Radiology: MRI quickly assesses hip abnormalities in those with in-toeing gait
Femoral antetorsion, or in-toeing, can be measured rapidly and with good reproducibility with MRI, and information from this scan can be useful in treatment planning for patients experiencing joint friction, according to a study published online March 8 in Radiology.
Abnormal femoral antetorsion could be a contributing factor in the development of femoroacetabular impingement (FAI), according to study authors Reto Sutter, MD, and colleagues from Orthopedic University Hospital Balgrist in Zurich. Their goal was to assess the range of femoral antetorsion using MRI in patients with different subtypes of FAI.
FAI is divided into two forms: cam-type hips with abnormalities in the femoral head and neck, or pincer-type hips which occur when the acetabulum, or socket, has too much coverage of the femoral head. The condition is thought to be a major cause of early-onset osteoarthritis of the hip.
Researchers gathered 63 asymptomatic volunteers and 63 patients with symptomatic FAI who were matched for age and sex. All patients underwent standard MR imaging (20 volunteers underwent a second MRI exam in the same leg) and two readers independently measured femoral antetorsion. Procedure time was also calculated.
“Femoral antetorsion can be assessed with MR imaging in about 80 seconds, with high interobserver agreement and high agreement between different MR examinations,” reported the authors. Femoral antetorsion was significantly higher in patients with pincer-type FAI than cam-type FAI. Reader one reported antetorsion of 18.3° in pincer-type FAI patients compared with 10° in cam-type FAI patients, while reader two reported antetorsion of 18.7° and 11.6° for pincer-type and cam-type FAI patients, respectively.
“With such fast acquisition times and highly reliable measurements, the evaluation of femoral antetorsion might be included in the routine MR evaluation of the hip,” wrote the authors. “This allows the evaluation of the morphology of the proximal femur and acetabulum, the detection of labrum and cartilage lesions, and the measurement of femoral antetorsion at one single examination, without the need of using radiation for measuring femoral antetorsion in these mostly young patients.”
Sutter et al noted that using MRI to assess femoral antetorsion could be useful in treatment planning for patients with FAI.
“Orthopedic surgeons might be interested to know the femoral antetorsion angle of a patient with FAI before performing osteochondroplasty of the proximal femur and acetabular rim resection, because abnormal antetorsion angles could influence their treatment plan. However, on the basis of the wide range of femoral antetorsion angles we found in the population of volunteers, there is no single cutoff value that separates a normal versus an abnormal femoral antetorsion.”
Abnormal femoral antetorsion could be a contributing factor in the development of femoroacetabular impingement (FAI), according to study authors Reto Sutter, MD, and colleagues from Orthopedic University Hospital Balgrist in Zurich. Their goal was to assess the range of femoral antetorsion using MRI in patients with different subtypes of FAI.
FAI is divided into two forms: cam-type hips with abnormalities in the femoral head and neck, or pincer-type hips which occur when the acetabulum, or socket, has too much coverage of the femoral head. The condition is thought to be a major cause of early-onset osteoarthritis of the hip.
Researchers gathered 63 asymptomatic volunteers and 63 patients with symptomatic FAI who were matched for age and sex. All patients underwent standard MR imaging (20 volunteers underwent a second MRI exam in the same leg) and two readers independently measured femoral antetorsion. Procedure time was also calculated.
“Femoral antetorsion can be assessed with MR imaging in about 80 seconds, with high interobserver agreement and high agreement between different MR examinations,” reported the authors. Femoral antetorsion was significantly higher in patients with pincer-type FAI than cam-type FAI. Reader one reported antetorsion of 18.3° in pincer-type FAI patients compared with 10° in cam-type FAI patients, while reader two reported antetorsion of 18.7° and 11.6° for pincer-type and cam-type FAI patients, respectively.
“With such fast acquisition times and highly reliable measurements, the evaluation of femoral antetorsion might be included in the routine MR evaluation of the hip,” wrote the authors. “This allows the evaluation of the morphology of the proximal femur and acetabulum, the detection of labrum and cartilage lesions, and the measurement of femoral antetorsion at one single examination, without the need of using radiation for measuring femoral antetorsion in these mostly young patients.”
Sutter et al noted that using MRI to assess femoral antetorsion could be useful in treatment planning for patients with FAI.
“Orthopedic surgeons might be interested to know the femoral antetorsion angle of a patient with FAI before performing osteochondroplasty of the proximal femur and acetabular rim resection, because abnormal antetorsion angles could influence their treatment plan. However, on the basis of the wide range of femoral antetorsion angles we found in the population of volunteers, there is no single cutoff value that separates a normal versus an abnormal femoral antetorsion.”
Evan Godt, Writer
Evan joined TriMed in 2011, writing primarily for Health Imaging. Prior to diving into medical journalism, Evan worked for the Nine Network of Public Media in St. Louis. He also has worked in public relations and education. Evan studied journalism at the University of Missouri, with an emphasis on broadcast media.