Is the bare spot a consistent landmark for shoulder arthroscopy? A study of 20 embalmed glenoids with 3-dimensional computed tomographic reconstruction.
OBJECTIVE
Our aim was to test a published methodology for arthroscopically quantifying glenoid bone loss for its dependability in a cadaver-based anatomic study with 3-dimensional (3-D) computed tomographic (CT) reconstructions of 20 embalmed glenoids.


METHODS
Manual macroscopic measurements were made in a standardized fashion. In addition, we marked the center of the visible bare spot in 20 embalmed glenoids with a titanium pin. The shoulder joints were carefully selected for intact rotator cuff, missing capsule-labral deficiency, and absence of severe cartilage degeneration. 3-D reconstructed CT scans were evaluated for consistency of the bare spot.


RESULTS
The mean distance from the bare spot to the anterior margin measured manually was 10.9 mm (CT-based, 13.9 mm), to the posterior margin 13.7 mm (CT-based, 16.4 mm), and to the inferior margin 9.7 mm (CT-based, 15.1 mm). Distances were significantly different.


CONCLUSIONS
The bare spot did not prove its consistency in 20 carefully selected specimens. Therefore, we conclude that this methodology is not a reliable way to intraoperatively determine bony glenoid deficiency.


CONCLUSIONS
We recommend preoperative bilateral CT scans for evaluation of bony glenoid deficiency for exact quantification of the bone loss.
Department of Trauma Surgery and Sports Medicine, Innsbruck Medical University, Innsbruck, Austria. F.Kralinger@uibk.ac.at
Franz
F
Kralinger
Felix
F
Aigner
Stefano
S
Longato
Michael
M
Rieger
Markus
M
Wambacher
D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D001182:Arthroscopy; D001858:Bone Nails; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D012540:Scapula / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed