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.
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.
Authors: Tyler W Knighton; Peter N Chalmers; Hema J Sulkar; Klevis Aliaj; Robert Z Tashjian; Heath B Henninger Journal: J Shoulder Elbow Surg Date: 2022-05-10 Impact factor: 3.507
Authors: Robert A Waltz; Annalise M Peebles; Justin J Ernat; Stephanie K Eble; Patrick J Denard; Anthony A Romeo; Petar Golijanin; Scott M Liegel; Matthew T Provencher Journal: JSES Int Date: 2022-02-11
Authors: Peter N Chalmers; Anthony A Romeo; Gregory P Nicholson; Pascal Boileau; Jay D Keener; James M Gregory; Dane H Salazar; Robert Z Tashjian Journal: Clin Orthop Relat Res Date: 2019-02 Impact factor: 4.176
Authors: Thomas M Gregory; Andrew Sankey; Bernard Augereau; Eric Vandenbussche; Andrew Amis; Roger Emery; Ulrich Hansen Journal: PLoS One Date: 2013-10-08 Impact factor: 3.240
Authors: Peter N Chalmers; Thomas Suter; Matthijs Jacxsens; Yue Zhang; Chong Zhang; Robert Z Tashjian; Heath B Henninger Journal: J Shoulder Elb Arthroplast Date: 2019-06-06