BACKGROUND: Stiff skin syndrome (SSS) is a rare disease characterized by sclerosis of the skin. Cases of both widespread and segmental SSS have been reported.
OBJECTIVE: To report the clinical and histopathological characteristics of a large series of SSS.
METHODS: We retrospectively analysed the clinical and histopathological characteristics of widespread and segmental SSS collected from a dermatology department. We also compared histopathology between segmental SSS and morphea.
RESULTS: Thirty-one cases, including three widespread SSS and 28 segmental SSS, were collected. Skin lesions of widespread SSS generally showed skin sclerosis concentrating over the lumbar, buttocks, thighs, proximal part of limbs, and shoulders with specific abnormal gait and posture. Skin lesions of segmental SSS generally showed sclerotic plaques involving the thigh, lumbar area and buttocks, associated with hypertrichosis, hyperpigmentation and a cobblestone appearance. Segmental SSS did not typically cause joint limitation or serious physical discomfort. Histopathologically, SSS showed proliferation of fibroblasts and sclerosis of collagen in the dermis or subcutaneous tissue. Compared with morphea, SSS showed more prominent proliferation of fibroblasts and completely lacked lymphocyte infiltration.
CONCLUSIONS: Segmental SSS represents the major variant of SSS. Histopathologically, SSS shows proliferation of fibroblasts, sclerosis and an absence of inflammation.

Introduction: To explore the value of serum sirtuin-1 (SIRT1) in the diagnosis and evaluation of joint mobility of rheumatoid arthritis (RA). Materials and Methods: Serum was randomly obtained from 212 RA patients,210 non-RA patients and 58 healthy controls in a large tertiary first-class hospital in Jiangxi province from November 2021 to June 2022. The level of serum Sirt1,anti-cyclic citrulline polypeptide antibody (anti-CCP), anti-mutant citrulline vimentin antibody (anti-MCV), rheumatoid factor (RF),high-mobility group box 1 (HMGB1), collagen triple helix repeat containing 1 (CTHRC1), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were detected by ELISA, to explore the correlation between them and their value in the diagnosis and evaluation of joint range of motion of RA and statistically analyse their diagnostic efficiency. Results: ① The level of all markers was higher in the RA group than in the non-RA group and the healthy controls (p < 0.05). ② The AUC of the SIRT1 was 0.882, second only to the anti-MCV and anti-CCP. ③ The anti-CCP showed the highest sensitivity to RA diagnosis of 0.948. The specificity and positive predictive value of SIRT1 for the diagnosis of RA were the highest, which are 0.959 and 0.934 respectively. ④ In serial combination, SIRT1/anti-CCP、SIRT1/anti-MCV showed the highest specificity.SIRT1/anti-CCP in parallel combination had the highest sensitivity. ⑤ SIRT1 showed a significant correlation with other markers and DAS28 scores (p < 0.01). Conclusion: SIRT1 can be used as a new serological marker for RA diagnosis, which has a significant correlation with RA joint mobility and has a certain reference value in RA differential diagnosis, providing a new detection basis for RA differential diagnosis.

BACKGROUND: Orthoses can stabilize the foot and restore the medial longitudinal arch for symptomatic flexible flatfoot. However, the effectiveness of orthoses remains controversial. The purpose of this study was to evaluate effectiveness of a customized soft inflatable orthosis on the medial longitudinal arch of flexible flatfoot patients under load.
METHODS: We obtained CT scans of the feet of 14 healthy volunteers and 14 patients with flexible flatfoot under non- and simulated weight-bearing conditions. Then CT scans under the same conditions were taken for patients with flexible flatfoot equipped with soft inflatable orthosis. Three-dimensional models of the medial longitudinal arch and hindfoot were constructed from CT images. The three-dimensional mobility of the medial longitudinal arch joints under load was compared between patients with flexible flatfoot equipped with soft inflatable orthosis or not.
RESULTS: From non- to simulated weight-bearing condition, the eversion and dorsiflexion of the talocalcaneal joint, the eversion of the talonavicular joint, the abduction and dorsiflexion of the cuneonavicular joint, and the dorsiflexion of the first tarsometatarsal joint were significantly larger in patients with flexible flatfoot than healthy volunteers. The customized soft inflatable orthosis could reduce the eversion of the talonavicular joint and the eversion and dorsiflexion of the talocalcaneal joint.
CONCLUSIONS: The soft inflatable orthosis is effective to improve medial longitudinal arch height and reduce excessive mobility of joints for flexible flatfoot deformity. The results of this study could provide evidence for the optimal orthosis design to treat flexible flatfoot in the future.

BACKGROUND: The purpose of this study was to evaluate correlation between three-dimensional medial longitudinal arch joint complex mobility and medial arch angle in stage II posterior tibial tendon dysfunction flatfoot under loading.
METHODS: CT scans of 15 healthy feet and 15 feet with stage II posterior tibial tendon dysfunction flatfoot were taken both in non- and simulated weight-bearing condition. The CT images of the hindfoot and medial longitudinal arch bones were reconstructed into three-dimensional models with Mimics and Geomagic reverse engineering software. The three-dimensional complex mobility of each joint in the medial longitudinal arch and their correlation with the medial arch angle change were calculated.
RESULTS: From non- to simulated weight-bearing condition, the medial arch angle change and the medial longitudinal arch joints mobility were significant larger in stage II posterior tibial tendon dysfunction flatfoot (p<0.05). The eversion of the talocalcaneal joint, the proximal translation of the calcaneus relative to the talus, the dorsiflexion of the talonavicular joint, the dorsiflexion and abduction of the medial cuneonavicular joint, and the lateral translation of the medial cuneiform relative to the navicular, and the dorsiflexion of the first tarsometatarsal joint were all significantly correlated to the medial arch angle change in stage II posterior tibial tendon dysfunction flatfoot (all r>0.5, p<0.05).
CONCLUSIONS: There is increased mobility in the medial longitudinal arch joints in stage II posterior tibial tendon dysfunction flatfoot and the medial arch angle change under loading causes displacement not only at hindfoot joints but also involve midfoot and forefoot joint.

BACKGROUND: As an important outcome measure among rheumatoid arthritis (RA) patients, functional disability may contribute to unemployment, loss of work productivity, and impaired quality of life. However, little is known about the risk factors of functional disability in Chinese RA patients. This study aimed (1) to examine the prevalence of functional disability in Chinese RA patients; (2) to explore factors associated with the health assessment questionnaire-disability index (HAQ-DI).
METHODS: A total of 101 RA patients in this cross-sectional study underwent standardized laboratory examinations and responded to the questionnaire for demographic data, the HAQ-DI for functional disability, the Compliance Questionnaire on Rheumatology (CQR) for medication adherence, the Hospital Anxiety and Depression Scale (HADS) for psychological status, and the Short Form 36 health survey (SF-36) for quality of life. Pain, grip/pinch strength, disease activity, and large joint mobility were recorded. Independent samples t-tests, chi-square analyses, and logistic regression modeling were used to analyze the data.
RESULTS: The mean ± SD age of RA patients was 54.9 ± 11.9 years. Approximately 15.8% RA patients in mainland China experience functional disability (defined as a HAQ-DI score ≥ 1). Long disease duration, pain, high disease activity, a larger number of tender and swollen joints, high C-reactive protein (CRP) level, decreased grip strength, and limitation of shoulder, elbow, wrist, knee, and ankle motion were associated with the HAQ-DI. Participants with functional disability tended to have more severe depressive symptoms and a lower quality of life compared with individuals without functional disability. Stepwise logistic regression analyses found that limitation of wrist extension (P = 0.001) and lower body pain (BP) score (P = 0.001) explained higher HAQ-DI score.
CONCLUSIONS: The present study reported that functional disability was common in Chinese RA patients. A low quality of life and limitation of joint mobility had great impacts on functional disability in Chinese RA patients. Targeted and culturally sensitive interventions should be strengthened to delay the onset of disabilities of this population.

The hand structure possesses a greater potential for performing manipulative skills than is typically observed, whether in humans or non-human anthropoids. However, a precise assessment of the potential manipulative skills of hands has been challenging, which hampers our understanding of the evolution of manipulative abilities in anthropoid hands. Here, we establish a functional model to quantitatively infer the manipulative potentials of anthropoid hands based on hand proportions. Our results reveal a large disparity of manipulative potentials among anthropoid hands. From the aspect of hand proportions, the human hand has the best manipulative potential among anthropoids. However, the species with a manipulative potential closer to that of humans are not our nearest relatives, chimpanzees, but rather, are certain monkey species. In combination with the phylogenetically informed morphometric analyses, our results suggest that the morphological changes of non-human anthropoid hands did not coevolve with the brain to facilitate the manipulative ability during the evolutionary process, although the manipulative ability is a survival skill. The changes in non-human anthropoid hands may have more likely evolved under selective pressure for locomotion than manipulation.