Thermal changes during healing of distal radius fractures-Preliminary findings

The bone nonunion microenvironment: A place where osteogenesis struggles with osteoclastic capacity

Bone nonunion is a common and serious orthopedic disorder, the occurrence of which is associated with a disruption of the dynamic balance between osteoblasts and osteoclasts during bone repair. However, the critical molecular mechanisms affecting this homeostasis are not well understood, and it is essential to investigate the specific components of this mechanism and to restore the balance between osteoblasts and osteoclasts to promote bone repair. First, we defined this complex local environmental factor as the "bone nonunion microenvironment" and identified the importance of the "struggle" between osteoblasts and osteoclasts, which is the most essential element in determining the process of repair. On this basis, we also explored the cellular factors that influence osteogenesis and the molecular signals that influence the balance between osteoclast and osteoblasts, which are important for restoring homeostasis. Further, we explored other factors involved in osteogenesis, such as the biomechanical environment, the nutritional environment, the acid-base environment, and the temperature environment, which are important players in osteogenesis. In conclusion, we found that the balance between osteoblasts and osteoclasts is the essence of bone healing, which is based on the "bone nonunion microenvironment". Therefore, investigating the role of the bone nonunion microenvironment in the system of osteoblast-osteoclast "struggle" provides an important basis for further understanding of the mechanism of nonunion and the development of new therapeutic approaches.

An Innovative Non-Invasive Method for Early Detection and Monitoring of Acute Compartment Syndrome

Background: Acute compartment syndrome is a major surgical emergency with complex pathophysiology and a highly unpredictable pattern of evolution. We hypothesized that the onset of acute compartment syndrome of the leg or forearm is associated with variations in the surface temperature of the distal segment (foot or hand) with a distinct pattern, which acts as an early warning sign. Materials and Methods: We developed a monitoring device that consists of two thermic sensors attached to a modular limb splint, which continuously measure the temperature difference between the proximal and distal regions of the limb (i.e., arm-hand, thigh-foot). Firstly, we investigated both the arm-hand and thigh-foot temperature gradients of hospitalized patients' healthy limbs (43 patients, 56 upper limbs, 64 lower limbs) in order to establish a baseline. Secondly, we examined the correlation between the thermic gradients and intracompartmental pressure values in compartment syndrome limbs (20 patients, 6 upper limbs, 14 lower limbs). Results: For the control group, the mean values for the normal limb thermic gradients were -0.17 °C for the upper limbs. and 0.03 °C for the lower limbs. In the impending compartment syndrome group (defined by intracompartmental pressure values), the mean index was -0.38 °C. In the fully developed compartment syndrome group, the mean value was 4.11 °C. Discussions: Analysis was performed using the ANOVA one-way statistical method. This showed significant differences between the compartment syndrome group and the impending and control groups. A decreasing trend in the thermic gradient in patients with impending compartment syndrome compared with the control group was noted. Conclusions: The thermic gradient of limbs presenting signs of impending compartment syndrome decreases as a result of the increased temperature of the distal segment. This pattern can be used as an early diagnostic method for acute compartment syndrome. This technique is non-invasive and bears no risk to the patient, allowing facile continuous monitoring during immobilization.

Deciphering the relationship between temperature and immunity

Fever is a hallmark symptom of disease across the animal kingdom. Yet, despite the evidence linking temperature fluctuation and immune response, much remains to be discovered about the molecular mechanisms governing these interactions. In patients with rheumatoid arthritis, for instance, it is clinically accepted that joint temperature can predict disease progression. But it was only recently demonstrated that the mitochondria of stimulated T cells can rise to an extreme 50°C, potentially indicating a cellular source of these localized 'fevers'. A challenge to dissecting these mechanisms is a bidirectional interplay between temperature and immunity. Heat shock response is found in virtually all organisms, activating protective pathways when cells are exposed to elevated temperatures. However, the temperature threshold that activates these pathways can vary within the same organism, with human immune cells, in particular, demonstrating differential sensitivity to heat. Such inter-cellular variation may be clinically relevant given the small but significant temperature differences seen between tissues, ages, and sexes. Greater understanding of how such small temperature perturbations mediate immune responses may provide new explanations for persistent questions in disease such as sex disparity in disease prevalence. Notably, the prevalence and severity of many maladies are rising with climate change, suggesting temperature fluctuations can interact with disease on multiple levels. As global temperatures are rising, and our body temperatures are falling, questions regarding temperature-immune interactions are increasingly critical. Here, we review this aspect of environmental interplay to better understand temperature's role in immune variation and subsequent risk of disease.

Infrared Thermography-A Novel Tool for Monitoring Fracture Healing: A Critically Appraised Topic With Evidence-Based Recommendations for Clinical Practice

CLINICAL SCENARIO

Stress fractures are one of the most common injuries in athletes. Unfortunately, they are hard to diagnose, require multiple radiology exams and follow-up which leads to more exposure to radiation and an increase in cost. Stress fractures that are mismanaged can lead to serious complications and poorer outcomes for the athlete. During the rehabilitation process, it would be beneficial to be able to monitor the healing of fractures to know when it is safe to gradually allow a patient to a return to sport because the return to activity is not usually objective and based on pain level.

CLINICAL QUESTION

Can infrared thermography (IRT) be a useful tool to measure the pathophysiological state of the fracture healing? The aim of this critically appraised topic is to analyze the current evidence of IRT for measuring the temperature change in fractures to provide recommendations for medical practitioners.

SUMMARY OF KEY FINDINGS

For this critically appraised topic, we examined 3 articles that compared medical imaging and IRT over multiple time points during the follow-up. The 3 articles concluded that a 1 °C asymmetry in temperature followed by a return to normal (less than 0.3 °C) temperature during the healing process of fractures can be monitored using IRT.

CLINICAL BOTTOM LINE

Once the patient has been diagnosed with a fracture, IRT can safely be used to monitor the evolution of a fracture. When the thermogram progresses from a hot thermogram to a cold thermogram, the healing is considered good enough to return to sport.

STRENGTH OF RECOMMENDATION

Grade 2 evidence exists to support IRT being used by clinicians to monitor fracture healing. Due to the limited research and novelty of the technology, the current recommendations are for following the treatment of the fracture once the initial diagnosis is made.

Detecting bone lesions in the emergency room with medical infrared thermography

Introduction

Low- to high-energy impact trauma may cause from small fissures up to extended bone losses, which can be classified as closed or opened injuries (when they are visible at a naked eye).

Objective

The aim of this study was to investigate the feasibility of clinical diagnosis of bone trauma through medical infrared thermography, in a hospital emergency room.

Methods

Forty-five patients with suspected diagnosis of bone fracture were evaluated by means of medical infrared images, and the data correlated with the gold standard radiographic images, in the anteroposterior, lateral, and oblique views, at the orthopedic emergency department. The control group consisted of thermal images of the contralateral reference limb of the volunteers themselves. Data were acquired with a medical grade infrared camera in the regions of interest (ROIs) of leg, hand, forearm, clavicle, foot, and ankle.

Results

In all patients evaluated with a diagnosis of bone fracture, the mean temperature of the affected limb showed a positive difference greater than 0.9 °C (towards the contralateral), indicating the exact location of the bone trauma according, while the areas diagnosed with reduced blood supply, showed a mean temperature with a negative variation.

Conclusion

Clinical evaluation using infrared imaging indicates a high applicability potential as a tool to support quick diagnosis of bone fractures in patients with acute orthopedic trauma in an emergency medical setting. The thermal results showed important physiological data related to vascularization of the bone fracture and areas adjacent to the trauma well correlated to radiographic examinations.

Evaluation of Tibia Bone Healing by Infrared Thermography: A Case Study

Background

Thermal imaging has been used as a clinical follow-up technique in several medical specialties.

Purpose

The aim of this study was to investigate the feasibility of using medical thermography in the diagnosis and follow-up assessment of a severe orthopedic trauma that requires the use of an external circular fixator.

Patients and Methods

Twenty clinical follow-ups of thermal imaging correlated with X-ray images were performed in a male volunteer, diagnosed with bone nonunion, during 11 months of treatment, in the hospital trauma and reconstruction department. Data were acquired in the regions of interest of the proximal tibia, diaphysis and distal, with a Flir T530 medical grade infrared camera from Flir Systems^®, and the data processed by the Matlab^® 2019 custom made software.

Results

Statistical analysis was performed by Wilcoxon signed-rank test. The results showed a median temperature of 22.2°C, and thus some periods of interruption in the healing process between the third and twentieth clinical follow-up, and a significant increase of the temperature to 34.6°C synchronous with a diagnosis of bone infection by the eleventh clinical follow-up. The thermal images acquired during the 20 clinical follow-ups allow a correlation with the data from the X-ray exams and also with the contralateral limb of the evaluated patient, showing thermal alterations greater than 0.3°C, which are significant of physiological abnormality.

Conclusion

The thermography exam can be a useful tool for applying on the follow-up of patients after trauma or bone fracture. The results showed important physiological data related to the vascularization necessary for bone repairing, being therefore a good indicator of the healing process. In addition, as infrared thermography does not use ionizing radiation, it can be used countlessly, in complement to the traditional X-ray exams that focus on anatomical data analysis.

Thermographic camera in traumatology, diabetic foot and reconstructive procedures

Traumatic lacerations, burns and ulcerations are a common cause of admission in the plastic surgery wards. Clinical evaluation alone sometimes provides insufficient or even inaccurate information. Thermographic camera is a new tool that could provide additional information regarding skin vascularization, presence of inflammation or involvement of deep tissue. A prospective study was realized for assessing pre and postoperative status of patients with lacerations, trauma, burn and diabetic foot. Preoperative evaluation helped in assessing bone involvement, inflammation and infection in order to decide the necessity of surgery. Postoperative evaluation was useful in preventing and lowering the rate of complications. Thermographic camera could be a new helpful and non-invasive tool especially in emergency hospitals in order to assess rapidly and objectively wound status and to start if necessary, a surgical treatment.

Infrared thermal imaging as a screening tool for paediatric wrist fractures

Wrist injuries are common in paediatric trauma; however, only half of children evaluated with an x-ray for possible fractures will have one. Thermal imaging offers a possible non-ionising method of screening for fractures and thus reducing negative x-ray rates. One hundred five children attending the Emergency Department for wrist injuries were recruited. Two 30-s thermal videos were recorded from injured and uninjured wrists-in flat and 45° elevated positions. A region of interest (ROI) was defined on each wrist. Cases in which the ROI was covered or had ice applied were excluded, leaving 40 patients for analysis. Comparisons of ROI included (i) injured and uninjured wrists-flat and elevated positions; (ii) as in (i) with a reference region on the proximal forearm subtracted; (iii) injured wrist ROI-flat and elevated positions. Fractures and sprains increased the mean skin surface temperature by 1.519% (p = 0.008) and 0.971% (p = 0.055) respectively compared with the uninjured wrist. The mean temperature difference between flat and elevated positions for fractures was 0.268% and - 0.1291% for sprains. This difference was statistically significant for fracture (p = 0.004) but not sprain (p = 0.500). The temperature differences recorded by thermal imaging between fractured and sprained wrists may assist in differentiation of these injuries. Graphical abstract Operational stages involved from thermal video recording to generation of results.

Value of Infrared Thermography Camera Attached to a Smartphone for Evaluation and Follow-up of Patients with Graves' Ophthalmopathy

PURPOSE

Graves' ophthalmopathy (GO) is the most common extra-thyroid manifestation of Graves' disease (GD). The Clinical Activity Score (CAS) has been widely used to evaluate GO inflammation severity and response to treatment; however, it is quite subjective. Infrared thermography (IRT) is a portable and low-cost device to evaluate local temperature and assess inflammation. The aim was to evaluate ocular temperature by IRT as an instrument for measuring inflammatory activity in GO and its correlation with CAS.

METHODS

This is a cross-sectional study involving 136 consecutive GD patients (12 with CAS ≥ 3/7, 62 with CAS < 3 and 62 without apparent GO) with 62 healthy controls. Patients with active ophthalmopathy were prospectively evaluated. Exophthalmometry, CAS, and thermal images from caruncles and upper eyelids were acquired from all subjects.

RESULTS

All eye areas of thermal evaluation had higher temperatures in GD patients with active ophthalmopathy (caruncles, p<0.0001; upper eyelids, p<0.0001), and it was positively correlated with CAS (r=0.60 and p<0.0001 at caruncles; r=0.58 and p<0.0001 at upper eyelids). No difference in temperature was found between other groups. Patients with active ophthalmopathy were prospectively evaluated after 6 or 12 months of the treatment and a significant difference was found in ophthalmometry (p=0.0188), CAS (p=0.0205), temperature of caruncles (p=0.0120), and upper eyelids (p=0.0066).

CONCLUSIONS

IRT was an objective and simple tool for evaluation and follow-up of inflammation in GO, allowed evidencing patients with significant inflammatory activity, and had a good correlation with the CAS score.