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Favorable clinical outcomes of intra-articular injection of adipose-derived stromal vascular fraction (SVF) cells for knee osteoarthritis (OA) have been reported, but the effects of different doses of SVF cells have not been examined. This study aimed to compare the short-term clinical and imaging outcomes of different doses of SVF cells for knee OA treatment. This study included 60 patients with knee OA who underwent intra-articular injection of SVF cells. The follow-up period was at least 12 months. Thirty patients received an intra-articular injection of 2.5×107 SVF cells (low-dose group), and the remaining 30 patients received an intra-articular injection of 5.0×107 SVF cells (high-dose group). Clinical evaluations were performed for the Knee injury and Osteoarthritis Outcome Score (KOOS). Imaging evaluations, including the magnetic resonance imaging Osteoarthritis Knee Score (MOAKS) features (bone marrow lesions, cartilage defects, osteophytes, Hoffa's synovitis, and effusion synovitis), were also performed. All clinical and imaging evaluations were performed preoperatively and 12 months postoperatively and compared between the groups. In demographic data, no significant differences were found between the two groups. The total score of KOOS at 12 months postoperatively was significantly more favorable than the preoperative score in the high-dose groups. Pain and symptoms subscale scores of KOOS at 12 months postoperatively were significantly better in the high-dose group than in the low-dose group. The bone marrow lesions, Hoffa's synovitis, and effusion synovitis improved approximately 30–40% at 12 months postoperatively compared to baseline in both groups. However, there were no significant differences in imaging evaluations between the two groups. In conclusion, the pain and symptoms subscale scores of KOOS from baseline to 12 months postoperatively improved better in the high-dose group than in the low-dose group. Our findings suggest that intra-articular injection of SVF cells for knee OA is an innovative approach. [ABSTRACT FROM AUTHOR]

The role of uncultured adipose‐derived stromal cells for osteoarthritis treatment remains unclear despite sporadic reports supporting their use in clinical settings. This study aimed to evaluate the therapeutic effects of autologous uncultured adipose‐derived stromal cell transplantation in a rabbit osteoarthritis model. Uncultured adipose‐derived stromal cells isolated from rabbits were administered via intra‐articular injection into the knees after osteoarthritis onset. Animals were sacrificed at 8 and 12 weeks after osteoarthritis onset to compare the macroscopic, histological, and immunohistochemical characteristics between the uncultured adipose‐derived stromal cell and control groups. Co‐culture assay was also performed. The chondrocytes isolated from the model were co‐cultured with adipose‐derived stromal cells. The cell viability of chondrocytes and expression of chondrocyte‐specific genes in the co‐culture (uncultured adipose‐derived stromal cell) group were compared with the mono‐culture (control; chondrocytes only) group. In macroscopic and histological analyses, the uncultured adipose‐derived stromal cell group showed less damage to the cartilage surface than the control group at 8 and 12 weeks after osteoarthritis onset. In immunohistochemical and co‐culture assay, the uncultured adipose‐derived stromal cell group showed higher expression of collagen type II and SRY box‐9 and lower expression of matrix metalloproteinase‐13 than the control group. The cell viability of chondrocytes in the uncultured adipose‐derived stromal cell group was higher than that in the control group. Intra‐articular autologous uncultured adipose‐derived stromal cell transplantation inhibited the progression of cartilage degeneration in a rabbit osteoarthritis model by regulating chondrocyte viability and secreting chondrocyte‐protecting cytokines or growth factors, which promote anabolic factors and inhibit catabolic factors. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1376–1386, 2019. [ABSTRACT FROM AUTHOR]

This study emphasizes the importance of early detection of osteonecrosis of the femoral head (ONFH) in young patients on long‐term glucocorticoid therapy, including those with acute lymphoblastic leukemia, lupus, and other diagnoses. While X‐ray and magnetic resonance imaging (MRI) are standard imaging methods for staging ONFH, MRI can be costly and time‐consuming. The research focuses on utilizing artificial intelligence (AI) to enhance the evaluation of radiographic images for ONFH detection. The study involved analyzing X‐ray and MRI from 102 control hips and 104 ONFH‐affected hips at Association Research Circulation Osseous (ARCO) Stage II and IIIa. We employed transfer learning with the YOLOv8 model for object detection, using 80% of the data for training and 20% for validation, then assessed detection accuracy through mean average precision (mAP) and a precision‐recall curve. Additionally, AI generated synthetic MRI (sMRI) from X‐ray images using a Generative Adversarial Network (GAN) and evaluated their similarity to original MRI. Results showed that the mAP for ONFH detection was 0.923 for the YOLOv8n model and 0.951 for YOLOv8x. The GAN‐generated sMRI exhibited lower image quality compared with originals but maintained potential for lesion assessment. Intrarater reliability among evaluators was high. The findings indicate that AI techniques, particularly YOLOv8 for object detection and GAN for image generation, can effectively assist in ONFH screening, despite some limitations in the generated MRI quality. [ABSTRACT FROM AUTHOR]

Purpose Methods Results Conclusion Level of Evidence The study aimed to determine the impact of intraoperative lateral laxity at extension on clinical and functional outcomes 1 year after posterior‐stabilised total knee arthroplasty (PS‐TKA).In total, 91 varus‐type osteoarthritic knees that underwent PS‐TKA using the medial preservation gap technique were included. After the femoral trial component placement and patellofemoral joint reduction, the soft‐tissue balance was assessed using an offset‐type tensor with a 40‐lb joint‐distraction force. Patients were divided into the following three groups according to the intraoperative lateral laxity at extension (i.e., varus ligament balance) using the mean ± 1 standard deviation: Groups A, ≤0°; B, 0–4°; and C, >4°. The 2011 Knee Society Score (KSS) and 3‐m timed up‐and‐go test (TUG) time 1‐year postoperatively, and their improvements were compared among the groups.While significant improvements were observed in all subscales of the 2011 KSS and TUG post‐TKA (p < 0.05), the improvement of functional activities and TUG time were significantly lower in Group C than in Group B (p < 0.05). However, no significant differences were observed in symptom improvement, patient satisfaction or patient expectation scores among the groups.An excessive lateral laxity (varus angle) >4° at extension was associated with lower improvement in functional ability 1‐year postoperatively. Therefore, excessive intraoperative lateral laxity should be avoided in PS‐TKA.Level IV. [ABSTRACT FROM AUTHOR]

Aims: Bone marrow mononuclear cells (BM-MNCs) are a rich source of hematopoietic stem cells that have been widely used in experimental therapies for patients with various diseases, including fractures.Activation of angiogenesis is believed to be one of the major modes of action of BM-MNCs; however, the essential mechanism by which BM-MNCs activate angiogenesis remains elusive. This study aimed to demonstrate that BM-MNCs promote bone healing by enhancing angiogenesis through direct cell-to-cell interactions via gap junctions, in addition to a previously reported method., Methods: Using a murine fracture model, we aimed to elucidate the relationship between gap junction-mediated cell-to-cell interactions and enhanced fracture healing after BM-MNC transplantation. We evaluated the transfer of substances from BM-MNCs to vascular endothelial cells and osteoblasts in the tissues surrounding the fracture site and assessed the effects of BM-MNC transplantation on bone healing, angiogenesis, and osteogenesis., Results: BM-MNCs transferred substances to vascular endothelial cells and osteoblasts in the tissues surrounding the fracture site. Moreover, BM-MNC transplantation promoted bone healing via gap junction-mediated cell-to-cell interactions, accelerating both angiogenesis and osteogenesis., Conclusions: Our findings provide a novel understanding of fracture healing mechanisms and suggest that BM-MNC transplantation enhances bone healing through gap junction-mediated cell-to-cell interactions, contributing to the development of regenerative medicine strategies targeting bone repair., (© The Author(s) 2025. Published by Oxford University Press. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

BACKGROUND Distal femoral and proximal tibial fractures often lead to nonunion and post-traumatic osteoarthritis, and total knee arthroplasty (TKA) has emerged as an effective alternative for older patients. This report includes 3 cases of successful TKA treatment. The cases involve a 42-year-old man and a 62-year-old man with Hoffa coronal fractures of the distal femur, and a 50-year-old man with a proximal tibial fracture. These patients underwent multiple osteosynthesis procedures before receiving TKA. CASE REPORT Case 1: A 42-year-old man with a displaced Hoffa's fracture had persistent knee pain. Nonunion post-initial fixation led to reoperation with iliac bone grafting and plate fixation. TKA using a Posterior Stabilized (PS)-type implant resulted in improved motion and function after 3 years. Case 2: A 62-year-old man suffered lateral condyle and ligament injuries from a displaced Hoffa's fracture. Despite plate fixation, dislocation occurred, requiring conversion. TKA with long-stem hinge-type implant, using augmentation block, led to enhanced stability and outcomes at 2 years. Case 3: A 50-year-old man's tibial nonunion, treated with plate fixation, resulted in infection and bone fusion. TKA using a constrained PS-type implant insert addressed the lateral tibial adhesions via iliotibial band (ITB) release and treated severe tibial plateau damage. Positive results were seen at 1 year. CONCLUSIONS The challenges of pseudarthrosis, like bone defects and compromised tissue, highlight the need for precise implant selection based on evaluations of bone quality, defects, knee stability, and hyperextension, rather than resorting to overly-constrained implants.