Total shoulder arthroplasty with a flat backed keeled component - results at 20 years

Survival of the Aequalis Total Shoulder Replacement at a Minimum 1 20-year Follow - A clinical and radiographic study

These authors aimed to quantify the 20-year survival and clinical outcomes for a cemented keeled ultra-high-molecular weight all-polyethylene, flat backed glenoid component and a cemented stemmed Aequalis humeral component.

An individual surgeon performed 44 shoulder replacements in 40 patients  (age at surgery 68.5yrs, 82.5% female. The indication for surgery was rheumatoid arthritis in 14 (35%) patients and

68 osteoarthritis in 26 (65%). 

29 patients  (72%) were deceased with the prostheses in place at the time of the latest review. Of the 11 remaining patients (12 arthroplasties), three had undergone revision surgery, two suffered from severe dementia leaving only six patients (seven arthroplasties) who completed the clinical review. 

Survival with all-cause revision as an end point was reported to be 94.6% at 10 years, 90.1% at 15 years and 84.1% at 20 years. Glenoid loosening was seen in all patients who survived to 20 years follow-up. 

Survival of rotator cuff integrity was reported to be 16.8% at 20 years. 

Radiographic loosening of components was reported to be  0/39 (0%) humeral implants and 20/39 (51.2%) glenoid implants. Glenoid loosening was first identified on radiographs at an average of 11.4 years post-surgery.

Comment: This study demonstrates that patients having shoulder arthroplasties performed 20 years ago with a flat-backed, keeled component are at risk for glenoid component loosening and cuff failure. However, only 7% (3/44) came to surgical revision. 72% of the patients died with their prosthesis in place.

It is of note that over a third of these patients had rheumatoid arthritiis (rather than osteoarthritis); patients with RA are at greater risk for cuff failure and glenoid loosening.

The manuscript demonstrates that long term followup studies usually involve prostheses and techniques that are no longer in common use.'

Furthermore, the longer the period of followup, the greater the percentage of patients that are lost to followup or that have expired. In this study only 7 of the original 44 shoulders had 20 year followup.

Finally, because of these issues it will be difficult to determine whether newer technologies are associated with better outcomes than those reported here (see this related 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).