Publications by Year: 2024

In hand trauma, the uninjured forearm has been touted as the ideal site for ectopic banking in digit/hand amputations. Here, we describe the temporary ectopic implantation and subsequent replantation of a partially amputated hand and highlight the "Three R's" - Recovery, Rehabilitation, and Revision over the first year of recovery.

Background and Objectives: Despite the promise of phage therapy (PT), its efficacy in prosthetic joint infection (PJI) management is unknown. Much of the current literature is largely limited to case reports and series. Materials and Methods: In order to help inform power calculations for future clinical trials and comparative analyses, we performed a systematic review and proportional meta-analysis of early PT outcomes to provide a preliminary assessment of early phage therapy treatment outcomes for cases of PJI. Results: In a search of available literature across MEDLINE (Ovid, Wolters Kluwer, Alphen aan den Rijn, The Netherlands), Embase (Elsevier, Amsterdam, The Netherlands), the Web of Science Core Collection (Clarivate, London, UK), and Cochrane Central (Wiley, Hoboken, NJ, USA) up to 23 September 2023, we identified 37 patients with PJIs receiving adjunctive PT. Patients most frequently reported Staphylococcal species infection (95%) and intraarticular phage delivery (73%). Phage cocktail (65%) and antibiotic co-administration (97%) were common. A random-effects proportional meta-analysis suggested infection remission in 78% of patients (95% CI: 39%, 95%) (I2 = 55%, p = 0.08) and 83% with a minimum 12-month follow-up (95% CI: 53%, 95%) (I2 = 26%, p = 0.26). Conclusions: Our study provides a preliminary estimate of PT's efficacy in PJIs and informs future comparative studies.

Hip fractures exceed 250,000 cases annually in the United States, with the worldwide incidence projected to increase by 240-310% by 2050. Hip fractures are predominantly diagnosed by radiologist review of radiographs. In this study, we developed a deep learning model by extending the VarifocalNet Feature Pyramid Network (FPN) for detection and localization of proximal femur fractures from plain radiography with clinically relevant metrics. We used a dataset of 823 hip radiographs of 150 subjects with proximal femur fractures and 362 controls to develop and evaluate the deep learning model. Our model attained 0.94 specificity and 0.95 sensitivity in fracture detection over the diverse imaging dataset. We compared the performance of our model against five benchmark FPN models, demonstrating 6-14% sensitivity and 1-9% accuracy improvement. In addition, we demonstrated that our model outperforms a state-of-the-art transformer model based on DINO network by 17% sensitivity and 5% accuracy, while taking half the time on average to process a radiograph. The developed model can aid radiologists and support on-premise integration with hospital cloud services to enable automatic, opportunistic screening for hip fractures.

Spine disorders can cause severe functional limitations, including back pain, decreased pulmonary function, and increased mortality risk. Plain radiography is the first-line imaging modality to diagnose suspected spine disorders. Nevertheless, radiographical appearance is not always sufficient due to highly variable patient and imaging parameters, which can lead to misdiagnosis or delayed diagnosis. Employing an accurate automated detection model can alleviate the workload of clinical experts, thereby reducing human errors, facilitating earlier detection, and improving diagnostic accuracy. To this end, deep learning-based computer-aided diagnosis (CAD) tools have significantly outperformed the accuracy of traditional CAD software. Motivated by these observations, we proposed a deep learning-based approach for end-to-end detection and localization of spine disorders from plain radiographs. In doing so, we took the first steps in employing state-of-the-art transformer networks to differentiate images of multiple spine disorders from healthy counterparts and localize the identified disorders, focusing on vertebral compression fractures (VCF) and spondylolisthesis due to their high prevalence and potential severity. The VCF dataset comprised 337 images, with VCFs collected from 138 subjects and 624 normal images collected from 337 subjects. The spondylolisthesis dataset comprised 413 images, with spondylolisthesis collected from 336 subjects and 782 normal images collected from 413 subjects. Transformer-based models exhibited 0.97 Area Under the Receiver Operating Characteristic Curve (AUC) in VCF detection and 0.95 AUC in spondylolisthesis detection. Further, transformers demonstrated significant performance improvements against existing end-to-end approaches by 4-14% AUC (p-values < 10-13) for VCF detection and by 14-20% AUC (p-values < 10-9) for spondylolisthesis detection.

The supraspinatus tendon plays a crucial role in shoulder abduction, making it one of the common structures affected by injury. Clinically, crescent-shaped tears are the most commonly seen tear shape. By developing six specimen-specific, three-dimensional, supraspinatus-infraspinatus finite element model with heterogeneous material properties, this study aimed to examine the changes in tissue deformation (maximum principal strain) of the supraspinatus tendon due to specimen-specific material properties and rotator cuff tear size. FE models with small- and medium-sized full-thickness crescent-shaped tears were subjected to loads seen during activities of daily living and physiotherapy. Six fresh-frozen cadaveric shoulders were dissected to mechanically test the supraspinatus tendon and develop and validate FE models that can be used to assess changes in strain due to small (< 1 cm, equivalent to 20-30% of the tendon width) and medium-sized (1-3 cm, equivalent to 40-50% of the tendon width) tears that are located in the middle and posterior regions of the supraspinatus tendon. FE predictions of maximum principal strain at the tear tips were examined to determine whether failure strain was reached during activities of daily living (drinking and brushing teeth) and physiotherapy exercises (prone abduction and external rotation at 90° abduction). No significant differences were observed between the middle and posterior tear failure loads for small- and medium-sized tears. For prone abduction, there was a potential risk for tear progression (exceeded failure strain) for medium-sized tears in the supraspinatus tendon's middle and posterior regions. For external rotation at 90° abduction, one model with a middle tear and two with posterior tears experienced failure. For all daily activity loads, the strain never exceeded the failure strain. Our three-dimensional supraspinatus-infraspinatus FE model shows that small tears appear unlikely to progress based on the regional strain response; however, medium-sized tears are at higher risk during more strenuous physiotherapy exercises. Furthermore, differences in patient-specific tendon material properties are important in determining whether the tear will progress. Therefore, patient-specific management plans based on tear size may be beneficial to improve clinical outcomes.

BACKGROUND: Pediatric fractures are common in Malawi, and surgical care, when needed, remains inaccessible to many. Understanding which children in Malawi receive surgery or nonsurgical treatment would help set priorities for trauma system development.

METHODS: We used multivariate logistic regression to evaluate associations between surgical treatment and age, sex, school enrollment, injury mechanism, fracture type, open fracture, referral status, hospital of presentation, delayed presentation (≥2 days), healthcare provider, and inpatient vs outpatient treatment.

RESULTS: From 2016 to 2020, 10,400 pediatric fractures were recorded in the Malawi Fracture Registry. Fractures were most commonly of the wrist (26%), forearm (17%), and elbow (14%). Surgical fixation was performed on 4.0% of patients, and 24 (13.0%) open fractures were treated nonsurgically, without débridement or fixation. Fractures of the proximal and diaphyseal humerus (odds ratio [OR], 3.72; 95% confidence interval [CI], 2.36 to 5.87), knee (OR, 3.16; 95% CI, 1.68 to 5.95), and ankle (OR, 2.63; 95% CI, 1.49 to 4.63) had highest odds of surgery. Odds of surgical treatment were lower for children referred from another facility (OR, 0.62; 95% CI, 0.49 to 0.77).

CONCLUSIONS: Most Malawian children with fractures are treated nonsurgically, including many who may benefit from surgery. There is a need to increase surgical capacity, optimize referral patterns, and standardize fracture management in Malawi.

Background: Lower extremity reconstructive surgery is an evolving field wherein patients rely on accessible online materials to engage with their perioperative care. This study furthers existing research in this area by evaluating the readability, understandability, actionability, and cultural sensitivity of online health materials for lower extremity reconstruction. Methods: We identified the 10 first-appearing, educational sites found by searching the phrases "leg saving surgery", "limb salvage surgery," and "leg reconstruction surgery". Readability analysis was conducted with validated tools, including Simple Measure of Gobbledygook (SMOG). Understandability and actionability were assessed with Patient Education and Materials Assessment Tool (PEMAT), while cultural sensitivity was measured with Cultural Sensitivity Assessment Tool (CSAT). A Cohen's κ value was calculated (PEMAT and CSAT analyses) for inter-rater agreement. Results: The mean SMOG reading level for websites was 13.12 (college-freshman reading level). The mean PEMAT understandability score was 61.8% and actionability score was 26.0% (κ = 0.8022), both below the 70% acceptability threshold. The mean CSAT score was 2.6 (κ = 0.73), exceeding the 2.5 threshold for cultural appropriateness. Conclusion: Online PEM for lower extremity reconstruction continue to fall below standards of readability, understandability, and actionability; however, they meet standards of cultural appropriateness. As patients rely on these materials, creators can use validated tools and positive examples from existing PEM for greater patient accessibility.

BACKGROUND: Stemless shoulder arthroplasty offers several advantages, such as preserving bone stock and reducing periprosthetic fracture risk. However, implant motion can deter osteointegration and increase bone resorption, where micromotion less than 0.150 mm is crucial for bony ingrowth and vital to the success of the implant. The interaction between the implant and the metaphyseal bone and its effects on stability remains unclear. Therefore, this cadaveric study aims to assess the immediate stability of two stemless prostheses in low bone density specimens.

METHODS: Twenty cadaveric shoulders were used to compare the stability of two stemless shoulder implants by Zimmer-Biomet (model A) and Exactech (model B), subjected to loads of 220 N, 520 N, and 820 N to assess strain and micromotion.

FINDINGS: Micromotion at 220 N load was 0.061 ± 0.080 mm and 0.053 ± 0.050 mm, and at 520 N load, 0.279 ± 0.37 mm and 0.311 ± 0.35 mm for models A and B, respectively. The estimated mean force required to achieve a 150 μm micromotion was 356 ± 116 N and 315 ± 61 N for models A and B, respectively. Motion analysis revealed distinct movement patterns for each implant, with model B demonstrating better force distribution on the bone despite no significance.

INTERPRETATION: Forces over 520 N (high postoperative rehabilitation force) could hinder bone integration with prostheses due to excessive micromotion. Conversely, forces around 220 N (preconditioning loading force) are considered safe for prosthesis stability even with low bone density. These insights may caution against using stemless implants when bone density is low, and help guide clinical decisions on the duration of rehabilitation and sling use after stemless arthroplasty.

INTRODUCTION: Over 6.8 million fractures occur annually in the US, with 10% experiencing delayed- or non-union. Anabolic therapeutics like PTH analogs stimulate fracture repair, and small molecule salt inducible kinase (SIK) inhibitors mimic PTH action. This study tests whether the SIK inhibitor YKL-05-099 accelerates fracture callus osteogenesis.

METHODS: 126 female mice underwent femoral shaft pinning and midshaft fracture, receiving daily injections of PBS, YKL-05-099, or PTH. Callus tissues were analyzed via RT-qPCR, histology, single-cell RNA-seq, and μCT imaging. Biomechanical testing evaluated tissue rigidity. A hydrogel-based delivery system for PTH and siRNAs targeting SIK2/SIK3 was developed and tested.

RESULTS: YKL-05-099 and PTH-treated mice showed higher mineralized callus volume fraction and improved structural rigidity. RNA-seq indicated YKL-05-099 increased osteoblast subsets and reduced chondrocyte precursors. Hydrogel-released siRNAs maintained target knockdown, accelerating callus mineralization.

DISCUSSION: YKL-05-099 enhances fracture repair, supporting selective SIK inhibitors' development for clinical use. Hydrogel-based siRNA delivery offers targeted localized treatment at fracture sites.