Robert Bleakney MBBCh, FRCPC, Abstract Co-Author: Nothing to Disclose

Linda Probyn MD, Presenter: Nothing to Disclose

Leon Lenchik MD, Abstract Co-Author: Nothing to Disclose

Catherine Lang, Abstract Co-Author: Nothing to Disclose

Jonathan D. Adachi MD, Abstract Co-Author: Consultant, Actavis, Inc Consultant, Amgen Inc Consultant, Eli Lilly and Company Consultant, Merck & Co, Inc Consultant, Novartis AG Speaker, Actavis, Inc Speaker, Amgen Inc Speaker, Eli Lilly and Company Speaker, Merck & Co, Inc Speaker, Novartis AG Research Grant, Amgen Inc Research Grant, Eli Lilly and Company Research Grant, Merck & Co, Inc Research Grant, Novartis AG

Aliya Khan MD, Abstract Co-Author: Consultant, Merck & Co, Inc Consultant, Amgen Inc Consultant, Eli Lilly and Company Consultant, Actavis, Inc Speaker, Merck & Co, Inc Speaker, Amgen Inc Speaker, Eli Lilly and Company Speaker, Actavis, Inc Research Grant, Merck & Co, Inc Research Grant, Amgen Inc Research Grant, NPS Pharmaceuticals

Earl R. Bogoch MD, Abstract Co-Author: Speaker, Merck KgaA Speaker, Merck & Co, Inc Speaker, Amgen Inc Research support, Amgen Inc Research support, Novartis AG Editorial Advisory Board, The Journal of Rheumatology Publishing Company Ltd

Angela Cheung, Abstract Co-Author: Speaker, Amgen Inc Speaker, Eli Lilly and Company Institutional Grant support, Amgen Inc Institutional Grant support, Eli Lilly and Company

Long-term bisphosphonate use has been associated with Atypical Femoral Fractures (AFFs). The purpose of this study is to evaluate the association of fracture morphology and hardware type with hardware failure in patients with AFFs.

Imaging studies of 100 patients with 131 AFFs (4 male, 96 female, mean age 68.1 years) with hardware instrumentation from July 2004 to February 2014 were reviewed. Type of instrumentation, fracture morphology (overall fracture morphology (OFM), lateral cortical fracture angle (LCFA), lateral cortical thickness, femoral angle), and fracture location were compared in the hardware complication group and control group using the Wilcoxon rank sum test or Fisher’s exact test.

131 AFFs had instrumentation (98 for complete and 33 for incomplete fractures). Instrumentation included intramedullary (IM) nailing (117), dynamic hip screw (7), lateral plate (2), short gamma nail (3), total hip arthroplasty (1), and compression plate (1). Hardware complications occurred in 15.3% (21/131) and were more common in complete (18/21) than incomplete (3/21) fractures. Complications included screw fractures in 19%(4/21), plate fractures in 14.3%(3/21), loosening of hardware in 28.6%(6/21), nonunion in 9.5%(2/21), and a combination of complications in 28.6%(6/21). Hardware failure was significantly less common after IM nailing (12.8%) compared to other hardware (35.7%) (p=0.04). Comparing failure to non-failure group, the mean OFM was 31.9° (vs 36.3°), the mean LCFA was 7.0° (vs 11.3°), the mean lateral cortical thickness was 12.1 mm (vs 12.1 mm), the mean medial cortical thickness was 8.9 mm (vs 7.8 mm), femoral angle 133° (vs 133°). Comparing the failure to the non-failure group, the location of fracture was 14.9 cm (vs 16.8 cm) from the greater trochanter. Of all measured parameters, only the LCFA was significantly associated with hardware failure (p= 0.03).

In patients with AFFs, hardware complications are not uncommon. Hardware failure is more common in AFFs with smaller LCFA and when fixation other than IM nailing is used.

Patients who undergo hardware fixation for AFFs are at risk for hardware failure and should be followed for development of complications. Surgeons should consider IM nailing for treatment of AFFs.

Bleakney, R, Probyn, L, Lenchik, L, Lang, C, Adachi, J, Khan, A, Bogoch, E, Cheung, A, Complications of Atypical Femoral Fractures: Does Fracture Morphology or Instrumentation Type Predict Hardware Failure?.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014361.html