Coraco-clavicular joint: normal variant in humans. A radiographic demonstration in the human and non-human primate.
The coraco-clavicular joint is a true synovial joint that may become painful in some patients after trauma. Among the descriptions of this entity is the assertion that the coraco-clavicular joint is routinely seen in gorillas and gibbons. We undertook to assess the incidence of this variant among gorillas, gibbons, and other non-human primates. All available radiographs of large primates performed at the International Wildlife Conservation Park/Bronx Zoo (IWCP) over the past 10 years were reviewed by a musculoskeletal radiologist (human radiology). All radiographs were taken during the normal clinical care of the non-human primate population of the IWCP and are a part of each animal's clinical record. Eighty-one non-human primate radiographs were suitable for study as they contained the region of interest. The 81 radiographic examinations included 14 different species of non-human primates. The coraco-clavicular joint was seen in 4 out of 9 silver-leaf langur, 2 out of 8 lowland gorilla, and in 1 out of 6 white-handed gibbon. In all non-human primate cases where the coraco-clavicular joint occurred, it was bilateral. In 1 out of 8 mandrill, there were very wide distal clavicular ends that articulated both with the coracoid and with the acromion. The coraco-clavicular joint differs from an ossified coraco-clavicular ligament. The radiographic appearance is characteristic and is found in both humans and some non-human primate species. It may rarely become painful following trauma. When symptomatic in humans, resection of this anomalous articulation is curative.
Haramati
N
N
Department of Radiology, Columbia University College of Physicians and Surgeons, New York, New York.
Cook
R A
RA
Raphael
B
B
McNamara
T S
TS
Staron
R B
RB
Feldman
F
F
D000173:Acromioclavicular Joint / Q000000981:diagnostic imaging*; D000328:Adult; D000717:Anatomy, Comparative; D000818:Animals; D002968:Clavicle / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D017746:Joint Capsule / Q000000981:diagnostic imaging; D007592:Joint Diseases / Q000000981:diagnostic imaging; D008022:Ligaments / Q000000981:diagnostic imaging; D011323:Primates / Q000033:anatomy & histology*; D011859:Radiography