Assessment of Femoral Torsion on Magnetic Resonance Imaging is More Reliable Using Axial-Oblique Sequences Compared with Standard Axial Slices in Patients with Femoroacetabular Impingement Syndrome

Author(s):  
Thomas D. Alter ◽  
Kyle N. Kunze ◽  
Alexander C. Newhouse ◽  
Felipe Bessa ◽  
Steven DeFroda ◽  
...  
2021 ◽  
Vol 9 (10) ◽  
pp. 232596712110345
Author(s):  
Steven F. DeFroda ◽  
Thomas D. Alter ◽  
Blake M. Bodendorfer ◽  
Alexander C. Newhouse ◽  
Felipe S. Bessa ◽  
...  

Background: The influence of femoral torsion on clinically significant outcome improvement after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) has not been well-studied. Purpose: To quantify femoral torsion in FAIS patients using magnetic resonance imaging (MRI) and explore the relationship between femoral torsion and clinically significant outcome improvement after hip arthroscopy. Study Design: Cohort study; Level of evidence, 3. Methods: Included were patients who underwent hip arthroscopy for FAIS between January 2012 and August 2018 and had 2-year follow-up and preoperative MRI scans containing transcondylar slices of the knee. Participants were categorized as having severe retrotorsion (SR; <0°), normal torsion (NT; 0°-25°), and severe antetorsion (SA; >25°) as measured on MRI. Patient-reported outcomes (PROs) included the Hip Outcome Score–Activities of Daily Living, Hip Outcome Score–Sports Subscale, modified Harris Hip Score, 12-item International Hip Outcome Tool (iHOT-12), and visual analog scale (VAS) for pain and satisfaction. Achievement of Patient Acceptable Symptom State (PASS) and substantial clinical benefit (SCB) were analyzed among cohorts. Results: Included were 183 patients (SR, n = 13; NT, n = 154; SA, n = 16) with a mean age, body mass index, and femoral torsion of 30.6 ± 12.1 years, 24.0 ± 4.4 kg/m2, and 12.55° ± 9.58°, respectively. The mean torsion was –4.5° ± 2.6° for the SR, 12.1° ± 6.8° for the NT, and 31.0° ± 3.6° for the SA group. There were between-group differences in the proportion of patients who achieved PASS and SCB on the iHOT-12, pain VAS, and any PRO ( P < .05). Post hoc analysis indicated that the SA group achieved lower rates of PASS and SCB on the iHOT-12 and pain VAS, and lower rates of PASS on any PRO versus the SR group ( P < .05); the SR group achieved higher rates of PASS and SCB on pain VAS scores versus the NT group ( P = .003). Conclusion: The orientation and severity of femoral torsion during hip arthroscopy influenced the propensity for clinically significant outcome improvement. Specifically, patients with femoral retrotorsion and femoral antetorsion had higher and lower rates of clinically significant outcome improvement, respectively.


2010 ◽  
Vol 90 (11) ◽  
pp. 1641-1648 ◽  
Author(s):  
Kornelia Kulig ◽  
Kellee Harper-Hanigan ◽  
Richard B. Souza ◽  
Christopher M. Powers

Background Abnormal femoral torsion has been linked to osteoarthritis in the knee as well as to patellofemoral pain. Inexpensive, valid, and reliable methods for assessing femoral torsion are needed. Ultrasound (US) is a noninvasive and clinically accessible method that can be used for the assessment of bone morphology, such as femoral torsion. Objective The objective of this study was to determine the concurrent validity of US for the measurement of femoral torsion with a reference method, magnetic resonance imaging (MRI). Design Repeated measurements of femoral torsion were obtained with US and MRI in a laboratory setting. Methods Twenty-eight people (4 men, 24 women; mean age=26.8 years [SD=4.0 years], mean body height=170.3 cm [SD=8.0 cm], mean body weight=64.7 kg [SD=9.8 kg]) participated in this study. T1-weighted axial oblique images of the femoral neck and epicondylar axis were acquired with a 1.5-T magnetic resonance system. Ultrasonographic measurements then were obtained by a tilting technique with a linear transducer that was 4.5 cm long and operated at a frequency of 10 MHz and a depth of 5 cm. Results The average angles of anteversion measured by US and by MRI were 20.7 degrees (SD=11.0) and 19 degrees (SD=11.3), respectively. The reliability, reported as the intraclass correlation coefficient [ICC (2,1)], of repeated measurements of in vivo femoral torsion by US was .98. The reliability [ICC (2,1)] of magnetic resonance image analysis was .96. The standard error of the measurement for US was 2.2 degrees, and that for MRI was 1.9 degrees. The concurrent validity of US with MRI (R2) was .93 (r=.96). Limitations Obtaining measurements by US requires appropriate training before data collection. Conclusions Ultrasound measurement of femoral torsion has high concurrent validity with in vivo MRI and may be used when an assessment of bony morphology is needed but MRI is not available.


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