^99Tc^m—MDP显像用于人工髋关节置换术后关节感染的鉴别诊断

^99Tc^m-MDP imaging for the diagnosis of joint infection after total hip arthroplasty

目的探讨^99Tc^m-MDP显像用于髋关节置换术后关节感染与无菌性假体松动鉴别诊断的适合方法。方法回顾性分析2008年2月至2011年8月间74例人工髋关节置换术后出现关节疼痛的患者资料，其中男32例，女42例，年龄（64．3±11．2）岁。所有患者均行^99Tc^mMDP血流、血池和骨骼三时相显像及血清C反应蛋白和血红细胞沉降率测定^99Tc^m-MDP显像分别以假体周围软组织放射性浓聚、假体周围骨骼放射性浓聚或两者同时存在作为关节感染的诊断依据；无上述阳性表现者即认为关节疼痛由无菌性假体松动所致。依据最终临床诊断，采用妒检验比较^99Tc^m-MDP显像中骨骼相、血流-血池相、血清学检查结果间诊断效能的差异。结果74例患者中，有症状关节74个，其中感染关节24个，无菌性假体松动50个。诊断关节感染的灵敏度和特异性：血流-血池相分别为91．7％（22／24）和90．0％（45／50），骨骼相分别为70．8％（17／24）和48．0％（24／50），血清c反应蛋白分别为62．5％（15／24）和78．0％（39／50），血红细胞沉降率分别为62．5％（15／24）和76．0％（38／50）。血流-血池相对假体周围感染诊断的准确性优于单纯骨显像[90．5％（67／74）和55．4％（41／74）；X^2=23．159，P〈0．001]，也优于血清c反应蛋白[73．0％（54／74）；X^2=7．656，P〈0．05]和血红细胞沉降率[71．6％（53／74）X^2=8．633，P〈0．05]检测。结论在髋关节置换术后关节感染与无菌性假体松动鉴别诊断中，^99Tc^mMDP血流-血池相具有较高的临床价值，建议作为常规检查方法。

Objective To investigate the value of ^99Tc^m-MDP imaging for the differential diagnosis between infection and aseptic loosening after total hip arthroplasty. Methods During February 2008 to Au- gust 2011, 74 patients （32 males, 42 females, average age （64.3±11.2） years） with hip pain after arthro- plasty underwent 3-phase （blood flow, blood pool and bone phases） 99Tcm-MDP imaging. All patients had measurements of serum C reactive protein （CRP） and erythroeyte sedimentation rate （ESR）. Joint infection was defined as either increased peri-prosthetic soft tissue activity during perfusion and blood pool phases or increased peri-prusthetic bone activity during uptake phase, or positive in all 3 phases. Aseptic loosening was defined as having negative 99Tcm-MDP in all 3 phases. Clinical diagnosis was chosen as the gold stan- dard. The blood flow-pool imaging was compared with the serum examinations. X^2 test was used for statistical analysis. Results There were 74 symptomatic joints in 74 patients, including 24 joint infections and 50 asep- tic loosening. For the detection of peri-prosthetie infection, combined perfusion-blood-pool phase was more accurate than bone uptake phase （90.5% （67/74） vs 55.4% （41/74） ;X^2= 23.159, P〈0.001 ） , with the sensitivity of 91.7% （22/24） vs 70.8% （17/24） and specificity of 90.0% （45/50） vs 48.0% （24/50）, respectively. The blood flow-pool imaging was also more accurate than CRP （73.0% （54/74） ;X^2= 7. 656, P〈0.05） and ESR （71.6% （53/74） ;X2=8.633, P〈0.05）, respectively. Conclusion 99Tcm-MDP perfu- sion/blood flow-pool imaging is an accurate modality for differentiating peri-prosthetic infection from aseptic loosening in patients with hip pain after arthroolastv.