Cam-type femoroacetabular impingement—correlations between alpha angle versus volumetric measurements and surgical findings

Dessouky, Riham; Chhabra, Avneesh; Zhang, Lihua; Gleason, Adam; Chopra, Rajiv; Chatzinoff, Yonatan; Fey, Nicholas P.; Xi, Yin; Wells, Joel

doi:10.1007/s00330-018-5968-z

Cited by 21 publications

(24 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…DDH is an abnormality of the acetabulum, while FAI mostly affects the femoral head and neck. DDH is characterized by a static overload [2], while FAI is a painful, dynamic and early osseous conflict between proximal femur and the acetabulum which limits range of motion (ROM) [1,3,4]. Commonly used clinical tests for diagnosis have a low sensitivity and specificity [5,6].…”

Section: Introductionmentioning

confidence: 99%

MRI-based 3D models of the hip joint enables radiation-free computer-assisted planning of periacetabular osteotomy for treatment of hip dysplasia using deep learning for automatic segmentation

Zeng

Schmaranzer

Degonda

et al. 2021

European Journal of Radiology Open

View full text Add to dashboard Cite

Introduction Both Hip Dysplasia(DDH) and Femoro-acetabular-Impingement(FAI) are complex three-dimensional hip pathologies causing hip pain and osteoarthritis in young patients. 3D-MRI-based models were used for radiation-free computer-assisted surgical planning. Automatic segmentation of MRI-based 3D-models are preferred because manual segmentation is time-consuming. To investigate(1) the difference and(2) the correlation for femoral head coverage(FHC) between automatic MR-based and manual CT-based 3D-models and (3) feasibility of preoperative planning in symptomatic patients with hip diseases. Methods We performed an IRB-approved comparative, retrospective study of 31 hips(26 symptomatic patients with hip dysplasia or FAI). 3D MRI sequences and CT scans of the hip were acquired. Preoperative MRI included axial-oblique T1 VIBE sequence(0.8 mm 3 isovoxel) of the hip joint. Manual segmentation of MRI and CT scans were performed. Automatic segmentation of MRI-based 3D-models was performed using deep learning. Results (1)The difference between automatic and manual segmentation of MRI-based 3D hip joint models was below 1 mm(proximal femur 0.2 ± 0.1 mm and acetabulum 0.3 ± 0.5 mm). Dice coefficients of the proximal femur and the acetabulum were 98 % and 97 %, respectively. (2)The correlation for total FHC was excellent and significant(r = 0.975, p < 0.001) between automatic MRI-based and manual CT-based 3D-models. Correlation for total FHC (r = 0.979, p < 0.001) between automatic and manual MR-based 3D models was excellent. (3)Preoperative planning and simulation of periacetabular osteotomy was feasible in all patients(100 %) with hip dysplasia or acetabular retroversion. Conclusions Automatic segmentation of MRI-based 3D-models using deep learning is as accurate as CT-based 3D-models for patients with hip diseases of childbearing age. This allows radiation-free and patient-specific preoperative simulation and surgical planning of periacetabular osteotomy for patients with DDH.

show abstract

Section: Introductionmentioning

confidence: 99%

MRI-based 3D models of the hip joint enables radiation-free computer-assisted planning of periacetabular osteotomy for treatment of hip dysplasia using deep learning for automatic segmentation

Zeng

Schmaranzer

Degonda

et al. 2021

European Journal of Radiology Open

View full text Add to dashboard Cite

show abstract

“…Cam type is characterized by abnormal or aspheric morphology of the femoral head, pincer type is characterized by focal or global acetabular overcoverage, and mixed type has both cam and pincer characteristics. [1][2][3][4]7,8,[15][16][17][18][19]22,50 In general, the acetabular opening of the normal hip is anteversion in the axial plane. 33,39,42,43,52 Acetabular retroversion results in a prominent anterolateral edge of the acetabulum and potentially increases anterolateral coverage of the femoral head.…”

mentioning

confidence: 99%

The Prevalence of Radiographic Findings of Structural Hip Deformities for Femoroacetabular Impingement in Patients With Hip Pain

et al. 2020

View full text Add to dashboard Cite

Background: Radiography is the initial imaging modality used to evaluate femoroacetabular impingement (FAI), and diagnostic radiographic findings are well-established. However, the prevalence of these radiographic findings in patients with hip pain is unknown. Purpose: The purpose was 3-fold: (1) to determine the overall prevalence of radiographic FAI deformities in young patients presenting with hip pain, (2) to identify the most common radiographic findings in patients with cam-type FAI, and (3) to identify the most common radiographic findings in patients with pincer-type FAI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A geographic database was used to identify patients aged 14 to 50 years with hip pain between the years 2000 to 2016. The following were evaluated on radiographs: cam type: typical pistol grip deformity, alpha angle >55°; pincer type: crossover sign (COS), coxa profunda or protrusio acetabuli, lateral center edge angle (LCEA) ≥40°, Tönnis angle <0°; and mixed type: both cam- and pincer-type features. Posterior wall sign (PWS) and ischial spine sign (ISS) were also evaluated. The prevalence of each was determined. Descriptive statistics were performed on all radiographic variables. Results: There were 1893 patients evaluated, and 1145 patients (60.5%; 1371 hips; 374 male and 771 female; mean age, 28.8 ± 8.4 years) had radiographic findings consistent with FAI. Of these hips, 139 (10.1%) had cam type, 245 (17.9%) had pincer type, and 987 (72.0%) had mixed type. The prevalence of a pistol grip deformity and an alpha angle >55° was 577 (42.1%) and 1069 (78.0%), respectively. The mean alpha angle was 66.9°± 10.5°. The prevalence of pincer-type radiographic findings was the following: COS, 1062 (77.5%); coxa profunda, 844 (61.6%); ISS, 765 (55.8%); PWS, 764 (55.7%); Tönnis angle <0°, 312 (22.8%); LCEA ≥40°, 170 (12.4%); and protrusio acetabuli, 7 (0.5%). Conclusion: The overall prevalence of radiographic findings consistent with FAI in young patients with hip pain was 60.5%. Radiographic findings for mixed-type FAI were the most prevalent. The most common radiographic finding for cam-type FAI was an alpha angle >55°. The most common radiographic finding for pincer-type FAI was the COS.

show abstract

“…Furthermore, they showed that agreement between CT and MRI depended on the underlying deformity, observing greater discrepancies for alpha angles in Cam deformities and acetabular parameters in dysplasia. Dessouky et al report fair to moderate agreement for CT with manual segmentation in both interobserver analysis (ICC: 0.48-0.05) and intraobserver analysis (ICC: 0.49-0.24) [16]. At the same time Xia et al present a patient collective in which they measured alpha angles in different MRI sequences with a fully automated software, as well as manually, and measured good ICCs (anterosuperior 0.84, anterior 0.92) [13].…”

Section: Discussionmentioning

confidence: 99%

MRI-based static and functional assessment of complex hip deformities in comparison with CT: a validation study

Blum

Franken

Hartmann

et al. 2020

Magn Reson Mater Phy

View full text Add to dashboard Cite

Objective This study aimed at investigating the agreement between predefined quantitative parameters of hip morphology derived from magnetic resonance imaging (MRI) and virtual range of motion (ROM) analysis using computed tomography (CT) as standard of reference. Methods Twenty patients (13 females, 7 males, 16-59 years) with hip deformities underwent MRI prior to surgery. Clockwise alpha angle, femoral head and neck diameter, collum caput diaphysis angle, femoral torsion, center-edge angles, acetabular coverage of the femoral head, sourcil angle, and acetabular anteversion were measured. Additionally, tern single and combined movements were simulated using a motion analysis program. The MRI findings were compared with the corresponding results obtained by CT. Correlation of MRI with CT was assessed using different statistical methods (intraclass correlation coefficient, Bland-Altmann plot, two one-sided t test), and linear regression analysis was performed. ResultsThe results showed near-perfect intraclass correlation coefficients (ICCs) for anteversion (0.95), acetabular sector angles (0.98-0.99), sourcil angle (0.95), and acetabular coverage (anterior 0.96, posterior 0.99). Intermethod correlation for femoral parameters showed almost perfect agreement except for the alpha angle (0.73-0.97). No significant proportional bias was detected for traditional acetabular and femoral parameters. ROM analysis was performed for 370 movements in 37 hips. For 78.4% (290/370) of the movements analysed, neither CT nor MRI detected impingement across the physiological ROM. For 18.6% (69/370) of the movements, impingement was detected by both CT and MRI, while 2.2% (8/370) of the movements with impingement in CT showed no impingement in MRI, and 0.8% (3/370) of the movements with impingement in MRI had no corresponding result in CT. Conclusion Finally, it was concluded that MRI-based assessment of hip morphology and virtual ROM analysis is feasible and can be performed with good intermethod agreement in comparison to the gold standard (CT). Therefore, MRI appears to be substantially equivalent to CT for use in virtual ROM analysis and so may reasonably be used in place of CT for this purpose.

show abstract

Cam-type femoroacetabular impingement—correlations between alpha angle versus volumetric measurements and surgical findings

Cited by 21 publications

References 32 publications

MRI-based 3D models of the hip joint enables radiation-free computer-assisted planning of periacetabular osteotomy for treatment of hip dysplasia using deep learning for automatic segmentation

MRI-based 3D models of the hip joint enables radiation-free computer-assisted planning of periacetabular osteotomy for treatment of hip dysplasia using deep learning for automatic segmentation

The Prevalence of Radiographic Findings of Structural Hip Deformities for Femoroacetabular Impingement in Patients With Hip Pain

MRI-based static and functional assessment of complex hip deformities in comparison with CT: a validation study

Contact Info

Product

Resources

About