Systematic study on nail plate assessment: differences in nail plate shape, thickness, power Doppler signal and scanning approach

High-resolution ultrasound imaging of elementary lesions in dactylitis

OBJECTIVE

The aim of the present study was to illustrate the (potential) diagnostic role of high resolution US images in assessing the elementary lesions of dactylitis.

METHODS

Using high-frequency US machines/probes, we matched the micro-anatomical cadaveric architecture of the digit with multiple sonographic findings of dactylitis. High-sensitive color/power Doppler assessments have also been performed to evaluate the digital microvasculature.

DISCUSSION

Modern US equipment/features guarantee prompt and in-depth B-mode and color/power Doppler imaging of tiny anatomical structures of the digit which are usually not properly visible with standard US machines. More specifically, hypervascularization of the digital subcutaneous tissue, fibrous pulleys of flexor tendons, dorsal synovial pads as well as pathological changes of the distal entheseal anchorage network can be accurately detected.

CONCLUSION

In clinical practice, high-end US equipment can be used to accurately assess the digits in patients with dactylitis. This way, simple and convenient sonographic diagnosis of different elementary lesions can be timely established.

Ultrasonographic Evaluation of Nail Involvement in Patients With Axial Spondyloarthritis

OBJECTIVES

This study aimed to evaluate the nail units of patients with axial spondyloarthritis (ax-SpA) using ultrasound and to identify any subclinical changes. We also aimed to examine the relationship between clinical enthesitis scores and nail involvement in patients with ax-SpA.

METHODS

The study included 40 patients with ax-Spa, 40 patients with psoriatic arthritis (PsA), and 40 healthy controls. The thickness of the nail plates, morphological changes, the thickness of the proximal nail units, the thickness of the nail beds, and power Doppler signal intensities were evaluated and compared. Maastricht Ankylosing Spondylitis Enthesitis Score and Spondyloarthritis Research Consortium of Canada Enthesitis Index were also evaluated in patients with ax-SpA.

RESULTS

There was no significant difference between the thickness of the nail plates of the three groups (P > .05). The first nail bed thickness of ax-SpA cases was significantly higher than the control group (P = .046), and the fourth and fifth nail proximal unit thicknesses of the control group were significantly lower than the ax-SpA and PsA groups (P = .023, P = .017). We also found that the Wortsman scores of the cases with PsA were significantly higher than the ax-SpA and control groups (P = .0001).

CONCLUSION

The thickness of the proximal nail unit adjacent to the insertion of the digital extensor tendon, which is considered as the enthesis area, is similar to the patients with PsA in patients with ax-SpA, especially in the fourth and fifth fingers compared to the control group. On the other hand, almost no structural changes in nail plates were observed in patients with ax-SpA group.

Ultrasound clinical references of the healthy toenail unit

The toenail unit, commonly called the nail, is one of the most frequently examined and treated structures in clinical podiatry. Ultrasound is a standard clinical technique because it is a noninvasive, painless, and rapid diagnostic tool. The main objective of this study was to obtain morphometric data of the healthy toenail unit by ultrasound for clinical application. The nails of 76 participants (152 hallux nails; 38 men, 38 women, average age 26.83 ± 12.20) were examined using a VINNO E35 ultrasound system and an X6-16L linear probe with a frequency of 18 MHz. Five ultrasound measures of the healthy toenail unit were obtained, of which only the distance from the center of the distal phalange to the nail plate varied with age, sex, weight, and foot (p-values ≤ 0.050). The other four parameters were less influenced by the variables analyzed, except sex, which influenced nearly all (p-values ≤ 0.050). In one of these variables, indications of significance were observed (p-values = 0.060), with greater distances in the men than in the women, except for nail plate curvature, which showed a higher value. The other variables studied did not influence the parameters analyzed. High-frequency ultrasound can be used to examine the healthy toenail unit and define anthropometric reference measurements that can be used for more accurate and comparative diagnosis.

Nail Ultrasound in Psoriasis and Psoriatic Arthritis-A Narrative Review

Ultrasonography has advantages for assessing psoriatic arthritis (PsA) due to its ability to evaluate several targets, including joints, entheses, and tendons, but also skin and nails. Although ultrasound is widely used in PsA, nail ultrasound, despite its potential as a non-invasive method for the early detection of inflammation in the nail apparatus, has low applicability in medical practice, as probes with a higher frequency are needed compared with the frequency of probes usually used. In the present article, we have narratively evaluated the studies published in the last 5 years (19 February 2018-18 February 2023) on nail ultrasound value in the diagnosis and monitoring of PsA. The studies published during this period share common measurement parameters, such as the OMERACT definition of enthesis published in 2018. We included original articles published in PubMed and Web of Science using the following search terms in all possible combinations: psoriatic arthritis, psoriasis, ultrasound, and nail. Articles were declared relevant if they presented data on nail morphology, power Doppler evaluation and nearby structure evaluation, while focusing on digitorum extensor enthesitis. In most of the studies, common morphological parameters were generally increased in patients with psoriasis or PsA and were demonstrated to change with medication. The thickness of the extensor tendon was greater in patients with PsA and psoriasis versus controls and it was correlated with nail clinical changes, especially the presence of onycholysis. The presence of PD showed large variability in healthy individuals. The link between enthesitis and nail involvement is still a subject of controversy, taking into account the latest histological findings. The use of ultrasound in the evaluation of nail and DIP enthesitis remains a challenge and an area of research in the coming years.