Substantially higher prevalence of postoperative periprosthetic fractures in octogenarians with hip fractures operated with a cemented, polished tapered stem rather than an anatomic stem: A prospective cohort study involving 979 hips

© 2016 The Author(s). Published by Taylor & Francis on behalf of the Nordic Orthopedic Federation. This is an Open Access article distributed under the terms of the Creative Commons Attribution-Non-Commercial License (https://creativecommons.org/licenses/by-nc/3.0) DOI 10.1080/17453674.2016.1247561 Sir,—We read with interest the paper by Mukka et al. (2016) concerning periprosthetic femoral fractures around a CPT versus SPII stem. On page 257 the authors write “the SHAR does not capture patients treated with open reduction and internal fi xation without exchange of the implant” referring to the annual report of SHAR (Swedish Hip Arthroplasty Register), 2014. At page 10–11 (English version) of this annual report we describe how many periprosthetic femoral fractures (PPFF) had not been registered to SHAR and analyze some characteristics of this patient category. SHAR registers both primary hip arthroplasties and reoperations. Reoperation includes all kinds of surgical intervention that can be directly related to an inserted hip arthroplasty irrespective of whether the prosthesis or one of its parts has been exchanged, extracted or left untouched (page 51, annual report 2014, English version). Periprosthetic fractures that are treated with open reduction and internal fi xation without exchange of the implants have been reported to the SHAR since 1979 as reoperations and not as revisions. In an ongoing study we have found that a relatively great proportion of the unreported reoperations due to PPFF belong to this category. Furthermore, on page 260 of the paper, Mukka et al. refer to the study of Thien et al. 2014 concerning the reporting of PPFF to the SHAR. Thien’s paper studies revisions due to PPFF based on the data from NARA (Nordic Arthroplasty Register Association) and not only from SHAR. All registries, except the SHAR, register only revisions and not all kinds of reoperations of hip arthroplasties.