COPYRIGHT © SLACK INCORPORATED n Feature Article C ement-in-cement revision total hip arthroplasty (THA) is defined as the removal of a femoral com- ponent from its intact cement mantle and the replacement of a cemented femoral component into the same cement mantle. This is a powerful technique for revision THA, especially to gain acetabular expo- sure; change a damaged or loose femoral component; change the version, offset, or length of a fixed femoral component; or repair a Vancouver B1 periprosthetic frac- ture with an intact cement mantle. 1 The cement-in-cement technique re- quires an intact bone–cement interface, removal of the femoral component with a high-speed burr and femoral extractor, reaming or roughening of the old cement mantle, meticulous drying of the canal, and application of wet cement to allow bonding and interdigitation to the old ce- ment mantle. 1-3 The new cement mantle has 94% of the shear strength of the old cement mantle and is stronger than the old cement–bone interface. 4,5 In addition, prior fatigue to the old cement mantle does not affect final construct strength. 6 Cementation of the femoral com- ponent is not as common in the United States as in Europe. Hence, opportuni- ties for more advanced cementation tech- niques are not encountered as frequently and may have drastically different results. Revision Total Hip Arthroplasty Using the Cement-in-Cement Technique DEREK F. AMANATULLAH, MD, PHD; GRAHAM D. PALLANTE, MD; LORENA V. FLOCCARI, MD; GEORGE I. VASILEIADIS, MD, PHD; ROBERT T. TROUSDALE, MD The authors are from Stanford University (DFA), Palo Alto, California; and the Department of Orthopedic Surgery (GDP, LVF, GIV, RTT), Mayo Clinic, Rochester, Minnesota. Drs Pallante, Floccari, and Vasileiadis have no relevant financial relationships to disclose. Dr Amanatullah is a paid consultant for Omni and Blue Jay Mobile Health, and his institution has received grants from Acumed and Blue Jay Mo- bile Health. Dr Trousdale receives royalties from DePuy. Correspondence should be addressed to: Robert T. Trousdale, MD, Department of Orthope- dic Surgery, Mayo Clinic, 200 First St SW, Roch- ester, MN 55905 (trousdale.robert@mayo.edu). Received: June 16, 2016; Accepted: October 31, 2016. doi: 10.3928/01477447-20161213-05 abstract The cement-in-cement technique is useful in the setting of revision total hip arthroplasty (THA), especially to gain acetabular exposure, change a dam- aged or loose femoral component, or change the version, offset, or length of a fixed femoral component. The goal of this retrospective study was to assess the clinical and radiographic characteristics of revision THA using the cement-in- cement technique. Between 1971 and 2013, a total of 63 revision THAs used an Omnifit (Osteonics, Mahwah, New Jersey) or Exeter (Howmedica, Mahwah, New Jersey) stem and the cement-in-cement technique at the senior author’s institution. Aseptic loosening (74%) was the predominant preoperative diag- nosis followed by periprosthetic fracture (14%), instability (8%), and implant fracture (6%). Mean clinical follow-up was 5.5±3.8 years. The Harris Hip Score had a statistically significant increase of 18.5 points (P<.001) after revision THA using the cement-in-cement technique. There were 13 returns to the op- erating room, resulting in an overall failure rate of 21%. Eleven (18%) cases required revision THA, but only 1 (2%) revision THA was for aseptic removal of the femoral component. All other femoral implants had no evidence of compo- nent migration, cement mantel fracture, or circumferential lucent lines at final follow-up. The patients who underwent cement-in-cement revision THA at the senior author’s institution had good restoration of function but a high compli- cation rate. [Orthopedics. 2017; 40(2):e348-e351.] e348