Development of the Shoulder Joint in Staged Human Embryos and Fetuses in Korean

Kim, Won Kyu; Lew, Eui Suk; Park, Hyoung Woo; Chung, Ho Sam

Abstract

The authors have studied 37 Korean embryos of Carnegie stage 11~23 and 18 fetuses to demonstrate the development of the shoulder joint. The external feature of the upperlimb bud is observed by stereoscope and camera, and the internal structures are studied by microscopic observation. The results obtained were as follows: In stage 12 upperlimb buds were appeared. In stage 17 mesenchymal condensations for humerus and scapula, and glenoid labrum were observed. In stage 19 one-layered interzone between the humerus and scapula was visible. In stage 22 three-layered interzone between the humerus and glenoid labrum was formed. In stage 23 three-layered interzone between the humerus and glenoid fossa of scapula was visible. In the 9th and 10th weeks distinct joint cavity was formed between humerus and glenoid labrum, and tendon of long head of Biceps brachii was attached to supraglenoid tuberosity and glenoid labrum. In the 11th week the joint cavity was formed between the midportion of humerus and glenoid fossa, and tendon of long head of Biceps brachii was more dense. In the 16th week the glenoid labrum was visible as fibrous cartilage, and joint cavity was more widened. In the 20th to 32nd week the shoulder joint was matured with the distinct joint cavity and glenoid labrum time after time.