Department of Orthopaedics, Traumatology and Spine Surgery, Ganga Hospital, 313, Mettupalayam Road, Coimbatore, 641043, India.
Eur Spine J. 2019 Apr;28(4):762-767. doi: 10.1007/s00586-018-5800-0. Epub 2018 Oct 23.
Unilateral sacroiliitis (US) is an uncommon disease with varied etiology. The differentiation between infective and inflammatory causes for US based on MRI alone is often difficult. We studied the efficacy of MRI findings in comparison with tissue studies in the diagnosis of US.
A retrospective analysis of patients who presented with US and evaluated with MRI, biopsy for histopathology and tissue cultures was performed. Patients with bilateral sacroiliitis, traumatic and postpartum sacroiliitis were excluded. Based on defined MRI criteria, the patients were divided into two groups-infective (group A) and inflammation (group B).
In total, 33 patients (mean age-33.4 ± 17.2 years) with MRI features of US had presented with unilateral gluteal pain (100%) and positive Patrick's test (91.9%). Based on the MRI features of severe subchondral marrow edema, widening of joint space, intra-articular abscess and periarticular muscle abscess, infective sacroiliitis (A) was diagnosed in 20/33 (60.6% cases). A total of 13/33 (39.3%) patients had features of inflammation (B), based on the following MRI criteria-subchondral sclerosis with minimal edema, erosions, maintained joint space without abscess/destruction. Tissue evidence of infection was positive in 13/20 (65%) patients in group A while it was negative in all group B patients.
MRI had high sensitivity (71%) and 100% specificity in diagnosing inflammatory sacroiliitis while it had low specificity, but 100% sensitivity for diagnosing infective sacroiliitis. Hence, patients diagnosed as inflammatory sacroiliitis in MRI are unlikely to benefit from further tissue studies while percutaneous biopsy is recommended in patients diagnosed in MRI as infective sacroiliitis.
单侧骶髂关节炎（US）是一种病因多样的罕见疾病。仅凭 MRI 很难区分 US 的感染性和炎症性病因。我们研究了 MRI 结果与组织研究在 US 诊断中的作用。
对表现为 US 并接受 MRI、组织活检进行组织病理学和组织培养评估的患者进行回顾性分析。排除双侧骶髂关节炎、创伤性和产后骶髂关节炎患者。根据定义的 MRI 标准，患者分为两组 - 感染性（A 组）和炎症性（B 组）。
共有 33 例（平均年龄 33.4±17.2 岁）患者具有单侧臀痛（100%）和 Patrick 试验阳性（91.9%）的 MRI 单侧骶髂关节炎特征。根据严重的软骨下骨髓水肿、关节间隙增宽、关节内脓肿和关节周围肌肉脓肿的 MRI 特征，诊断感染性骶髂关节炎（A）20/33（60.6%）例。根据以下 MRI 标准，33 例患者中 13/33（39.3%）例有炎症表现（B）：软骨下硬化伴轻度水肿、侵蚀、关节间隙保持不变无脓肿/破坏。A 组 13/20（65%）例患者的组织感染证据为阳性，而 B 组所有患者均为阴性。
MRI 诊断炎症性骶髂关节炎的敏感性（71%）和特异性（100%）均较高，而诊断感染性骶髂关节炎的特异性较低，但敏感性为 100%。因此，MRI 诊断为炎症性骶髂关节炎的患者不太可能从进一步的组织研究中获益，而 MRI 诊断为感染性骶髂关节炎的患者建议进行经皮活检。
