gms | German Medical Science

54. Jahrestagung der Norddeutschen Orthopädenvereinigung e. V.

Norddeutsche Orthopädenvereinigung

16.06. bis 18.06.2005, Hamburg

Anterior capsular shift increases strain in the posterior capsule and reduces range of motion in the glenohumeral joint

Meeting Abstract

  • corresponding author N. Hellmers - General Hospital Eilbek, Orthopedic and Tramatic Surgery, Hamburg
  • N. Wülker - Tübingen
  • H. Windhagen - Hannover
  • C. Hurschler - Hannover

Norddeutsche Orthopädenvereinigung. 54. Jahrestagung der Norddeutschen Orthopädenvereinigung e.V.. Hamburg, 16.-18.06.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05novEP37

The electronic version of this article is the complete one and can be found online at:

Published: June 13, 2005

© 2005 Hellmers et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




Capsular shift procedures are performed in cases of multidirectional shoulder instability which do not respond to conservative treatment. This study was performed to answer the question: does an anterior capsular shift affect strain in the posterior capsule? The primary effect of a glenoid based anterior T-shift capsular shift on posterior capsular strain was thus investigated in a human in vitro shoulder model. In addition, the effect of the procedure on maximum internal, external, as well as anterior-posterior and inferior translation was also investigated.

Materials and Methods

Six roentgenographically normal shoulders were harvested and frozen. Specimens were thawed and dissected to expose the anterior, posterior and inferior aspects of the capsule. The scapula was mounted in a kinematic testing device as previously described, and the humerus was transected ≈ 20 cm distal to the head and mounted in an industrial robot (KUKA GmbH, Augsburg) equipped with a 6-axis force-moment sensor (KMS) and specially adapted feedback-control software (IpeA GmbH, Berlin). Anterior, posterior and superior translations were measured in response to a 20 N force in each respective direction, and maximum internal and external rotation were measured under 1.8 Nm torque applied simultaneous to a 20 N centering force. Posterior capsular strain as a function of internal rotation was measured in the superior, medial, and inferior aspects of the capsule using specially constructed mini-extensometers. Measurements were performed before and after capsular shift at 0°, 30°, 60°, and 90° of glenohumeral elevation. A standardized anterior capsule T-shift was performed.


Strain in the posterior capsule increased. The increase in strain was highly variable occurring the least often in the medial portion (14% at 30°) and most often in the superior capsule (100% at 60°). Maximum internal rotation decreased although the decrease was less than the decrease in external rotation. Posterior translation decreases at elevations above 60° but remained unchanged at 0° and 30°. Anterior translation is also decreased. Inferior strain decreased after T-Shift at all but 0° elevation.


The results of this study suggest that the primary mechanical effects of an anterior capsular shift reach as far as the posterior capsular structures. This study thus provides biomechanical evidence supporting the use of the anterior T-Shift proceedure in treating multidirectional instabilities.