Abstract
Objective The aim of this study was to define the extent of the biceps tendon, subscapularis
tendon, and cranial border of the medial glenohumeral ligament within the field of
view during standard lateral shoulder arthroscopy in the dog. We also examine the
effect of joint flexion on the field of view of the biceps tendon.
Study Design This was a cadaveric study using 21 shoulders of large breed dogs. Each shoulder
was explored with a 30-degree arthroscope using standard lateral ports. For each supporting
structure, the margins within the arthroscopic field of view were marked with ink.
In 11 shoulders, the distal margin of the biceps tendon was identified and marked
first with the limb at a standing angle and then in flexion. The margins of the cranial
border of the medial glenohumeral ligament were marked at the standing angle. In 10
additional shoulders, the margins of the subscapularis tendon were evaluated. Each
joint was fully dissected and the portion of each stabilizing structure within the
field of view was quantified.
Results Fifty-eight percent of the cranial border of the medial glenohumeral ligament was
within the arthroscopic view. At a standing angle, 48% of the intra-articular length
of the biceps tendon was within the arthroscopic view, compared to 63% with the limb
flexed. Twenty percent of the subscapularis tendon was within the arthroscopic view.
Conclusion A significant portion of the biceps tendon and medial stabilizing structures of the
canine shoulder are outside the field of view of arthroscopy through a standard lateral
approach. The limitations of the arthroscopic field of view should be appreciated
when evaluating the shoulder.
Keywords
arthroscopy - shoulder - biceps - subscapularis - canine
