Showing posts with label cementless. Show all posts
Showing posts with label cementless. Show all posts

Friday, June 5, 2020

Glenoid component fixation: why go "cementless"?

Clinical and radiographic outcomes of an all-polyethylene fluted central peg glenoid component, implanted utilizing an off-label, uncemented technique, at a minimum 5-year

These authors sought to evaluate the clinical and radiographic results of a fully uncemented all-polyethylene fluted central peg bone-ingrowth glenoid component at a minimum 5-year follow-up.



The study included 35 shoulders in 31 patients (mean age, 73 years) with a mean follow-up of 100 months (8.3 years). The study included  patients presenting with avascular necrosis or primary osteoarthritis excluding patients with glenoid type C. The glenoid types for the included shoulders are not reported. Patients having an impaired functional outcome due to medical conditions were excluded. The components were inserted using an off-label technique without the cement fixation of the peripheral pegs as recommended by the manufacturer. The rationale for this technique was "potentially reducing heat-induced necrosis, having a shorter operating time, and potentially reducing cement-related difficulties in case of revision".

The mean Constant score improved from 40 preoperatively to 74 at early followup dropping to 66 at final followup. The drop in CS over time was attributed primarily to a decrease in strength at the later time points.

CT scans found an initial osseointegration rate of 81% at early follow-up that decreased to 71% at a mean follow-up of 8.4 years. 7 shoulders demonstrated isolated radiographic loosening around the central peg. 3 shoulders demonstrated isolated radiographic loosening around the peripheral pegs, and 1 shoulder with gross radiographic loosening demonstrating a combined loosening of all pegs. 74% (26 of 35) of the shoulders demonstrated progression of radiolucent lines.  The radiographic loosening rate was 31%.



Of the 35 shoulders, 4 (12%) required revision. Two patients were revised because of symptomatic loosening, 1 patient underwent a revision because of a subscapularis insufficiency, and 1 patient was revised because of a  Cutibacterium infection.

Comment: This is an interesting study with CT scans evaluating the glenoid component fixation at early and intermediate time points after total shoulder arthroplasty using an off-label technique.

The 12% revision rate at 8 years in this study can be compared to the 3% revision rate at 8 years for cemented all-polyethylene (cross linked) components reported by the Australian Orthopaedic Association (see below).


These results can also be compared to those of Noyes et al (see this link) with similar length of followup. In the Noyes study of 76 total shoulders using the same glenoid component as in this study, but inserted with cementing of the peripheral pegs as recommended by the manufacturer, there was 97% survivorship at 80 months. On radiographs, 81% of the central fluted pegs had complete incorporation with no lucent lines.






Cemented fixation of this component has shown great clinical utility in a large international study (see this link).

Thus it does not appear that using an off-label cementless insertion technique is an attractive method for glenoid arthroplasty.

To see a YouTube on how we do total shoulder arthroplasty with an emphasis on glenoid preparation, click on this link.

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Saturday, February 25, 2017

Failed shoulder arthroplasty

Is reverse total shoulder arthroplasty a feasible treatment option for failed shoulder arthroplasty? A retrospective study of 44 cases with special regards to stemless and stemmed primary implants

Revisions of failed shoulder arthroplasties are on the rise.  From 2010 to 2012 60 failed shoulder arthroplasties were converted to reverse total shoulder arthroplasty by an individual surgeon.

Forty-four of these patients were available for follow-up after a mean of 24 months. Seven (16%) of these revisions had complications:


Comment: We found the two case examples particularly interesting, not because of the revisions, but because of the implants requiring revision.

Here is an unstable total shoulder arthroplasty in which a metal backed, cementless glenoid component had become loose. The ingrowth humeral stem required extensive osteotomy for removal.



And here is a stemless humeral component complicated by a proximal humeral fracture.


 In reading papers on revisions, it is always worthwhile to ask whether revisions might have been (a) less likely and (b) less complex with more conventional implants, such as an all-polyethylene ingrowth glenoid component

and a non-ingrowth humeral stem

inserted with impaction autografting.


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Sunday, May 4, 2014

Total shoulder with cementless glenoids have a high failure rate

Anastasios Papadonikolakis pointed us to the Supplementary Report of the Australian National Joint Registry.

He called attention to several of the figures from this report.

The first shows that uncemented glenoid components have a much higher rate of revision than cemented glenoids. Click on the graph for a magnified view.




The second excludes the SMR prosthesis


The third shows the reasons for revision.


These data seem to have influenced the choice of prosthesis:


Comment: While some are enthusiastic about cementless glenoid components, these data are not encouraging.

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Saturday, March 1, 2014

Cementless reverse total shoulder

Clinical and radiographic results of cementless reverse total shoulder arthroplasty: a comparative study with 2 to 5 years of follow-up.

The authors report a retrospective review of  patients having reverse total shoulder arthroplasty for a diagnosis of cuff tear arthropathy or severe rotator cuff deficiency. Of these, 37 patients had cemented RTSA and 64 patients had cementless RTSA. The cemented RTSAs were implanted between 2005 and 2007, and the uncemented RTSAs were implanted between 2007 and 2008.

There were no significant differences in clinical or radiographic outcomes between the two groups of patients. There was one revision for prosthetic instability  in the cemented group and three such cases in two patients in the cemented group.

Comment: This series represents the results by a surgeon with extensive experience with reverse total shoulders in patients with the optimal diagnoses: cuff tears and cuff tear arthropathy. Results are not presented for patients having reverse total shoulders for failed anatomic arthroplasty or fractures.

The authors observed stress shielding exclusively in the cement less stems, noting that stress shielding has been noted to be inversely proportional to the diameter of the stem: increased stiffness of the larger diameter press-fit implants leads to more stress shielding and increased proximal bone resorption around the implant.

In order to achieve fixation without cement, the average stem diameters were greater in the uncemented group.

This observation suggests that care needs to be exerted when inserting press-fit humeral stems in fragile bone because of the risk of fracture at surgery. Many patients having reverse total shoulders have poor humeral bone quality. Special approaches may be needed to avoid the risk of fracture at and after surgery.

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Consultation for those who live a distance away from Seattle.

Check out the new Shoulder Arthritis Book - click here.

Click here to see the new Rotator Cuff Book

To see the topics covered in this Blog, click here

Use the "Search" box to the right to find other topics of interest to you.

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