Does Radiographic Coxa Profunda Indicate Increased Acetabular Coverage or Depth in Hip Dysplasia?

Abstract

Background Although radiographic coxa profunda has been considered an indicator of acetabular overcoverage, recent studies suggest that radiographic coxa profunda is a nonspecific finding seen even in hip dysplasia. The morphologic features of coxa profunda in hip dysplasia and the frequency with which the two overlap are not well defined. Questions/purposes We determined (1) the prevalence of radiographic coxa profunda in patients with hip dysplasia;(2) the morphologic differences of the acetabulum and pelvis between patients with hip dysplasia and control subjects; and (3) the morphologic differences between hip dysplasia with and without coxa profunda. Methods We retrospectively reviewed the pelvic radiographs and CT scans of 70 patients (70 hips) with hip dysplasia. Forty normal hips were used as controls. Normal hips were defined as those with a lateral center-edge angle between 25°and 40°. Coxa profunda was defined as present when the acetabular fossa was observed to touch or was medial to the ilioischial line on an AP pelvic radiograph. CT measurements included acetabular version, acetabular coverage, acetabular depth, and rotational alignment of the innominate bone. Results The prevalence of coxa profunda was 44% (31 of 70 hips) in dysplastic hips and 73% (29 of 40 hips) in the control hips (odds ratio, 3.32; 95% CI, 1.43-7

Reference values and variation of acetabular angles measured by computed tomography in 170 asymptomatic hips

“…lower than those on the younger patients from the two other studies. The patient selection may also have affected the measurements, because we did not exclude patients with borderline hip dysplasia (CE angle ¼ 20-25 ) coxa profunda or pincer morphology since these are highly prevalent conditions in the general population (11,(16)(17)(18). Tallroth et al (6) excluded patients with signs of osteoarthritis, arthritis, hip dislocation, subluxation or dysplasia, previous surgery, or trauma that had deformed the hip joint.…”

Ptosis of the hip: a new radiographic finding in patients undergoing femoroacetabular osteoplasty

“…Additional studies determining the prevalence of a positive ptosis sign in pincer type FAI patients would be needed to support this hypothesis. Recent studies also argue that coxa profunda is a nonspecific finding that is seen commonly in classic hip dysplasia [17, 19]. Due to the high prevalence (75.5%) of coxa profunda in the normal population [17], it is possible that a positive ptosis sign is also commonly seen in normal, asymptomatic hips.…”

CORR Insights®: Acetabular Wall Indices Help to Distinguish Acetabular Coverage in Asymptomatic Adults with Varying Morphologies

“…Although acetabular morphology can be quantified accurately with the aid of CT scans or specialized computer software [1,2,5,8,9], an affordable and intraoperative reproducible method is a valuable resource. More-recently introduced radiographic parameters like AWI and PWI may help overcome the limitations of current parameters.…”