Shoulder Arthritis / Rotator Cuff Tears: causes of shoulder pain: Glenoid component rertroversion – what to do about…

Shoulder Arthritis / Rotator Cuff Tears: causes of shoulder pain: Glenoid component rertroversion – what to do about…: It is recognized that glenoid loosening is the leading cause of failure in total shoulder arthroplasty and that the risk of this complicati…

Saturday, April 12, 2014

Glenoid component rertroversion – what to do about it?

It is recognized that glenoid loosening is the leading cause of failure in total shoulder arthroplasty and that the risk of this complication is increased with increased glenoid deformity and glenoid bone loss.

Champions of special glenoid components state that «studies have shown that adequate correction of glenoid disease and accurate placement of prosthetic components are necessary to restore normal glenohumeral motion», yet the references in support of this statement (Effect of glenoid deformity on glenoid component placement in primary total shoulder arthroplasty and Glenoid implant orientation and cement failure in total shoulder arthroplasty: a finite element analysis) are based on computer simulations and finite element analyses rather than clinical data.

While has been said that ideal glenoid position is close to perpendicular to the plane of the scapula with the center peg of the component within bone and that the goal of glenoid implantation is to correct the glenoid version, this is but an hypothesis: it has not been demonstrated in clinical practice that correction of a retroverted glenoid to this position or that avoidance of peg penetration yield better results.

Postoperative humeral subluxation is associated with poor outcomes,  However a recent study found that there was no significant correlation between posterior humeral subluxation and postoperative glenoid version.

Thus the recent interest in augmented glenoid components needs to be tempered while we await a matched comparison between this approach and, for example, accepting a reasonable amount of retroversion and a reasonable amount of peg penetration while using asymmetric humeral heads and rotator interval plication to control the static posterior humeral head subluxation.