Purpose: The purpose of this study was to estimate the radiographic prevalence of CAM-type femoroacetabular impingement (FAI) in elderly patients (≥50 years) who have undergone internal fixation for femoral neck fracture. Methods: A total of 187 frog-leg lateral radiographs of elderly patients who underwent internal fixation for a femoral neck fracture were reviewed by two independent reviewers. The alpha angle, beta angle, and femoral head-neck offset ratio were calculated. The presence of two abnormal radiographic parameters was deemed to be diagnostic of radiographic CAM-type impingement. Results: Radiographic CAM-type FAI was identified in 157 out of 187 (84 %) patients who underwent internal fixation for fractures of the femoral neck. Moderate-to-good inter-observer reliability was achieved in the measurement of radiographic parameters. With reference to fracture subtypes and prevalence of radiographic features of CAM-type morphology, 97 (72 %) out of 134 patients were positive for CAM in Garden subtypes I and II, whereas 49 (85.9 %) out of 57 patients had radiographic CAM in Garden III and IV subtypes. Conclusion: There was a high prevalence of CAM-type FAI in patients that underwent surgical fixation of femoral neck fractures. This is significantly higher than the reported prevalence in non-fracture patient populations. The high prevalence of CAM morphology could be related to several factors, including age, fracture morphology, quality of reduction, type of fixation, and fracture healing. Level of evidence: IV.
Bibliographical noteFunding Information:
Research grants were received from the following: Canadian Institutes of Health Research (CIHR) (PI: Mohit Bhandari); National Institutes of Health (NIH) (PI: Marc Swiontkowski); Stichting NutsOhra (PI: Martin J. Heet-veld), The Netherlands Organisation for Health Research and Development (PI: Esther M.M. Van Lieshout); Physicians’ Services Incorporated (PI: Mohit Bhandari). Dr. Bhandari was also funded, in part, by a Canada Research Chair in Musculoskeletal Trauma which is unrelated to the present study (McMaster University, Hamilton, ON, Canada). The funding sources had no role in design or conduct of the study; the collection, management, analysis, or interpretation of the data; or the preparation, review, or approval of the manuscript. Dr. Mohit Bhandari had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Copyright 2014 Elsevier B.V., All rights reserved.
- Femoral neck fractures
- Femoroacetabular impingement
- Internal fixation
- Open reduction