Effect of Topical Oxygen Therapy on Chronic Wounds.

Over the past three decades, there has been a growing interest in the use of oxygen therapy to promote wound healing. Although the most commonly recognized oxygen therapy for the treatment of chronic wounds is hyperbaric oxygen therapy, topical oxygen therapy has a greater level of evidence supporting its use in chronic wound care. Still, it is imperative that these two treatment modalities be recognized not merely as competitors, but as distinct therapeutic entities. Through personal experience and a thorough literature review, we investigated the use of topical oxygen therapy in the management of chronic wounds. The benefits of using topical oxygen therapy have been demonstrated in patients with diabetic foot ulcers, ischemic ulcers, post-revascularization ulcers, and pressure ulcers. There are several topical oxygen devices currently on the market that are versatile, relatively low-risk, and generally well-tolerated by patients. While these devices have been used in the treatment of chronic wounds at different locations and of different etiologies, other uses of these devices are still being investigated. Topical oxygen therapy is yet another tool in our arsenal to be used in treating difficult to heal chronic wounds and could potentially be used more readily.

Components of the Gut Microbiome That Influence Bone Tissue-Level Strength.

Modifications to the constituents of the gut microbiome influence bone density and tissue-level strength, but the specific microbial components that influence tissue-level strength in bone are not known. Here, we selectively modify constituents of the gut microbiota using narrow-spectrum antibiotics to identify components of the microbiome associated with changes in bone mechanical and material properties. Male C57BL/6J mice (4 weeks) were divided into seven groups (n = 7-10/group) and had taxa within the gut microbiome removed through dosing with: (i) ampicillin; (ii) neomycin; (iii) vancomycin; (iv) metronidazole; (v) a cocktail of all four antibiotics together (with zero-calorie sweetener to ensure intake); (vi) zero-calorie sweetener only; or (vii) no additive (untreated) for 12 weeks. Individual antibiotics remove only some taxa from the gut, while the cocktail of all four removes almost all microbes. After accounting for differences in geometry, whole bone strength was reduced in animals with gut microbiome modified by neomycin (-28%, p = 0.002) and was increased in the group in which the gut microbiome was altered by sweetener alone (+39%, p < 0.001). Analysis of the fecal microbiota detected seven lower-ranked taxa differentially abundant in animals with impaired tissue-level strength and 14 differentially abundant taxa associated with increased tissue-level strength. Histological and serum markers of bone turnover and trabecular bone volume per tissue volume (BV/TV) did not differ among groups. These findings demonstrate that modifications to the taxonomic components of the gut microbiome have the potential to decrease or increase tissue-level strength of bone independent of bone quantity and without noticeable changes in bone turnover. © 2021 American Society for Bone and Mineral Research (ASBMR).

The Role of Intermittent Pneumatic Compression in the Treatment of Lower Extremity Chronic Wounds.

Intermittent pneumatic compression devices (IPC) are often used as noninvasive adjuncts in patients with lymphedema, and more recently with venous stasis disease, to promote flow and reduce the adverse effects of interstitial edema associated with both disorders. We will be focusing on lower extremity wounds associated with venous and/or lymphatic disease, the combination often referred to as "lymphophlebitic" disease, and the treatment effect of IPC on this disease process and its sequelae. The function and purpose of pneumatic compression is closely examined along with a variety of pneumatic compression devices that currently exist in the market. A thorough review of the literature was conducted to evaluate the utility of intermittent pneumatic compression in the treatment of lower extremity venous stasis ulcers. Additionally, the author describes personal experience with the use of pneumatic compression on 10 patients with venous stasis ulcers at a single center. There is significant data supporting the use of IPC in patients with lymphophlebitic disease. Overall, ideal patient selection may be crucial. Previous data has shown that patients with high body mass index (>33 kg/m2) and poor functional status (walking less than 200m a day) are related to poor ulcer healing. Therefore, a study that looks primarily at this group (as our small quality assurance [QA] project did) may show increased benefit in this population. It is clear that IPC is of benefit to some patient cohorts with lymphophlebitic disease. This advanced therapy would help patients who have failure of their calf muscle pump and an inability to improve it through other means. However, it is only part of an algorithm that includes: direct wound bed management, moisture control, possible primary venous disease intervention, physical therapy, weight loss, and improved nutrition.

Obesity and load-induced posttraumatic osteoarthritis in the absence of fracture or surgical trauma.

Osteoarthritis is increasingly viewed as a heterogeneous disease with multiple phenotypic subgroups. Obesity enhances joint degeneration in mouse models of posttraumatic osteoarthritis (PTOA). Most models of PTOA involve damage to surrounding tissues caused by surgery/fracture; it is unclear if obesity enhances cartilage degeneration in the absence of surgery/fracture. We used a nonsurgical animal model of load-induced PTOA to determine the effect of obesity on cartilage degeneration 2 weeks after loading. Cartilage degeneration was caused by a single bout of cyclic tibial loading at either a high or moderate load magnitude in adult male mice with severe obesity (C57Bl6/J + high-fat diet), mild obesity (toll-like receptor 5 deficient mouse [TLR5KO]), or normal adiposity (C57Bl6/J mice + normal diet and TLR5KO mice in which obesity was prevented by manipulation of the gut microbiome). Two weeks after loading, cartilage degeneration occurred in limbs loaded at a high magnitude, as determined by OARSI scores (P < .001). However, the severity of cartilage damage did not differ among groups. Osteophyte width and synovitis of loaded limbs did not differ among groups. Furthermore, obesity did not enhance cartilage damage in limbs evaluated 6 weeks after loading. Constituents of the gut microbiota differed among groups. Our findings suggest that, in the absence of surgery/fracture, obesity may not influence cartilage loss after a single mechanical insult, suggesting that either damage to surrounding tissues or repeated mechanical insult is necessary for obesity to influence cartilage degeneration. These findings further illustrate heterogeneity in PTOA phenotypes and complex interactions between mechanical/metabolic factors in cartilage loss.

The Gut Microbiome and Bone Strength.

PURPOSE OF REVIEW: Osteoporosis is commonly diagnosed through the clinical assessment of bone quantity using bone mineral density; however, the primary clinical concern is bone fragility. Bone fragility is determined by both bone quantity and bone quality. Over the past decade, the gut microbiome has emerged as a factor that can regulate diseases throughout the body. This review discusses how microbial organisms and their genetic products that inhabit the gastrointestinal tract influence bone quantity, bone quality, and bone strength. RECENT FINDINGS: Recent studies have shown that the gut microbiome regulates bone loss during estrogen depletion and glucocorticoid treatment. A series of studies has also shown that the gut microbiome influences whole bone strength by modifying bone tissue quality. The possible links between the gut microbiome and bone tissue quality are discussed focusing on the effects of microbiome-derived vitamin K. We provide a brief introduction to the gut microbiome and how modifications to the gut microbiome may lead to changes in bone. The gut microbiome is a promising target for new therapeutic approaches that address bone quality in ways not possible with current interventions.