Acetabular Morphology: Implications for Joint-preserving Surgery

Abstract

Appropriate anatomic concepts for surgery to treat femoroacetabular impingement require a precise appreciation of the native acetabular anatomy. We therefore determined (1) the spatial acetabular rim profile, (2) the topography of the articular lunate surface, and (3) the 3-D relationships of the acetabular opening plane comparing 66 bony acetabula from 33 pelves in female and male pelves. The acetabular rim profile had a constant and regular wave-like outline without gender differences. Three prominences anterosuperiorly, anteroinferiorly and posteroinferiorly extended just above hemispheric level. Two depressions were below hemispheric level, of 9°at the anterior wall and of 21°along the posterosuperior wall. In 94% of all acetabula, the deepest extent of the articular surface was within 30°of the anterosuperior acetabular sector. In 99% of men and in 91% of women, the depth of the articular surface was at least 55°along almost half of the upper acetabular cup. The articular surface was smaller in women than in men. The acetabular opening plane was orientated in 21°± 5°for version, 48°± 4°for inclination and 19°± 6°for acetabular tilt with no gender differences. We defined tilt as forward rotation of the entire acetabular cup around its central axis; because of interindividual variability of acetabular tilt, descriptions of acetabular lesions during surgery, CT scanning and MRI should be defined and recorded in relation to the acetabular notch. Acetabular tilt and pelvic tilt should be separately identified. We believe this information important for surgeons performing rim trimming in FAI surgery or performing acetabular osteotomies.

Tailor-made Surgical Guide Reduces Incidence of Outliers of Cup Placement

“…2A). Because the acetabular shape is not perfectly hemispheric and the height of the acetabular edge is asymmetric [13,28,29], the surgical guide could be placed using the rather more complex shape of the acetabulum captured by the customized guide. Then, the Kirschner wire was inserted on the superior acetabulum through one foramen of the guide part.…”

Is Increased Acetabular Cartilage or Fossa Size Associated With Pincer Femoroacetabular Impingement?

“…Cadaveric studies have looked at the overall size, topography, and orientation of the normal acetabulum [15,16]. Previous studies using CT of human hips have measured the contours of the bony acetabulum [13], the relative coverage of the femoral head by the acetabulum in developmental dysplasia of the hip [1,2,5,7], and the contact pressure between the acetabulum and the femoral head [12].…”

Hip Arthroscopy Improves Symptoms Associated with FAI in Selected Adolescent Athletes

“…Later, after impingement had been proposed by Ganz et al as a cause of osteoarthritis of the hip, surgical treatment of FAI in adults continued with open surgical dislocation via a novel transtrochanteric approach [26]. This involves performing a greater trochanteric osteotomy and osteoplasty of the femoral head-neck junction and acetabulum, thereby improving clearance for hip motion and alleviating femoral abutment against the acetabular rim [6,37,39,46,51,54]. Since that time, combined open and arthroscopic approaches have been described [17].…”