Background: Human muscle satellite (stem) cells (MuSCs) are essential for investigating muscle physiology, regeneration, and disease mechanisms. Primary cultures derived directly from human tissues offer a more physiologically relevant model than immortalized cell lines. However, the isolation and characterization of MuSCs from human upper limb tissues are limited. Therefore, this study aimed to establish and characterize a primary culture system for MuSCs obtained from human upper limb muscle tissue. Methods: Human muscle tissues were obtained from upper limb surgical specimens. Muscle samples were mechanically and enzymatically dissociated to isolate muscle-derived cells, which were cultured under standard growth conditions. Cell morphology and proliferation were monitored during the culture period. Myogenic characteristics were assessed by examining the expression of muscle-specific markers including myogenic regulatory factors and structural proteins. Additionally, myogenic differentiation capacity was evaluated by inducing differentiation and analyzing the formation of multinucleated myotubes. Results: Primary MuSCs were isolated from human upper limb tissues and expanded in vitro. The cultured cells exhibited a typical spindle-shaped morphology and demonstrated significant proliferative capacity. Characterization confirmed the expression of myogenic markers, indicating the presence of muscle-derived precursor cells. Following induction of differentiation, the cells formed multinucleated myotube-like structures and expressed muscle proteins associated with differentiation, highlighting their potential for myogenic differentiation. Conclusion This study established a reliable protocol for isolating and culturing MuSCs from human upper limb tissues. Cultured cells displayed typical myogenic characteristics and differentiation capacity, indicating that this model could be a valuable platform for studying human muscle biology and potential therapeutic applications.

Radiographic axial spondyloarthritis (r-axSpA), a chronic inflammatory disease, can cause significant radiographic damage to the axial skeleton. Regarding the pathogenic mechanism, association of r-axSpA with tumor necrosis factor (TNF) and the interleukin-23/17 (IL­23/IL­17) pathway has been reported. Development of extraarticular manifestations, including uveitis, inflammatory bowel disease, and psoriasis, has been reported in some patients. The pivotal role of human leukocyte antigenB27 in the pathogenesis of r-axSpA remains to be clarified. Symptoms usually start in late adolescence or early adulthood, and disease progression can vary in each patient, with clinical manifestations ranging from mild joint stiffness without radiographic changes to advanced manifestations including complete fusion of the spine, and severe arthritis of the hip, and could include peripheral arthritis and extraarticular manifestations. The modified New York criteria was used previously in diagnosis of r-axSpA. However, early diagnosis of the disease prior to development of bone deformity was required due to development of biological agents. As a result of Assessment of SpondyloArthritis international Society (ASAS), the classification was improved in part for diagnosis of spondyloarthritis prior to development of bone deformity. The diagnosis is based on comprehensive laboratory findings, physical examinations, and radiologic findings. Medical treatment for r-axSpA involves the use of a stepwise strategy, starting with administration of nonsteroidal anti-inflammatory drugs and physiotherapy, and progressing to sulfasalazine or methotrexate and biologics including TNF-α inhibitors or IL-17 inhibitors as needed. Use of Janus kinase inhibitors has been recently reported.

Radiographic axial spondyloarthritis (r-axSpA), a chronic inflammatory disease, can cause significant radiographic damage to the axial skeleton. Regarding the pathogenic mechanism, association of r-axSpA with tumor necrosis factor (TNF) and the interleukin-23/17 (IL­23/IL­17) pathway has been reported. Development of extraarticular manifestations, including uveitis, inflammatory bowel disease, and psoriasis, has been reported in some patients. The pivotal role of human leukocyte antigenB27 in the pathogenesis of r-axSpA remains to be clarified. Symptoms usually start in late adolescence or early adulthood, and disease progression can vary in each patient, with clinical manifestations ranging from mild joint stiffness without radiographic changes to advanced manifestations including complete fusion of the spine, and severe arthritis of the hip, and could include peripheral arthritis and extraarticular manifestations. The modified New York criteria was used previously in diagnosis of r-axSpA. However, early diagnosis of the disease prior to development of bone deformity was required due to development of biological agents. As a result of Assessment of SpondyloArthritis international Society (ASAS), the classification was improved in part for diagnosis of spondyloarthritis prior to development of bone deformity. The diagnosis is based on comprehensive laboratory findings, physical examinations, and radiologic findings. Medical treatment for r-axSpA involves the use of a stepwise strategy, starting with administration of nonsteroidal anti-inflammatory drugs and physiotherapy, and progressing to sulfasalazine or methotrexate and biologics including TNF-α inhibitors or IL-17 inhibitors as needed. Use of Janus kinase inhibitors has been recently reported.

Radiographic axial spondyloarthritis (r-axSpA), a chronic inflammatory disease, can cause significant radiographic damage to the axial skeleton. Regarding the pathogenic mechanism, association of r-axSpA with tumor necrosis factor (TNF) and the interleukin-23/17 (IL­23/IL­17) pathway has been reported. Development of extraarticular manifestations, including uveitis, inflammatory bowel disease, and psoriasis, has been reported in some patients. The pivotal role of human leukocyte antigenB27 in the pathogenesis of r-axSpA remains to be clarified. Symptoms usually start in late adolescence or early adulthood, and disease progression can vary in each patient, with clinical manifestations ranging from mild joint stiffness without radiographic changes to advanced manifestations including complete fusion of the spine, and severe arthritis of the hip, and could include peripheral arthritis and extraarticular manifestations. The modified New York criteria was used previously in diagnosis of r-axSpA. However, early diagnosis of the disease prior to development of bone deformity was required due to development of biological agents. As a result of Assessment of SpondyloArthritis international Society (ASAS), the classification was improved in part for diagnosis of spondyloarthritis prior to development of bone deformity. The diagnosis is based on comprehensive laboratory findings, physical examinations, and radiologic findings. Medical treatment for r-axSpA involves the use of a stepwise strategy, starting with administration of nonsteroidal anti-inflammatory drugs and physiotherapy, and progressing to sulfasalazine or methotrexate and biologics including TNF-α inhibitors or IL-17 inhibitors as needed. Use of Janus kinase inhibitors has been recently reported.

BACKGROUND: Although core decompression (CD) with stem cell for the treatment of osteonecrosis of the femoral head (ONFH) showed promising results in many reports, the efficacy remains uncertain. We aimed to evaluate the efficacy of CD with culture-expanded autologous bone marrow-derived mesenchymal stem cell (BM-MSC) implantation in early stage ONFH. METHODS: A total of 18 patients (22 hips) with ONFH who underwent CD with culture-expanded BM-MSC implantation from September 2013 to July 2020 were retrospectively reviewed. The median age was 35.0 years [interquartile range (IQR), 28.5–42.0], and the median follow-up period was 4.0 years (IQR, 2.0–5.3). The median number of MSCs was 1.06 x 108 . To evaluate radiographic and clinical outcomes, Association Research Circulation Osseous (ARCO) classifications, Japanese Investigation Committee classification, combined necrotic angle (CNA) visual analogue scale (VAS) and Harris Hip Score (HHS) were checked at each follow-up. RESULTS: The preoperative stage of ONFH was ARCO 2 in 14 hips and ARCO 3a in 8 hips. The ARCO staging was maintained in 7 hips in ARCO 2 and 4 hips in ARCO 3a. The radiographic failure rate of ARCO 2 and 3a was 14.3 and 50%, respectively. Furthermore, CNA decreased to more than 20° in 6 hips (four were ARCO 2 and two were ARCO 3a).There was no significant difference in the VAS and HHS (P = 0.052 and P = 0.535, respectively). Total hip arthroplasty was performed in 4 hips. CONCLUSION CD with culture-expanded autologous BM-MSCs showed promising results for the treatment of early stage ONFH.

Background: Stem cell therapy for the treatment of osteonecrosis of the femoral head (ONFH) showed promising outcomes. However, ONFH with a large lesion in the weight-bearing portion is a poor prognostic factor and still challenging issue to be solved. We aimed to evaluate the effect of tissue-engineered bone regeneration for this challenging condition to preserve the femoral head. Methods: A total of 7 patients (9 hips) with ONFH who received osteoblasts expanded ex vivo from bone marrow-derived mesenchymal stem cells (BMdMSCs) and calcium metaphosphate (CMP) as scaffolds from March 2002 to March 2004 were retrospectively reviewed. The median age was 27.0 years (interquartile range [IQR], 23.0–34.0 years), and the median follow-up period was 20.0 years (IQR, 11.0–20.0 years). After culture and expansion of stem cells, we performed core decompression with BMdMSC implantation at a median number of 10.1 ×107 (IQR, 9.9–10.9 ×107 ). To evaluate radiographic outcomes, the Association Research Circulation Osseous (ARCO) classifications, the Japanese Investigation Committee (JIC) classification, and modified Kerboul combined necrotic angle (mKCNA) were evaluated preoperatively and during follow-up. Clinical outcomes were evaluated by a visual analog scale (VAS) and Harris Hip Score (HHS). Results: The preoperative stage of ONFH was ARCO 2 in 5 hips and ARCO 3a in 4 hips. The ARCO staging was maintained in 3 hips of ARCO 2 and 4 hips of ARCO 3a. Two hips of ARCO 2 with radiographic progression underwent total hip arthroplasty. According to mKCNA, 2 hips showed medium lesions, and 7 hips showed large lesions. The size of necrotic lesion was decreased in 4 hips (2 were ARCO 2 and 2 were ARCO 3a). There were no significant changes in JIC classification in all hips (type C1: 3 hips and type C2: 6 hips) (p = 0.655). Clinically, there were no significant changes in the VAS and HHS between preoperative and last followup (p = 0.072 and p = 0.635, respectively). Conclusions Tissue engineering technique using osteoblasts expanded ex vivo from BMdMSC and CMP showed promising outcomes for the treatment of pre-collapsed and early-collapsed stage ONFH with medium-to-large size, mainly located in weightbearing areas.