What is the Case Volume of Orthopaedic Trauma Surgeons in the Military Health System? An Assessment of Wartime Readiness and Skills Sustainment.

INTRODUCTION: Complex, high-energy extremity trauma secondary to explosive mechanisms has been increasingly common in modern warfare, accounting for a majority of combat wounds throughout the conflicts in Iraq and Afghanistan. Fellowship-trained orthopaedic trauma surgeons treated many of these complex injuries; however, as the number of casualties continue to decrease during a period of relative peace, a growing concern over maintaining military trauma readiness exists. METHODS: The Military Health System Data Repository was queried for all Common Procedural Terminology (CPT) codes associated with 18 fellowship-trained orthopaedic trauma surgeons from 2013 to 2019. The codes were further analyzed and categorized based on common trauma subspecialty procedures such as fracture fixation of the pelvic ring, acetabulum, upper and lower extremity, peri-articular, and nonunion/malunion surgery. We used descriptive statistics to quantify both the average number of cases per surgeon per year in each of the subcategories and case volume among Military Treatment Facilities (MTFs) during the study period. RESULTS: We identified 7,769 CPT codes for surgical procedures throughout the study period. The most common surgical procedures performed were: removal of implant (n = 836, 11%), knee arthroscopy (n = 507, 7%), and debridement of devitalized tissue (n = 345, 4%). The total trauma subspecialty procedural codes and average cases per surgeon per year were as follows: pelvic ring (n = 54, <1 case/year), acetabulum (n = 90, 1 case/year), upper extremity (n = 1,314, 15 cases/year), lower extremity (n = 2,286, 25 cases/year), peri-articular (n = 675, 8 cases/year), and nonunion/malunion (n = 288, 3 cases/year). San Antonio Military Medical Center (SAMMC) accounted for the most fracture-related CPT codes overall (35%), while all other MTFs contributed approximately 10% or less of all fracture-related codes. CONCLUSIONS: These results highlight the lack of orthopaedic trauma volume at other MTFs outside of SAMMC, raising concern for maintaining military readiness during an inter-war period of relative peace. The DoD continues to make concerted efforts to maintain readiness through civilian partnerships and subsequently increase surgical case volume for military trauma surgeons. Future efforts should include an in-depth analysis of caseloads of military trauma surgeons providing care at both MTFs and civilian institutions to optimize preparedness in future conflicts.

White matter trajectories over the lifespan.

White matter (WM) changes occur throughout the lifespan at a different rate for each developmental period. We aggregated 10879 structural MRIs and 6186 diffusion-weighted MRIs from participants between 2 weeks to 100 years of age. Age-related changes in gray matter and WM partial volumes and microstructural WM properties, both brain-wide and on 29 reconstructed tracts, were investigated as a function of biological sex and hemisphere, when appropriate. We investigated the curve fit that would best explain age-related differences by fitting linear, cubic, quadratic, and exponential models to macro and microstructural WM properties. Following the first steep increase in WM volume during infancy and childhood, the rate of development slows down in adulthood and decreases with aging. Similarly, microstructural properties of WM, particularly fractional anisotropy (FA) and mean diffusivity (MD), follow independent rates of change across the lifespan. The overall increase in FA and decrease in MD are modulated by demographic factors, such as the participant's age, and show different hemispheric asymmetries in some association tracts reconstructed via probabilistic tractography. All changes in WM macro and microstructure seem to follow nonlinear trajectories, which also differ based on the considered metric. Exponential changes occurred for the WM volume and FA and MD values in the first five years of life. Collectively, these results provide novel insight into how changes in different metrics of WM occur when a lifespan approach is considered.

Rapid Return to Braking After Anterior and Posterior Approach Total Hip Arthroplasty.

BACKGROUND: Little is known about the effect of surgical approach on return to braking after total hip arthroplasty (THA), and few studies have investigated braking after THA with modern surgical techniques and rehabilitation protocols. METHODS: In a prospective comparative design, we enrolled 65 patients who received right-sided primary THA at our institution from April 2018 through March 2020, 34 with a direct anterior approach (DAA) and 31 with a posterior approach (PA). Braking tests measuring brake reaction time (BRT) and brake pedal depression (BPD) were administered to patients preoperatively and at 1, 2, and 4 weeks postoperatively using a realistic driving simulator. BRT and BPD were compared between groups and preoperatively versus postoperatively using mixed-effects models. RESULTS: Preoperative BRT averaged 638 msec in the DAA group and 604 msec in the PA group (P = 0.31). At 1 week postoperatively, the DAA group had significantly prolonged BRT compared with preoperatively (694 msec, P = 0.02). No significant difference was observed in the PA group (633 msec, P = 0.31). Both groups had returned to baseline by 2 weeks, and both had significantly faster BRT at 4 weeks compared with preoperatively (583 msec for DAA, P = 0.01; 537 msec for PA, P < 0.001). BPD was similar between groups, and there were no significant differences between preoperative and postoperative BPD at any time point. CONCLUSIONS: With modern surgical techniques, BRT after right-sided THA returns to baseline levels approximately 2 weeks after surgery. There seems to be a quicker return to preoperative BRT observed in patients with a PA.

Fix or Replace? Patient Preferences for the Treatment of Geriatric Lower Extremity Fractures: A Discrete Choice Experiment.

Introduction: When considering treatment options for geriatric patients with lower extremity fractures, little is known about which outcomes are prioritized by patients. This study aimed to determine the patient preferences for outcomes after a geriatric lower extremity fracture. Materials and Methods: We administered a discrete choice experiment survey to 150 patients who were at least 60 years of age and treated for a lower extremity fracture at a Level I trauma center. The discrete choice experiment presented study participants with 8 sets of hypothetical outcome comparisons, including joint preservation (yes or no), risk of reoperation at 6 months and 24 months, postoperative weightbearing status, disposition, and function as measured by return to baseline walking distance. We estimated the relative importance of these potential outcomes using multinomial logit modeling. Results: The strongest patient preference was for maintained function after treatment (59%, P < .001), followed by reoperation within 6 months (12%, P < .001). Although patients generally favored joint preservation, patients were willing to change their preference in favor of joint replacement if it increased function (walking distance) by 13% (SE, 66%). Reducing the short-term reoperation risk (12%, P < .001) was more important to patients than reducing long-term reoperation risk (4%, P = .33). Disposition and weightbearing status were lesser priorities to patients (9%, P < .001 and 7%, P < .001, respectively). Discussion: After a lower extremity fracture, geriatric patients prioritized maintained walking function. Avoiding short-term reoperation was more important than avoiding long-term reoperation. Joint preservation through fracture fixation was the preferred treatment of geriatric patients unless arthroplasty or arthrodesis provides a meaningful functional benefit. Hospital disposition and postoperative weightbearing status were less important to patients than the other included outcomes. Conclusions: Geriatric patients strongly prioritize function over other outcomes after a lower extremity fracture.

Infant sustained attention differs by context and social content in the first 2 years of life.

Sustained attention (SA) is an endogenous form of attention that emerges in infancy and reflects cognitive engagement and processing. SA is critical for learning and has been measured using different methods during screen-based and interactive contexts involving social and nonsocial stimuli. How SA differs by measurement method, context, and stimuli across development in infancy is not fully understood. This 2-year longitudinal study examines attention using one measure of overall looking behavior and three measures of SA-mean look duration, percent time in heart rate-defined SA, and heart rate change during SA-in N = 53 infants from 1 to 24 months across four unique task conditions: social videos, nonsocial videos, social interactions (face-to-face play), and nonsocial interactions (toy engagement). Results suggest that developmental changes in attention differ by measurement method, task context (screen or interaction), and task stimulus (social or nonsocial). During social interactions, overall looking and look durations declined after age 3-4 months, whereas heart rate-defined attention measures remained stable. All SA measures were greater for videos than for live interaction conditions throughout the first 6 months, but SA to social and nonsocial stimuli within each task context were equivalent. In the second year of life, SA measured with look durations was greater for social videos compared to other conditions, heart rate-defined SA was greater for social videos compared to nonsocial interactions, and heart rate change during SA was similar across conditions. Together, these results suggest that different measures of attention to social and nonsocial stimuli may reflect unique developmental processes and are important to compare and consider together, particularly when using infant attention as a marker of typical or atypical development. RESEARCH HIGHLIGHTS: Attention measure, context, and social content uniquely differentiate developmental trajectories of attention in the first 2 years of life. Overall looking to caregivers during dyadic social interactions declines significantly from 4 to 6 months of age while sustained attention (SA) to caregivers remains stable. Heart rate-defined SA generally differentiates stimulus context where infants show greater SA while watching videos than while engaging with toys.

The Agonist-Antagonist Myoneural Interface in a Transtibial Amputation.

Background: The agonist-antagonist myoneural interface (AMI) technique at the time of transtibial amputation involves the use of agonist-antagonist muscle pairs to restore natural contraction-stretch relationships and to improve proprioceptive feedback when utilizing a prosthetic limb1. Description: Utilizing the standard incision for a long posterior myofasciocutaneous flap, the lateral and medial aspects of the limb are dissected, identifying and preserving the superficial peroneal and saphenous nerve, respectively. The tendons of the tibialis anterior and peroneus longus are transected distally to allow adequate length for the AMI constructs. After ligation of the anterior tibial vessels, the deep peroneal nerve is identified and tagged to create a regenerative peripheral nerve interface (RPNI). The tibia and fibula are cut approximately 15 cm from the medial joint line, facilitating dissection of the deep posterior compartment and ligation of the peroneal and posterior tibial vessels. The tendons of the lateral gastrocnemius and tibialis posterior are transected distally, and the amputation is completed. The extensor retinaculum is harvested from the residual limb along with multiple 2 × 3-cm free muscle grafts, which will be used for the RPNI constructs. The retinaculum is secured to the tibia with suture anchors, and AMI pairs of the lateral gastrocnemius and tibialis anterior as well as the tibialis posterior and peroneus longus are constructed. Separate RPNIs of the major lower-extremity nerves are performed, and the wound is closed in a standard layered fashion. Alternatives: An isometric myodesis of the gastrocnemius without coaptation of agonist-antagonist muscle pairs can be performed at the time of transtibial amputation. Rationale: The AMI technique restores natural agonist-antagonist relationships at the time of transtibial amputation to increase proprioceptive feedback and improve prosthetic control. These outcomes contrast with those of a traditional isometric myodesis, which prevents proprioceptive communication from the residual limb musculature to the central nervous system. Additionally, the AMI technique allows for concentric and eccentric muscular contractions, which may contribute to the maintenance of limb volume and aid with prosthetic fitting, as opposed to the typical limb atrophy observed following standard transtibial amputation1,2. With the development and availability of more advanced prostheses, the AMI technique offers more precise control and increases the functionality of these innovative devices. Expected Outcomes: Early clinical outcomes of the AMI technique at the time of transtibial amputation have been promising. In a case series of the first 3 patients who underwent the procedure, complications were minor and consisted of 2 episodes of cellulitis and 1 case of delayed wound healing1. Muscle activation measured through electromyography demonstrated an improved ability to limit unintended muscular co-contraction with attempted movement of the phantom limb, as compared with patients who underwent a standard transtibial amputation1. Additionally, residual limb volume was maintained postoperatively without the need for substantial prosthetic modifications. Important Tips: The tendons of the tibialis anterior, peroneus longus, tibialis posterior, and lateral gastrocnemius should be transected as distal as possible to allow adequate length for creation of the AMI constructs.Approximately 2 × 3-cm free muscle grafts are harvested from the amputated extremity for RPNI3.Smooth tendon-gliding through the synovial tunnels should be confirmed before closure. If necessary, muscle debulking can improve gliding and decrease the size of the residual limb.Harvesting the extensor retinaculum for synovial tunnels has been our preferred method, although we acknowledge that other grafts options such as the tarsal tunnel are available1. Acronyms & Abbreviations: RPNI = regenerative peripheral nerve interfaceAMI = agonist-antagonist myoneural interfaceEMG = electromyographic.