External Validation of a Predictive Score for Fracture-Related Infections in Orthopedic Trauma Surgery.

BACKGROUND: The purpose of this study was to externally validate a predictive score for fracture-related infections, establishing generalizability for absolute and relative risk of infection in the setting of orthopedic fracture surgery. MATERIALS AND METHODS: This was a retrospective, case-control study performed at a level I academic trauma center that included 147 patients with fracture-related infection in the study group and 300 control patients. We analyzed the same 8 independent predictors of fracture-related infection cited by a previous study. We then used the area under the receiver operating characteristics curve (AUC) to compare the derivation and validation cohorts. The validation and derivation cohorts were then compared by grouping patients into 4 strata of Wise score groups. This allowed for comparison of AUC and risk of fracture-related infection in our institution with those in the previously studied institution. RESULTS: The resulting data yielded an AUC (0.74) nearly identical to that of the previously studied institution. It was also found that the relative risk of infection correlated with the Wise score in the same way the initial model did with the absolute risks being similar. CONCLUSION: The previous predictive model was externally validated and shown to be generalizable to a different patient population. The relative risk of a fracture-related infection can be determined using this scoring model preoperatively with the goal of aiding in patient counseling and surgical decision-making, giving a quantitative value to patient risk factors. [Orthopedics. 202x;4x(x):xx-xx.].

Maintenance of an Intraoperative External Fixator Is Associated With Decreased Postoperative Stiffness After Definitive Management of High-Energy Tibial Plateau Fractures.

Introduction Postoperative stiffness is a common complication after high-energy tibial plateau fractures. Investigation into reported surgical techniques for the prevention of postoperative stiffness is limited. The purpose of this study was to compare the rates of postoperative stiffness after second-stage definitive surgery for high-energy tibial plateau fractures between groups of patients who had the external fixator prepped into the surgical field and those who did not. Methods Two hundred forty-four patients met the inclusion criteria between the two academic Level I trauma centers, representing the retrospective observational cohort. Patients were separated based on prepping of the external fixator into the surgical field during second-stage definitive open reduction and internal fixation. One hundred sixty-two patients were in the prepped group and 82 were in the non-prepped group. Post-operative stiffness was determined by the need to return to the operating room for subsequent procedures. Results At the final follow-up (mean = 14.6 months), patients in the non-prepped group had an increased rate of stiffness post-operatively (18.3% non-prepped versus 6.8% prepped; p = 0.006). No other investigated variables were associated with increased post-operative stiffness, including the number of days spent in the fixator and operative time. The relative risk for post-operative stiffness associated with complete fixator removal was 2.54 (95% CI 1.26-4.41; p = 0.008 on binary logistic regression; absolute risk reduction 11.5%). Conclusion At the final follow-up, maintenance of an intraoperative external fixator as a reduction aid was associated with a clinically significant decrease in post-operative stiffness after definitive management of high-energy tibial plateau fractures, when compared with complete removal prior to prepping.

Teaching of Cost-Effective Care in Orthopaedic Surgery Residency Training: A Survey of Residency Programs in the US.

Costs of healthcare in the US continue to rise at rates that are unsustainable. Prior studies, most of which come from non-surgical specialties, indicate that a variety of strategies to teach this material are utilized but without consensus on best practices. No studies exist regarding the teaching of cost-effective care in orthopaedic residency training programs. The goal of this study was to assess the landscape in this area from the perspective of program leadership. Methods: A survey was developed that was sent to orthopaedic residency program leadership via email through their interaction with the COERG. Additional programs were included to enhance diversity of responding programs. The survey, based on those published from other areas of medicine, included questions about the experiences of the respondents in learning about cost-effective care, as well as how faculty and residents learned about this topic. Results: Seventy one percent (30) of respondents noted that their faculty did not receive formal training in cost-effective care, and education in this area was likely to come from the department, especially review of practice data (12, 44%). Only 19% (8) of respondents agreed with the statement that "the majority of teaching faculty in our program consistently model cost-effective healthcare to residents". Few of the programs (10, 24%) had formal curricula for residents regarding cost-effective care, and the primary mode of education in cost-effective care was through informal discussions with faculty (17, 43%). Few residents (3, 13%) were able to easily find the costs of tests or procedures. Discussion: There is not consistent education in cost-effective care for orthopaedic surgery program leadership, faculty, or trainees. The results of this survey demonstrate a need for discussion of best practices, including increasing access to cost data at a local level, and engaging with the AOA, CORD, and the American Academy of Orthopaedic Surgeons more broadly in the development of standard education modules for faculty and residents, to improve the current and future delivery of cost-effective musculoskeletal care.

Radiographic parameters associated with fracture-related infection in high energy bicondylar tibial plateau fractures managed with two-stage treatment: Identifying the bad actors.

INTRODUCTION: High energy tibial plateau fractures are fraught with complications, particularly fracture-related infection (FRI). Previous studies have evaluated patient demographics, fracture classification, and injury characteristics as risk factors for FRI in patients with these injuries. This study evaluated the relationship between radiographic parameters (fracture length relative to femoral condyle width (FLF ratio), initial femoral displacement (FD ratio), and tibial widening (TW ratio)) and fracture-related infection following internal fixation in high energy bicondylar tibial plateau fractures. METHODS: 225 patients treated for bicondylar tibial plateau fractures at two level I trauma centers were retrospectively reviewed. Patient characteristics, fracture classification, and radiographic measurements were analyzed to determine association with FRI. RESULTS: The rate of FRI was 13.8%. Increased fracture length, FLF ratio, FD ratio, TW ratio, and fibula fracture were each associated with FRI on regression analysis, independent of clinical variables. Cutoff values were identified for each parameter and patients were risk stratified based on these radiographic parameters. High-risk patients had a 2.68- and 12.36-times risk of FRI compared to medium and low-risk patients, respectively. DISCUSSION: This study is the first to examine the relationship between radiographic parameters and FRI in high energy bicondylar tibial plateau fractures. Fracture length, FLF ratio, FD ratio, TW ratio, and fibula fracture were identified as radiographic parameters associated with FRI. More importantly, risk stratifying patients based on these parameters accurately identified patients at increased risk of FRI. Not all bicondylar tibial plateau fractures are created equal and radiographic parameters can be utilized to help identify the bad actors.

Perioperative allogenic blood transfusions are associated with increased fracture related infection rates, but not nonunion in operatively treated distal femur fractures.

INTRODUCTION: Distal femur fractures are common injuries that remain difficult for orthopedic surgeons to treat. High complication rates, including nonunion rates as high as 24% and infection rates of 8%, can lead to increased morbidity for these patients. Allogenic blood transfusions have previously been identified as risk factors for infection in total joint arthroplasty and spinal fusion surgeries. No studies have explored the relationship between blood transfusions and fracture related infection (FRI) or nonunion in distal femur fractures. METHODS: 418 patients with operatively treated distal femur fractures at two level I trauma centers were retrospectively reviewed. Patient demographics were collected including age, gender, BMI, medical comorbidities, and smoking. Injury and treatment information was also collected including open fracture, polytrauma status, implant, perioperative transfusions, FRI, and nonunion. Patients with less than three months of follow up were excluded. RESULTS: 366 patients were included in final analysis. One hundred thirty-nine (38%) patients received a perioperative blood transfusion. Forty-seven (13%) nonunions and 30 (8%) FRI were identified. Allogenic blood transfusion was not associated with nonunion (13% vs 12%, P = 0.87), but was associated with FRI (15% vs 4%, P<0.001). Binary logistic regression analysis identified a dose dependent relationship between number of perioperative blood transfusions and FRI: total transfusion ≥2 U PRBC RR= 3.47(1.29, 8.10, P = 0.02), ≥3 RR= 6.99 (3.01, 12.40, P<0.001), and ≥4 RR= 8.94 (4.03, 14.42, P<0.001). DISCUSSION: In patients undergoing operative treatment of distal femur fractures, perioperative blood transfusions are associated with increased risk of fracture related infection, but not the development of a nonunion. This risk association increases in a dose-dependent relationship with increasing total blood transfusions received.

External fixator pin placement during initial management of tibial plateau fractures: are there parameters to minimize pin-plate overlap?

PURPOSE: External fixator pin site overlap with definitive fixation implants (pin-plate overlap) has been identified as a risk factor for surgical site infection in tibial plateau fractures. Despite this, pin-plate overlap occurs in 24-38% of patients. This study sought to identify radiographic characteristics associated with pin-plate overlap to help minimize occurrences. METHODS: 283 patients at two Level I trauma centers were retrospectively reviewed. Radiographic measurements were recorded including fracture length, distance from fracture to proximal tibial pin site, and pin site distance-to-fracture (PSF) ratio. RESULTS: 70 (24.7%) cases of pin-plate overlap were identified. Pin-plate overlap was associated with increased fracture length (81.5 ± 32.1 mm vs 56.9 ± 26.1 mm, p < 0.001) and decreased distance from fracture to proximal tibial pin site (84.5 ± 37.1 mm vs 126.9 ± 35.8 mm). Pins placed greater than 100 mm and 150 mm from the fracture eliminated 36/70 (51%) and 67/70 (96%) pin-plate overlaps, respectively. Pins placed with a PSF ratio greater than 1.5 and 2.0 eliminated 47/70 (67%), and 57/70 (81%) of pin-plate overlaps, respectively. CONCLUSIONS: Longer fractures, pins closer to the fracture, and decreased PSF ratio were associated with overlap. Placing proximal tibial pins more than 100 mm from the fracture eliminated most pin-plate overlaps.

Do number and location of plates impact infection rates after definitive fixation of high energy tibial plateau fractures?

PURPOSE: Surgical trauma may confer additional infectious risk after operative fixation for high energy tibial plateau fractures. This study aims to determine the impact of plate number and location on infection rates after these injuries. METHODS: This retrospective cohort study completed at two level one trauma centers included patients who underwent staged fixation for a tibial plateau fracture between 2015 and 2019. Plate number and location (lateral, medial, posteromedial, and anterior quadrants) used in the definitive fixation construct were collected from post-operative radiographs. Deep infection rate was primary the outcome. RESULTS: A total of 244 patients met inclusion criteria. The overall infection rate was 13.9% (34/244). Infection rates increased with each additional quadrant utilized (8.0% one quadrant, 13.0% two quadrants, 27.3% three quadrants, 100% four quadrants; p < 0.001), independent of plate number, fracture severity, operative time, number of incisions, external fixator pin and plate construct overlap, and days in the external fixator on multivariate analysis. CONCLUSIONS: Infection risk increases with each quadrant utilized in the fixation of high energy tibial plateau fractures. Providers should attempt to limit the dissection of soft tissue for hardware placement in the fixation of these injuries to limit infection risk. LEVEL OF EVIDENCE: Level III, retrospective therapeutic study.

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.

Microbial Interspecies Associations in Fracture-Related Infection.

OBJECTIVES: Describe co-occurrence or clustering of microbial taxa in fracture-related infections to inform further exploration of infection-related interactions among them. DESIGN: Retrospective review. SETTING: Level 1 trauma center. PATIENTS/PARTICIPANTS: Four hundred twenty-three patients requiring surgical intervention for deep surgical site infection between January 2006 and December 2015. INTERVENTION: None. MAIN OUTCOME MEASUREMENT: Connection between microbial taxa. RESULTS: Methicillin-resistant Staphylococcus aureus, methicillin-sensitive Staphylococcus aureus, and coagulase-negative Staphylococcus represented the majority of monomicrobial observations (71%). Gram-negative rods, gram-positive rods, and anaerobes presented more frequently in polymicrobial infections. Enterobacter, vancomycin-sensitive Enterococcus, and Pseudomonas are present in polymicrobial infections with the highest frequencies and represent the top 3 most important nodes within the microorganism framework, with the highest network centrality scores. CONCLUSIONS: The present study indicates that there are common microbial taxa (Enterobacter, Enterococcus, and Pseudomonas) that tend to co-occur with other microbes greater than 75% of the time. These commonly co-occurring microbes have demonstrated interactive relationships in other disease pathologies, suggesting that there may be similar important interactions in fracture-related infections. It is possible that these microbial communities play a role in the persistently high failure rate associated with management of infection after trauma. Future studies are needed to study the intermicrobial interactions that explain the frequency at which taxa co-occur. Understanding and potentially disrupting these intermicrobial relationships could inform improvements in the treatment of established infections and in the prevention of infection in high-risk patients. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Are Infection Rates Increased After Sterilization of the External Fixator During Staged Internal Fixation of High-Energy Tibial Plateau Fractures?

OBJECTIVES: To compare infection rates after second-stage definitive surgery for high-energy tibial plateau fractures between groups of patients who had the external fixator prepped into the surgical field and those who did not. DESIGN: Retrospective cohort study. SETTING: Two academic Level 1 trauma centers. PATIENTS/PARTICIPANTS: Two hundred forty-four patients met inclusion and exclusion criteria between the 2 institutions. INTERVENTION: Prepping of the external fixator into the surgical field during second-stage definitive open reduction and internal fixation. 162 patients were in the prepped group, and 82 patients were in the nonprepped group. MAIN OUTCOME MEASUREMENTS: The primary outcome was the rate of deep infection after definitive fixation. Secondary outcome was operative time. RESULTS: There were no significant differences in infection rates between prepped (11.7%) and nonprepped (18.3%) groups ( P = 0.162). Patients in the prepped groups had significantly decreased operative time (168.2 minutes vs. 221.9 minutes, P < 0.001) even after controlling for confounders in regression analysis. CONCLUSIONS: There is no increased risk of infection associated with prepping and maintenance of the external fixator during definitive internal fixation for high-energy tibial plateau fractures. These data suggest that this practice may lead to shorter operative times as well. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Is pin-plate overlap in tibial plateau fractures associated with increased infection rates?

INTRODUCTION: Despite advances in the treatment of high energy proximal tibia fractures, including the utilization of staged management with external fixation, the infection rate remains high. Overlap between external fixator pin sites and definitive internal fixation has been proposed as a risk factor for infection. METHODS: This retrospective study reviews 244 patients with staged knee-spanning external fixation followed by delayed definitive internal fixation at two separate level one trauma centers. Presence of pin-plate overlap as well as several other known risk factors for infection were recorded and measured to include open fractures, compartment syndrome, operative time and number of incisions. Development of deep infection was the primary outcome. Both univariate and multivariate statistics were applied to determine differences in rates of infection. RESULTS: 65 (26.6%) patients had presence of pin-plate overlap while 179 (73.4%) patients had no overlap. There were no differences between overlapping and non-overlapping groups with respect to other infectious risk factors. Deep infection occurred in 34 (13.9%) total patients, 18 (27.7%) were in patients with pin-plate overlap and 16 (8.9%) in those without overlap. (P = 0.003; RR 3.01, 95% CI 1.51-4.76). DISCUSSION: This large, multicenter study demonstrated a statistically significant association between pin-plate overlap and the development of deep infection in tibial plateau fractures. On multivariate analysis, pin-plate overlap was identified as an independent risk factor for infection. When treating these complex injuries, surgeons should consider the definitive fixation construct when placing external fixation pins.

Are deep infections that present before and after 90 days from orthopaedic trauma different? An analysis of the validity of the recent change in CDC criteria for infections.

BACKGROUND: In 2016, the Centers for Disease Control and Prevention (CDC) changed the time frame for their definition of deep surgical site infection (SSI) from within 1 year to within 90 days of surgery. We hypothesized that a substantial number of infections in patients who have undergone fracture fixation present beyond 90 days and that there are patient or injury factors that can predict who is more likely to present with SSI after 90 days. METHODS: A retrospective review yielded 452 deep SSI after fracture fixation. These patients were divided into two groups-those infected within 90 days of surgery and those infected beyond 90 days . Data were collected on risk factors for infection. Univariate and multiple logistic regression analyses were performed to compare the two groups. A randomly selected control group was used to build infection prediction models for both outcomes. The two outcomes were then modelled against each other to determine whether differences in predictors for early versus late infection exist. RESULTS: Of the 452 infections, 144 occurred beyond 90 days (32% [95% CI, 28%-36%]). No statistically significant patient factors were found in multivariable analysis between the early and late infection groups. The need for flap coverage was the only injury characteristic that differed significantly between groups, with patients in the late infection group more likely to have needed a flap. When modelled against the control group and directly comparing the two models, predictors for early infection include male sex and fractures of the pelvis, acetabulum, or hip, whereas predictors of late infection include hepatitis C and/or human immunodeficiency virus (HIV) and admission to the intensive care unit (ICU). CONCLUSION: Use of the recent CDC definition will underestimate the rate of actual postoperative infections when applied to orthopaedic trauma patients. Hepatitis C and/or HIV and ICU admission are predictors of late infection, whereas male sex and pelvis, acetabulum, or hip fractures are predictors of early infection. Patients who receive flap coverage may be more likely to present with late infection.

Admission Hyperglycemia Is a Risk Factor for Deep Surgical-Site Infection in Orthopaedic Trauma Patients.

OBJECTIVES: To evaluate the association of admission blood glucose ≥200 mg/dL and surgical site infection in orthopaedic trauma surgery. DESIGN: Retrospective, case control study. SETTING: Academic trauma center. PATIENTS: Four hundred sixty-five nondiabetic, noncritically ill orthopaedic trauma patients with an extremity, pelvic, or acetabular fracture and requiring open reduction and internal fixation or intramedullary nailing. INTERVENTION: None. MAIN OUTCOME MEASUREMENTS: Ninety-day deep surgical site infection. RESULTS: Admission blood glucose ≥200 mg/dL was significantly associated with the primary outcome (8/128, 6.3% vs. 35/337, 1.8%; P = 0.01). Multivariable logistic regression modeling demonstrated that admission blood glucose ≥200 mg/dL was a significant risk factor for deep surgical site infections [odds ratio (OR): 4.7, 95% confidence interval (CI) 1.4-15.7], after controlling for male gender (OR: 1.8, 95% CI: 1.1-3.1), prior drug or alcohol abuse (OR: 1.9, 95% CI 0.9-4.0), open fracture (OR: 6.4, 95% CI 3.7-11.0), and fracture region (upper extremity OR: reference; pelvis/hip OR: 3.9, 95% CI 1.6-9.7; femur OR: 2.0, 95% CI 0.88-4.8; tibia/ankle OR: 3.3, 95% CI 1.7-6.2; and foot OR: 2.7, 95% CI 1.2-6.3). CONCLUSIONS: Admission glucose ≥200 mg/dL was a significant independent risk factor for 90-day deep surgical site infections in orthopaedic trauma patients and may serve as an important marker for infection risk. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Fully threaded sacroiliac lag screws have higher load to failure when compared to partially threaded screws: A biomechanical study.

The purpose of this study is to compare biomechanical properties of fully and partially threaded iliosacral screws. We hypothesise that fully threaded screws will have a higher yield force, and less deformation than partially threaded screws following axial loading. Twenty sawbone blocks were uniformly divided to simulate vertical sacral fractures. Ten blocks were affixed with fully threaded iliosacral screws in an over-drilled, lag-by-technique fashion whilst the remaining ten were fixed with partially threaded lag-by-design screws. All screws measured 7.3-mm x 145 mm, and were inserted to a 70% of calculated maximal insertional torque, ensuring uniform screw placement throughout across models. Continuous axial loads were applied to 3 constructs of each type to failure to determine baseline characteristics. Five hundred loading cycles of 500 N at 1 Hz were applied to 4 constructs of each type, and then axially loaded to failure. Force displacement curves, elastic, and plastic deformation of each construct was recorded. Fully threaded constructs had a 428% higher yield force, 61% higher stiffness, 125% higher ultimate force, and 66% lower yield deformation (p < 0.05). The average plastic deformation for partially threaded constructs was 336% higher than fully threaded constructs (p = 0.071), the final elastic deflection was 10% higher (p = 0.248), and the average total movement was 21% higher (p = 0.107). We conclude from this biomechanical study that fully threaded, lag-by-technique iliosacral screws can withstand significantly higher axial loads to failure than partially threaded screws. In addition, fully threaded screws trended towards exhibiting a significantly lower plastic deformation following cyclical loading.

Surgeons Cannot Predict Pilon Fracture Outcomes Based on Initial Radiographs.

This study sought to determine (1) whether surgeons can accurately predict functional outcomes of operative fixation of pilon fractures based on injury and initial postoperative radiographs, (2) whether the surgeon's level of experience is associated with the ability to successfully predict outcome, and (3) the association between patients' demographic and clinical characteristics and surgeons' prediction scores. A blinded, randomized provider survey was conducted at a level I trauma center. Seven fellowship-trained orthopedic traumatologists and 4 orthopedic trauma fellows who were blinded to outcome reviewed data regarding 95 pilon fractures in random order. Injury ankle radiographs, initial postoperative fixation radiographs, and brief patient histories were assessed. Midterm follow-up functional outcome scores obtained a mean 4.9 years after surgery were available for all patients. Main outcome measures were Pearson correlation coefficient-assessed functional outcomes and surgeon-predicted outcomes. A mixed-effect model determined the association between patients' characteristics and surgeons' prediction scores. Minimal positive correlation was observed between functional outcomes and prediction scores. No difference was noted between the attending and fellow groups in prediction ability. When surgeons' prediction confidence level was greater than 1 SD above the mean confidence level, correlation between functional outcome and prediction improved, although poor correlation was still observed. AO/OTA type 43C fractures, high-energy mechanisms, and older patient age were characteristics associated with lower prediction scores. Surgeons had poor ability to predict functional outcomes of patients with pilon fractures based on injury and initial postoperative radiographs, and level of experience was not associated with ability to predict outcome. [Orthopedics. 2020; 43(1): e43-e46.].

A Predictive Score for Determining Risk of Surgical Site Infection After Orthopaedic Trauma Surgery.

OBJECTIVES: To determine factors predictive of postoperative surgical site infection (SSI) after fracture fixation and create a prediction score for risk of infection at time of initial treatment. DESIGN: Retrospective cohort study. SETTING: Level I trauma center. PATIENTS/PARTICIPANTS: Study group, 311 patients with deep SSI; control group, 608 patients. INTERVENTION: We evaluated 27 factors theorized to be associated with postoperative infection. Bivariate and multiple logistic regression analyses were used to build a prediction model. A composite score reflecting risk of SSI was then created. MAIN OUTCOME MEASURES: Risk of postoperative infection. RESULTS: The final model consisted of 8 independent predictors: (1) male sex, (2) obesity (body mass index ≥ 30) (3) diabetes, (4) alcohol abuse, (5) fracture region, (6) Gustilo-Anderson type III open fracture, (7) methicillin-resistant Staphylococcus aureus nasal swab testing (not tested or positive result), and (8) American Society of Anesthesiologists classification. Risk strata were well correlated with observed proportion of SSI and resulted in a percent risk of infection of 1% for ≤3 points, 6% for 4-5 points, 11% for 6 to 8-9 points, and 41% for ≥10 points. CONCLUSION: The proposed postoperative infection prediction model might be able to determine which patients have fractures at higher risk of infection and provides an estimate of the percent risk of infection before fixation. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Risk Factors for Knee Stiffness Surgery After Tibial Plateau Fracture Fixation.

OBJECTIVE: To determine the risk factors for knee stiffness surgery after tibial plateau fixation. DESIGN: Retrospective observational cohort study. SETTING: Academic Level I trauma center. PATIENTS/PARTICIPANTS: A study group of 110 patients who underwent knee stiffness surgery (manipulation while under anesthesia, arthroscopic lysis of adhesion, or quadricepsplasty) at a time remote from open reduction and internal fixation of tibial plateau fractures and a control group of 319 patients with tibial plateau fractures treated with open reduction and internal fixation who did not undergo knee stiffness surgery and who had either a minimum of 1 year of follow-up or clearly documented range of motion ≥110 degrees with a minimum of 90 days of follow-up. INTERVENTION: Each case was assessed from the time of index admission through study event, end of minimum follow-up, or achievement of ≥110 degrees range of motion. MAIN OUTCOME MEASUREMENTS: Knee stiffness surgery. RESULTS: Total number of weeks in an external fixator (odds ratio, 1.5 per week; 95% confidence interval, 1.3-1.7; P < 0.001) and the presence of bilateral tibial plateau fractures (odds ratio, 3.3; 95% confidence interval, 1.2-9.1; P = 0.02) were significant predictors of knee stiffness intervention. CONCLUSION: Clinicians should be aware that the time spent in external fixation and the presence of bilateral tibial plateau injuries are strong risk factors for requiring subsequent surgery to treat knee stiffness. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Long-term results of extensor mechanism reconstruction using Achilles tendon allograft after total knee arthroplasty.

PURPOSE: Disruption of the extensor mechanism after total knee arthroplasty (TKA) is an infrequent but devastating complication. Presently, limited data exists regarding the optimal treatment and long-term outcomes. METHODS: Patients who underwent reconstruction of their knee extensor mechanism using Achilles tendon allograft following TKA between January 2003 and January 2012 were identified. Sixteen patients with 17 reconstructions (10 patellar tendons, 7 quadriceps tendons) were studied. All patients underwent evaluation at an average of 45.7 months. Ten of the patients were followed to an average of 65.4 months. RESULTS: After reconstruction, the average extensor lag was 6.6° and average knee flexion was 105.1°. Of the patients with a minimum follow-up of two years and an average follow-up of 65.4 months, the average extensor lag and knee flexion was 8.4° and 107.9°, respectively, with quadriceps strength maintained at an average of 4/5. The quadriceps tendon reconstructions had an average extensor lag and flexion of 2.9° and 103°, respectively. The patellar tendon reconstructions, excluding one re-rupture, had an average extensor lag and flexion of 9.6° and 105.1°, respectively. Four patients died during the follow-up period. All but one of the patients were below the mean for age-matched controls on the SF-36. CONCLUSION: Achilles tendon allograft reconstruction is a reliable and durable treatment for patients who sustain not only patellar tendon ruptures, but also quadriceps tendon ruptures following TKA. Despite the success of this technique, the injury and procedure have a profound impact on overall function.

Risk Factors for Failure of Bone Grafting of Tibia Nonunions and Segmental Bone Defects: A New Preoperative Risk Assessment Score.

OBJECTIVE: To develop a clinically useful prediction model of success at the time of surgery to promote bone healing for established tibial nonunion or traumatic bone defects. DESIGN: Retrospective case controlled. SETTING: Level 1 trauma center. PATIENTS: Adult patients treated with surgery for established tibia fracture nonunion or traumatic bone defects from 2007 to 2016. Two hundred three patients met the inclusion criteria and were available for final analysis. INTERVENTION: Surgery to promote bone healing of established tibia fracture nonunion or segmental defect with plate and screw construct, intramedullary nail fixation, or multiplanar external fixation. MAIN OUTCOME MEASURES: Failure of the surgery to promote bone healing that was defined as unplanned revision surgery for lack of bone healing or deep infection. No patients were excluded who had a primary outcome event. RESULTS: Multivariate logistic modeling identified 5 significant (P < 0.05) risk factors for failure of the surgery to promote bone healing: (1) mechanism of injury, (2) Increasing body mass index, (3) cortical defect size (mm), (4) flap size (cm), and (5) insurance status. A prediction model was created based on these factors and awarded 0 points for fall, 17 points for high energy blunt trauma (OR = 17; 95% CI, 1-286, P = 0.05), 22 points for industrial/other (OR = 22; 95% CI, 1-4, P = 0.04), and 28 points for ballistic injuries (OR = 28; 95% CI, 1-605, P = 0.04). One point is given for every 10 cm of flap size (OR = 1; 95% CI, 1-1.1, P < 0.001), 10 mm of mean cortical gap distance (OR = 1; 95% CI, 1-2, P = 0.004), and 10 units BMI, respectively (OR = 1.5; 95% CI, 1-3, P = 0.16). Two points are awarded for Medicaid or no insurance (OR = 2; 95% CI, 1-5, P = 0.035) and 3 points for Medicare (3; 95% CI, 1-9, P = 0.033). Each 1-point increase in risk score was associated with a 6% increased chance of requiring at least 1 revision surgery (P < 0.001). CONCLUSIONS: This study presents a clinical score that predicts the likelihood of success after surgery for tibia fracture nonunions or traumatic bone defects and may help clinicians better determine which patients are likely to fail these procedures and require further surgery.

Outcomes of ACL Reconstruction With Fixed Versus Variable Loop Button Fixation.

Suspensory femoral fixation of anterior cruciate ligament (ACL) grafts with fixed loop button and variable loop button devices has gained popularity for ACL reconstruction. This study examined these 2 methods of fixation to determine their effect on graft laxity and patient-reported outcome scores. A database search was performed to identify patients who had undergone ACL reconstruction with either a fixed loop or a variable loop button technique performed by the primary surgeon. Lysholm, Tegner, and 12-Item Short Form Health Survey scores were obtained, and KT-1000 knee ligament arthrometer (MEDmetric, San Diego, California) mechanical knee testing was performed. Results were compared with the uninjured knee. Of the 112 patients who were identified, 91 met the study criteria. Of these patients, 57 completed KT-1000 knee testing, 33 in the variable group and 24 in the fixed group. The average KT-1000 value for the variable group was 0.38 mm, and the average for the closed group was 0.92 mm (P=.19; 95% confidence interval, -0.28 to 1.35). Among the 19 patients in the variable group and the 13 in the closed group who completed the subjective outcomes questionnaires, no statistically significant difference was found. Clinically lax knees (KT-1000>3 mm) were found in 6.1% and 12.5% of patients in the variable group and the fixed group, respectively (P=.2). The variable group had a rerupture rate of 4.7%, whereas the fixed group had a rerupture rate of 8.7% (P=.21). The study found no statistical difference in ACL graft laxity or postoperative functional outcomes between grafts fixed with the variable loop or fixed loop button technique. [Orthopedics. 2017; 40(2):e275-e280.].