Faculty Bibliography

BACKGROUND/UNASSIGNED:Bone regeneration following a fracture is dependent on multiple factors including skeletal stem cells (SSCs). Recruitment, proliferation, and differentiation of the SSCs is guided by the proteins and metabolites found within the fracture microenvironment. Understanding how intrinsic factors affect the fracture microenvironment has been a topic of ongoing investigation. This study sought to determine whether the levels of select proteins and metabolites within the fracture hematoma would be differentially expressed depending on the age of the patient. We hypothesized that a distinct set of proteins and metabolites found within the fracture hematoma microenvironment would be present at varying levels depending on patient age. METHODS/UNASSIGNED:The research study was reviewed and approved by an Institutional Review Board. Hematomas were collected from subjects aged 18 years old or older undergoing surgical intervention for a fracture. Hematoma samples were selected from the biorepository and assigned to one of two fracture groups including young ankle/hindfoot and aged ankle/hindfoot. Protein and metabolite levels within each hematoma were analyzed by liquid chromatography-mass spectrometry. RESULTS/UNASSIGNED:A total of seven hematomas were included in each the young ankle/hindfoot and aged ankle/hindfoot groups. From the global metabolomic analysis, creatine, 2-methylindoline, and acetyl-L-carnitine were identified as being differentially expressed between both groups. An untargeted metabolomic analysis of the two groups identified significant differences in the levels of an additional 66 metabolites. Proteomic analysis identified 34 proteins that were expressed at significantly different levels. CONCLUSIONS/UNASSIGNED:The level of metabolites and proteins found within the local fracture environment vary by patient age. Future investigations will focus on identifying a role for these proteins and metabolites in bone homeostasis and fracture healing. LEVEL OF EVIDENCE/UNASSIGNED:N/A, basic science investigation. SUPPLEMENTARY INFORMATION/UNASSIGNED:The online version contains supplementary material available at 10.1007/s43465-024-01284-3.

The purpose of this study was to assess the biomechanical contributions of the nail and the plate individually to a complete nail-plate construct in the setting of comminuted distal femur fractures. For this biomechanical study, comminuted extra-articular distal femur fractures were created in 24 synthetic osteoporotic femur models. These were then split into three groups: the nail-only group, the plate-only group, and the nail-plate group. After fixation, each specimen underwent sequential axial and torsional loading, and axial and torsional stiffness were calculated and compared. The addition of a nail to a plate-only construct increased axial stiffness by 19.7% and torsional stiffness by 59.4%. The plate-only group and nail-plate group both demonstrated significantly greater axial and torsional stiffness than the nail-only group at all levels of axial and torsional load. (p < 0.001) At 1000 and 2000 N of cyclic loading, the nail-plate group demonstrated significantly greater axial stiffness than the plate-only group (p ≤ 0.018). The nail-plate group demonstrated greater torsional stiffness than the plate-only groups at all levels of torsional loading (p < 0.001). In osteoporotic comminuted distal femur fracture models, most of the axial stiffness in a nail-plate construct comes from the plate. While the combination of the two constructs is not fully additive, the plate contributes the majority of the axial and torsional stiffness in a nail-plate construct. The supplementation of the plate with a nail primarily helps to increase resistance to rotational forces. Level of Evidence: III.

INTRODUCTION/BACKGROUND:To assess whether a diagnosis of preexisting anemia impacts outcomes of geriatric hip fractures. METHODS:This is a retrospective comparative study conducted at a single, urban hospital system consisting of an orthopaedic specialty hospital, two level 1 trauma centers, and one university-based tertiary care hospital. Data of patients aged 55 years or older with a femoral neck, intertrochanteric, or subtrochanteric hip fracture (AO/OA 31A, 31B, and 32A-C) at a single hospital center treated from October 2014 to October 2023 were retrieved from an institutional review board-approved database. Patients were included if they had a hemoglobin measurement recorded between 6 and 12 months before hospitalization for their hip fracture. Patients were cohorted based on whether their hemoglobin values recorded anemic or not. Comparative analysis was conducted to analyze 1-year mortality, 30-day mortality, 30-day readmission, 90-day readmission, and inpatient major complications. RESULTS:Four hundred ninety-eight patients had hemoglobin values recorded at 6 to 12 months before their surgery in the electronic medical record. Two hundred seventy-three patients (54.8%) were considered anemic at that time, whereas 225 patients (45.2%) were not. Cohorts were markedly different regarding sex, Charlson Comorbidity Index, preinjury ambulatory status, and Score for Trauma Triage in Geriatric and Middle-Aged Patients (STTGMA) score (P < 0.05 for all). Multivariable analysis revealed that chronic preinjury anemia patients had a higher likelihood of 1-year mortality and a higher risk of major inpatient complication and 30- and 90-day readmission (P < 0.05 for all). CONCLUSION/CONCLUSIONS:Chronic preinjury anemia within 6 to 12 months before a hip fracture is associated with an increased risk of 1-year mortality, inpatient major complications, and 30- and 90-day readmission after hip fracture fixation. LEVEL OF EVIDENCE/METHODS:Level III.

Patients with 5th metatarsal (MT) fractures encompass a broad age distribution. This study evaluated the impact of age on the differences in clinical outcomes and management of these fractures. This was a retrospective cohort study of patients presenting to a single large, urban, academic hospital system with a 5th MT fracture over a 10-year period. Patients were stratified into groups of younger than 65 years old and equal to or greater than 65 years old. Initial and successive radiographs were reviewed, and fractures were categorized as Zone 1, Zone 2, Zone 3, Shaft, Neck, or Head fractures. 2,461 patients with 5th MT fractures were evaluated. Patients who did not follow up after initial evaluation in the emergency department or urgent care were excluded. Among 2,020 patients with mean follow-up of 1.03 years who met inclusion criteria, 76.2% were younger than 65 years and 23.8% were greater than or equal to 65 years. There was a significant difference in fracture type between groups as older patients were more likely to sustain metatarsal neck fractures but less likely to sustain Zone 1 base fractures (p < 0.05). There was no difference in time to clinical healing (p = 0.108) or time to radiographic union (p = 0.367) for all fractures between age groups. In conclusion, older patients sustain different 5th metatarsal fracture patterns compared to younger patients. However, despite the differences in age, there was no evidence for any difference in clinical and radiographic outcomes between groups.

AIMS/UNASSIGNED:This study evaluated the effect of treating clinician speciality on management of zone 2 fifth metatarsal fractures. METHODS/UNASSIGNED:(SD 6.0)) with a mean follow-up duration of 2.57 years (SD 2.64). RESULTS/UNASSIGNED:Overall, 281 patients (57.7%) were treated by orthopaedic surgeons, and 206 patients (42.3%) by podiatrists. When controlling for age, sex, and time between symptom onset and presentation, the likelihood of undergoing operative treatment was significantly greater when treated by a podiatrist (odds ratio (OR) 2.9 (95% CI 1.2 to 8.2); p = 0.029). A greater proportion of patients treated by orthopaedic surgeons were allowed to immediately bear weight on the injured foot (70.9% (178/251) vs 47.3% (71/150); p < 0.001). Patients treated by podiatrists were immobilized for significantly longer (mean 8.4 weeks (SD 5.7) vs 6.8 weeks (SD 4.3); p = 0.002) and experienced a significantly longer mean time to clinical healing (12.1 (SD 10.6) vs 9.0 weeks (SD 7.3), p = 0.003). CONCLUSION/UNASSIGNED:Although there was considerable heterogeneity among zone 2 fracture management, orthopaedic surgeons were less likely to treat patients operatively and more likely to allow early full weightbearing compared to podiatrists.

OBJECTIVES/OBJECTIVE:To compare 3 different cancellous screw configurations used for Garden 1 femoral neck fractures (FNFs). DESIGN/METHODS:Retrospective review. SETTING/METHODS:A large urban academic medical center. PATIENT SELECTION CRITERIA/UNASSIGNED:All patients with Orthopaedic Trauma Association 31B1.1 FNF who underwent in situ fixation with cancellous screws between 2012 and 2021 were included. Patients were divided into 3 groups: 2 screws placed in a parallel fashion, 3 screws placed in an inverted triangle configuration, and 3-screw fixation with placement of 1 "out-of-plane" screw perpendicular to the long axis of the femur. OUTCOME MEASURES AND COMPARISONS/UNASSIGNED:Postoperative femoral neck shortening (mm) was the primary outcome, which was compared among the 3 groups of different screw configurations. RESULTS:Sixty-one patients with a median follow-up of 1 year (interquartile range 0.6-1.8 years) and an average age of 72 years (interquartile range 65.0-83.0 years) were included. All fractures demonstrated bony healing. Overall, 68.9% of the cohort had ≤2 mm of femoral neck shortening. There was no difference between groups in the proportion of patients who experienced greater than 2 mm of shortening (P = 0.839) or in the amount (mm) of femoral neck shortening (Kruskal-Wallis χ2 = 0.517, P = 0.772). CONCLUSIONS:Although most patients with valgus-impacted FNF treated with screw fixation do not experience further femoral neck shortening, some patients demonstrated continued radiographic shortening during the healing process. The development of further femoral neck shortening and the amount of shortening that occurs do not differ based on implant configuration. Multiple different screw configurations seem to be acceptable for achieving healing and minimizing further femoral neck impaction. LEVEL OF EVIDENCE/METHODS:Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND/UNASSIGNED:To determine differences in functional outcomes, return to work, and complications, in operatively vs. nonoperatively treated diaphyseal humeral shaft fractures. METHODS/UNASSIGNED:150 patients who presented to our center with a diaphyseal humeral shaft fracture (Orthopedic Trauma Association type 12) treated by open reduction internal fixation or closed reduction with bracing were retrospectively reviewed. Data collected included patient demographics, injury information, surgical details, and employment data. Clinical, radiographic, and patient-reported functional outcomes were recorded at routine standard-of-care follow-ups. Complications were recorded. Outcomes were analyzed using standard statistical methods and compared. RESULTS/UNASSIGNED: = .031). Three (4.5%) patients in the operative group developed iatrogenic, postoperative nerve palsy. Two patients in the operative group (4%) had a superficial surgical site infection. CONCLUSION/UNASSIGNED:More patients treated surgically had functional range of motion by 6 weeks. Functional gains should be weighed by the patient and surgeon against risk of surgery, nonunion, nerve injury, and infection when considering various treatment options to better accommodate patients' needs.

BACKGROUND:Infected fracture nonunions often require prolonged treatment and recovery courses. It is unclear whether the bacterial microbiome influences the time to healing as well as the eradication of infection. The goals of this study are (1) to assess the bacterial microbiome affecting infected nonunions and (2) to evaluate the effects of bacterial speciation on associated outcomes. METHODS:Between 2006 and 2022, data from 551 adult patients from a single academic institution who presented with a fracture nonunion were analyzed retrospectively for infection. All patients underwent revision surgery with three sets of cultures obtained intra-operatively. Patients with significant intra-operative cultures were grouped into gram-positive and gram-negative culture cohorts. These patients were managed with a standardized protocol involving surgical debridement, nonunion site fixation, and culture-directed antibiotic treatment. Primary outcome was time to fracture union. Secondary outcomes included number of re-operations and eventual amputation or reconstructive surgery. RESULTS:56 nonunion patients (10 %) were diagnosed with an infected nonunion (44 g-positive, 12 g-negative). Of these, 3 g-positive patients received an amputation or arthroplasty procedure prior to fracture union, and seven were lost to follow-up. There were no significant differences in age, gender, or nonunion site between cohorts. Most nonunions occurred in the lower extremity. The most common bacteria were staph species (54.3 %). 36 g-positive and 10 g-negative patients achieved fracture union. Time to union was on average 158.4 days longer in the gram-negative cohort-but did not reach statistical significance (446.8 days gram-positive, 662.3 days gram-negative, p = 0.69). There was no difference in re-operation rates (1.9 % gram-positive, 2.2 % gram-negative, p = 0.84). CONCLUSIONS:Patients with infected nonunions had wide-ranging bacterial contamination that were treated successfully using a standardized protocol. However, patients with any gram-negative culture trended toward a delay in time to union.

BACKGROUND:The purpose of this study was to compare the ICU length of stay (LOS), overall hospital LOS, in-hospital complications, and mortality rate between trauma ICU patients with orthopedic injuries versus those without. METHODS:This was a retrospective cohort study in which the trauma registry of a single level 1 trauma center was queried over a 6-year period for patients admitted to the ICU during hospitalization. Patients were stratified based on the presence/absence of an orthopedic fracture. Negative binomial regression was used to evaluate the effect of orthopedic injury on overall hospital and ICU LOS while controlling for confounding factors. Secondary outcomes included group differences with respect to in-hospital complications, mortality, and discharge disposition. RESULTS:A total of 1,785 trauma patients were admitted to the ICU and included. Among all trauma ICU patients, 61.1 % (n = 1,091) had no associated orthopedic injuries whereas 38.9 % (n = 694) had at least one. Patients with orthopedic injuries had higher odds of being severely injured (ISS ≥ 16: OR [CI] =1.47 [1.2-1.8]; p < 0.001) despite presenting with a higher level of consciousness than those without orthopedic injuries (mean GCS: 13.3 ± 3.5 vs 12.5 ± 4.1, p < 0.001). Multivariable models demonstrated having an orthopedic injury did not moderate ICU LOS (IRR [CI] = 0.93 [0.9-1.0]; p = 0.110) but did contribute significantly to increasing hospital LOS (IRR [CI] = 1.23 [1.1-1.3]; p < 0.001). There was no evidence to suggest that orthopedic injury increases the risk of in-hospital complication or in-hospital mortality. Orthopedically injured trauma ICU patients were less likely to be discharged home than those without orthopedic injuries. CONCLUSIONS:Trauma ICU patients with an associated orthopedic injury have significantly longer hospital stays compared to those without an orthopedic injury, despite no evidence to suggest that the orthopedic injury affects the duration of ICU stay or in-hospital complications. LEVEL OF EVIDENCE/METHODS:III, Retrospective cohort study.

PURPOSE/OBJECTIVE:To determine when patients return to work following operative repair of tibial shaft fractures (TSF) and what risk factors are associated with a delayed return to work (RTW), defined as greater than 180 days after operative repair. METHODS:Retrospective chart review was performed on a consecutive series of TSF patients who underwent operative repair. Time to RTW was based on documented work-clearance communications from the operating surgeon. Patients were divided into 3 groups based on when they returned to work: early (≤ 90 days), average (91-80 days), and late (≥ 180 days). Univariate analysis was performed, and significant variables were included in multinomial logistic regression. RESULTS:There were 168 patients identified. Eighteen were excluded (retired, unemployed, or never returned to work) leaving 150 patients. The average time to RTW for the overall study population was 4.17 ± 2.06 months. There were 39 (26.0%) patients in the early RTW group, 85 (56.7%) in the average RTW group, and 26 (17.3%) in the late RTW group. Patient with high-energy injuries (p = 0.024), open fractures (p = 0.001), initial external-fixation (p = 0.036), labor-intensive job (p = 0.018) and post-operative non-weight bearing status (p = 0.023) all had significantly longer RTW. Multinomial logistic regression including these parameters found a closed fracture was associated with a 1.9 decreased risk of delayed RTW (p = 0.004, 95% CI 0.039-0.533). CONCLUSIONS:Open fractures, initial external-fixation, restricted post-operative weight-bearing and labor-intensive jobs are associated with a delayed RTW following operative repair of TSFs. LEVEL OF EVIDENCE/METHODS:Therapeutic Level III.