Higuchi Chikahisa, Otsuki Dai, Kobayashi Masato, Yamanaka Ayana, Tamura Daisuke, Okada Seiji, Kawabata Hidehiko
Department of Orthopedic Surgery, Osaka Women's and Children's Hospital, Izumi, JPN.
Department of Orthopedic Surgery, Osaka Rehabilitation Hospital for Children, Osaka, JPN.
Cureus. 2025 Jun 18;17(6):e86325. doi: 10.7759/cureus.86325. eCollection 2025 Jun.
Introduction Pyomyositis, also known as tropical pyomyositis, has traditionally been considered more prevalent in tropical regions. The number of pediatric pyomyositis cases has been increasing in several temperate countries. In this study, we examined the characteristics of pyomyositis in a single pediatric hospital in Japan, a temperate country. Methods We analyzed 108 patients diagnosed with pyogenic arthritis, pyogenic osteomyelitis, and pyomyositis who were followed up at our hospital over a 32-year period. Data were collected on sex, age of onset, affected site, causative organism, and year of occurrence. The characteristics of pyomyositis were identified through comparison with pyogenic osteomyelitis and pyogenic arthritis. Results The number of patients with pyogenic osteomyelitis, pyogenic arthritis, and pyomyositis was 44, 51, and 13, respectively. In pyogenic arthritis, the hip joint was the most commonly affected site (24 of 51 patients, 47.1%), where the femur was the most frequently involved site in osteomyelitis (14 of 44 patients, 31.8%). Among 13 patients with pyomyositis, 12 (92.3%) had muscle involvement around the hip joint, with the obturator muscles being the most commonly affected. Bacterial organisms were identified by venous blood or pus culture in 11 pyomyositis patients, with methicillin-sensitive (MSSA) detected in five cases. During the first 16 years of the study period, 43 patients were diagnosed with pyogenic arthritis or osteomyelitis, while only two cases of pyomyositis were recorded. In contrast, over the most recent 16 years, pyogenic arthritis and osteomyelitis cases increased to 53, while pyomyositis cases rose to 10. Conclusions At our institution, pediatric pyomyositis primarily affected the periarticular muscles of the hip. Although a rising trend in cases was observed, the difference between the earlier and later periods was not statistically significant (p=0.069). These findings emphasize the importance of including pyomyositis in the differential diagnosis of pyogenic hip infections and recommend early MRI evaluation prior to joint aspiration.
脓性肌炎，也被称为热带脓性肌炎，传统上被认为在热带地区更为普遍。在一些温带国家，儿童脓性肌炎病例数一直在增加。在本研究中，我们调查了日本（一个温带国家）一家儿科医院中脓性肌炎的特征。
我们分析了在我院接受了32年随访的108例被诊断为化脓性关节炎、化脓性骨髓炎和脓性肌炎的患者。收集了患者的性别、发病年龄、受累部位、致病微生物及发病年份等数据。通过与化脓性骨髓炎和化脓性关节炎进行比较来确定脓性肌炎的特征。
化脓性骨髓炎、化脓性关节炎和脓性肌炎的患者数分别为44例、51例和13例。在化脓性关节炎中，髋关节是最常受累的部位（51例患者中有24例，占47.1%），而在骨髓炎中，股骨是最常受累的部位（44例患者中有14例，占31.8%）。在13例脓性肌炎患者中，12例（92.3%）髋关节周围肌肉受累，闭孔肌是最常受累的肌肉。通过静脉血或脓液培养在11例脓性肌炎患者中鉴定出了细菌病原体，其中5例检测到对甲氧西林敏感的金黄色葡萄球菌（MSSA）。在研究期的前16年，43例患者被诊断为化脓性关节炎或骨髓炎，而仅记录到2例脓性肌炎病例。相比之下，在最近16年中，化脓性关节炎和骨髓炎病例增加到53例，而脓性肌炎病例增加到10例。
在我们的机构中，儿童脓性肌炎主要影响髋关节的关节周围肌肉。尽管观察到病例有上升趋势，但早期和后期之间的差异无统计学意义（p = 0.069）。这些发现强调了在化脓性髋关节感染的鉴别诊断中纳入脓性肌炎的重要性，并建议在关节穿刺前进行早期MRI评估。
