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· DOS Abstracts
Anatomical changes in the aging sternoclavicular joint
Martin Wyman Ratchke, Jørgen Tranum-Jensen,
Michael R. Krogsgaard
Section for Sportstraumatology M51, Bispebjerg Hospital; (1) Department of
Cellular and Molecular Medicine , Copenhagen University
Background:
The prevalence of degenerative changes of the sternoclavicular
joints (SCJ) is unknown. Some cases are so painful that surgical treatment is
indicated. Degeneration of the intraarticular disc with a central hole and the
cartilage on the clavicle is reported in cadaver studies, but in sternoclavicular
arthroscopies we often find detachment of the disc from the anterior capsule
and marked disintegration of the disc.
Purpose / Aim of Study:
To study the anatomy of the SCJ in detail and de-
scribe occurrence of conditions, that are potentially surgically accessible.
Materials and Methods:
Both SCJs from 39 formalin embalmed (age mean:
79, range: 59-96, 13 F/26 M) were frozen and divided frontally with a thin
band saw, so both SCJs were opened through the centre of the disc. Examination
of the joints was performed after the specimens had been thawed and stored
in 30% ethanol.
Findings / Results:
We found a typical pattern: detachment of the disc infe-
rior from the manubrium and from anterior and posterior capsule, in connection
with thinning and fragmentation of the inferior part of the disc. Generally the
disc was thickest superior and thinnest inferior. With inferior detachment we
found a marked supero-medial instability of the medial clavicular end. In all ca-
davers but one there were cartilage changes on the clavicle and sternum. The
manubrium joint surface was much smaller that the clavicular surface.
Conclusions:
The superior part of the clavicular cartilage is only in contact with
the cartilage of manubrium during extensive elevation off the clavicle, e.g. in
abduction of the arm. Therefore it is mainly the inferior part of the discus that is
compressed between articular surfaces and subject to age related degenerative
tearing. This disc pathology can be trimmed but not reinserted. If instability is
symptomatic, the joint can be stabilized.
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