Arthroscopic study of the shoulder joint in fetuses.
OBJECTIVE
The purpose of this study was to macroscopically examine the fetal shoulder joint using arthroscopy. We attempted to identify and describe the specific characteristics of the fetal shoulder joint, how it evolves during the last few weeks of intrauterine development, and any possible variations with regard to the adult shoulder.


METHODS
Observational anatomic case series.


METHODS
We used 20 frozen fetuses with a gestational age of 24 to 40 +/- 2 weeks, obtained from spontaneous abortions. Examination was performed with standard arthroscopic surgical equipment, using a 2.7-mm optical lens. Whenever possible, we tried to use the standard arthroscopic portals. Images were obtained for comparison with the adult shoulder.


RESULTS
The arthroscopic images of the fetal glenohumeral joint are similar to those of an adult shoulder, with the only differences being those related to the stage of development. In this study we observed no so-called bare spot in the glenoid cavity such as has been described in treatises on the adult shoulder joint. The arthroscopic images of the anterosuperior region of the fetal joint show more highly defined structures than in the adult shoulder, especially the coracohumeral and glenohumeral ligaments.


CONCLUSIONS
To our knowledge, this is the first arthroscopic study to target the fetal shoulder joint. The results indicate minimal differences when compared with the adult shoulder joint; for some structures, particularly in the anterosuperior region, the anatomy observed was easier to discern than what is observed in adult shoulder arthroscopy.


CONCLUSIONS
Our study obtained clear images of virgin shoulder joints that had never been subjected to deterioration from wear or other distorting forces. The clarity of these images is useful for locating and identifying structures in the adult shoulder.
Tena-Arregui
José
J
C.O.A. Servicio de Traumatología y Cirugía Ortopédica, Clínica Santa Elena, Madrid, Spain.
Barrio-Asensio
Carmen
C
Puerta-Fonollá
Javier
J
Murillo-González
Jorge
J
D001182:Arthroscopy; D005260:Female; D005865:Gestational Age; D006801:Humans; D006811:Humerus / Q000196:embryology; D008023:Ligaments, Articular / Q000196:embryology; D008297:Male; D017006:Rotator Cuff / Q000196:embryology; D012540:Scapula / Q000196:embryology; D012785:Shoulder Joint / Q000196:embryology*; D013710:Tendons / Q000196:embryology