Department of Radiology, Hospital Clinic, University of Barcelona, Barcelona, Spain.
Department of Infectious Diseases, Hospital Clinic, University of Barcelona, Barcelona, Spain.
J Arthroplasty. 2019 Aug;34(8):1776-1782. doi: 10.1016/j.arth.2019.04.018. Epub 2019 Apr 12.
Infection after total hip arthroplasty remains a diagnostic challenge. We assessed the accuracy of computed tomography (CT)-guided joint aspiration combined with CT findings for prediction of septic hip prosthesis before revision surgery.
A total of 96 patients (64.6% men; mean age, 68 years) scheduled for elective revision surgery due to suspicion of infection after total hip arthroplasty underwent CT-guided joint aspiration. Volume and microbiological cultures of aspirated fluid and salient findings on CT scans, including periprosthetic soft-tissue mass, malpositioning of the prosthesis, periprosthetic osteolysis, reactive enlarged lymph nodes, and heterotopic ossification, were assessed by a blinded radiologist.
Septic hip prosthesis was shown on revision surgery in 35 patients (36.4%), with Staphylococcus epidermidis isolated in 54.3% of cases. Culture of the aspirated fluid yielded the same microorganism in 24 patients (68.6%). The accuracy of preoperative CT-guided joint aspiration was 86.5%. High volume (>1 mL) of aspirated fluid was recorded in 32 patients (33.3%). In the multivariate analysis, high volume on CT aspiration, accumulation of soft tissue exceeding the joint margin, osteolysis without bone insufflation, and enlarged iliac lymph nodes were significant predictors of infected hip prosthesis. Similar results were obtained after adjustment of the model by the presence of aggressive granulomatosis.
Preoperative CT-guided joint aspiration is accurate to diagnose septic hip prosthesis based on CT imaging findings and volume and bacterial culture of the aspirated fluid. Enlarged iliac lymph nodes emerged as a strong predictor of infection.
全髋关节置换术后感染仍然是一个诊断难题。我们评估了 CT 引导下关节抽吸术联合 CT 检查结果对翻修术前感染性髋关节假体的预测准确性。
共有 96 例患者（64.6%为男性；平均年龄 68 岁）因全髋关节置换术后感染怀疑而行 CT 引导下关节抽吸术，计划行择期翻修手术。由一位盲法放射科医生评估抽吸物的体积和微生物培养结果以及 CT 扫描的特征性表现，包括关节周围软组织肿块、假体位置不当、假体周围骨溶解、反应性增大的淋巴结和异位骨化。
35 例（36.4%）患者在翻修手术中证实为感染性髋关节假体，其中 54.3%的病例分离出表皮葡萄球菌。24 例（68.6%）患者的抽吸液培养出相同的微生物。术前 CT 引导下关节抽吸术的准确性为 86.5%。32 例（33.3%）患者抽吸的关节液体积较大（>1ml）。多变量分析显示，CT 抽吸时关节液体积大、关节边缘软组织堆积、无骨扩张的骨溶解和髂淋巴结增大是感染性髋关节假体的显著预测因素。在调整模型以存在侵袭性肉芽肿的情况下，也得到了相似的结果。
术前 CT 引导下关节抽吸术基于 CT 影像学表现和抽吸物的体积及细菌培养结果，对诊断感染性髋关节假体是准确的。髂淋巴结增大是感染的强有力预测因素。
