Femoral Significantly Better Predictor of Hip ROM

Don’t forget femoral version when working up patients with hip pain, says new multicenter research.

The study, “Femoral Version Abnormalities Significantly Outweigh Effect of Cam Impingement on Hip Internal Rotation,” was published in the February 7, 2018 edition of The Journal of Bone and Joint Surgery.

Omer Mei-Dan, M.D. co-author on the study with the Department of Orthopedics at the University of Colorado School of Medicine in Aurora, told OTW, “Femoral version is an under-recognized contributor to hip pathology and most hip preservation specialists do not include measurement of femoral version in their routine work-up for patients with hip pain.”

“Furthermore, it is widely believed that the femoral cam lesion in FAI [femoroacetabular impingment] is responsible for the loss of internal rotation on physical examination. Our experience led us to believe that femoral version was the dominant predictor of hip rotational range of motion.

The authors wrote, “We prospectively analyzed a consecutive cohort of 220 patients (440 hips) who presented with unilateral or bilateral hip pain. The passive hip ROM [range of motion] was measured bilaterally with the patient in prone, supine, and lateral positions. Femoral version was measured and the presence of cam-type deformity was determined on preoperative computed tomography (CT) scans.”

Dr. Mei-Dan told OTW, “All of our patients undergo routine preoperative CT scanning which enables accurate assessment of both the cam lesion and femoral version. Our standardized approach and high volume of patients are major strengths to this study and enable us to draw conclusions with a higher degree of scientific certainty.”

“We found femoral version to be a more significant predictor of hip range of motion when compared to the cam lesion. Additionally, the cam lesion was found to be a greater predictor of hip flexion than internal rotation, contradictory to what has been commonly believed in the hip preservation community.”

“We recommend routine measurement of femoral version in the workup of pre-arthritis patients with hip pain and correlation with hip rotational range of motion on physical examination. Patient counseling with regard to expected gains in post-operative range of motion following arthroscopic surgery for hip impingement should also take into account that removal of the cam lesion may be more likely to affect post-operative hip flexion than hip rotation.”

“Femoral torsion is an important contributor to hip pathology and should be included in the algorithm for treating pre-arthritic hip disorders.”