[Development of the human hip joint and its innervation]

Thickening of mesenchyma at the place of the future coxofemoral joint (embryos 10.5--14 mm of parietal-coccygeal length) is defined in the area limited by the lumbar and sacral spinal nerves behind, by the femoral nerve in front and above and by the ischiatic nerve underneath and behind. The femoral head surrounded with anlages of the iliac, pubic and ischiatic bones is defined in 16 mm long embryos. The vascular canal ends blindly or penetrates through the wall of the cotyloid cavity at the place where lately fusion of the iliac and the pubic bones takes place. A special attention is paid, at the embryonic level, to variants of the iliolumbar muscle fixation and to participation of its tendons, in some cases, information of the femoral joint circular zone. The joint capsule, presented as a condensed mesenchyma is defined in prefetuses 18 mm of parietal-coccygeal length. To its inferior fragment, branches of the obturative and the accessory obturative nerves, to its superior fragment--branches of the superior gluteal nerve, to its posterior fragment--branches of the ischiatic nerve, and to its anterior fragment--branches of the femoral nerve grow out. Taking into account the time when these nerves grow into the innervated substrate, they should be considered as the most important for innervating the capsule, it being realized mainly by mixed, or more exactly by the musculo-articular branches. As the branches of the nerves mentioned above penetrate into the capsule thickness, the latter is differentiating into certain layers. Owing to the results obtained, it is possible to conclude that the anlage and further formation of the femoral joint elements is taking place simultaneously with the development and complication of its innervational connections.