There have been many attempts to improve the excellent outcomes of anatomic total shoulder arthroplasty (TSA) that have for many decades been obtained with all-polyethylene glenoid components. Such attempts include metal backed and hybrid glenoid components; data demonstrating the superiority of these innovations is lacking.

The authors of Mid- to long-term outcomes of a cemented all-polyethylene pegged glenoid component in anatomic total shoulder arthroplasty evaluated the mid- to long-term survival and outcomes of 108 total shoulders (98 patients, 18 males and 80 females) using a conventional cemented anatomic all-polyethylene pegged glenoid component (convex, roughened back surface with four fluted pegs).

There was a mean follow-up of 5.1 years (range, 2 years to 10.6 years). Included patients had symptomatic primary or secondary glenohumeral osteoarthritis with an intact cuff as well as those shoulders revised to a TSA for failed Copeland resurfacing or hemiarthroplasty for trauma. Patients were excluded if there were concerns about cuff integrity or significant bone loss with retroversion greater than >15⁰.

Survival analysis was possible in 101 shoulders (94%); only 7 patients were lost to follow-up.

Six TSAs (5.9%) were revised. Mean time from primary surgery to revision was 27.5 months (range, 1 month to 56 months). The reason for revision was rotator cuff failure in four and instability in two. Glenoid loosening was not found on radiographic review or intra-operatively in any of the cases undergoing revision surgery. No revisions were performed because of glenoid component failure.

Kaplan-Meier survival analysis revealed a six-year survival estimate of 94.1% for all cause revision.

Clinical outcomes were maintained at long term follow-up (>8 years) with the exception of the Pain VAS score which increased by 2.1 points.

Radiological assessment revealed that 28 patients had radiolucency consistent with a Lazarus grade of 3 and above but these findings did not affect the clinical outcomes. The 6 patients with a Lazarus Grade of 4 and the two patients with Lazarus Grade 5 were not symptomatic and had good clinical outcomes.

Comment: This study demonstrates the long term effectiveness and safety of a standard cemented all-polyethylene glenoid component in anatomic shoulder arthroplasty. This study can serve as a baseline for studies on the value of more complex glenoid components.

The post below is of relevance in this regard.