临床上，脊椎骨髓炎常见于免疫系统受损的个体，如糖尿病患者、免疫抑制、慢性肝病和恶性肿瘤患者。从微生物学角度来看，脊椎骨髓炎常由金黄色葡萄球菌引起，但短链链球菌的一种亚种镰刀状链球菌也有可能引起脊椎骨髓炎，尽管这种情况很少见。由于目前没有病例报告记录了伴有进行性寰枢关节亚脱位的镰刀状链球菌颈椎骨髓炎的发生，其临床特征仍然不确定。因此，我们在此报道了首例免疫功能正常个体镰刀状链球菌引起的寰枢关节脓性关节炎伴颈椎骨髓炎并进行了相关文献回顾。一名63岁的男性患者，患有高血压，但无外伤或肌肉骨骼疾病的病史，1个月来颈部疼痛加重，无发热。体格检查发现颈部疼痛，颈部后过度屈曲，上颈椎肿胀并有压痛。未观察到神经功能缺失。磁共振成像显示C2、C5和C6椎体同时出现T1加权图像低信号区和短时间倒置恢复加权图像高信号区，并有寰枢关节亚脱位。进行了两套血培养试验（厌氧和好氧）。厌氧血培养瓶检测显示β溶血性脲胺酶阴性的镰刀状链球菌表达A抗血清组的Lancefield分组。因此，患者被诊断为镰刀状链球菌引起的颈椎骨髓炎伴寰枢关节亚脱位；输注了对镰刀状链球菌有效的强化静脉注射氨苄西林（每6小时2g）。第33天进行了后路融合手术（枕骨、C4），因为第31天的随访磁共振成像显示寰枢关节亚脱位进展，寰枢关节软组织增厚。患者在接受6周静脉注射氨苄西林治疗后，颈痛完全缓解，随后口服阿莫西林（每日1500毫克）治疗4周。在2年的随访期间，患者未出现复发或后遗症。镰刀状链球菌表达A抗血清组可引起无发热脊椎骨髓炎和进行性寰枢关节亚脱位，由于脊椎骨髓炎后脊柱内植入物可能在经过6周抗微生物治疗后是可接受的。版权所有 © 2023 作者。 Wolters Kluwer Health, Inc. 发布。

Clinically, vertebral osteomyelitis commonly occurs in immunocompromised individuals, such as people with diabetes, immunosuppression, chronic liver disease, and malignancy. Microbiologically, vertebral osteomyelitis is commonly caused by Staphylococcus aureus; however, Streptococcus dysgalactiae subspecies equisimilis (SDSE) may also potentially cause vertebral osteomyelitis, albeit rarely. Since no case reports have documented the occurrence of SDSE cervical osteomyelitis accompanied by progressive atlantoaxial subluxation, its clinical characteristics remain uncertain. Herein, we report the first case of progressive atlantoaxial subluxation in addition to cervical osteomyelitis due to septic atlantoaxial arthritis caused by SDSE in an immunocompetent individual, and provide a review of the relevant literature.A 63-year-old man with hypertension but no history of trauma or musculoskeletal disorders presented with worsening neck pain for 1 month without fever. Physical examination revealed neck pain due to neck retroflexion and tenderness with swelling of the upper cervical spine. No neurological deficit was observed. Magnetic resonance imaging revealed low-intensity areas on a T1-weighted image and high-intensity areas on a short tau inversion recovery image at the C2, C5, and C6 vertebral bodies with atlantoaxial subluxation. Two sets of blood culture tests (aerobic and anaerobic) were performed.The anaerobic blood culture bottle showed the presence of beta-hemolytic pyrrolidonyl arylamidase-negative SDSE expressing Lancefield group A antiserum. Hence, the patient was diagnosed with SDSE cervical osteomyelitis with atlantoaxial subluxation; intensive intravenous ampicillin (2 g every 6 hours) - which is effective against SDSE - was administered.Posterior fusion (occipital bone, C4) was performed on day 33 because a follow-up magnetic resonance imaging on day 31 revealed progression of atlantoaxial subluxation with thickened atlantodental soft tissue.The patient's neck pain was completely relieved after treatment with intravenous ampicillin for 6 weeks, followed by oral amoxicillin (1500 mg) daily for an additional 4 weeks. The patient did not experience recurrence or sequelae during the 2-year follow-up period.SDSE expressing Lancefield group A antiserum can cause afebrile vertebral osteomyelitis and progressive atlantoaxial subluxation due to the occurrence of septic atlantoaxial arthritis in immunocompetent individuals. Spinal instrumentation for vertebral osteomyelitis may be acceptable after 6 weeks of antimicrobial therapy.Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.