Reverse shoulder arthroplasty with two Wright Medical designs

Grammont humeral design versus onlay curved-stem reverse shoulder arthroplasty: comparison of clinical and radiographic outcomes with minimum 2-year follow-up

These authors assessed the outcomes of two Wright Medical reverse total shoulder designs: Grammont (below left) or an onlay curved short-stem humeral component (below right) in 68 patients with cuff tear arthropathy.

Both prostheses provided significant differences between preoperative and postoperative scores and both provided similar postoperative shoulder mobility. 

The lateralized curved stem was associated with higher delta scores for external rotation (P = .002) and lower rates of scapular notching (P = .0003), glenoid radiolucency (P = .016), and humeral bone remodeling (P = .004 and P = .030 for cortical thinning and spot weld, respectively).

Complications were reported for 8% (3 of the 36) Aequalis II Grammont prostheses: two dislocations and one "feeling of instability" all managed without surgical revision.

Complications were reported for 18% (7 of the 38) Ascend Flex curved stems: two fractures of the scapular spine (treated without surgery) and an acromial fracture treated with surgery. In this group there were three infections, and one case of instability. There were two shoulders in the Ascend Flex group that had prosthesis revision surgery: one because of instability and one because of infection.

Comment: It is not clear how patients were assigned to receive one prothesis or the other and it is not clear whether the same surgeons used both prostheses or whether some surgeons used the Grammont and other surgeons used the onlay short stem.

In any event, it is not clear from this study whether there is an advantage to the patient of one design or the other.

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How you can support progress in shoulder surgery

You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'

Glenoid component failure, osteolysis - sterilized by radiation in air

We had an interesting day yesterday in the OR. Among other revisions, smooth and moves, and ream and runs, we revised two Tornier total shoulders. The first case had already had a revision (elsewhere) of a Tornier total shoulder on the left shoulder for a failed glenoid. The right arthroplasty had been done in 2005. In 10/2012 we saw him for the first time because of pain in the right shoulder. His x-ray is shown below, revealing glenoid osteolysis.

In 5/2013 he decided to proceed with revision. At that time his films showed a dramatic increase in the osteolysis as well as evidence of a shift in the position of the glenoid component markers.

At surgery his component was loose and worn.

There was no obvious evidence of infection, but the shoulder was filled with non-inflammatory reactive tissue, such as the below.

We obtained multiple cultures for Propionibacterium and other bacteria before administering Ceftriaxone and Vancomycin (which we will continue for 6 weeks followed by a year of oral antibiotics).

After a thorough cleanout, we reconstructed his shoulder using a press fit humeral prosthesis that articulated with the rim of his residual glenoid. No glenoid bone graft was used. Post op we are starting him on our routine post-arthroplasty rehabilitation.

The second case had a Tornier total shoulder implanted in 2000. At the time of presentation to us, the radiographs, like the first case, showed massive osteolysis and glenoid component loosening.

The operative findings and the procedure were identical to the prior case. The postoperative films are shown here.

Comment: the surgical findings in these cases are consistent with either a Propionibacterium infection or with 'polyethylene disease' resulting from particles of poly released into the shoulder by component wear. Each of these glenoid components were not only loose, but the poly was degenerated suggesting that they may have been sterilized by gamma radiation in air. This is a problem previously noted in DePuy glenoids as well when the component was sterilized in air. The only way to distinguish them is by cultures of multiple samples (at least 5) of tissue and explants, holding them for three weeks and using multiple culture media.  For that reason we have both of these patients on the 'red' protocol of IV antibiotics via a PICC line for six weeks. If cultures are negative, we will discontinue antibiotics afterwards. Otherwise the patients will be on oral antibiotics for a year.

The humeral head prostheses have the largest diameter so that they will sit on the rim of the osteolytic glenoid. No glenoid bone grafting is used, but Vancomycin / allograft is used for humeral component fixation.

The histology on such cases usually looks like that shown below

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