Atypical femoral fractures are a separate entity, characterized by highly specific radiographic features. A comparison of 59 cases and 218 controls
(2013) In Bone 52(1). p.389-392- Abstract
- Background: Estimations of the risk of bisphosphonate associated atypical femoral fractures vary between different population-based studies, from considerable to neglectable. A possible explanation for these discrepancies could be different definitions of atypical fractures. We aimed to identify specific radiographic fracture characteristics associated with bisphosphonate use. Methods: In a previous nationwide study, 59 atypical and 218 ordinary fractures were diagnosed. The atypical fractures were defined by their stress-type fracture pattern. All fractures were now re-assessed by a physician in training, without information about bisphosphonate use. The fracture angle (0-180 degrees) was measured. Presence of local lateral cortical... (More)
- Background: Estimations of the risk of bisphosphonate associated atypical femoral fractures vary between different population-based studies, from considerable to neglectable. A possible explanation for these discrepancies could be different definitions of atypical fractures. We aimed to identify specific radiographic fracture characteristics associated with bisphosphonate use. Methods: In a previous nationwide study, 59 atypical and 218 ordinary fractures were diagnosed. The atypical fractures were defined by their stress-type fracture pattern. All fractures were now re-assessed by a physician in training, without information about bisphosphonate use. The fracture angle (0-180 degrees) was measured. Presence of local lateral cortical thickening (a callus reaction), more than 2 fragments, or a medial spike was noted. The reader then made a judgment whether the fracture appeared as an atypical fracture based on the ASBMR criteria. Results: Frequency distribution analysis of the fracture angle showed a distinct subgroup, comprising 25% of all 277 fractures, with a mean of 89 and SD of 10 degrees. Forty-two of 57 patients in this subgroup used bisphosphonates, whereas only 27 of 213 others did (specificity 0.93; 95% CI 0.88-0.96). Presence of a callus reaction had also a high specificity for bisphosphonate use (0.96; 95% CI 0.92-0.98). The ASBMR criteria had a lower specificity, increasing the number of atypical fractures without bisphosphonate use from 13 to 31. This led to a decrease in age-adjusted relative risk associated with bisphosphonate use from 47 (95% CI 26-87) to 19 (95% CI 12-29). Interpretation: Stress fractures of the femoral shaft are a specific entity, which is easily diagnosed on radiographs and strongly related to bisphosphonate use. Differences in diagnostic criteria may partially explain the large differences in relative risk between different population-based studies. (C) 2012 Elsevier Inc. All rights reserved. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/3481019
- author
- Schilcher, Jorg ; Koeppen, Veronika ; Ranstam, Jonas LU ; Skripitz, Ralf ; Michaelsson, Karl and Aspenberg, Per
- organization
- publishing date
- 2013
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Atypical femoral fracture, Bisphosphonate, Stress fracture, Osteoporosis
- in
- Bone
- volume
- 52
- issue
- 1
- pages
- 389 - 392
- publisher
- Elsevier
- external identifiers
-
- wos:000312750700046
- scopus:84868651511
- pmid:23098829
- ISSN
- 1873-2763
- DOI
- 10.1016/j.bone.2012.10.016
- language
- English
- LU publication?
- yes
- id
- 96552efa-a589-4e37-b5e6-bd46b442971b (old id 3481019)
- date added to LUP
- 2016-04-01 13:28:01
- date last changed
- 2022-02-04 07:40:58
@article{96552efa-a589-4e37-b5e6-bd46b442971b,
abstract = {{Background: Estimations of the risk of bisphosphonate associated atypical femoral fractures vary between different population-based studies, from considerable to neglectable. A possible explanation for these discrepancies could be different definitions of atypical fractures. We aimed to identify specific radiographic fracture characteristics associated with bisphosphonate use. Methods: In a previous nationwide study, 59 atypical and 218 ordinary fractures were diagnosed. The atypical fractures were defined by their stress-type fracture pattern. All fractures were now re-assessed by a physician in training, without information about bisphosphonate use. The fracture angle (0-180 degrees) was measured. Presence of local lateral cortical thickening (a callus reaction), more than 2 fragments, or a medial spike was noted. The reader then made a judgment whether the fracture appeared as an atypical fracture based on the ASBMR criteria. Results: Frequency distribution analysis of the fracture angle showed a distinct subgroup, comprising 25% of all 277 fractures, with a mean of 89 and SD of 10 degrees. Forty-two of 57 patients in this subgroup used bisphosphonates, whereas only 27 of 213 others did (specificity 0.93; 95% CI 0.88-0.96). Presence of a callus reaction had also a high specificity for bisphosphonate use (0.96; 95% CI 0.92-0.98). The ASBMR criteria had a lower specificity, increasing the number of atypical fractures without bisphosphonate use from 13 to 31. This led to a decrease in age-adjusted relative risk associated with bisphosphonate use from 47 (95% CI 26-87) to 19 (95% CI 12-29). Interpretation: Stress fractures of the femoral shaft are a specific entity, which is easily diagnosed on radiographs and strongly related to bisphosphonate use. Differences in diagnostic criteria may partially explain the large differences in relative risk between different population-based studies. (C) 2012 Elsevier Inc. All rights reserved.}},
author = {{Schilcher, Jorg and Koeppen, Veronika and Ranstam, Jonas and Skripitz, Ralf and Michaelsson, Karl and Aspenberg, Per}},
issn = {{1873-2763}},
keywords = {{Atypical femoral fracture; Bisphosphonate; Stress fracture; Osteoporosis}},
language = {{eng}},
number = {{1}},
pages = {{389--392}},
publisher = {{Elsevier}},
series = {{Bone}},
title = {{Atypical femoral fractures are a separate entity, characterized by highly specific radiographic features. A comparison of 59 cases and 218 controls}},
url = {{http://dx.doi.org/10.1016/j.bone.2012.10.016}},
doi = {{10.1016/j.bone.2012.10.016}},
volume = {{52}},
year = {{2013}},
}