Rethinking the glenoid component in total shoulder arthroplasty - big data

 Three recent publications clarify our thinking about the glenoid component.

The association between glenoid component design and revision risk in anatomic total shoulder arthroplasty

These authors reviewed 5,566 total shoulder arthroplasties.

3.6% were polyethylene cemented keeled (below left)

26.0% were polyethylene all-cemented pegged (below left middle)

39.2% of glenoid implants were polyethylene central-pegged ingrowth (below right middle)

31.1% were polyethylene-metal hybrid (below right).

In this large series, the keeled and the all-cemented pegged components had the highest risk of revision over the 6 years of observation. The metal hybrid had no advantage over the all polyethylene central pegged ingrowth design. 

In the 2020 report of Australian Orthopedic Association (see this link) the risk of revision for 14,231 anatomic total shoulders, all polyethylene glenoid components had the lowest risk of revision at 12 years.

These two large studies with long term followup provide support for the use of an all-polyethylene glenoid component with an ingrowth central peg,

avoiding the potential problems with metal hybrid components:

Another recent study, Outcomes of anatomic shoulder arthroplasty performed on B2 vs. A1 type glenoids, ask the question, "is a posteriorly augmented glenoid component necessary to manage B2 glenoid pathoanatomy?"

Two hundred eighty-nine shoulders met inclusion criteria of a preoperative Walch type A1 (178) or B2 (111) glenoid morphology, treatment with a standard all-polyethylene glenoid component with an ingrowth central peg, asymmetric reaming in the B2 group, and an average of 40 months clinical and radiographic follow-up.

Both groups had similar Constant Strength scores preoperatively, but the B2 group improved significantly more at final follow-up. 

The total Constant score was also significantly better at follow-up in the B2 glenoid group. Other outcome measures showed no significant differences between the A1 and B2 glenoid groups. A similar proportion of patients rated their satisfaction as either very satisfied or satisfied between the A1 and B2 groups. Lazarus scores were also similar between the A1 and B2 groups as were the rates of humeral radiolucent lines and humeral osteolysis.

Taken together, these three studies indicate that anatomic total shoulder arthroplasty using a standard all-polyethylene glenoid component with an ingrowth central peg can successfully manage the great majority of osteoarthritic glenohumeral joints. 

Related posts with similar findings can be accessed by this link, this link, and this link.

The question of whether recent innovations have led to better patient outcomes is addressed in a recent post (see this link).

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Here are some videos that are of shoulder interest

Shoulder arthritis - what you need to know (see this link).

How to x-ray the shoulder (see this link).

The ream and run procedure (see this link).

The total shoulder arthroplasty (see this link).

The cuff tear arthropathy arthroplasty (see this link).

The reverse total shoulder arthroplasty (see this link).

The smooth and move procedure for irreparable rotator cuff tears (see this link).

Shoulder rehabilitation exercises (see this link).