Superior-inferior stability of the shoulder: Role of the coracohumeral ligament and the rotator interval capsule

Eiji Itoi, Lawrence J. Berglund, John J. Grabowski, Leslie Naggar, Bernard F. Morrey, A. N. Kai-Nan

Research output: Contribution to journalArticle

67 Citations (Scopus)

Abstract

Objective: To study the superior-inferior stabilizing functions of the coracohumeral ligament (CHL) and the rotator interval capsule (RIC) with use of a material testing machine. Material and Methods: The axial translations of the humerus with the superior-inferior translation force of 30 N applied were recorded under the following joint capsule conditions: (1) intact, (2) vented, (3) the CHL sectioned, and (4) the RIC incised in six cadaver shoulders. The order of sectioning was changed for conditions 3 and 4 in six other cadaver shoulders. Results: With the arm in internal and neutral rotations, venting the capsule significantly increased the superior-inferior translation, which was unaffected by further sectioning of the CHL and the RIC. With the arm in external rotation, only the CHL contributed significantly to inferior stability, whereas both this ligament and the RIC contributed to superior stability to a lesser degree. Conclusion: The CHL is a stabilizer in superior-inferior directions with the arm in external rotation, and the intra-articular pressure that is maintained by the intact RIC is a stabilizer in superior-inferior directions with the arm in internal and neutral rotations. These findings may provide a scientific background to support closure of the interval space to stabilize the shoulder and may explain part of the superior instability observed in shoulders with rotator cuff tears.

Original languageEnglish (US)
Pages (from-to)508-515
Number of pages8
JournalMayo Clinic Proceedings
Volume73
Issue number6
StatePublished - 1998

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Ligaments
Capsules
Arm
Cadaver
Materials Testing
Joint Capsule
Humerus
Joints
Pressure

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Itoi, E., Berglund, L. J., Grabowski, J. J., Naggar, L., Morrey, B. F., & Kai-Nan, A. N. (1998). Superior-inferior stability of the shoulder: Role of the coracohumeral ligament and the rotator interval capsule. Mayo Clinic Proceedings, 73(6), 508-515.

Superior-inferior stability of the shoulder : Role of the coracohumeral ligament and the rotator interval capsule. / Itoi, Eiji; Berglund, Lawrence J.; Grabowski, John J.; Naggar, Leslie; Morrey, Bernard F.; Kai-Nan, A. N.

In: Mayo Clinic Proceedings, Vol. 73, No. 6, 1998, p. 508-515.

Research output: Contribution to journalArticle

Itoi, E, Berglund, LJ, Grabowski, JJ, Naggar, L, Morrey, BF & Kai-Nan, AN 1998, 'Superior-inferior stability of the shoulder: Role of the coracohumeral ligament and the rotator interval capsule', Mayo Clinic Proceedings, vol. 73, no. 6, pp. 508-515.
Itoi E, Berglund LJ, Grabowski JJ, Naggar L, Morrey BF, Kai-Nan AN. Superior-inferior stability of the shoulder: Role of the coracohumeral ligament and the rotator interval capsule. Mayo Clinic Proceedings. 1998;73(6):508-515.
Itoi, Eiji ; Berglund, Lawrence J. ; Grabowski, John J. ; Naggar, Leslie ; Morrey, Bernard F. ; Kai-Nan, A. N. / Superior-inferior stability of the shoulder : Role of the coracohumeral ligament and the rotator interval capsule. In: Mayo Clinic Proceedings. 1998 ; Vol. 73, No. 6. pp. 508-515.
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