Scott T Nishioka1, Samantha N Andrews2,3, Kristin Mathews1, Cass K Nakasone1,4. 1. Bone & Joint Center, Straub Medical Center, 888 South King Street, Honolulu, HI, 96818, USA. 2. Bone & Joint Center, Straub Medical Center, 888 South King Street, Honolulu, HI, 96818, USA. samantha.andrews@straub.net. 3. Department of Surgery, University of Hawai'i, John A. Burns School of Medicine, 1356 Lusitana Street, Honolulu, HI, 96813, USA. samantha.andrews@straub.net. 4. Department of Surgery, University of Hawai'i, John A. Burns School of Medicine, 1356 Lusitana Street, Honolulu, HI, 96813, USA.
Abstract
INTRODUCTION: Periprosthetic femoral fractures are an increasingly common post-operative complication of total hip arthroplasty (THA). Though varus malalignment is known to increase fracture risk in standard-length femoral stems, varus malalignment is not as well studied in short stems. Therefore, the purpose of this study was to determine if varus malalignment contributes to early periprosthetic fracture risk in a cementless taper-wedged, short femoral stem. MATERIALS AND METHODS: This retrospective review included 366 consecutive patients (441 THAs) having undergone THA via anterior approach by a single surgeon between July 2014 and December 2016. All patients received the same short, cementless femoral stem. Femoral component angle was measured on 6-week post-THA weight-bearing radiographs, with malalignment defined as a femoral component angle exceeding 0° ± 3°. Periprosthetic femoral fracture and aseptic loosening occurring within 2 years post-THA were recorded. RESULTS: The final data analysis included 426 hips with a mean follow-up time of 32.9 ± 10.2 months. Varus and neutral alignment occurred in 84 (19.6%) and 342 (79.9%) of stems, respectively. Three (0.7%) periprosthetic femoral fractures occurred within 2 years, all occurring in patients with neutrally aligned femoral stems. One (0.2%) stem failed due to aseptic loosening and was malaligned. CONCLUSION: Despite nearly 20% of stems placed in varus alignment, three of the four early complications occurred in a neutrally aligned stem. Based on these results, forceful intraoperative realignment of a short femoral stem with good initial fixation may present an unnecessary increased risk of intraoperative fracture.
INTRODUCTION: Periprosthetic femoral fractures are an increasingly common post-operative complication of total hip arthroplasty (THA). Though varus malalignment is known to increase fracture risk in standard-length femoral stems, varus malalignment is not as well studied in short stems. Therefore, the purpose of this study was to determine if varus malalignment contributes to early periprosthetic fracture risk in a cementless taper-wedged, short femoral stem. MATERIALS AND METHODS: This retrospective review included 366 consecutive patients (441 THAs) having undergone THA via anterior approach by a single surgeon between July 2014 and December 2016. All patients received the same short, cementless femoral stem. Femoral component angle was measured on 6-week post-THA weight-bearing radiographs, with malalignment defined as a femoral component angle exceeding 0° ± 3°. Periprosthetic femoral fracture and aseptic loosening occurring within 2 years post-THA were recorded. RESULTS: The final data analysis included 426 hips with a mean follow-up time of 32.9 ± 10.2 months. Varus and neutral alignment occurred in 84 (19.6%) and 342 (79.9%) of stems, respectively. Three (0.7%) periprosthetic femoral fractures occurred within 2 years, all occurring in patients with neutrally aligned femoral stems. One (0.2%) stem failed due to aseptic loosening and was malaligned. CONCLUSION: Despite nearly 20% of stems placed in varus alignment, three of the four early complications occurred in a neutrally aligned stem. Based on these results, forceful intraoperative realignment of a short femoral stem with good initial fixation may present an unnecessary increased risk of intraoperative fracture.
Authors: Colin G Murphy; Michel P Bonnin; Antoine H Desbiolles; Yannick Carrillon; Tarik Aїt Si Selmi Journal: Hip Int Date: 2016-10-15 Impact factor: 2.135
Authors: Jeffrey N Katz; Elizabeth A Wright; John Wright; Henrik Malchau; Nizar N Mahomed; Margaret Stedman; John A Baron; Elena Losina Journal: J Bone Joint Surg Am Date: 2012-10-17 Impact factor: 5.284