Showing posts with label all-polyethylene. Show all posts

Wednesday, September 28, 2022

The value of a standard glenoid component in anatomic shoulder arthroplasty.

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.

Glenohumeral osteoarthritis - what type of arthroplasty has the lowest 10 year revision rate?

Our approach to anatomic shoulder arthroplasty is shown in this link

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You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link.

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).

Sunday, May 15, 2022

Glenohumeral osteoarthritis - what type of arthroplasty has the lowest 10 year revision rate?

Total Shoulder Replacement Stems in 1 Osteoarthritis – short, long or reverse? An analysis of the impact of cross-linked polyethylene.

In their analysis of different types of total shoulder arthroplasty for osteoarthritis (OA) in the 2021 Australian Orthopaedic Association National Joint Replacement Registry (see this link), these authors considered five implant types separately:

(1) stemmed anatomic total shoulder arthroplasty (aTSA) with metaphyseal or diaphyseal humeral component fixation with either cross-linked polyethylene ("total stemmed XLPE") or non-cross-linked polyethylene ("total stemmed non XLPE")

(2) stemless anatomic total shoulder arthroplasty with epiphyseal fixation with either cross-linked polyethylene ("total mid head XLPE") or non-cross-linked polyethylene ("total mid head non XLPE")

and

(3) reverse total shoulder arthroplasty ("total reverse").

Due to the previously documented higher revision rate compared to other anatomic total shoulder replacement options, those arthroplasties using a cementless metal backed glenoid components were excluded.

Of note, this registry provided data on a substantial number of shoulders many years out from their index arthroplasty.

For the primary diagnosis of OA, aTSA with a cemented XLPE glenoid component had the lowest revision rate with a 12-year cumulative revision rate of 4.7%, compared to aTSA with cemented non-XLPE glenoid component of 8.7%, and RTSA of 6.8%.

The principal reason for revision for the total stemmed non XLPE was component loosening.

The lower rate of revision for component loosening with cross-linked polyethylene is shown below.

Comment: In this large national database study of 28,467 primary total shoulder replacement procedures the best 10 year survivorship was seen for anatomic stemmed total shoulder replacement with a cemented cross-linked polyethylene glenoid component in comparison to reverse total shoulder and in comparison to anatomic arthroplasty with a non cross-linked polyethylene glenoid component. Results in this study for short or mid head stems were inconclusive, but initial indications were that they were not substantially better than the long stem implants utilizing crosslinked polyethylene.

We are reminded that in reading studies of arthroplasty revision rates, it is important to understand whether the study includes metal back glenoids or glenoid components with non cross-linked polyethylene.

This study of arthroplasties by all surgeons in Australia found a 10 year cumulative percent revision rate of 4.1 percent for anatomic stemmed total shoulder replacements with a cemented cross-linked polyethylene glenoid component. This is an important benchmark against which reverse total shoulder arthroplasty and future shoulder arthroplasty innovations should be compared.

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on 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).

Thursday, November 21, 2019

Total shoulder arthroplasty - selecting the glenoid component

Clinical and radiographic comparison of a hybrid cage glenoid to a cemented polyethylene glenoid in anatomic total shoulder arthroplasty

These authors report the clinical and radiographic outcomes of 316 Exactech hybrid cage glenoids below left) to an age-matched, sex-matched, and follow-up–matched cohort of 316 Exactech cemented all polyethylene glenoid (below right) in patients undergoing anatomic total shoulder arthroplasty with 2 years’ minimum follow-up.

The Exactech cage glenoid patients had significantly lower rates of radiolucent glenoid lines (9.0% vs. 37.6%, P < .0001) and radiolucent humeral lines (3.0% vs. 9.1%, P . .0088) than the Exactech all-polyethylene peg glenoid patients. In the cage glenoid cohort, 4 cases of aseptic glenoid loosening (1.3%) and 4 cases of articular surface dissociation (1.3%) occurred as shown below.

In the all-polyethylene peg cohort, 12 cases of aseptic loosening (3.8%) occurred. Cage glenoid patients had a significantly lower revision rate than all-polyethylene peg glenoid patients (2.5% vs. 6.9%, P . .0088).

Comment: These authors point out the importance of exact alignment of the drilled holes and the direction of impaction required by the metal-coated pegs.

The required direction and accuracy may be difficult to achieve because of challenges with exposure, especially in retroverted glenoids.

Failure to achieve the desired alignment of the holes with the reamed bony surface can result in failure of the component as shown below.

In contrast to the all-polyethylene component with smooth pegs used in this study, we prefer a component with a fluted central peg.

This component has several advantages, including (1) the flexibility of the pegs that can better accommodate minor degrees of malalignment in comparison to the more rigid hybrid pegs and (2) the fluted central peg that allows bone ingrowth which cannot occur with the smooth pegs used in this study.

To see a YouTube of our technique for total shoulder arthroplasty, click on this link.

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

Sunday, October 22, 2017

Advantages of an all-polyethylene ingrowth glenoid component

Clinical and Radiographic Results of an All-Polyethylene Pegged Bone-Ingrowth Glenoid Component

These authors evaluated the early clinical and radiographic results in 83 shoulders having total shoulder arthroplasty with an all-polyethylene pegged glenoid component designed for hybrid (biological and cement) fixation.

At a mean followup of 46.7 months (range, 24 to 99 months), the median ASES score was 97 points (range, 43 to 100 points) and the median Oxford score was 48 points (range, 24 to 48 points). The median active forward elevation was 130 (range, 65 to 170), median external rotation was 45 (range, 5 to 80), and median internal rotation was to T11 (range, buttock to T4). Seventy-eight shoulders demonstrated a perfect Lazarus score for radiolucency (0, indicating no radiolucency). Sixty-eight shoulders demonstrated complete osseointegration, with bone ingrowth between all of the flanges seen on coronal CT.

5 demonstrated partial osseointegration; and 10 demonstrated osteolysis around the central peg. Most radiolucent lines were in the inferior pegs of the prosthesis. There were no correlations between the Yian CT scores and either the ASES or Oxford score (rho = 0.13 and 0.07, respectively).

The glenoid inclination and version ranged from 62 to 96 degrees and from -20 to 15 degrees, respectively. No association was found between glenoid inclination or version and the presence of radiolucent lines.

In addition to the 83 implants included in the study, 4 glenoid implants were revised, although only 1 revision was due to aseptic loosening; the others were due to rotator cuff failure, glenoid fracture, and Propionibacterium infection.

Comment: As seen in the figure below from the Australian national joint registry (see this link), all-polyethylene glenoid components have demonstrated the best survivorship. The particular all-polyethylene design discussed in this paper has the advantage of bone ingrowth without the disadvantages of a metal backing.

This all-poly glenoid also has the advantage of easy and bone preserving revision to a reverse, should that become necessary. In the revision. The central hole is drilled out and, if necessary, filled with bone graft followed by the usual insertion of the base plate and glenosphere.