Total shoulder arthroplasty: Downward inclination of the glenoid component to balance supraspinatus deficiency

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• 作者：Alex ; re Terrier ; Francesco Merlini ; Dominique P. Pioletti ; Alain Farron
• 关键词：Glenoid inclination ; subchondral bone support ; total shoulder arthroplasty ; supraspinatus tendon deficiency
• 刊名：Journal of Shoulder and Elbow Surgery
• 出版年：2009
• 出版时间：May-June 2009
• 年：2009
• 卷：18
• 期：3
• 页码：360-365
• 全文大小：341 K

文摘

Hypothesis

Supraspinatus deficiency associated with total shoulder arthroplasty (TSA) provokes eccentric loading and may induce loosening of the glenoid component. A downward inclination of the glenoid component has been proposed to balance supraspinatus deficiency.

Methods

This hypothesis was assessed by a numeric musculoskeletal model of the glenohumeral joint during active abduction. Three cases were compared: TSA with normal muscular function, TSA with supraspinatus deficiency, and TSA with supraspinatus deficiency and downward inclination of the glenoid.

Results

Supraspinatus deficiency increased humeral migration and eccentric loading. A downward inclination of the glenoid partly balanced the loss of stability, but this potential advantage was counterbalanced by an important stress increase within the glenoid cement. The additional subchondral bone reaming required to incline the glenoid component indeed reduced the bone support, increasing cement deformation and stress.

Conclusion

Glenoid inclination should not be obtained at the expense of subchondral bone support.

Level of evidence

Basic science study.