title: Ultrasound-guided versus landmark in knee arthrocentesis: A systematic review.
abstract: OBJECTIVE
  The objective was to assess the efficacy of ultrasound-guided (USG) versus landmark (LM) knee arthrocentesis in adults with knee pain or effusion.
  
  
  METHODS
  A systematic review of the literature was performed until August 2015. All controlled trials reporting the accuracy or clinical efficacy between USG and LM knee joint arthrocentesis were selected. Pooled weighted mean difference (WMD) using the D-L fixed models for continuous outcomes and the risk ratio (RR) for dichotomous outcomes were assessed by meta-analysis. Heterogeneity between studies was estimated by I(2) statistic.
  
  
  RESULTS
  Nine studies including 715 adult patients (725 knee joints) were eligible for this review versus LM group; there was a statistically significant difference in favor of USG for knee arthrocentesis accuracy rate (risk ratio = 1.21; 95% CI: 1.13-1.29; P < 0.001; I(2) = 37%), lower procedural pain scores (WMD = -2.24; 95% CI: -2.92 to -1.56; P < 0.001; I(2) = 4%), more aspiration volume (WMD = 17.06; 95% CI: 5.98-28.13; P = 0.003; I(2) = 57%), and decreased pain score 2 weeks after injection (WMD = 0.84; 95% CI: 0.42-1.27; P < 0.001; I(2) = 0). There was no statistically significant difference in procedural duration between two groups (WMD = -0.8; 95% CI: -2.24 to 0.74; P = 0.31; I(2) = 0).
  
  
  CONCLUSIONS
  Ultrasound-guided knee joint arthrocentesis offer a significantly greater accuracy and clinical improvement over landmark technique in adults with knee pain or joint effusion.
authors.affiliation: Department of Rehabilitation Medicine, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, 3 E Qin Chun Rd, Hang Zhou 310016, PR China. Electronic address: Wutao1880@163.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Wu
authors.affiliation: Department of Rehabilitation Medicine, Hang Zhou Hospital of Zhejiang CAPF, Hang Zhou 310016, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Department of Rehabilitation Medicine, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, 3 E Qin Chun Rd, Hang Zhou 310016, PR China.
authors.forename: Hai xin
authors.initials: Hx
authors.lastname: Song
authors.affiliation: Department of Rehabilitation Medicine, Alxa League Central Hospital, Inner Mongolia Autonomous Region 750306, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Department of Rehabilitation Medicine, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, 3 E Qin Chun Rd, Hang Zhou 310016, PR China.
authors.forename: Jian Hua
authors.initials: JH
authors.lastname: Li
mesh_terms: D000069237:Arthrocentesis / Q000379:methods*; D006801:Humans; D007270:Injections, Intra-Articular / Q000379:methods; D007719:Knee Joint / Q000000981:diagnostic imaging*; D018084:Ultrasonography, Interventional
keywords: Accuracy; Arthrocentesis; Knee; Ultrasound