Surgery for nonunion stratified by risk for nonunion. RESULTS: The cohort included 615 patients with supracondylar distal femur fractures. The median patient age was 61 years old (interquartile range: 46 -72years) and 375 (61%) were female. Observed were nonunion rates of 2% in a low risk of nonunion group (n = 129), 4% in a medium-risk group (n = 333), and 14% in a high-risk group (n = 153). Varus malreduction with an anatomic lateral distal femoral angle greater than 84 degrees, was associated with double the odds of nonunion compared to those without such varus [odds ratio, 2.1; 95% confidence interval (CI), 1.1-4.2; P = 0.03]. Malreduction by medial translation of the articular block increased the odds of nonunion, with 30% increased odds per 4 mm of medial translation (95% CI, 1.0-1.6; P = 0.03). Working length increased the odds of nonunion in the medium risk group, with an 18% increase in nonunion per 10-mm increase in working length (95% CI, 1.0-1.4; P = 0.01). Increased proximal screw density was protective against nonunion (odds ratio, 0.71; 95% CI, 0.53-0.92; P = 0.02) but yielded lower mRUST scores with each 0.1 increase in screw density associated with a 0.4-point lower mRUST (95% CI, -0.55 to -0.15; P < 0.001). Lateral plate length and type of plate material were not associated with nonunion. ( P > 0.05). CONCLUSIONS: Malreduction is a surgeon-controlled variable associated with nonunion after lateral locked plating of supracondylar distal femur fractures. Longer working lengths were associated with nonunion, suggesting that bridge plating may be less likely to succeed for longer fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Tibial Plateau Fractures: Addressing Commonly Encountered Challenges in Reduction and Fixation.

Tibial plateau fractures encompass a broad array of injuries. The mechanism of injury ranges from low to high energy. Devastating complications and associated injuries can occur in both low-energy and high-energy mechanisms; therefore, a careful and detailed physical examination and review of imaging must be performed. Furthermore, a mechanistic approach to fracture classification and morphology enhances the surgeon's understanding of the injury and the ability to predict associated injuries and develop effective strategies for management.

Nail Plate Combination Fixation Versus Lateral Locked Plating for Distal Femur Fractures: A Multicenter Experience.

OBJECTIVES: To (1) report on clinical, radiographic, and functional outcomes after nail-plate fixation (NPF) of distal femur fractures and (2) compare outcomes after NPF with a propensity matched cohort of fractures treated with single precontoured lateral locking plates. DESIGN: Multicenter retrospective cohort study. SETTING: Ten Level 1 trauma centers. PATIENTS/PARTICIPANTS: Patients with OTA/AO 33A or 33C fractures. INTERVENTION: Fixation with (1) retrograde intramedullary nail combined with lateral locking plate (n = 33) or (2) single precontoured lateral locking plate alone (n = 867). MAIN OUTCOME MEASUREMENTS: The main outcomes of interest were all-cause unplanned reoperation and presence of varus collapse at final follow-up. RESULTS: One nail-plate patient underwent unplanned reoperation excluding infection and 2 underwent reoperation for infection at an average of 57 weeks after surgery. No nail-plate patients required unplanned reoperation to promote union and none exhibited varus collapse. More than 90% were ambulatory with no or minimal pain at final follow-up. In comparison, 7 of the 30 matched lateral locked plating patients underwent all-cause unplanned reoperation excluding infection (23% vs. 3%, P = 0.023), and an additional 3 lateral locked plating patients were found to have varus collapse on final radiographs (10% vs. 0%, P = 0.069). CONCLUSIONS: Despite a high proportion of high-energy, open, and comminuted fractures, no NPF patients underwent unplanned reoperation to promote union or demonstrated varus collapse. Propensity score matched analysis revealed significantly lower rates of nonunion for NPF compared with lateral locked plating alone. Larger studies are needed to identify which distal femur fracture patients would most benefit from NPF. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Timing of venous thromboemboli in patients with acetabular and pelvic ring fractures.

PURPOSE: To determine the timing of symptomatic venous thromboemboli (VTE) in patients sustaining a pelvic and/or acetabular fracture. Secondly, to evaluate for any factors that may influence this timing. METHODS: A retrospective cohort of 47 patients with acetabular and/or pelvic ring injuries who developed VTEs at a single academic level I trauma center were identified from 2012 to 2018. The chronology of VTE diagnosis in relation to date of injury, initial surgery, final surgery, and date of discharge was evaluated. Patients who developed VTEs were then evaluated based on known risk factors for VTE to determine if any of these affected timing. RESULTS: Symptomatic VTEs were diagnosed in 3.8% of patients with pelvic and/or acetabular fractures. In patients who developed a thromboembolism, diagnosis occurred on average 21.5 (± 19.2), 20.7 (± 19.9), 9.8 (± 23.4), and 4.3 (± 27.6) days after injury, index procedure, final procedure, and date of discharge. 25% of patients developed VTE more than 4 weeks after their initial injury. No known risk factors effected the timing of VTE. CONCLUSION: The 2015 OTA expert panel recommends 4 weeks of anticoagulation for orthopedic trauma patients at high risk of VTE, which may be too short a duration. In our cohort, 25% of VTEs occurred greater than 4 weeks after injury. Additional research is needed to clarify the exact duration of anticoagulation after pelvic and acetabular fractures; however, surgeons may want to consider anticoagulating patients for greater than 4 weeks. LEVEL OF EVIDENCE: Level III-retrospective cohort.

Predictors of Deep Infection After Distal Femur Fracture: A Multicenter Study.

OBJECTIVES: To identify potentially modifiable risk factors for deep surgical site infection after distal femur fracture. DESIGN: Multicenter retrospective cohort study. SETTING: Ten Level-I trauma centers. PATIENTS/PARTICIPANTS: Patients with OTA/AO 33A or C distal femur fractures (n = 1107). INTERVENTION: Surgical fixation of distal femur fracture. MAIN OUTCOME MEASUREMENT: The outcome of interest was deep surgical site infection. RESULTS: There was a 7% rate (79/1107) of deep surgical site infection. In the multivariate analysis, predictive factors included alcohol abuse [odds ratio (OR) = 2.36; 95% confidence interval (CI), 1.17-4.46; P = 0.01], intra-articular injury (OR = 1.73; 95% CI, 1.01-3.00; P = 0.05), vascular injury (OR = 3.90; 95% CI, 1.63-8.61; P < 0.01), the use of topical antibiotics (OR = 0.50; 95% CI, 0.25-0.92; P = 0.03), and the duration of the surgery (OR = 1.15 per hour; 95% CI, 1.01-1.30; P = 0.04). There was a nonsignificant trend toward an association between infection and type III open fracture (OR = 1.73; 95% CI, 0.94-3.13; P = 0.07) and lateral approach (OR = 1.60; 95% CI, 0.95-2.69; P = 0.07). The most frequently cultured organisms were methicillin-resistant Staphylococcus aureus (22%), methicillin-sensitive Staphylococcus aureus (20%), and Enterobacter cloacae (11%). CONCLUSIONS: Seven percent of distal femur fractures developed deep surgical site infections. Alcohol abuse, intra-articular fracture, vascular injury, and increased surgical duration were risk factors, while the use of topical antibiotics was protective. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Risk Factors for Reoperation to Promote Union in 1111 Distal Femur Fractures.

OBJECTIVES: To identify modifiable and nonmodifiable risk factors for reoperation to promote union after distal femur fracture. DESIGN: Multicenter retrospective cohort study. SETTING: Ten Level-I trauma centers. PATIENTS/PARTICIPANTS: Patients with OTA/AO 33A or C distal femur fractures (n = 1111). INTERVENTION: Surgical fixation of distal femur fracture. Fixation constructs were classified as lateral plate, dual plate, nail, or nail plate combination. MAIN OUTCOME MEASUREMENTS: The outcome of interest was unplanned reoperation to promote union. RESULTS: There was an 11% (121/1111) rate of unplanned reoperation to promote union. In the multivariate analysis, predictive factors included body mass index [odds ratio (OR) = 1.18; 95% confidence interval (CI), 1.06-1.32; P < 0.01], intra-articular fracture (OR = 1.57; 95% CI, 1.01-2.45; P = 0.04), type III open injury (OR = 2.29; 95% CI, 1.41-3.72; P < 0.01), the presence of medial comminution (OR = 1.85; 95% CI, 1.14-3.06; P = 0.01), and medial translation on postoperative radiographs (OR = 1.23 per one 10th of condylar width; 95% CI, 1.01-1.48; P = 0.03). Construct type was not significantly predictive. CONCLUSIONS: Eleven percent of distal femur fractures underwent unplanned reoperation to promote union. Body mass index, intra-articular fracture, type III open injury, medial comminution, and medial translation on postoperative radiographs were predictive factors. Construct type was not associated with unplanned reoperation; however, this conclusion was limited by small numbers in the dual plate and nail plate groups. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Is the timing of fixation associated with fracture-related infection among tibial plateau fracture patients with compartment syndrome? A multicenter retrospective cohort study of 729 patients.

BACKGROUND: Tibial plateau fractures with an ipsilateral compartment syndrome are a clinical challenge with limited guidance regarding the best time to perform open reduction and internal fixation (ORIF) relative to fasciotomy wound closure. This study aimed to determine if the risk of fracture-related infection (FRI) differs based on the timing of tibial plateau ORIF relative to closure of ipsilateral fasciotomy wounds. METHODS: A retrospective cohort study identified patients with tibial plateau fractures and an ipsilateral compartment syndrome treated with 4-compartment fasciotomy at 22 US trauma centers from 2009 to 2019. The primary outcome measure was FRI requiring operative debridement after ORIF. The ORIF timing relative to fasciotomy closure was categorized as ORIF before, at the same time as, or after fasciotomy closure. Bayesian hierarchical regression models with a neutral prior were used to determine the association between timing of ORIF and infection. The posterior probability of treatment benefit for ORIF was also determined for the three timings of ORIF relative to fasciotomy closure. RESULTS: Of the 729 patients who underwent ORIF of their tibial plateau fracture, 143 (19.6%) subsequently developed a FRI requiring operative treatment. Patients sustaining infections were: 21.0% of those with ORIF before (43 of 205), 15.9% at the same time as (37 of 232), and 21.6% after fasciotomy wound closure (63 of 292). ORIF at the same time as fasciotomy closure demonstrated a 91% probability of being superior to before closure (RR, 0.75; 95% CrI, 0.38 to 1.10). ORIF after fasciotomy closure had a lower likelihood (45%) of a superior outcome than before closure (RR, 1.02; 95% CrI; 0.64 to 1.39). CONCLUSION: Data from this multicenter cohort confirms previous reports of a high FRI risk in patients with a tibial plateau fracture and ipsilateral compartment syndrome. Our results suggest that ORIF at the time of fasciotomy closure has the highest probability of treatment benefit, but that infection was common with all three timings of ORIF in this difficult clinical situation.

Agricultural Trauma Causing Open Fractures: Is Antibiotic Coverage Against Anaerobic Organisms Indicated?

OBJECTIVE: To compare deep infection rate and causative organisms in open fractures of the lower extremity from agricultural trauma with similar injuries in nonagricultural trauma. DESIGN: Retrospective. SETTING: Two tertiary care institutions. METHODS: Open lower extremity fractures sustained between 2003 and 2018 caused by agriculture-related trauma in adult patients were reviewed. A nonagriculture open fracture control group (NAG) was identified for comparison. Patient demographics and injury characteristics were assessed. Outcomes included occurrence of deep infection and causative organisms. RESULTS: One hundred seventy-eight patients were identified in the agriculture (AG) (n = 89) and control (NAG) (n = 89) groups. Among patients with agricultural injury, farm machinery was the most common mechanism in 69 (77.5%) of them. Open injuries of the foot (38.2%) and tibial shaft injuries (25.8%) were the most common in the AG and NAG groups, respectively. Deep infection was seen in 21% of patients in the AG group compared with 10% in the NAG group (P < 0.05). In the AG group, anaerobic infection occurred in 44% of patients with deep infection compared with 9.1% in the NAG group (P < 0.05). The most common anaerobic organisms included enterococci, Pseudomonas aeruginosa, and Clostridium perfringens. CONCLUSIONS: This study supports that open fractures due to agricultural trauma have a high infection rate, with anaerobic infection occurring at higher rates than in injuries due to nonagricultural trauma. Prophylactic treatment with antibiotics directed against anaerobes is indicated in these injuries. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Geriatric Acetabular Fractures and Femoral Head Protrusio: Methods of Fixation and the Option of Total Hip Arthroplasty.

SUMMARY: Currently, the literature is unclear regarding the optimal treatment algorithm for geriatric acetabular fractures. In a recent epidemiological study, 70% of all acetabular fractures in patients older than 65 years were classified as either associated both column or anterior column/posterior hemitransverse. Within the subset of these fractures, variants with significant femoral head protrusio, which is defined as the displacement of the femoral head medial to the ilioischial line, present with unique challenges. Goals of treatment in these cases should include surgical techniques that minimize the physiologic insult for the patient yet restore hip congruity and stability. "Fix and replace" is becoming an increasingly popular approach in the acute setting; however, its indications are not yet well-established. At our institution, we often favor open reduction and internal fixation alone as an effective and efficient way to treat the protrusio variant, even at the expense of protected weight-bearing. In the following article, we present a systematic approach for the management of geriatric acetabular fracture femoral head protrusio along with specific case examples.

Low-energy Gunshot-induced Tibia Fractures: What Proportion Develop Complications?

BACKGROUND: Gunshot injuries of the extremities are common in the United States, especially among people with nonfatal gunshot wounds. Controversy persists regarding the proper management for low-energy gunshot-induced fractures, likely stemming from varying reports on the likelihood of complications. There has yet to be published a study on a large cohort of patients with gunshot-induced tibia fractures on which to base our understanding of complications after this injury. QUESTIONS/PURPOSES: (1) What percentage of patients with low-energy gunshot-induced tibia fractures developed complications? (2) Was there an association between deep infection and fracture location, injury characteristics, debridement practices, or antibiotic use? METHODS: This was a multicenter retrospective study. Between January 2009 and December 2018, we saw 201 patients aged 16 years or older with a gunshot-induced fracture who underwent operative treatment; 2% (4 of 201) of those screened had inadequate clinical records, and 38% (76 of 201) of those screened had inadequate follow-up for inclusion. In all, 121 patients with more than 90 days of follow-up were included in the study. Nonunion was defined as a painful fracture with inadequate healing (fewer than three cortices of bridging bone) at 6 months after injury, resulting in revision surgery to achieve union. Deep infection was defined according to the confirmatory criteria of the Fracture-Related Infection Consensus Group. These results were assessed by a fellowship-trained orthopaedic trauma surgeon involved with the study. Complication proportions were tabulated. A Kaplan-Meier chart demonstrated presentations of deep infection by fracture location (proximal, shaft, or distal). Univariate statistics and multivariate Cox regression were used to examine the association between deep infection and fracture location, entry wound size, vascular injury, intravenous (IV) antibiotics in the emergency department (ED), deep and superficial debridement, the duration of postoperative IV antibiotics, and the use of topical antibiotics, while adjusting for age, race/ethnicity, smoking status, and BMI. A power analysis for the result of deep infection demonstrated that we would have had to observe a hazard ratio of 4.28 or greater for shaft versus proximal locations to detect statistically significant results at 80% power and alpha = 0.05. RESULTS: The overall complication proportion was 49% (59 of 121), with proportions of 14% (17 of 121) for infection, 27% (33 of 121) for wound complications, 20% (24 of 121) for nonunion, 9% (11 of 121) for hardware breakage, and 26% (31 of 121) for revision surgery. A positive association was present between deep infection and deep debridement (HR 5.51 [95% confidence interval 1.12 to 27.9]; p = 0.04). With the numbers available, we found no association between deep infection and fracture location, entry wound size, vascular injury, IV antibiotics in the ED, superficial debridement, the duration of postoperative IV antibiotics, and the use of topical antibiotics. CONCLUSION: In this multicenter study, we found a higher risk of complications in operative gunshot-induced tibia fractures than prior studies have reported. Infection, in particular, was much more common than expected based on prior studies. Consequently, surgeons might consider adopting the general management principles for nongunshot-induced open tibia fractures with gunshot-induced fractures, such as the use of IV antibiotics both initially and after surgery. Further research is needed to test and validate these approaches. LEVEL OF EVIDENCE: Level IV, therapeutic study.

What Is the Long-Term Impact of an Implant Stewardship Program on Orthopaedic Trauma Implant Pricing?

OBJECTIVES: To analyze the effectiveness of an implant stewardship program on implant cost containment and to estimate surgeons' responsiveness to implant price changes. DESIGN: Interrupted time series. SETTING: Level I trauma center. PATIENTS/PARTICIPANTS: Monitored usage of 5 trauma constructs by 10 surgeons over a 5-year period. INTERVENTION: Red-Yellow-Green (RYG) implant pricing comparison chart. MAIN OUTCOME MEASUREMENTS: Primary outcomes were changes in the mean price, minimum price, and the number of price changes. The secondary outcome was surgeons' responsiveness to RYG/cost changes. RESULTS: The study consisted of 2468 procedures. A mean construct price decrease of $66 per year [95% confidence interval (CI), $-170 to $-151], with distal femoral plates demonstrating the largest mean annual price decline ($486; 95% CI, $-540 to $-432). The minimum construct price decreased by $131 per year (95% CI, $-155 to $-111), with the largest reductions observed for distal femoral plates (-$436 per year; 95% CI, $-516 to $-354) and external fixators (-$122 per year; 95% CI, $-258 to $-136). The median price decrease was $407 (range: $6 to $2491) or 12.5% of the previous price. Positive changes in RYG levels increased surgeons' usage of tibial nails by 115%, femoral nails by 106%, and external fixators by 104%. Surgeons' implant selection was insensitive to RYG changes for distal femoral plates [RYG elasticity (ERYG): -0.74] and proximal tibia plates (ERYG: -0.21). CONCLUSIONS: The implant stewardship program was associated with substantial implant price reductions. Surgeons' implant selection was especially sensitive to price changes for intramedullary nails and external fixators.

Does an Implant Usage Report Card Impact Orthopaedic Trauma Implant Stewardship?

OBJECTIVES: As hospitals seek to control variable expenses, orthopaedic surgeons have come under scrutiny because of relatively high implant costs. We aimed to determine whether feedback to surgeons regarding implant costs results in changes in implant selection. METHODS: This study was undertaken at a statewide trauma referral center and included 6 fellowship-trained orthopaedic trauma surgeons. A previously implemented implant stewardship program at our institution using a "red-yellow-green" (RYG) implant selection tool classifies 7 commonly used trauma implant constructs based on cost and categorizes each implant as red (used for patient-specific requirements, most expensive), yellow (midrange), and green (preferred vendor, least expensive). The constructs included were femoral intramedullary nail, tibial intramedullary nail, long and short cephalomedullary nails, distal femoral plate, proximal tibial plate, and lower-limb external fixator. Baseline implant usage from the previous year was obtained and provided to each surgeon. Each surgeon received a monthly feedback report containing individual implant utilization and overall ranking. RESULTS: The overall RYG score increased from 68.7 to 79.1 of 100 (P < 0.001). Three of the 7 implants (tibial and femoral nails and lower-limb external fixation) had significant increases in their RYG scores; implant selections for the other 4 implants were not significantly altered. A decrease of 1.8% (95% confidence interval, 0.4-3.2, P = 0.01) was noted in overall implant costs over the study period. CONCLUSION: Our intervention resulted in changes in surgeons' implant selections and cost savings. However, surgeons were unwilling to change certain implants despite their being more expensive.

Anterior Intrapelvic Approaches: Fracture Patterns You May Want to Reconsider.

The anterior intrapelvic approach with a lateral window is gaining popularity for the surgical treatment of anterior fracture patterns of the acetabulum. Certain fracture patterns and characteristics present challenges when using anterior approaches. This article aims to describe some of the fracture patterns that may be particularly difficult to address using the anterior intrapelvic approach with or without the lateral window.

Posterior malleolus exposure.

Objectives: Posterior malleolus (PM) fractures are common in rotational ankle injuries, tibial plafond fractures, and distal third tibia fractures. Surgical indications continue to evolve as we improve our understanding of ankle and syndesmotic stability. These fractures remain technically challenging with respect to both exposure and fixation. Our biomechanical cadaveric study compared posterolateral versus modified posteromedial surgical approaches to define the following: maximal surface area exposed, and maximal screw trajectory obtainable for fixation. Methods: Twelve fresh-frozen cadaver limbs were thawed at room temperature. Posterolateral and modified posteromedial approaches were performed on each limb. Margins of exposure were marked. A 2.5 mm drill was advanced at the extreme medial and lateral extents of each exposure, standardized at 1 cm proximal to the joint line and perpendicular to the bone. Computed tomography (CT) scans were performed to identify the maximal trajectory. Limbs were stripped of soft tissue, and the exposed bony surface area was measured using a validated laser surface-scanning technique. Results: The modified posteromedial approach allowed for a larger exposed surface area compared to the posterolateral exposure (median 99% vs 64%, respectively; P < .05). The modified posteromedial approach allowed for instrumentation of up to a median of 77% of the posterior distal tibia as opposed to 46% through the posterolateral approach (P < .05). Conclusion: The modified posteromedial approach allowed for increased exposure and wider access for instrumentation of the PM when compared to the posterolateral approach. We advocate use of this approach when addressing complex PM fractures, in particular the Haraguchi type 2 fracture pattern.

Quantitative spectral assessment of intracardiac electrogram characteristics associated with post infarct fibrosis and ventricular tachycardia.

BACKGROUND: Post-myocardial infarction (MI) remodeling contributes to increased electrophysiological and structural heterogeneity and arrhythmogenesis. Utilising the post-infarct ovine model our aim was to determine unipolar electrogram frequency characteristics consequent to this remodeling and the development of Ventricular Tachycardia (VT). METHODS AND RESULTS: Mapping studies were performed on 14 sheep at >1 month post-MI induction. Sheep were divided into VT inducible (n = 7) and non-inducible (n = 7) groups. Multielectrode needles (n = 20) were deployed within and surrounding ventricular scar for electrophysiological assessment of electrogram amplitude and width. Spectral analysis of electrograms was undertaken using wavelet and fast fourier transformations (WFFT) to calculate root mean square (RMS) power intervals spanning 0-300Hz in 20Hz intervals. Quantitative assessment between electrophysiological and histological parameters including collagen density, and structural organization of the myocardium was performed. Increasing myocardial scar density resulted in attenuation of electrogram amplitude and RMS values. (all p<0.01). Between groups there were no differences in electrogram amplitude (p = 0.37), however WFFT analysis revealed significantly higher RMS values in the VT group (p<0.05) in association with high frequency fractional components of the electrogram. As scar density increased, greater between-group differences in RMS were observed spanning this high frequency (200-280Hz) spectrum and which were proportionally dependent on the degree of structural disorganisation of the myocardium (p<0.001) and number of extrastimuli required to induce VT (p<0.05). CONCLUSION: High frequency unipolar electrogram spectral characteristics were quantitatively co-influenced by the presence of fibrosis and degree of myocardial structural dissorganisation and were associated with the propensity for development of VT.

Fixation of Anteromedial Coronoid Facet Fractures: A Biomechanical Evaluation of Plated Versus Screw Constructs.

OBJECTIVE: To examine the stability of plate (locking and non-) versus screw constructs in the fixation of these fractures. METHODS: An anteromedial coronoid facet fracture (OTA/AO type 21-B1, O'Driscoll type 2, subtype 3) was simulated in 24 synthetic ulna bones that were then assigned to 3 fracture fixation groups: non-locking plate, locking plate (LP), or screw fixation. Each construct was first cycled in tension (through a simulated medial collateral ligament) and then in compression. They were then loaded to failure (displacement >2 mm). Fracture fragment displacement was recorded with an optical tracking system. RESULTS: During tension testing, a mean maximum fragment displacement of 12 ± 13 and 14 ± 9 µm was seen in the locking and non-locking constructs, respectively. There was no difference in fragment motion between the plated constructs. All screw-only fixed constructs failed during the tension protocol. During compression testing, the mean maximum fragment displacement for the screw-only construct (64 ± 79 µm) was significantly greater than locking (9 ± 5 µm) and non-locking constructs (10 ± 9 µm). During load to failure testing, the maximum load to failure in the screw-only group (316 ± 83 N) was significantly lower than locking (650.4 ± 107 N) and non-locking constructs (550 ± 76 N). There was no difference in load to failure between the plated groups. CONCLUSION: Fixation of anteromedial coronoid fractures (type 2, subtype 3) is best achieved with a plating technique. Although LPs had greater stiffness, they did not offer any advantage over conventional non-LPs with respect to fracture fragment displacement in this study. CLINICAL RELEVANCE: Isolated screw fixation showed inferior stability when compared with plate constructs for these fractures. This could result in loss of fracture reduction leading to instability and posttraumatic arthrosis.

The Effect of Varying Tension of a Suture Button Construct in Fixation of the Tibiofibular Syndesmosis-Evaluation Using Stress Computed Tomography.

BACKGROUND/PURPOSE: There have been no studies assessing the optimal biomechanical tension of suture button constructs. The purpose of this study was to assess optimal tensioning of suture button fixation and its ability to maintain reduction under loaded conditions using a stress computed tomography (CT) model. METHODS: Ten cadaveric lower limbs disarticulated at the knee were used. The limbs were placed in a modified ankle load frame that allowed for the application of sustained torsional axial or combined torsional/axial loads. The syndesmosis and the deep deltoid ligaments complex were sectioned and the limbs were randomized to receive a suture button construct tightened at 4, 8, or 12 kg. The specimens were loaded under the 3 loading scenarios with CT scans performed after each and at the conclusion of testing. Multiple measurements of translation and rotation were compared with baseline CT scan taken before sectioning. RESULTS: Significant lateral (maximum 5.26 mm) and posterior translation (maximum 6.42 mm) and external rotation (maximum 11.71 degrees) was noted with the 4 kg repair. Significant translation was also seen with both the 8 and the 12 kg repairs; however, the incidence was less than with the 4 kg repair. Significant overcompression (ML = 1.69 mm, B = 2.69 mm) was noted with the 12 kg repair and also with the 8 kg repair (B = 2.01 mm). CONCLUSION: Suture button constructs must be appropriately tensioned to maintain reduction and re-approximate the degree of physiological motion at the distal tibiofibular joint. These constructs also demonstrate overcompression of the syndesmosis; however, the clinical effect of this remains to be determined.

Predictive factors for ankle syndesmosis injury in football players: a prospective study.

OBJECTIVES: Up to 25% of all ankle injuries involve the ankle syndesmosis and factors that increase risk have yet to be investigated prospectively. This study aimed to identify predictors of ankle syndesmosis injury in football players. DESIGN: A prospective study. METHODS: Rugby Union and Australian Football League players were recruited during 2010. Rugby League and different Rugby Union players were recruited during 2011. Baseline data collection included: age, body size, flexibility, strength and balance. Bivariate correlations were performed between all predictors. Variables with r ≥ 0.7 had only one variable entered in further analysis. Remaining predictor variables were analysed for association with the presence/absence of ankle syndesmosis injury. Variables with non-significant association with injury (p>0.2) were included in a backward step-wise Cox regression model. RESULTS: 202 male participants aged 21 ± 3.3 years (mean ± SD) were recruited of whom 12 (5.9%) sustained an ankle syndesmosis injury. The overall incidence rate was 0.59/1000 h sport participation for Rugby Union and Rugby League. Australian Football League training data was not available. No significant predictors were identified; however, participants who sustained an injury during the season performed a higher vertical jump (63.6 ± 8.2 cm) and greater Star Excursion Balance Test reach (80.5 ± 5.3 cm), than participants who did not sustain an injury: 59.1 ± 7.8 cm for Vertical Jump and 77.9 ± 6.1 cm for Star Excursion Balance Test. This was normalised for height. CONCLUSIONS: Variables such as age, body size, foot posture, flexibility and muscle strength did not increase risk of ankle syndesmosis injury. Jump height and balance performance may play a role in predicting ankle syndesmosis sprains.