Rethinking the 10% strain rule in fracture healing: A distal femur fracture case series

Since the 1970s, the 2%-10% rule has been used to describe the range of interfragmentary gap closure strains that are conducive for secondary bone healing. Interpreting the available evidence for the association between strain and bone healing remains challenging because interfragmentary strain is impossible to directly measure in vivo. The question of how much strain occurs within and around the fracture gap is also difficult to resolve using bench tests with osteotomy models because these do not reflect the complexity of injury patterns seen in the clinic. To account for these challenges, we used finite element modeling to assess the three-dimensional interfragmentary strain in a case series of naturally occurring distal femur fractures treated with lateral plating under load conditions representative of the early postoperative period. Preoperative computed tomography scans were used to construct patient-specific finite element models and plate fixation constructs to match the operative management of each patient. The simulations showed that gap strains were within 2%-10% only for the lowest load application level, 20% static body weight (BW). Moderate loading of 60% static BW and above caused gap strains that far exceeded 10%, but in all cases, strains in the periosteal region external to the fracture line remained low. Comparing these findings with postoperative radiographs suggests that in vivo secondary healing of distal femur fractures may be robust to early gap strains much greater than 10% because formation of new bone is initiated outside the gap where strains are lower, followed by later consolidation within the gap.

Distal Radius Fractures in Diabetic Patients: An Analysis of Surgical Timing and Other Factors That Affect Complication Rate

BACKGROUND

While not studied for distal radius fractures, the effect of surgical timing on complication rate has been extensively analyzed in the treatment of pilon fractures. The primary aim of this study was to identify any effect surgical timing has on postoperative complication rates after surgical fixation of distal radius fractures in diabetic patients.

METHODS

All patients who underwent surgical fixation of distal radius fractures at a single suburban academic hospital between 2012 and 2019 were reviewed. For each patient, demographics, comorbidities, injury details, fixation method, and postoperative complications were noted. The effect surgical delay, among other factors, had on complication rate in diabetic and nondiabetic patients was explored.

RESULTS

Overall, 124 diabetic and 371 nondiabetic distal radius fractures were included. While diabetics had a statistically higher rate of total complications (21.0 vs. 13.5%, P = .045) but similar major complications requiring surgery (P = .12), there was no difference in surgical delay between groups among patients who had total (P = .31) or major (P = .69) complications. Surgical timing was not a risk factor for total (P = .50) or major complications (P = .32) in diabetic fracture bivariate or multivariate analysis. Only younger age and higher energy injuries were significant risk factors for total complications in bivariate (P = .02, P = .03) and multivariate (P = .04, P < .05) analysis.

CONCLUSION

Complication rates after surgically stabilized distal radius fractures in diabetic patients are higher than in nondiabetic patients. However, this rate is not affected by surgical timing. Instead, surgeons should consider factors such as diabetic control in an effort to maximize outcomes and decrease complications.

LEVEL OF EVIDENCE

Prognostic Level III.

International Orthopaedic Volunteer Opportunities in Low and Middle-Income Countries

Globally, the burden of musculoskeletal conditions continues to rise, disproportionately affecting low and middle-income countries (LMICs). The ability to meet these orthopaedic surgical care demands remains a challenge. To help address these issues, many orthopaedic surgeons seek opportunities to provide humanitarian assistance to the populations in need. While many global orthopaedic initiatives are well-intentioned and can offer short-term benefits to the local communities, it is essential to emphasize training and the integration of local surgeon-leaders. The commitment to developing educational and investigative capacity, as well as fostering sustainable, mutually beneficial partnerships in low-resource settings, is critical. To this end, global health organizations, such as the Consortium of Orthopaedic Academic Traumatologists (COACT), work to promote and ensure the lasting sustainability of musculoskeletal trauma care worldwide. This article describes global orthopaedic efforts that can effectively address musculoskeletal care through an examination of 5 domains: clinical care, clinical research, surgical education, disaster response, and advocacy.

Effect of Intrawound Vancomycin Powder in Operatively Treated High-risk Tibia Fractures: A Randomized Clinical Trial

Importance

Despite the widespread use of systemic antibiotics to prevent infections in surgically treated patients with fracture, high rates of surgical site infection persist.

Objective

To examine the effect of intrawound vancomycin powder in reducing deep surgical site infections.

Design, Setting, and Participants

This open-label randomized clinical trial enrolled adult patients with an operatively treated tibial plateau or pilon fracture who met the criteria for a high risk of infection from January 1, 2015, through June 30, 2017, with 12 months of follow-up (final follow-up assessments completed in April 2018) at 36 US trauma centers.

Interventions

A standard infection prevention protocol with (n = 481) or without (n = 499) 1000 mg of intrawound vancomycin powder.

Main Outcomes and Measures

The primary outcome was a deep surgical site infection within 182 days of definitive fracture fixation. A post hoc comparison assessed the treatment effect on gram-positive and gram-negative-only infections. Other secondary outcomes included superficial surgical site infection, nonunion, and wound dehiscence.

Results

The analysis included 980 patients (mean [SD] age, 45.7 [13.7] years; 617 [63.0%] male) with 91% of the expected person-time of follow-up for the primary outcome. Within 182 days, deep surgical site infection was observed in 29 of 481 patients in the treatment group and 46 of 499 patients in the control group. The time-to-event estimated probability of deep infection by 182 days was 6.4% in the treatment group and 9.8% in the control group (risk difference, -3.4%; 95% CI, -6.9% to 0.1%; P = .06). A post hoc analysis of the effect of treatment on gram-positive (risk difference, -3.7%; 95% CI, -6.7% to -0.8%; P = .02) and gram-negative-only (risk difference, 0.3%; 95% CI, -1.6% to 2.1%; P = .78) infections found that the effect of vancomycin powder was a result of its reduction in gram-positive infections.

Conclusions and Relevance

Among patients with operatively treated tibial articular fractures at a high risk of infection, intrawound vancomycin powder at the time of definitive fracture fixation reduced the risk of a gram-positive deep surgical site infection, consistent with the activity of vancomycin.

Trial Registration

ClinicalTrials.gov Identifier: NCT02227446.

The Effect of an Orthopedic Hand Surgeon's Attire on Patient Confidence and Trust

Background: Multiple studies have concluded that patients are more likely to understand and trust physicians who dress in more formal attire (shirt and tie) as opposed to casual attire (t-shirts and jeans). The white coat has repeatedly been reported as a major source of trust and confidence in a patient's eyes. Methods: This study explores the effect an orthopedic hand surgeon's attire has on a patient's perception of their surgeon's clinical values. All patients 18 years of age and older who visited our orthopedic hand surgeon's suburban outpatient practice were asked to participate in our survey-based study. Results: Ninety-seven surveys were completed and included. A majority of our responders are female (n = 59, 60.8%), Caucasian (n = 83, 85.6%) between the ages of 55 and 74 years (n = 40, 41.2%), currently employed (n = 59, 60.8%) with private health insurance (n = 69, 71.1%), and married (n = 64, 66.0%). Patients rated male and female hand surgeons wearing a white coat highest using the Likert scale and when asked about their perceived clinical qualities. Patients consistently poorly rated their surgeons wearing casual attire. Patients did note that the white coat, or any specific attire, was not necessary during the initial encounter to build a strong patient-surgeon relationship. Finally, goatees and beards do not positively or negatively impact a surgeon's patient-constructed image. Conclusions: Combining strong clinical skills with appropriate clinical attire highlighted by the physician wearing a white coat appears to be an effective way to enhance patient satisfaction while ultimately gaining the trust and respect needed to properly care for patients.

Mechanical characterization of bone quality in distal femur fractures using pre-operative computed tomography scans

BACKGROUND

Mechanical testing of implant constructs designed to treat distal femur fractures has been hampered by a lack of clinical data on the biomechanical properties of the distal femur in patients who sustain these fractures. Therefore, the purpose of this study was to use quantitative computed tomography (qCT) to investigate the mechanical characteristics of fractured distal femurs to inform the selection of synthetic materials for biomechanical testing.

METHODS

Distal femur fractures treated at a Level I trauma center were retrospectively reviewed and 43 cases with preoperative CT scans were identified for analysis. Scans were segmented and each bone fragment was reconstructed as a 3D model. The Young's modulus of the distal femur was determined from voxel-based radiodensity.

FINDINGS

Median patient age was 72 years (IQR = 57-81), with 26% males and 74% females. Young's modulus in the distal femur was negatively correlated with patient age (R² = 0.50, p < 0.001). The distribution of patient-specific modulus values was also compared with the compressive modulus ranges for graded polyurethane foams according to ASTM F1839. Bone quality ranged from Grade 25 in younger individuals to Grade 5 in older individuals.

CONCLUSION

No single grade of synthetic polyurethane foam can be selected to model all clinically important scenarios for biomechanical testing of distal femur fracture fixation devices. Rather, this data can be used to select an appropriate material for a given clinical scenario. A Grade 25 foam is appropriate for implant longevity, whereas for implant stability, Grades 5-15 are more appropriate.

A Comprehensive Framework for International Medical Programs: A 2017 consensus statement from the American College of Academic International Medicine

The American College of Academic International Medicine (ACAIM) represents a group of clinicians who seek to promote clinical, educational, and scientific collaboration in the area of Academic International Medicine (AIM) to address health care disparities and improve patient care and outcomes globally. Significant health care delivery and quality gaps persist between high-income countries (HICs) and low-and-middle-income countries (LMICs). International Medical Programs (IMPs) are an important mechanism for addressing these inequalities. IMPs are international partnerships that primarily use education and training-based interventions to build sustainable clinical capacity. Within this overall context, a comprehensive framework for IMPs (CFIMPs) is needed to assist HICs and LMICs navigate the development of IMPs. The aim of this consensus statement is to highlight best practices and engage the global community in ACAIM's mission. Through this work, we highlight key aspects of IMPs including: (1) the structure; (2) core principles for successful and ethical development; (3) information technology; (4) medical education and training; (5) research and scientific investigation; and (6) program durability. The ultimate goal of current initiatives is to create a foundation upon which ACAIM and other organizations can begin to formalize a truly global network of clinical education/training and care delivery sites, with long-term sustainability as the primary pillar of international inter-institutional collaborations.

The treatment of periprosthetic femur fractures after total knee arthroplasty

Periprosthetic femur fractures after total knee arthroplasty are a rising concern; however, when properly diagnosed, they can be managed nonoperatively or operatively in the form of locking plate fixation, intramedullary nailing, and arthroplasty. The degree of osteoporosis, stability of the femoral implant, and goals of the patient are a few critical variables in determining the ideal treatment. Despite excellent outcomes from each of these operative choices, the risk of nonunion, malunion, instability, and refracture cannot be ignored.