Finger Joint Cartilage Evaluated by Semiquantitative Ultrasound Score in Patients With Rheumatoid Arthritis

Anatomically-Inspired Robotic Finger with SMA Tendon Actuation for Enhanced Biomimetic Functionality

This research introduces an advanced robotic finger designed for future generalist robots, closely mimicking the natural structure of the human finger. The incorporation of rarely discussed anatomical structures, including tendon sheath, ligaments, and palmar plates, combined with the usage of anatomically proven 3D models of the finger, give rise to the highly accurate replication of human-like soft mechanical fingers. Benefiting from the accurate anatomy of muscle insertions with the utilization of Shape Memory Alloy (SMA) wires' muscle-like actuation properties, the bonding in-between the flexor tendons and extensor tendons allows for the realization of the central and lateral band of the finger anatomy. Evaluated using the computer vision method, the proposed robotic finger demonstrates a range of motion (ROM) equivalent to 113%, 87% and 88% of the human dynamic ROM for the DIP, PIP and MCP joints, respectively. The proposed finger possesses a soft nature when relaxed and becomes firm when activated, pioneering a new approach in biomimetic robot design and offering a unique contribution to the future of generalist humanoid robots.

Cartilage evaluation by ultrasonography in patients with rheumatoid arthritis: a scoping review

BACKGROUND

This study aimed to provide an overview of ultrasonographic cartilage evaluation in patients with rheumatoid arthritis (RA) and identify research gaps in the utilization of cartilage evaluation.

METHODS

The study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. A systematic literature search of the PubMed, Embase, and Cochrane Library databases was conducted for articles published up to July 2022 using the search term variations of "cartilage," "ultrasonography," and "rheumatoid arthritis." Studies that included patients with RA who underwent cartilage evaluation by ultrasonography were selected. Articles published in languages other than English and about juvenile idiopathic arthritis were excluded.

RESULTS

Twenty-nine articles were identified. Most were cross-sectional studies (86%), mainly involving the metacarpophalangeal (55%) and knee (34%) joints. Assessments were performed using quantitative, binary, and semi-quantitative methods in 15, 10, and 15 studies, respectively. Reliability assessments were conducted in 10 studies, which showed feasible reliability but were limited to the finger joints. The validity assessment was validated in one study each that compared cartilage thickness measurements with cadaveric specimens and histological and semi-quantitative methods with surgical specimens, respectively. Comparisons with conventional radiography were also performed in six studies, which showed significant correlations. However, there was heterogeneity in the examination and assessment methods, and no adequate longitudinal evaluation was conducted.

CONCLUSION

This review highlights the need for further research and validation of ultrasonographic cartilage assessment in patients with RA.

Researchers in rheumatology should avoid categorization of continuous predictor variables

BACKGROUND

Rheumatology researchers often categorize continuous predictor variables. We aimed to show how this practice may alter results from observational studies in rheumatology.

METHODS

We conducted and compared the results of two analyses of the association between our predictor variable (percentage change in body mass index [BMI] from baseline to four years) and two outcome variable domains of structure and pain in knee and hip osteoarthritis. These two outcome variable domains covered 26 different outcomes for knee and hip combined. In the first analysis (categorical analysis), percentage change in BMI was categorized as ≥ 5% decrease in BMI, < 5% change in BMI, and ≥ 5% increase in BMI, while in the second analysis (continuous analysis), it was left as a continuous variable. In both analyses (categorical and continuous), we used generalized estimating equations with a logistic link function to investigate the association between the percentage change in BMI and the outcomes.

RESULTS

For eight of the 26 investigated outcomes (31%), the results from the categorical analyses were different from the results from the continuous analyses. These differences were of three types: 1) for six of these eight outcomes, while the continuous analyses revealed associations in both directions (i.e., a decrease in BMI had one effect, while an increase in BMI had the opposite effect), the categorical analyses showed associations only in one direction of BMI change, not both; 2) for another one of these eight outcomes, the categorical analyses suggested an association with change in BMI, while this association was not shown in the continuous analyses (this is potentially a false positive association); 3) for the last of the eight outcomes, the continuous analyses suggested an association of change in BMI, while this association was not shown in the categorical analyses (this is potentially a false negative association).

CONCLUSIONS

Categorization of continuous predictor variables alters the results of analyses and could lead to different conclusions; therefore, researchers in rheumatology should avoid it.

The Reliability of Ultrasound in the Assessment of Hyaline Cartilage in Rheumatoid Arthritis and Healthy Metacarpal Heads

PURPOSE

 i) To assess the inter- and intra-observer reliability of ultrasound (US) in the evaluation of the hyaline cartilage (HC) of the metacarpal head (MH) in patients with rheumatoid arthritis (RA) and in healthy subjects (HS) both qualitatively and quantitatively. ii) To calculate the smallest detectable difference (SDD) of the MH cartilage thickness measurement. iii) To correlate the qualitative scoring system and the quantitative assessment.

MATERIALS AND METHODS

 US examination was performed on 280 MHs of 20 patients with RA and 15 HS using a very high frequency probe (up to 22 MHz). HC status was evaluated both qualitatively (using a five-grade scoring system) and quantitatively (using the average value of the longitudinal and transverse measures). The HC of MHs from II to V metacarpophalangeal joint of both hands were scanned independently on the same day by two rheumatologists to assess inter-observer reliability. All subjects were re-examined using the same scanning protocol and the same US setting by one sonographer after a week to assess intra-observer reliability.

RESULTS

 The inter-observer agreement and intra-observer agreement were moderate to substantial (k = 0.66 and k = 0.73) for the qualitative scoring system and high (ICC = 0.93 and ICC = 0.94) for the quantitative assessment. The SDD of the MH cartilage thickness measurement was 0.09 mm. A significant correlation between the two scoring systems was found (r = -0.35; p < 0.001).

CONCLUSION

 The present study describes the main methodological issues of HC assessment. Using a standardized protocol, both the qualitative and the quantitative scoring systems can be reliable.

Sonographic assessment of cartilage damage at metacarpal head in rheumatoid arthritis: qualitative versus quantitative methods

OBJECTIVE

To test the validity of the Outcome Measure in Rheumatology (OMERACT) semiquantitative score by comparing with a quantitative method in the sonographic (US) assessment of hyaline cartilage at the metacarpal head (MH) in patients with rheumatoid arthritis (RA) and healthy subjects (HS).

METHODS

The hyaline cartilage from second to fifth MHs of both hands was scanned. Hyaline cartilage was scored semiquantitatively and quantitatively (by measuring cartilage thickness and comparing with reference values). In RA patients, radiographic joint space narrowing (JSN) was scored on the same joints using the Simple Erosion Narrowing Score (SENS).

RESULTS

Four-hundred and eight MHs in 51 RA patients and 320 MHs in 40 HS were evaluated. The OMERACT semiquantitative score was quicker to perform than the quantitative method (6.0 ± 0.5 vs 8.0 ± 1.5 min, p< 0.01). A significant correlation between the US scores (R = 0.68), and between the US scores and the JSN-SENS (R = 0.61 and R = 0.63, for semiquantitative and quantitative method, respectively) was found. The frequency of cartilage abnormalities was similar between the two US methods in RA patients (58.8% and 51.0% RA patients for semiquantitative and quantitative method, p= 0.46), while the former revealed more abnormalities in HS (27.5% and 7.5% of HS, p= 0.02).

CONCLUSION

The higher feasibility of the OMERACT semiquantitative score suggests its use as first-choice method in the evaluation of cartilage damage. However, despite its limits, the quantitative assessment of HC, providing patient-tailored information due to age- and sex-corrected cut-off values, may represent a valid supplement for optimizing the evaluation of cartilage damage in selected cases.