Suppressing inflammation and abnormal subchondral bone turnover is essential for reducing osteoarthritis (OA) progression and pain relief. This study focused on calcitonin gene-related peptide (CGRP), which is involved in inflammation and bone metabolism, and investigated whether a CGRP receptor antagonist (rimegepant) could suppress OA progression and relieve pain in two OA models. C57BL/6 mice (10-week-old) underwent surgical destabilization of the medial meniscus, and Rimegepant (1.0 mg/kg/100 μL) or phosphate-buffered saline (100 μL) was administered weekly intraperitoneally after OA surgery and evaluated at 4, 8, and 12 weeks. In the senescence-accelerated mice (SAM)-prone 8 (SAMP8), rimegepant was administered weekly before and after subchondral bone sclerosis and sacrificed at 9 and 23 weeks, respectively. Behavioral assessment and immunohistochemical staining (CGRP) of the dorsal root ganglion (DRG) were conducted to assess pain. In DMM mice, synovitis, cartilage degeneration, and osteosclerosis were significantly suppressed in the rimegepant group. In SAMP8, synovitis, cartilage degeneration, and osteosclerosis were significantly suppressed by rimegepant at 9 weeks; however, not at 23 weeks. Behavioral assessment shows the traveled distance and the number of standings in the rimegepant group were significantly longer and higher. In addition, CGRP expression of the DRG was significantly lower in the rimegepant group at 8 and 12 weeks of DMM and 9 weeks of SAMP8 treatment. No adverse effects were observed in either of the mouse models. Inhibition of CGRP signaling has the potential to be a therapeutic target to prevent OA progression and suppress pain through the attenuation of subchondral bone sclerosis and synovitis.

Osteoarthritis (OA) is a common joint disorder characterized by cartilage degeneration, often leading to pain and functional impairment. Minced cartilage implantation (MCI) has emerged as a promising one-step alternative for large cartilage defects. However, the source of chondrocytes for MCI remains a challenge, particularly in advanced OA, as normal cartilage is scarce. We performed in vitro studies to evaluate the feasibility of MCI using osteophyte cartilage, which is present in patients with advanced OA. Osteophyte and articular cartilage samples were obtained from 22 patients who underwent total knee arthroplasty. Chondrocyte migration and proliferation were assessed using cartilage fragment/atelocollagen composites to compare the characteristics and regenerative potential of osteophytes and articular cartilage. Histological analysis revealed differences in cartilage composition between osteophytes and articular cartilage, with higher expression of type X collagen and increased chondrocyte proliferation in the osteophyte cartilage. Gene expression analysis identified distinct gene expression profiles between osteophytes and articular cartilage; the expression levels of COL2A1, ACAN, and SOX9 were not significantly different. Chondrocytes derived from osteophyte cartilage exhibit enhanced proliferation, and glycosaminoglycan production is increased in both osteophytes and articular cartilage. Osteophyte cartilage may serve as a viable alternative source of MCI for treating large cartilage defects in OA.

Iatrogenic hallux varus is a difficult complication of hallux valgus surgery. Although tendon transfer combined with bony correction is performed for hallux varus, tendon transfer has several disadvantages, such as the complicated nature of the procedure and the donor site morbidity. We describe the case of a 70-year-old woman with iatrogenic hallux varus treated by lateral collateral ligament (LCL) reconstruction using a suture tape anchor with bony correction. Tarsometatarsal joint arthrodesis was performed to correct the narrow intermetatarsal angle (IMA), and the varus deformity of the great toe at the metatarsophalangeal joint was corrected by anatomical reconstruction of the LCL using the suture tape anchor. One year postoperatively, the Japanese Society for Surgery of the Foot Hallux Metatarsophalangeal-Interphalangeal Scale had improved from 37 to 90 points. Radiography confirmed that the hallux valgus angle had been corrected from -24 to 4 and the IMA from 0 to 8. Reconstruction of the LCL using suture tape anchor is an easy procedure for iatrogenic hallux varus which can achieve good stabilization.

Purpose: Medial meniscus extrusion (MME) is exaggerated by mechanical loading and exhibits a significant response during gait. Open‐wedge (OW) and closed‐wedge (CW) high tibial osteotomy (HTO) can reduce the mechanical loading associated with MME during walking; however, the impact of the differences in these surgical procedures remains unclear. This study aimed to compare MME behaviour during walking between OWHTO and CWHTO. It was hypothesised that CWHTO would demonstrate superior outcomes compared to OWHTO in terms of reducing mechanical stress. Methods: Twenty‐one knees from twenty‐one patients with knee osteoarthritis were enrolled and allocated to CW and OW groups. MME during walking was evaluated using ultrasonography synchronised with three‐dimensional motion analysis. The dynamic behaviour of MME was assessed by calculating the change between the MME value at initial contact and the maximum value observed during walking. Mechanical stress was evaluated using the knee adduction moment. These measurements were performed at two time points: preoperatively and postoperatively at approximately 24 months. Results: Both MME behaviour and knee adduction moment impulse values during walking were significantly reduced compared to baseline measurements MME behaviour ( p = 0.0001) and knee adduction moment ( p = 0.001), whereas no significant differences were observed between the groups. Conclusions: The differences between CWHTO and OWHTO were not detected in MME behaviour during walking. Level of Evidence: Level IV.