title: Radiological Stability after Revision of Infected Total Knee Arthroplasty Using Modular Metal Augments.
abstract: OBJECTIVE
  To evaluate the radiological stability according to the number of modular augments after revision of infected total knee arthroplasty (TKA).
  
  
  METHODS
  Between February 2006 and September 2013, 37 patients (39 knees) followed ≥2 years after revision of infected TKA using modular metal augments for bone defects were reviewed retrospectively. We divided the patients into 3 groups according to the number of augments into group A (≤2 augments, 14 knees), group B (3-4 augments, 18 knees), and group C (5≥ augments, 7 knees) and evaluated the width of radiolucent zones around the implant at the last follow-up.
  
  
  RESULTS
  There were 3 Anderson Orthopedic Research Institute type I, 33 type II, and 3 type III bone defects. The mean number of radiolucent zones of group A was 3 and the sum of width averaged 4.4 mm. In group B, the values were 4.8 and 6.2 mm, respectively. In group C, the values were 8.1 and 12.9 mm, respectively. The differences between the three groups were statistically significant.
  
  
  CONCLUSIONS
  In revision TKA with modular metal augmentation caused by infected TKA, increased modularity can result in radiological instability.
authors.affiliation: Department of Orthopedic Surgery, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Kyung-Jae
authors.initials: KJ
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Ki-Cheor
authors.initials: KC
authors.lastname: Bae
authors.affiliation: Department of Orthopedic Surgery, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Chul-Hyun
authors.initials: CH
authors.lastname: Cho
authors.affiliation: Department of Orthopedic Surgery, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Eun-Seok
authors.initials: ES
authors.lastname: Son
authors.affiliation: Department of Orthopedic Surgery, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Jae-Won
authors.initials: JW
authors.lastname: Jung
keywords: Knee; Modular metal augmentation; Radiologic stability; Revision arthroplasty