Hip preservation surgery and the acetabular fossa

Abstract

As our understanding of hip function and disease improves, it is evident that the acetabular fossa has received little attention, despite it comprising over half of the acetabulum’s surface area and showing the first signs of degeneration. The fossa’s function is expected to be more than augmenting static stability with the ligamentum teres and being a templating landmark in arthroplasty. Indeed, the fossa, which is almost mature at 16 weeks of intrauterine development, plays a key role in hip development, enabling its nutrition through vascularization and synovial fluid, as well as the influx of chondrogenic stem/progenitor cells that build articular cartilage. The pulvinar, a fibrofatty tissue in the fossa, has the same developmental origin as the synovium and articular cartilage and is a biologically active area. Its unique anatomy allows for homogeneous distribution of the axial loads into the joint. It is composed of intra-articular adipose tissue (IAAT), which has adipocytes, fibroblasts, leucocytes, and abundant mast cells, which participate in the inflammatory cascade after an insult to the joint. Hence, the fossa and pulvinar should be considered in decision-making and surgical outcomes in hip preservation surgery, not only for their size, shape, and extent, but also for their biological capacity as a source of cytokines, immune cells, and chondrogenic stem cells. Cite this article: Bone Joint Res 2020;9(12):857–869.

Femoral impingement in maximal hip flexion is anterior-inferior distal to the cam deformity in femoroacetabular impingement patients with femoral retroversion

“…This study also has limitations: first, although the software used for impingement simulation is based on bone segmentation and calculates the osseous ROM, it was impossible to take into account soft-tissue such as acetabular labrum, 47 muscles, cartilage, ligaments, 53 or the pulvinar in the acetabular fossa. 54 This prevents direct comparison to motion capture studies. 52 This is unavoidable when using pelvic CT scans, but could be done in the future using MRI of the hip.…”

Central acetabular osteophytes (CAO) are more prevalent in the borderline developmental dysplastic hip (BDDH) patients: a propensity-score matched CT study

“…The acetabular fossa is a distinctive area in which osteophytes develops, CT is recommended for assessing the morphology of the acetabular fossa. On an anteroposterior pelvic radiograph, the acetabular fossa extends from the teardrop to an ill-defined area between the medial sourcil and the superior edge of the fovea capitis [ 11 , 20 ], CAO in advanced osteoarthritis patients can be detected as saber-tooth bony excrescence on cross-sectional imaging, or cause the buttressing effect medial to the head of the femur and yield a double teardrop view in radiographs [ 21 ]. But the mild CAO may easily be neglected in the plain radiograph, they are more likely to lie inside the joint, not visible on conventional radiographs.…”

“…Despite this key role, the acetabular fossa receives relatively little attention in this discussion of hip pathology. The fossa is filled with the ligamentum teres, synovial membrane, and intra-articular adipose tissue(IAAT), which has adipocytes, fibroblasts, leucocytes, and abundant mast cells [ 11 ]. The acetabular fossa also contributes to the lubrication of the hip joint; the fossa is the only intra-articular tissue associated with fluid production, which is essential for cartilage nutrition and load transmission [ 12 ].…”

Morphometric study of acetabular depth and coverage and their clinical importance

“…The acetabulum is a cup shaped vault with a diameter of 52 mm. 1 It is formed from the ilium, ischium and pubis parts of hip bone. 2 The pubis contributes the anterior one-fifth, the ileum forms posterosuperior two-fifth and the ischium contributes to posteroinferior two-fifth of the acetabulum.…”