Background: Occult instability of lateral compression type-1 (LC1) pelvic ring injuries may be determined with a fluoroscopic stress examination under anesthesia (EUA) performed in the operating room. We hypothesized that LC1 injuries, similar to some fractures of the extremities, could be radiographically stressed for stability in the emergency department (ED). Our primary objective was to determine if stress examination of LC1 fractures could be safely and accurately performed in the ED and could be tolerated by patients. Methods: A prospective, consecutive series of 70 patients with minimally displaced LC1 pelvic injuries (<10-mm displacement on presentation) underwent stress examinations performed by the on-call orthopaedic resident in the ED radiology suite. The stress examination series included static 40° inlet, internal rotation stress inlet, and external rotation stress inlet views. Pelvic fractures that had positive stress results (≥10 mm of overlap of the rami) were indicated for a surgical procedure. These fractures also underwent EUA in order for the 2 techniques to be compared. Results: All patients tolerated the ED stress examination without general anesthetic or hemodynamic instability. Fifty-seven patients (81%) had negative stress results and were allowed to bear weight. All patients with negative stress results who had 3-month follow-up went on to radiographic union without substantial displacement. For the patients with a positive stress result in the ED, the mean displacement was 15.15 mm (95% confidence interval [CI], 10.8 to 19.4 mm) for the ED stress test and 15.60 mm (95% CI, 11.7 to 19.4 mm) for the EUA (p = 0.86). Two patients with a negative ED stress test did not mobilize during their hospitalization and underwent EUA and conversion to a surgical procedure. Thus, a total of 11 patients underwent both stress testing in the ED and EUA; no patient had a positive result on one test but a negative result on the other. Conclusions: ED stress examination of LC1 injuries is a safe and reliable method to determine pelvic ring stability. The displacement measured in the ED stress examination is similar to the displacement measured under general anesthesia. Furthermore, a negative ED stress examination predicts successful nonoperative treatment. Given the results of this study, we encourage the use of stress examination in the ED for LC1-type injuries involving complete sacral fractures only. Widescale adoption of this streamlined protocol may substantially diminish cost, anesthetic risk, and potential operations for patients. Level of Evidence: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Journal of Medical Internet Research - International Scientific Journal for Medical Research, Information and Communication on the Internet #Preprint #PeerReviewMe: Warning: This is a unreviewed preprint. Readers are warned that the document has not been peer-reviewed by expert/patient reviewers or an academic editor, may contain misleading claims, and is likely to undergo changes before final publication, if accepted, or may have been rejected/withdrawn. Readers with interest and expertise are encouraged to sign up as peer-reviewer, if the paper is within an open peer-review period. Please cite this preprint only for review purposes or for grant applications and CVs (if you are the author). Background: Heterotopic ossification (HO) is a significant complication for wounded warriors with traumatic limb loss. Although this pathologic condition negatively impacts the general population, ectopic bone has been observed with higher frequency for those injured in theatre. Several factors including a traumatic blast, bioburden, tourniquet and wound vacuum usage, and/or bone fractures/fragments have been associated with the increased HO formation for service members. The first step in assessing the effect of these factors on HO formation in a large animal model was to establish a repeatable and reproducible high pressure air system that could simulate a battlefield-relevant blast Objective: N/A Methods: The repeatability and reproducibility of a high-power air delivery system was determined by collecting force data across a spectrum of PSI settings. In addition, the ability of the higher power air delivery system to affect host tissue, displace metal particulate and disperse bone chips was assessed in cadaveric sheep limbs. Results: Data demonstrated that the air delivery setup could generate battlefield-relevant blast forces. Dispersion data likewise indicated that the delivery system would have the ability to cause host tissue trauma and effectively disperse metal particulate and/or host bone chips in local musculature. Conclusions: Taken together, data showed that a high pressure air impact device will have the ability to function as a simulated battlefield blast scenario and allow factors including blast trauma to translate toward a large animal model. Clinical Trial: N/A

Lower extremity fractures pose challenges due to prolonged healing times and limited assessment methods. Integrating wearable sensors with machine learning can help overcome these challenges by providing objective assessment and predicting fracture healing. In this retrospective study, data from a gait monitoring insole on 25 patients with closed lower extremity fractures were analyzed. Continuous underfoot loading data were processed to isolate steps, extract metrics, and feed them into three white-box machine learning models. Decision tree and Lasso regression aided feature selection, while a logistic regression classifier predicted days until fracture healing within a 30-day range. Evaluations via 10-fold cross-validation and leave-one-out validation yielded stable metrics, with the model achieving a mean accuracy, precision, recall, and F1-score of approximately 76%. Feature selection revealed the importance of underfoot loading distribution patterns, particularly on the medial surface. Our research facilitates data-driven decisions, enabling early complication detection, potentially shortening recovery times, and offering accurate rehabilitation timeline predictions.

Background: Dual plating of the distal femur is indicated for the treatment of complex intra-articular fractures, supracondylar femoral fractures, low periprosthetic fractures, and nonunions. The aim of this procedure is anatomical alignment of the articular surface, restoration of the articular block, and prevention of varus collapse. Description: Following preoperative planning, the patient is positioned supine with the knee flexed at 30°. The lateral incision is made first, with a mid-lateral incision that is in line with the femoral shaft. If intra-articular work is needed this incision can be extended by curving anteriorly over the lateral femoral condyle. Next, the iliotibial band is transected in line with its fibers. The vastus lateralis fascia is incised and elevated off the septum, working distal to proximal. Care should be taken to maintain hemostasis when encountering femoral artery perforating vessels. Once there is adequate exposure, several reduction aids can be utilized, including a bump under the knee, Schanz pins, Kirschner wires, and reduction clamps. A lateral precontoured plate is placed submuscularly, and the most proximal holes are filled percutaneously. The medial incision begins distally at the adductor tubercle and is a straight incision made proximally in line with the femoral shaft. The underlying fascia is transected in line with the skin incision, and the vastus medialis is elevated. Care should be taken to avoid the descending geniculate artery, as well as its articular branch and the muscular branch to the vastus medialis. A lateral tibial plateau plate is contoured and placed. Alternatives: Nonoperative treatment of distal femoral fractures is rare, but relative indications for nonoperative treatment include frailty of the patient, lack of ambulatory status, a non-reconstructible fracture, or a stable fracture. These patients are placed in a long-leg cast followed by a hinged knee brace ¹ . There are several other surgical fixation options, including lateral plating, retrograde intramedullary nailing, distal femoral replacement, and augmentation of a retrograde nail with a plate. Rationale: Dual plating has several benefits, depending on the clinical scenario. Biomechanical studies have found that dual plating results in increased stiffness and construct strength ^2,3 . Additional construct stability can be offered through the use of locking plates, particularly in osteoporotic bone. Taken together, this increased stability and construct strength can allow for earlier weight-bearing, which is particularly important for fractures in the geriatric population. Furthermore, the increased stiffness and construct strength make this procedure a favorable treatment option for nonunion, and it has been shown to result in lower rates of postoperative nonunion compared with lateral plating alone ^4–7 . Adjunctive use of a medial plate also has been suggested to prevent varus collapse, particularly with metaphyseal comminution and poor bone quality ^2,3,8 . Finally, in the periprosthetic fracture population, dual plating also removes the concern of incompatibility with a retrograde nail. Expected Outcomes: The outcomes of dual plating are promising, given the severity of the injury. When comparing operative to nonoperative treatment outcomes, nonoperatively managed patients had worse functional outcomes and higher rates of complications related to immobility ¹ . Dual plating of supracondylar fractures and intra-articular distal femoral fractures yields nonunion rates ranging from 0% to 12.5%, lower than the 18% to 20% reported with lateral locking plates ^4–7,9–12 . This reduction in nonunions has been shown to lead to fewer revisions when compared with single-plating techniques ⁷ . In prior studies, 95% of nonunions treated with the dual-plating technique achieved union postoperatively ¹¹ . One concern when utilizing the medial approach is critical damage to medial vascularity; however, this result has not been reported in the literature, and there is a safe operating window ¹³ . Despite the benefits of dual plating, there are relatively high rates of infection following dual plating (0% to 16.7%) compared with lateral plating alone (3.6% to 8.5%) ^5,14–17 . However, many of these studies are small case series, highlighting that a surgeon’s comfort and skill with these procedures is paramount to patient outcomes. Important Tips: Meticulous placement and contouring of lateral and medial plates are required to prevent malreduction of the articular block that creates a “golf-club deformity.” ^18,19 During the medial approach, be aware of descending geniculate artery—particularly its muscular branch, which is ∼5 cm from the adductor tubercle/medial epicondyle, and its root, which enters the compartment at the adductor hiatus at ∼16 cm ¹³ .