Abstract
Background
In shoulders with multidirectional instability, translation of the humeral head on the glenoid is increased in the midrange because of the following three reasons: the increased retroversion, a hypoplastic posteroinferior rim, and decreased scapular abduction during arm elevation. This study aimed to clarify the relationship between glenoid inclination and glenohumeral joint stability.
Methods
Nine fresh-frozen cadaveric shoulders were tested. With a 50-N compressive load, the translation force was measured in the 3-o’clock, 6-o’clock, 9-o’clock, and 12-o’clock directions by using a tilt of 0°, 5°, 10°, 15°, and 20°. When the glenoid was tilted in one direction, the translation force was measured in the direction of inclination and in the opposite direction. The stability ratio was then calculated.
Results
The stability ratio in the 3-o’clock direction significantly decreased with a tilt of more than 5° in the 3-o’clock direction. The stability ratio in the 9-o’clock direction significantly decreased with a tilt of more than 15° in the 9-o’clock direction and significantly increased with a tilt of more than 5° in the 3-o’clock direction. The stability ratio in the 6-o’clock direction significantly increased with a tilt of more than 10° in the 6-o’clock direction.
Conclusions
The posterior and inferior stability increased with an anterior tilt of more than 5° and with a superior tilt of 10°, respectively. The anterior and posterior stability decreased with an anterior tilt of 5° and with a posterior tilt of 15°, respectively.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Lippitt SB, Vanderhooft JE, Harris SL, Sidles JA, Harryman DT II, Matsen FA III. Glenohumeral stability from concavity-compression: a quantitative analysis. J Shoulder Elbow Surg 1993;2:27–35.
Kim SH, Noh KC, Park JS, Ryu BD, Oh I. Loss of chondrolabral containment of the glenohumeral joint in atraumatic posteroinferior multidirectional instability. J Bone Joint Surg Am 2005;87:92–98.
Edelson JG. Localized glenoid hypoplasia. An anatomic variation of possible clinical significance. Clin Orthop 1995;321:189–195.
Ozaki J. Glenohumeral movements of the involuntary inferior and multidirectional instability. Clin Orthop 1989;238:107–111.
Metcalf MH, Duckworth DG, Lee SB, Sidles JA, Smith KL, Harryman DT II, et al. Posteroinferior glenoplasty can change glenoid shape and increase the mechanical stability of the shoulder. J Shoulder Elbow Surg 1999;8:205–213.
Fukuda K, Chen CM, Cofield RH, Chao EY. Biomechanical analysis of stability and fixation strength of total shoulder prostheses. Orthopedics 1988;11:141–149.
Lazarus MD, Sidles JA, Harryman DT II, Matsen FA III. Effect of a chondral-labral defect on glenoid concavity and glenohumeral stability. A cadaveric model. J Bone Joint Surg Am 1996;78:94–102.
Halder AM, Kuhl SG, Zobitz ME, Larson D, An KN. Effects of the glenoid labrum and glenohumeral abduction on stability of the shoulder joint through concavity-compression: an in vitro study. J Bone Joint Surg Am 2001;83:1062–1069.
Itoi E, Motzkin NE, Morrey BF, An KN. Scapular inclination and inferior stability of the shoulder. J Shoulder Elbow Surg 1992;1:131–139.
Scott DJ Jr. Treatment of recurrent posterior dislocations of the shoulder by glenoplasty. Report of three cases. J Bone Joint Surg Am 1967;49:471–476.
Nobuhara K. Loose shoulder. The shoulder: its function and clinical aspects. River Edge, NJ: World Scientific; 2003. p. 254–283.
Author information
Authors and Affiliations
About this article
Cite this article
Kikuchi, K., Itoi, E., Yamamoto, N. et al. Scapular inclination and glenohumeral joint stability: a cadaveric study. J Orthop Sci 13, 72–77 (2008). https://doi.org/10.1007/s00776-007-1186-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00776-007-1186-2