To determine if significant differences exist between male and female CAM deformities using quantitative 3-dimensional (3D) volume and location analysis.
Retrospective analysis of preoperative computed tomographic (CT) scans for 138 femurs (69 from male patients and 69 from female patients) diagnosed with impingement from November 2009 to November 2011 was completed. Those patients who presented with hip complaints and had a history, physical examination (limited range of motion, positive impingement signs), plain radiographs (anteroposterior pelvis, 90° Dunn view, false profile view), and magnetic resonance images consistent with femoroacetabular impingement (FAI) and in whom a minimum of 6 months of conservative therapy (oral anti-inflammatory agents, physical therapy, and activity modification) had failed were indicated for arthroscopic surgery and had a preoperative CT scan. Scans were segmented, converted to point cloud data, and analyzed with a custom-written computer program. Analysis included mean CAM height and volume, head radius, and femoral version. Differences were analyzed using an unpaired t test with significance set at P < .05.
Female patients had greater femoral anteversion compared with male patients (female patients, 15.5° ± 8.3°; male patients, 11.3° ± 9.0°; P = .06). Male femoral head radii were significantly larger than female femoral heads (female patients, 22.0 ± 1.3 mm; male patients, 25.4 ± 1.3 mm; P < .001). Male CAM height was significantly larger than that in female patients (female patients, 0.66 ± 0.61 mm; male patients, 1.51 ± 0.75 mm; P < .001). Male CAM volume was significantly larger as well (male patients, 433 ± 471 mm3; female patients, 89 ± 124 mm3; P < .001). These differences persisted after normalizing height (P < .001) and volume (P < .001) to femoral head radius. Average clock face distribution was from the 1:09 o'clock position ± the 2:51 o'clock position to the 3:28 o'clock position ± the 1:59 o'clock position, with an average span from the 3:06 o'clock position ± the 1:29 o'clock position (male patients, the 11:23 o'clock position ± the 0:46 o'clock position to the 3:05 o'clock position ± the 1:20 o'clock position; female patients, the 11:33 o'clock position ± the 0:37 o'clock position to the 2:27 o'clock position ± the 0:45 o'clock position). There were no differences in the posterior (P = .60) or anterior (P = .14) extent of CAM deformities. However, the span on the clock face of the CAM deformities varied when comparing men with women (male patients, the 3:43 o'clock position ± the 1:29 o'clock position; female patients, the 2:54 o'clock position ± the 1:09 o'clock position; P = .02).
Our data show that female CAM deformities are shallower and of smaller volume than male lesions. Further studies will allow further characterization of the 3D geometry of the proximal femur and provide more precise guidance for femoral osteochondroplasty for the treatment of CAM deformities.
Female CAM deformities may not be detectable using current 2D nonquantitative methods. These findings should raise the clinician's index of suspicion when diagnosing a symptomatic CAM lesion in female patients.
To read this article in full you will need to make a payment
Purchase one-time access:Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
One-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:Subscribe to Arthroscopy
Already a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
- Femoroacetabular impingement: A cause for osteoarthritis of the hip.Clin Orthop Relat Res. 2003; 417: 112-120
- Computed tomography assessment of hip joints in asymptomatic individuals in relation to femoroacetabular impingement.Am J Sports Med. 2010; 38: 1160-1165
- Imaging of femoroacetabular impingement.J Bone Joint Surg Am. 2009; 91: 138-143
- The young adult with hip impingement: Deciding on the optimal intervention.J Bone Joint Surg Am. 2009; 91: 210-221
- The contour of the femoral head-neck junction as a predictor for the risk of anterior impingement.J Bone Joint Surg Br. 2002; 84: 556-560
- A new radiological index for assessing asphericity of the femoral head in cam impingement.J Bone Joint Surg Br. 2007; 89: 1309-1316
- Sex differences of hip morphology in young adults with hip pain and labral tears.Arthroscopy. 2013; 29: 54-63
- Femoroacetabular impingement magnetic resonance imaging.Top Magn Reson Imaging. 2009; 20: 123-128
- Assessment of osteoarthritis in hips with femoroacetabular impingement using delayed gadolinium enhanced MRI of cartilage.J Magn Reson Imaging. 2009; 30: 1110-1115
- Relationship between offset angle alpha and hip chondral injury in femoroacetabular impingement.Arthroscopy. 2008; 24: 669-675
- Cam-type femoral-acetabular impingement: Is the alpha angle the best MR arthrography has to offer?.Skeletal Radiol. 2009; 38: 855-862
- Cam and pincer femoroacetabular impingement: Characteristic MR arthrographic findings in 50 patients.Radiology. 2006; 240: 778-785
- Comparison of six radiographic projections to assess femoral head/neck asphericity.Clin Orthop Relat Res. 2006; 445: 181-185
- Comparison of MRI alpha angle measurement planes in femoroacetabular impingement.Clin Orthop Relat Res. 2009; 467: 660-665
- Gender differences in 3D morphology and bony impingement of human hips.J Orthop Res. 2011; 29: 333-339
- Routine complete capsular closure during hip arthroscopy.Arthrosc Tech. 2013; 2: e89-e94
- The use of double-loaded suture anchors for labral repair and capsular repair during hip arthroscopy.Arthrosc Tech. 2012; 1: e213-e217
- Arthroscopic management of femoroacetabular impingement: Osteoplasty technique and literature review.Am J Sports Med. 2007; 35: 1571-1580
- Femoroacetabular impingement and the cam-effect. A MRI-based quantitative anatomical study of the femoral head-neck offset.J Bone Joint Surg Br. 2001; 83: 171-176
- The prevalence of cam-type femoroacetabular deformity in asymptomatic adults.J Bone Joint Surg Br. 2011; 93: 1303-1307
- An alternative radiographic measure for cam-type FAI in patients with idiopathic hip pain.Hip Int. 2011; 21: 146-153
- Cam type femoro-acetabular impingement: Quantifying the diagnosis using three dimensional head-neck ratios.Skeletal Radiol. 2013; 42: 329-333
- The Frank Stinchfield Award: Morphologic features of the acetabulum and femur: Anteversion angle and implant positioning.Clin Orthop Relat Res. 2001; 393: 52-65
- Gender differences in frontal and sagittal plane biomechanics during drop landings.Med Sci Sports Exerc. 2005; 37 (discussion 1013): 1003-1012
Published online: July 25, 2015
Accepted: June 5, 2015
Received: February 10, 2014
The authors report the following potential conflict of interest or source of funding: S.N. receives support from Stryker, Pivot Medical, Ossur, Arthrex, Linvatec, Smith & Nephew, DJ Orthopaedics, Miomed, Athletico, and Allosource.
© 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.
ScienceDirectAccess this article on ScienceDirect
- ErratumArthroscopyVol. 32Issue 2
- PreviewIn the article, “Sex Differences in Patients With CAM Deformities With Femoroacetabular Impingement: 3-Dimensional Computed Tomographic Quantification,” in the December 2015 issue (Arthroscopy 2015;31:2301-2306), the name of author Dr. Alejandro Espinoza Orías was listed incorrectly. The correct article title and byline appear below.