Genome-wide comparisons of gene expression in adult versus elderly burn patients.

PURPOSE: Mortality and morbidity rates of elderly burn patients remain high despite numerous advancements in modern burn care. While prior studies have offered first insights on the biochemical changes in elderly burn patients compared to adults, the underlying cellular responses remain largely unknown. In this study, we aim to characterize the transcriptome of elderly burn patients and compare it to adult burn patients to obtain insights into the underlying molecular responses post-burn and to elucidate the effect of advanced age on the acute burn response. MATERIALS AND METHODS: Microarray data obtained from the Glue Grant Trauma-Related Database was obtained from blood specimens for ten elderly patients (n = 10), each with a set of two sex and total body surface area (TBSA) matched adult controls (n = 20), during the acute phase post-burn. Adult and elderly demographics and clinical outcomes were contrasted using using the Chi-Square test, Fisher's Exact Test, or two-sample t-tests, as appropriate (p<0.05). Enrichment and heat maps were generated to compare gene expression in elderly versus adult burn patients. RESULTS: Supervised analysis identified multiple genes that were differentially expressed between the elderly and adult groups. Pathway analysis and heatmap generation suggest that elderly patients share a distinct hypo-inflammatory response in the acute post-burn phase with downregulation of a number of immune-related pathways, including those related to antigen processing, specifically via MHC class I, ubiquitination and proteasome degradation (p<0.001, FDR < .001). Cell signalling pathways, such as NF-κB, C-type lectin receptor, and T cell receptor signalling were also significantly downregulated in elderly burn patients, as well as those relating to antiviral immunity (p<0.001, FDR < .001). Many genes which were observed to be upregulated in elderly patients with high TBSA burn injuries were associated with destruction-related cellular pathways such as complement activation and immunoglobulin production (p<0.005, FDR <0.01). CONCLUSIONS: The altered inflammatory and immune responses at the transcriptome level in elderly patients after burn are indicative of a failure in elderly burn patients to initiate an appropriate inflammatory and stress response during the acute phase post-burn.

Utility of Specialized Imaging for Diagnosis of Chronic Wrist Pain.

Background Patients with chronic wrist pain often undergo imaging (such as magnetic resonance imaging [MRI], computed tomography [CT], or ultrasound [US]) prior to specialist assessment. Questions Is specialized wrist imaging performed prior to expert consultation necessary? Are there demographic differences between patients who do or do not receive preconsultation imaging? Patients and Methods A total of 115 patients referred to a tertiary hand center for chronic wrist pain and assessed by a hand surgeon were included. At initial consultation, surgeons were blinded to referral information and previous imaging results. The specialist performed a history, physical examination and reviewed X-rays. They established a clinical diagnosis and whether any additional investigations were needed. Prior MRI, CT, and/or US results were then reviewed and the specialists' clinical diagnosis was compared with the blinded referral diagnosis. Preconsultation imaging was categorized as having no value for diagnosis/management, some value, or high value. Results A total of 82 patients had imaging prior to specialist referral (69 MRIs, 11 CTs, and 16 ultrasounds). The majority of additional imaging (73%) was classified as unnecessary, including 77% of the MRIs and 100% of the ultrasounds. Of all the investigations performed, two CT scans were labeled highly valuable clinical aids. Older patients and those with radial-sided pain were less likely to receive preconsultation imaging. Six patients required further imaging after consultation. Conclusion Clinical assessment and X-rays are typically sufficient for a hand specialist to diagnose and manage chronic wrist pain and few patients require additional imaging. Level of Evidence This is a Level III study.

Modeling the Articular Surface of the Hamate with the Fourth and Fifth Metacarpal Bases with Three-dimensional Laser Scanning.

Introduction Our purpose is to highlight the articulating surfaces between the hamate and fourth and fifth metacarpal (MC) bases of the hand using three- dimensional (3D) laser scanning. This joint surface is used for osteochondral grafting of small joints such as the proximal interphalangeal joint using the hamate articular surface. It is an important joint for hand function and can develop osteoarthritis.  Methods NextEngine (NextEngine, Santa Monica, CA) 3D laser scanner (accurate to ±100 µm) was used to capture the articular surfaces of the hamate with the fourth and fifth MC bases of 10 embalmed cadaver right hands. Articular surfaces were defined and modeled using Amira (Visage Imaging, Andover, MA) and MatLab7 (MathWorks, Natick, MA). Articular surfaces were evaluated in terms of size, shape, the radius of curvature (ROC) by three points and sphere-fit (SF) and inter-facet angles. Results In the fourth carpometacarpal (CMC) joint, the hamate articular surface with the 4th MC was single, concave, and well approximated by SF ROC (mean: 11.18 mm). The fourth MC base was convex; SF ROC mean was 9.94 mm. Six of the 10 articulations flattened from volar to dorsal. In the fifth CMC joint, we noted a bicondylar construct. The two hamate surfaces were concave while MC bases were convex. The joint surface was best approximated with two overlapping spheres. Ulnar sphere averaged 30.21% of the surface of the hamate and 29% of the MC base. Ulnar hamate SF ROC mean was 11.63 mm, and ulnar fifth MC SF ROC mean was 8.07 mm. Radial SF hamate mean was 7.92 mm, and the radial fifth MC SF mean was 7.47 mm. The mean of the angle of divergence between the condylar spheres represented on the hamate surface was 21.4°, while that of the fifth MC base angle of divergence was 10.99°. The mean of the angle formed between the fourth and fifth CMC joints at the hamate was 31.69°. A single articular facet between the fourth and fifth MC bases was concave on fourth and convex on the fifth MC base. Conclusions and clinical relevance Laser scanning of cadaver fourth and fifth CMC joints clarified the normal anatomy of the osteochondral joint surface. The topography of the joints was well-approximated by SF with curved surfaces in both the anteroposterior and radial-ulnar planes with the fifth CMC having two unique surfaces for articulation. We noted the distinct radial and ulnar articulating surfaces of the fifth CMC joint, which would permit flexion and limited supination.