Wednesday, November 28, 2012

The case for and art of impaction grafting

As we've pointed out before we prefer impaction grafting to cementing, broaching to a tight fit or trabecular metal ingrowth for fixation of the humeral component.

Yesterday's cases provide some useful examples.
Here are the x-rays of  a man who came to us with a painful shoulder after a prior arthroplasty. The problem is apparent, the surgeon could not fully seat the component because of a too-tight diaphyseal fit. Driving it down further would have risked a fracture. Additional reaming would have weakened the bone. The decision was made to leave it too high.

To avoid such problems, we prefer impaction grafting because it enables us to fit the humerus to the prosthesis (much as Procrustes fit his guests to his bed).

To start, we recognize that the humeral canal dimensions do not conform to any prosthesis.

So, like Procrustes, we shape our patient's canal to the prosthesis, simultaneously avoiding loosening and fracture.
Selective placement of the graft, enables us to fine tune the position of the prosthesis in the bone, noting the tendency to angle the prosthetic stem in varus and with the proximal end too anterior.

Here are some results from yesterday's OR. Note the centering of the stem in both AP and axillary projections and the lack of cortical contact by the tip of the prosthesis.
Case I - Total Shoulder

Case II - Ream and Run

Case III - Total Shoulder

----

If you have suggestions for topics you'd like us to address in this blog, please send an email to
shoulderarthritis@uw.edu

Use the "Topics" box to the right to find other posts of interest to you.

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.

See the countries from which our readers come on this post.