Intravenous Cefazolin Achieves Sustained High Interstitial Concentrations in Open Lower Extremity Fractures.

BACKGROUND: Infection remains a serious clinical concern in patients with open fractures, despite timely antibiotic administration and surgical debridement. Soft tissue and periosteal stripping may alter local tissue homeostasis and antibiotic pharmacokinetics in the injured limb. The tissue (interstitial) concentration of intravenously administered antibiotics at an open fracture site has not been characterized using direct sampling techniques. QUESTION/PURPOSE: We performed this study to evaluate the concentration and pharmacokinetics of intravenously delivered cefazolin at an open fracture site after surgical debridement. METHODS: Twelve patients with an open fracture distal to the knee who presented at a regional Level I trauma center were approached for enrollment in this nonrandomized, observational study. Of the 12 patients, eight adults (one female, seven male) with a median age of 32 years (range 23 to 51 years) were enrolled and underwent successful sample collection for analysis. Three patients had incomplete datasets because of equipment malfunction and one elected not to participate. Seven patients had open tibia fractures, and one patient had an open fibula fracture associated with a closed tibia fracture. There were six Gustilo-Anderson Type II injuries and two Type IIIA injuries. Empiric antibiotics were administered in the prehospital setting or in the emergency department according to institutional protocol. When patients were taken to the operating room, a 2-g intravenous dose of cefazolin was administered. After surgical debridement, fracture stabilization, and wound closure, a microdialysis catheter was placed transdermally into the injury zone (within 5 cm of the fracture site) and a second catheter was placed in the contralateral uninjured (control) limb. Additional doses of cefazolin were administered every 8 hours postoperatively. Baseline and periodic interstitial fluid and whole blood (plasma) samples were collected in the operating room and at prespecified times for 24 hours postoperatively. Free cefazolin in the interstitial fluid and plasma samples were analyzed by ultra-high-performance liquid chromatography using C 18 column separation with quadrupole time-of-flight mass spectrometry detection. Data from the second postoperative dose of cefazolin were used to characterize pharmacokinetic parameters through a noncompartmental analysis using time-concentration curves of free cefazolin and assuming first-order elimination. For pharmacodynamic analyses, the modal cefazolin minimum inhibitory concentration (MIC) of Staphylococcus aureus (1 µg/mL) was used. RESULTS: With the samples available, no difference was observed in the median free cefazolin exposure over 24 hours ( f area under the curve [AUC] 0→24hrs ) between injured limbs (352 µg∙hr/mL [IQR 284 to 594 µg∙hr/mL]) and uninjured limbs (341 µg∙hr/mL [IQR 263 to 438 µg∙hr/mL]; p = 0.64). The median time to achieve the maximum concentration of free cefazolin ( f T max ) for injured limbs was delayed (2.7 hours [IQR 2.2 to 3.1 hours]) compared with control limbs (1.7 hours [IQR 1.2 to 2.0 hours]; p = 0.046). The time to the maximum concentration for plasma was not different from that of control limbs (p = 0.08). The time the cefazolin concentration was above the modal S. aureus MIC (T > MIC) in the injured and control limbs over 24 hours was 100% (IQR 100% to 100%) and 100% (IQR 97% to 100%), respectively. CONCLUSION: These preliminary findings suggest that current prophylactic cefazolin dosing regimens result in successful antibiotic delivery to the traumatized limb in moderately severe open fractures. Although cefazolin delivery to open-fracture wound beds was delayed compared with healthy tissues, the cefazolin concentration was sustained above the European Union Committee Antimicrobial Susceptibility Testing modal MIC for S. aureus , demonstrating a high likelihood of a prophylactic antimicrobial environment at an open fracture site with this empiric antimicrobial regimen. Importantly, patients in this analysis had Gustilo-Anderson Types II and IIIA injuries. Further research with a larger patient cohort is needed to determine whether antibiotic delivery to traumatized soft tissues in patients with higher-grade open fractures (Gustilo-Anderson Types IIIB and IIIC) demonstrates similar pharmacokinetic characteristics. LEVEL OF EVIDENCE: Level II, therapeutic study.

Distal Femoral Stress Fractures Has High Operation Rates in Adolescent and Young Adult Athletes.

BACKGROUND: Although stress fractures of the distal femur are rare, symptoms can overlap with other peri-articular knee pathology, delaying diagnosis. Untreated stress fractures have the potential to progress into completed fractures with a higher likelihood for requiring surgery and longer recovery times in otherwise healthy adolescents and young adults. This case series represents the largest cohort of adolescent athletes with distal femoral stress fractures who presented with activity-related knee pain. METHODS: Patients treated nonoperatively and operatively for metaphyseal distal femur stress fractures at a tertiary referral center over a four-year period were retrospectively identified from the medical record. RESULTS: Eight patients (mean age 16.8 y; range 14 to 22 y; 87.5% male; mean body mass index [BMI] 20.9) with a total of 10 distal femur stress fractures were identified. All patients were involved in competitive sports or military training. There was an average of 3.8 encounters with a medical provider between presentation with activity-related knee pain and diagnosis with distal femur stress fracture. All except 1 patient (87.5%) were initially incorrectly diagnosed with another type of peri-articular knee pathology. Six stress fractures (60%) were treated conservatively with protected weight bearing, activity modification, and gradual return to activity. Four completed stress fractures (40%) required operative fixation-3 healed uneventfully, while 1 had an asymptomatic delayed union. Vitamin D insufficiency (<30 ng/mL) was identified in 7 of 8 patients (87.5%) and 3 patients (37.5%) had an underweight BMI (<18.5). The mean clinical follow-up was 13.1 weeks (range, 2.8 to 32.0 wk). CONCLUSIONS: High clinical suspicion for distal femoral stress fractures is needed to avoid misdiagnosis or delayed diagnosis in young, active individuals with activity-related knee pain refractory to conservative management. In this patient population, activity-related knee pain recalcitrant to activity modification, rest, and physical therapy warrants further workup with magnetic resonance imaging and orthopaedic evaluation. Though rare, misdiagnosis can result in catastrophic fractures with prolonged rehabilitation needs. An open line of communication and streamlined access for referral between primary care providers and orthopaedic surgeons is critical in preventing misdiagnosis and delayed treatment. Furthermore, the treatment of concomitant metabolic disorders and nutritional deficiency should not be neglected when treating distal femoral stress fractures. LEVEL OF EVIDENCE: Level-IV (case series).

Pilot randomized trial of pre-hospital advanced therapies for the control of hemorrhage (PATCH) using pelvic binders.

BACKGROUND: Pelvic fractures represent a small percent of all skeletal injuries but are associated with significant morbidity and mortality secondary to hemodynamic instability from bleeding bone surfaces and disrupted pelvic vasculature. Stabilization of the pelvis prior to arrival at a treatment facility may mitigate the hemodynamic consequences of pelvic ring injuries and improve morbidity and mortality. Whether pelvic compression devices such as pelvic binders or sheets can be safely applied in the prehospital setting has not been well-studied. This study aims to evaluate the safety of applying a pelvic binder to at-risk patients in the field after scalable training and the feasibility of conducting a randomized trial evaluating this practice in the prehospital setting. METHODS: A pilot study (prospective randomized trial design) was conducted in the pre-hospital environment in an urban area surrounding a level-one trauma center. Pre-hospital emergency medical (EMS) personnel were trained to identify patients at high-risk for pelvic fracture and properly apply a commercial pelvic binder. Adult patients with a high-energy mechanism, suspected pelvic fracture, and "Priority 1" criteria were prospectively identified by paramedics and randomized to pelvic binder placement or usual care. Medical records were reviewed for safety outcomes. Secondary outcomes were parameters of efficacy including interventions needed to control hemorrhage (such as angioembolization and surgical control of bleeding) and mortality. RESULTS: Forty-three patients were randomized to treatment (binder: N=20; nonbinder: N=23). No complications of binder placement were identified. Eight patients (40%) had binders placed correctly at the level of the greater trochanter. Two binders (10%) were placed too proximally and 10 (50%) binders were not visualized on x-ray. Two binder group patients and three nonbinder group patients required angioembolization. None required surgical control of pelvic bleeding. Two nonbinder group patients and one binder group patient were readmitted within 30 days and one nonbinder group patient died within 30 days. CONCLUSION: Identification of pelvic fractures in the field remains a challenge. However, a scalable training model for appropriate binder placement was successful without secondary injury to patients. The model for conducting prospective, randomized trials in the prehospital setting was successful.

Targeted Muscle Reinnervation for Prosthesis Optimization and Neuroma Management in the Setting of Transradial Amputation.

Targeted muscle reinnervation (TMR) is a surgical technique that improves modern myoelectric prosthesis functionality and plays an important role in the prevention and treatment of painful postamputation neuromas. Originally described for transhumeral amputations and shoulder disarticulations, the technique is being adapted for treatment of transtibial, transfemoral, transradial, and partial hand amputees. We describe a new technique for forearm TMR following transradial amputation with an emphasis on selecting nerve transfer patterns, managing sensory nerves, improving terminal soft tissue coverage, and employing pattern recognition technology.

Current Concepts in Upper-Extremity Amputation.

Advances in motor vehicle safety, trauma care, combat body armor, and cancer treatment have enhanced the life expectancy and functional expectations of patients with upper-extremity amputations. Upper-extremity surgeons have multiple surgical options to optimize the potential of emerging prosthetic technologies for this diverse patient group. Targeted muscle reinnervation is an evolving technique that improves control of myoelectric prostheses and can prevent or treat symptomatic neuromas. This review addresses current strategies for the care of patients with amputations proximal to the wrist with an emphasis on recent advancements in surgical techniques and prostheses.

Deep genome-wide measurement of meiotic gene conversion using tetrad analysis in Arabidopsis thaliana.

Gene conversion, the non-reciprocal exchange of genetic information, is one of the potential products of meiotic recombination. It can shape genome structure by acting on repetitive DNA elements, influence allele frequencies at the population level, and is known to be implicated in human disease. But gene conversion is hard to detect directly except in organisms, like fungi, that group their gametes following meiosis. We have developed a novel visual assay that enables us to detect gene conversion events directly in the gametes of the flowering plant Arabidopsis thaliana. Using this assay we measured gene conversion events across the genome of more than one million meioses and determined that the genome-wide average frequency is 3.5×10(-4) conversions per locus per meiosis. We also detected significant locus-to-locus variation in conversion frequency but no intra-locus variation. Significantly, we found one locus on the short arm of chromosome 4 that experienced 3-fold to 6-fold more gene conversions than the other loci tested. Finally, we demonstrated that we could modulate conversion frequency by varying experimental conditions.

Acute shortening and angulation for complex open fractures: an updated perspective.

Reestablishing an intact, healthy soft tissue envelope is a critical step in managing lower extremity injuries, particularly high-grade open tibia fractures. Acute shortening and angulation can be used independently or together to address complex soft tissue injuries, particularly when bone loss is present. These techniques facilitate management of difficult wounds and can be combined with local soft tissue rearrangement or pedicled flaps as needed, avoiding the need for free tissue transfer. After angular deformity correction, adjacent bone loss can be addressed with bone grafting or distraction histogenesis. This article discusses the indications for, surgical technique for, and limitations of acute shortening and angulation for management of open lower extremity fractures.

Bias in Care: Impact of Ethnicity on Time to Emergent Surgery Varies Between Subspecialties.

INTRODUCTION: Disparity in access to emergency care among minority groups continues to exist despite growing awareness of the effect of implicit bias on public health. In this study, we evaluated ethnicity-based differences in time between admission and surgery for patients undergoing emergent procedures at hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program. METHODS: We conducted a retrospective review of 249,296 National Surgical Quality Improvement Program cases from 2006 to 2018 involving general, orthopaedic, and vascular surgeries. Analysis of variance was used to compare "time to operating room" (OR) between ethnic groups. RESULTS: Notable differences in time to OR were noted among general and vascular surgeries but not orthopaedic surgery. Post hoc comparison identified notable variation in general surgery between White and Black/African Americans. In vascular surgery, notable variations were identified between White and Black/African Americans and White and Native Hawaiian/Pacific Islanders. DISCUSSION: These findings suggest that certain surgical subspecialties continue to exhibit disparities in care that may manifest as surgical delay, most notably between White and Black/African Americans. Interestingly, variation in time to OR for patients treated by orthopaedic surgery was not notable. Overall, these results highlight the need for additional research into the role of implicit bias in emergent surgical care in the United States.

Mobility Solutions After a Lower Extremity Fracture and Applicability to Battlefield and Wilderness Medicine.

The potential for delayed evacuation of injured Service members from austere environments highlights the need to develop solutions that can stabilize a wound and enable mobility during these prolonged casualty care (PCC) scenarios. Lower extremity fractures have traditionally been treated by immobilization (splinting) followed by air evacuation - a paradigm not practical in PCC scenarios. In the civilian sector, treatment of extremity injuries sustained during remote recreational activities have similar challenges, particularly when adverse weather or terrain precludes early ground or air rescue. This review examines currently available fracture treatment solutions to include splinting, orthotic devices, and biological interventions and evaluates their feasibility: 1) for prolonged use in austere environments and 2) to enable patient mobilization. This review returned three common types of splints to include: a simple box splint, pneumatic splints, and traction splints. None of these splinting techniques allowed for ambulation. However, fixed facility-based orthotic interventions that include weight-bearing features may be combined with common splinting techniques to improve mobility. Biologically-focused technologies to stabilize a long bone fracture are still in their infancy. Integrating design features across these technologies could generate advanced treatments which would enable mobility, thus maximizing survivability until patient evacuation is feasible.

Diversity in orthopaedic trauma: where we are and where we need to be.

Diversity has multiple dimensions, and individuals' interpretation of diversity varies broadly. The Orthopaedic Trauma Association (OTA) leadership recognized the need to address issues of diversity within the organization and appointed the OTA Diversity Committee in 2020. The OTA Diversity Committee has produced a statement that was confirmed by the OTA's board of directors reflecting the organization's position on diversity: "The OTA promotes and values diversity and inclusion at all levels with the goal of creating an environment where every member has the opportunity to excel in leadership, education, and culturally-competent orthopaedic trauma care." The OTA Diversity Committee surveyed its 1907 OTA members in the United States and Canada to assess its membership's attitudes toward and interpretation of this important topic. METHODS: Two surveys were distributed. One 15-question survey was sent to 1907 OTA members with different membership categories in the United States and Canada requesting basic demographic information and asking how members felt about the degree to which women and underrepresented minorities (URM) are represented within the OTA and within its leadership. A second 11-question survey was sent to 30 past chairs of 2017-2019 OTA educational courses and meetings evaluating their criteria for choosing faculty for OTA courses. Comments were reviewed and summarized to identify recurring themes. RESULTS: Two hundred seven responses from the membership and 14 from course chairs were received from the 1907 surveys that were emailed to OTA members in the United States and Canada. The results reveal awareness of the limited female and URM representation within the OTA. However, there is disagreement in how or even whether this should be addressed at an organizational level. Review of comments from both surveys reveals a number of common themes on these important topics. CONCLUSION: The members and course chairs surveyed recognize that there is limited diversity at the OTA leadership and faculty level. Many members feel that the OTA would benefit from increasing female and URM representation in committees, within the leadership, and as faculty at OTA-sponsored courses. However, survey comments reveal that many members and course chairs feel it is not the organization's role to regulate diversity and that diversity initiatives themselves may introduce an unnecessary form of bias.

Technological Advances in Prosthesis Design and Rehabilitation Following Upper Extremity Limb Loss.

PURPOSE OF REVIEW: The complexity of the human extremity, particularly the upper extremity and the hand, allows us to interact with the world. Prosthetists have struggled to recreate the intuitive motor control, light touch sensation, and proprioception of the innate limb in a manner that reflects the complexity of its native form and function. Nevertheless, recent advances in prosthesis technology, surgical innovations, and enhanced rehabilitation appear promising for patients with limb loss who hope to return to their pre-injury level of function. The purpose of this review is to illustrate recent technological advances that are moving us one step closer to the goal of multi-functional, self-identifiable, durable, and intuitive prostheses. RECENT FINDINGS: Surgical advances such as targeted muscle reinnervation, regenerative peripheral nerve interfaces, agonist-antagonist myoneural interfaces, and targeted sensory reinnervation; development of technology designed to restore sensation, such as implanted sensors and haptic devices; and evolution of osseointegrated (bone-anchored) prostheses show great promise. Augmented and virtual reality platforms have the potential to enhance prosthesis design, pre-prosthetic training, incorporation, and use. Emerging technologies move surgeons, rehabilitation physicians, therapists, and prosthetists closer to the goal of creating highly functional prostheses with elevated sensory and motor control. Collaboration between medical teams, scientists, and industry stakeholders will be required to keep pace with patients who require durable, high-functioning prostheses.

Characteristics of Pyogenic Musculoskeletal Infections in Older Children and Adolescents.

The characteristics and clinical consequences of pyogenic bone and joint infections in older children and adolescents have received little attention. This study evaluated the presentation and complications of musculoskeletal infections involving the pelvis and extremities in children older than 10 years. Thirty patients 10 to 17 years old (mean, 12.7 years old) were treated for musculoskeletal infections. Mean time to diagnosis was 9.2 days. Prior to correct diagnosis, 83% were assessed by at least 1 outpatient provider. At the time of admission, 55% were weight bearing and 93% were afebrile. Twenty-eight percent had a multifocal infection. More than one-third had serious medical complications or orthopedic sequelae; compared with patients without complications, this group had a significantly higher admission C-reactive protein and longer hospital stay. Symptoms of musculoskeletal infection common among young children may be absent in adolescents. Axial imaging is recommended to identify adjacent or multifocal disease. The Kocher criteria are less sensitive for septic hip arthritis in the adolescent population. Prompt recognition and treatment are critical to avoid medical and musculoskeletal complications. [Orthopedics. 2020;43(4):e291-e298.].

Virtual Reality and Augmented Reality-Translating Surgical Training into Surgical Technique.

PURPOSE OF REVIEW: As immersive learning outside of the operating room is increasingly recognized as a valuable method of surgical training, virtual reality (VR) and augmented reality (AR) are increasingly utilized in orthopedic surgical training. This article reviews the evolving nature of these training tools and provides examples of their use and efficacy. The practical and ethical implications of incorporating this technology and its impact on both orthopedic surgeons and their patients are also discussed. RECENT FINDINGS: Head-mounted displays (HMDs) represent a possible adjunct to surgical accuracy and education. While the hardware is advanced, there is still much work to be done in developing software that allows for seamless, reliable, useful integration into clinical practice and training. Surgical training is changing: AR and VR will become mainstays of future training efforts. More evidence is needed to determine which training technology translates to improved clinical performance. Volatility within the HMD industry will likely delay advances in surgical training.

Pre-Hip Fracture Falls: A Missed Opportunity for Intervention.

INTRODUCTION: The purpose of this study is to examine utilization of acute care services in the year prior to hip fracture to inform development and implementation of an intervention to prevent subsequent falls and hip fracture that targets high-risk patients. METHODS: Elderly patients (age >55) with hip fractures managed at a level one trauma center during 1 year (n = 134) were included. All "preadmissions," defined as an emergency department (ED) visit or inpatient admission within our hospital system in the year before fall with fracture, were documented. Proportion of patients with a "preadmission," reason for "preadmission," demographic characteristics, medical comorbidities, history of falls with fracture, cause of fracture, and time between preadmission and fracture were documented and described. RESULTS: Of all, 45.5% of patients (n = 61) had a preadmission. Falls was the reason for presentation in 27.5% of the preadmission encounters, and the median interval between preadmission and fracture was 217 days. Only 8% of the patients presenting for falls in the ED received falls counseling. Patients who experienced preadmission were younger, had a higher Charlson Comorbidity Index, and were more likely to be male. Seventy-nine percent were community dwelling at the time of preadmission, and 68% were discharged home. DISCUSSION: Nearly half of hip fracture patients were seen in a high acuity care environment in the year prior to fracture. A quarter presented for falls, supporting previous findings that history of falls is an important risk factor for future falls and injury. However, very few received falls counseling, documenting a major missed opportunity to address falls prevention in the acute care setting. CONCLUSIONS: Preventing subsequent falls and hip fractures in a targeted, high-risk population in the year prior to potential hip fracture has important implications for improving individual morbidity and mortality and population health. Community-based falls prevention programs are a viable option for this high-risk, community-dwelling population. Collaborative interventions are needed to actively link patients to evidence-based community resources.

Shortening and Angulation Strategies to Address Composite Bone and Soft Tissue Defects.

Gustilo-Anderson IIIB tibial fractures and infected tibial nonunions represent particular challenges for the orthopaedic trauma surgeon. Debridement of dysvascular bone and soft tissues can create composite bone and soft tissue defects. Restoring the soft tissue envelope is a critical step in preventing or treating ongoing infection and in restoring local blood supply. Shortening and angulation techniques, including the gradual expansion muscle flap, rely on distraction histogenesis to address composite bone and soft tissue loss. These strategies can be used to treat large soft tissue defects when flap coverage or free tissue transfer is not available.

Lower Extremity Limb Salvage: Lessons Learned From 14 Years at War.

American survivability during the current conflicts in Iraq and Afghanistan continues to improve, though the rate of extremity injury remains quite high. The decision to proceed with amputation versus limb salvage remains controversial. Exposure to combat wound with severe high-energy lower extremity trauma during the previous 14 years at war has incited important advances in limb salvage technique and rehabilitation.

Limited Added Value of the Posterolateral Approach.

BACKGROUND: Posterolateral tibial plateau fractures (AO/OTA 41-B or 41-C) represent a minority of proximal tibia fractures. Numerous surgical approaches have been described, each with unique variations and limitations. The purpose of this study is to quantitatively and qualitatively compare the surface area and structures exposed by four surgical approaches to the posterolateral proximal tibia. METHODS: Four published surgical approaches-direct posterolateral (DPL), transfibular (TF), posteromedial (PM), and anterolateral (AL)-were performed on 10 fresh-frozen cadavers. Once each exposure was obtained, a ruler was placed in the surgical field and calibrated digital images obtained. Overall, 10 bony and soft tissue landmarks were identified and the surgeon's ability to see or touch each landmark was recorded sequentially for each exposure. RESULTS: An average of 3.9 ± 2.7 cm(2) of posterolateral proximal tibial cortex was exposed by the DPL approach with significantly more surface area exposed by the TF, PM, and AL approaches (p < 0.01). The AL and PM approaches revealed a significantly larger area of tibial metaphysis and, when used together, consistently exposed posterior metaphyseal and intra-articular structures. CONCLUSION: A combination of the AL and PM approaches allows comparable surgical exposure to the proximal tibial when compared with two posterolateral approaches. These approaches can be employed together for reduction and fixation of injuries to the posterolateral tibial plateau and allow direct evaluation of the articular surface. Dedicated posterolateral approaches should be reserved for certain clinical situations, including proximal tibiofibular joint fracture or dislocation.