Basic ScienceMechanical Influence of Pubic Nonunion on the Stress Distribution After Curved Periacetabular Osteotomy: Patient-Specific Three-Dimensional Finite Element Analysis
Section snippets
Materials and Methods
This study was approved by our Institutional Review Board (approval no. 2018M057).
From January to December 2016, CPO was performed in 28 hips of 27 patients for the treatment of symptomatic dysplasia at our hospital. All surgical procedures were performed by 2 surgeons. We excluded 7 hips because postoperative radiographs or postoperative CT scans after CPO were incomplete. We also excluded 3 hips because the osteotomy sites in the pubic ramus exhibited nonunion after CPO.
Preoperative and
Results
This study included 18 consecutive hips (17 patients: 1 male, 16 females) with union of all the osteotomy sites (pubic ramus, ischial ramus, and ilium) on postoperative CT scans after CPO (Fig. 1). Table 1 presents the patients’ demographic data. Patients’ mean age at the time of surgery was 35.5 (range 23.8-44.3) years, and their mean body mass index was 23.4 (range 21.0-25.8) kg/m2. Follow-up postoperative CT scanning was performed at 13.7 (range 10.1-24.6) months.
The mean contact area in the
Discussion
The primary finding of this study was that pubic nonunion did not influence mechanical joint stress distribution in the hip joint. Additional findings of the study included increases in mechanical stress concentration at the ischial ramus.
Computational FE analysis is considered to be useful for the evaluation of mechanical stress distribution and direction in the hip joint as well as in the upper extremities [[9], [10], [11], [12],18]. The accuracy of FE analysis has been proven based on
Conclusion
FE analysis revealed that pubic nonunion did not affect the mechanical distribution in the hip joint itself but increased the mean equivalent stress at the ischial ramus. This finding suggests the importance of achieving pubic union after CPO to avoid the risk of ischial ramus stress fracture.
Acknowledgments
We thank Edanz (https://jp.edanz.com/ac) for editing a draft of this manuscript.
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
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No author associated with this paper has disclosed any potential or pertinent conflicts which may be perceived to have impending conflict with this work. For full disclosure statements refer to https://doi.org/10.1016/j.arth.2022.02.071.