title: Digital tomosynthesis with metal artifact reduction for assessing cementless hip arthroplasty: a diagnostic cohort study of 48 patients.
abstract: OBJECTIVE
  For postoperative imaging assessment of cementless hip arthroplasty, radiography and computed tomography (CT) were restricted by overlapping structures and metal artifacts, respectively. A new tomosynthesis with metal artifact reduction (TMAR) is introduced by using metal extraction and ordered subset-expectation maximization (OS-EM) reconstruction. This study investigated the effectiveness of TMAR in assessing fixation stability of cementless hip arthroplasty components.
  
  
  METHODS
  We prospectively included 48 consecutive patients scheduled for revision hip arthroplasty in our hospital, with 41 femoral and 35 acetabular cementless components available for evaluation. All patients took the three examinations of radiography, CT, and TMAR preoperatively, with intraoperative mechanical tests, and absence or presence of osteointegration on retrieved prosthesis as reference standards. Three senior surgeons and four junior surgeons evaluated these images independently with uniform criteria.
  
  
  RESULTS
  For TMAR, 82 % diagnoses on the femoral side and 84 % diagnoses on the acetabular side were accurate. The corresponding values were 44 and 67 % for radiography, and 39 % and 74 % for CT. Senior surgeons had significantly higher accuracy than junior surgeons by radiography (p < 0.05), but not by TMAR or CT.
  
  
  CONCLUSIONS
  By minimizing metal artifacts in the bone-implant interface and clearly depicting peri-implant trabecular structures, the TMAR technique improved the diagnostic accuracy of assessing fixation stability of cementless hip arthroplasty, and shortened the learning curve of less experienced surgeons.
  
  
  METHODS
  Level II, diagnostic cohort study.
authors: Department of Orthopaedic Surgery, Beijing Jishuitan Hospital, Fourth Clinical College of Peking University, Beijing, 100035, China.
authors: Hao
authors: H
authors: Tang
authors: Department of Orthopaedic Surgery, Beijing Jishuitan Hospital, Fourth Clinical College of Peking University, Beijing, 100035, China.
authors: Dejin
authors: D
authors: Yang
authors: Department of Orthopaedic Surgery, Beijing Jishuitan Hospital, Fourth Clinical College of Peking University, Beijing, 100035, China.
authors: Shengjie
authors: S
authors: Guo
authors: Department of Orthopaedic Surgery, Beijing Jishuitan Hospital, Fourth Clinical College of Peking University, Beijing, 100035, China.
authors: Jing
authors: J
authors: Tang
authors: Department of Orthopaedic Surgery, Beijing Jishuitan Hospital, Fourth Clinical College of Peking University, Beijing, 100035, China.
authors: Jian
authors: J
authors: Liu
authors: Department of Orthopaedic Surgery, Beijing Jishuitan Hospital, Fourth Clinical College of Peking University, Beijing, 100035, China.
authors: Dacheng
authors: D
authors: Wang
authors: Department of Orthopaedic Surgery, Beijing Jishuitan Hospital, Fourth Clinical College of Peking University, Beijing, 100035, China. orthoyixin@yahoo.com.
authors: Yixin
authors: Y
authors: Zhou
mesh_terms: D000368:Aged; D001175:Arthrography / Q000379:methods; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation / Q000379:methods*; D016477:Artifacts; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D061825:Metal-on-Metal Joint Prostheses; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods*; D012086:Reoperation / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
keywords: Cementless total hip arthroplasty; Diagnostic accuracy; Digital tomosynthesis; Fixation stability; Radiolucent line; Spot weld