JB JS Open Access. 2020 Oct-Dec; 5(4): e20.00002.

Anatomic Total Shoulder Arthroplasty with All-Polyethylene Glenoid Component for Primary Osteoarthritis with Glenoid Deficiencies

Frederick A. Matsen, III, MD,1,a Anastasia J. Whitson, BSPH,1,b Jeremy S. Somerson, MD,2,c and Jason E. Hsu, MD1,d
Shoulder

This study evaluated the ability of shoulder arthroplasty using a standard glenoid component to improve patient self-assessed comfort and function and to correct preoperative humeral-head decentering on the face of the glenoid in patients with primary glenohumeral arthritis and type-B2 or B3 glenoids.

Methods:

We identified 66 shoulders with type-B2 glenoids (n = 40) or type-B3 glenoids (n = 26) undergoing total shoulder arthroplasties with a non-augmented glenoid component inserted without attempting to normalize glenoid version and with clinical and radiographic follow-up that was a minimum of 2 years. The Simple Shoulder Test (SST), the percentage of humeral-head decentering on the glenoid face, and bone ingrowth into the central peg were the main outcome variables of interest. Similar analyses were made for concurrent patients with type-A1, A2, B1, and D glenoid pathoanatomy to determine if the outcomes for type-B2 and B3 glenoids were inferior to those for the other types.

Results:

The SST score (and standard deviation) improved from 3.2 ± 2.1 points preoperatively to 9.9 ± 2.4 points postoperatively (p < 0.001) at a mean time of 2.8 ± 1.2 years for type-B2 glenoids and from 3.0 ± 2.5 points preoperatively to 9.4 ± 2.1 points postoperatively (p < 0.001) at a mean time of 2.9 ± 1.5 years for type-B3 glenoids; these results were not inferior to those for shoulders with other glenoid types. Postoperative glenoid version was not significantly different (p > 0.05) from preoperative glenoid version. The mean humeral-head decentering on the glenoid face was reduced for type-B2 glenoids from −14% ± 7% preoperatively to −1% ± 2% postoperatively (p < 0.001) and for type-B3 glenoids from −4% ± 6% preoperatively to −1% ± 3% postoperatively (p = 0.027). The rates of bone integration into the central peg for type-B2 glenoids (83%) and type-B3 glenoids (81%) were not inferior to those for other glenoid types.

Conclusions:

Shoulder arthroplasty with a standard glenoid inserted without changing version can significantly improve patient comfort and function and consistently center the humeral head on the glenoid face in shoulders with type-B2 and B3 glenoids, achieving >80% osseous integration into the central peg. These clinical and radiographic outcomes for type-B2 and B3 glenoids were not inferior to those outcomes for other glenoid types.

Level of Evidence:

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.


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