This study aimed to clarify the relationship between knee flexor strength and hamstring muscle morphology after anterior cruciate ligament (ACL) reconstruction using the semitendinosus (ST) tendon and to determine the causative factors of decreased knee flexor muscle strength. Fourteen male and ten female patients who resumed sports activities after surgery participated in the experiment. Isometric knee flexion torque was measured at 30°, 45°, 60°, 90°, and 105° of knee flexion. Magnetic resonance imaging (MRI) was used to calculate ST muscle length and hamstring muscle volume, and to confirm the status of ST tendon regeneration. The correlation between the MRI findings and flexor strength was analyzed. Regenerated ST tendon was confirmed in 21 of the 24 patients, but muscle volume (87.6%) and muscle length (74.5%) of the ST in the operated limb were significantly smaller than those in the normal limb. The percentage of the knee flexion torque of the operated limb compared with that of the normal was apparently lower at 105° (69.1%) and 90° (68.6%) than at 60° (84.4%). Tendon regeneration, ST muscle shortening, and ST muscle atrophy correlated with decreased knee flexion torque. These results indicated that preserving the morphology of the ST muscle-tendon complex is important.

Overall benefits were provided by orthopedic surgical intervention generally in patients with RA.

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Objective To investigate the serum total antibody (immunoglobulin M and immunoglobulin G) titre against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein receptor-binding domain following BNT162b2 messenger ribonucleic acid (mRNA) coronavirus disease 2019 (COVID-19) vaccination in Japanese rheumatic disease patients undergoing immunosuppressive therapy. Methods The serum antibody titre against SARS-CoV-2 spike protein was analysed in 123 outpatients with rheumatic diseases at Kagawa University Hospital and 43 healthy volunteers who had received 2 doses of the BNT162b2 mRNA vaccine with at least 14 days elapsing since the second dose. Results The antibody titre in rheumatic disease patients was significantly lower than that in healthy subjects (p<0.0001). The antibody titres of the 41 patients who received biologics or Janus kinase inhibitors and the 47 patients who received conventional immunosuppressive agents were significantly lower than those of the 35 patients who did not receive immunosuppressive agents (p<0.0001 and p<0.0001, respectively). In addition, the mean antibody titre of the 43 patients on methotrexate was significantly lower than that of the 80 patients not on methotrexate (p=0.0017). Conclusion Immunogenicity to the BNT162b2 mRNA COVID-19 vaccine in rheumatic disease patients was found to be reduced under immunosuppressive treatment. In particular, methotrexate seems to be associated with a decreased antibody response.

The present study aims to evaluate changes in plantar pressure distribution after joint-preserving surgery for rheumatoid forefoot deformity. A retrospective study was performed on 26 feet of 23 patients with rheumatoid arthritis (RA) who underwent the following surgical combination: modified Mitchell’s osteotomy (mMO) of the first metatarsal and shortening oblique osteotomy of the lateral four metatarsals. Plantar pressure distribution and clinical background parameters were evaluated preoperatively and one year postoperatively. A comparison of preoperative and postoperative values indicated a significant improvement in the visual analog scale, Japanese Society for Surgery of the Foot scale, and radiographic parameters, such as the hallux valgus angle. A significant increase in peak pressure was observed at the first metatarsophalangeal joint (MTPJ) (0.045 vs. 0.082 kg/cm2; p < 0.05) and a significant decrease at the second and third MTPJs (0.081 vs. 0.048 kg/cm2; p < 0.05, 0.097 vs. 0.054 kg/cm2; p < 0.05). While overloading at the lateral metatarsal heads following mMO has been reported in previous studies, no increase in peak pressure at the lateral MTPJs was observed in our study. The results of our study show that this surgical combination can be an effective and beneficial surgical combination for RA patients with mild to moderate joint deformity.

We report the clinical results and problems of combined administration of rifampicin, ethambutol, and clarithromycin (REC) for the treatment of Mycobacterium avium complex (MAC) infection of the hand (hand MAC). Participants included 7 patients with hand MAC. After resection of the infected lesion, REC was prescribed for 12 months. For these patients, the site of infection, clinical course after initiation of REC, adverse drug effects (ADEs), and incidence of recurrence were evaluated. Sites of infection were the flexor tenosynovium in 5 patients, extensor tenosynovium in 1 patient, and both flexor and extensor tenosynovium in 1 patient. ADEs of REC occurred in 5 patients, and included visual disturbance caused by ethambutol in 2 patients, liver function abnormality caused by rifampicin in 2 patients, and fever with diarrhea caused by rifampicin in 1 patient. For 2 of these 5 patients, desensitization therapy was applied and REC was able to be reinstated. In the remaining 3 patients, the causative drugs were discontinued and levofloxacin, a new quinolone, was administered. Complete healing was achieved in 5 patients, and recurrence was observed in 2 patients. These 2 patients with recurrence included 1 patient in whom REC was completed and 1 patient in whom REC therapy was modified due to ADE. REC provided relatively good clinical results as a treatment for hand MAC. However, recurrences were observed even after the completion of REC and the use of an alternative drug. Optimal duration of REC and appropriate alternative drugs need to be identified in the future.

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Background We have developed a prefabricated vascularized allo-bone graft (PVAG) by implanting the saphenous vascular bundles of recipient rats into transplanted donor bones in a flow-through manner. We previously demonstrated that the angiogenetic and bone formative abilities of the PVAG are stimulated by the addition of a basic fibroblast growth factor (bFGF)-containing hydroxyapatite/collagen (HAp/Col). This study aimed to demonstrate that the bone union ability of the PVAG is similarly stimulated by the bFGF-containing HAp/Col composite. Methods Sprague-Dawley donor rats (n = 32) and Wistar recipient rats (n = 32) were used in this study. The PVAG was fixed to the femur of the recipient rat using K-wire (dimeter: 0.7 mm) pinning, followed by suturing with a 4–0 nylon suture. Recipients were divided into four groups: with or without vascular bundles, and with or without bFGF-containing HAp/Col. Rats were sacrificed 6 weeks after transplantation, and bone union, bone resorption, and angiogenesis were radiologically and histologically evaluated. Results Radiological analysis revealed a significant increase in callus formation and union rate, while histological analysis showed a significant increase in bone formation and angiogenesis in the group treated with both vascular bundles and bFGF. Bone resorption did not significantly increase in any of the evaluated groups. Conclusion Osteogenic cells, osteoconductive scaffolds, growth factors, and mechanical environment are known to be important factors in the process of fracture healing. The PVAG developed herein contains osteogenic cells, osteoconductive scaffolds, and growth factors. In addition, the PVAG is rigidly fixed to the fracture site, providing a stable mechanical environment. Together, these four factors contributed to a good bone union. Furthermore, this method did not promote bone resorption. Thus, the addition of a vascular bundle and bFGF-containing HAp/Col makes it possible to create an ideal vascularized allo-bone graft for the reconstruction of massive bone defects.