寛骨臼とは
寛骨臼を構成する要素としては以下のようなものが挙げられる。
※「寛骨臼縁」を寛骨臼の構成要素と見るかどうかは意見が分かれる可能性もあると思われる。
以下は「船戸和弥のホームページ」の解説文となる。
「寛骨の外側面の中央部で腸骨、恥骨、坐骨の３骨の合するところには大腿骨と股関節をつくる深い寛骨臼がある。大腿骨頭の先端には長さ約３ｃｍの関節内靱帯（大腿骨頭靱帯）がついており、これが関節窩（寛骨臼）の切痕部に付着している。寛骨臼はその辺縁に線維軟骨性の関節唇が取り巻いてその深さをましている。寛骨臼(Acetabulum)はラテン語のacetum（酢）＋abrum（支持台・入れ物）の縮小形abulumからきたacetabulum（酢を入れる小さなびん）に由来する。 」
そして以下が「Wikipedia」の解説となる。
「The acetabulum /æs??tæbj?l?m/ (cotyloid cavity) is a concave surface of the pelvis. The head of the femur meets with the pelvis at the acetabulum, forming the hip joint.[1][2]
Structure： There are three bones of the os coxae (hip bone) that come together to form the acetabulum. Contributing a little more than two-fifths of the structure is the ischium, which provides lower and side boundaries to the acetabulum. The ilium forms the upper boundary, providing a little less than two-fifths of the structure of the acetabulum. The rest is formed by the pubis, near the midline.
It is bounded by a prominent uneven rim, which is thick and strong above, and serves for the attachment of the acetabular labrum, which reduces its opening, and deepens the surface for formation of the hip joint. At the lower part of the acetabulum is the acetabular notch, which is continuous with a circular depression, the acetabular fossa, at the bottom of the cavity of the acetabulum. The rest of the acetabulum is formed by a curved, crescent-moon shaped surface, the lunate surface, where the joint is made with the head of the femur. Its counterpart in the pectoral girdle is the glenoid fossa.[3]
The acetabulum is also home to the acetabular notch, an attachment site for the ligamentum teres, a triangular, somewhat flattened band implanted by its apex into the antero-superior part of the fovea capitis femoris. The notch is converted into a foramen by the transverse acetabular ligament; through the foramen nutrient vessels and nerves enter the joint. This is what holds the head of the femur securely in the acetabulum.[1]
The well-fitting surfaces of the femoral head and acetabulum, which face each other, are lined with a layer of slippery tissue called articular cartilage, which is lubricated by a thin film of synovial fluid. Friction inside a normal hip is less than one-tenth that of ice gliding on ice.[4][5]
Blood supply：
The acetabular branch of the obturator artery supplies the acetabulum through the acetabular notch. The pubic branches supply the pelvic surface of the acetabulum. Deep branches of the superior gluteal artery supply the superior region and the inferior gluteal artery supplies the postero-inferior region.[6]
Development：
In infants before complete ossification at the time of skeletal maturation, a 'Y'-shaped epiphyseal plate called the triradiate cartilage exists within the acetabulum.」
【参考になるサイト】
・イラストや写真を掲載しているサイト-Ⅰ（骨標本の写真）
・イラストや写真を掲載しているサイト-Ⅱ（骨標本の写真）
・イラストや写真を掲載しているサイト-Ⅲ（骨標本の写真）
・イラストや写真を掲載しているサイト-Ⅳ（月状面の軟骨が確認できる写真）
・イラストや写真を掲載しているサイト-Ⅴ（月状面の軟骨が確認できる写真）
