The Journal of Bone and Joint Surgery (American). 2005;87:1928-1936.
doi:10.2106/JBJS.D.02675
© 2005 The Journal of Bone and Joint Surgery, Inc.
Radiographic and Computed Tomography Analysis of Cemented Pegged Polyethylene Glenoid Components in Total Shoulder Replacement
Edward H. Yian, MD1,
Clément M.L. Werner, MD2,
Richard W. Nyffeler, MD2,
Christian W. Pfirrmann, MD2,
Arun Ramappa, MD2,
Atul Sukthankar, MD2 and
Christian Gerber, MD2
1 Southern California Permanente Medical Group, 3401 South Harbor Boulevard,
Santa Ava, CA 92704
2 Department of Orthopaedic Surgery, University of Zurich, Balgrist,
Forchstrasse 340, 8008 Zurich, Switzerland. E-mail address for C. Gerber:
christian.gerber{at}balgrist.ch
Investigation performed at the Department of Orthopaedic Surgery,
University of Zurich, Balgrist, Zurich, Switzerland
In support of their research or preparation of this manuscript, one or more
of the authors received grants or outside funding from the ResOrtho
Foundation, Zurich, Switzerland. In addition, one or more of the authors
received payments or other benefits or a commitment or agreement to provide
such benefits from a commercial entity (Zimmer, Inc.). Also, a commercial
entity (Zimmer, Inc.) paid or directed, or agreed to pay or direct, benefits
to a research fund, foundation, educational institution, or other charitable
or nonprofit organization with which the authors are affiliated or
associated.
Background: Glenoid loosening continues to be the primary reason for
failure of total shoulder arthroplasty. The purpose of this study was to
evaluate, with use of a sensitive and reproducible imaging method, the
radiographic and clinical results of total shoulder replacement with a pegged,
cemented polyethylene glenoid implant.
Methods: Forty-three patients (forty-seven shoulders) underwent a
total shoulder replacement with a cemented polyethylene glenoid component with
four threaded pegs. The patients were examined clinically, with
fluoroscopically guided radiographs, and with computed tomography at an
average of forty months. In addition to conventional scoring of radiographic
lucency, an 18-point scoring system was used to quantify cement-peg lucencies
in six zones of the back surface of the glenoid component as seen on computed
tomography scans.
Results: On the average, the absolute Constant score improved from
39 points preoperatively to 70 points at the time of follow-up (p = 0.0001)
and the pain score improved from 5 to 13 points (p = 0.001). The mean active
anterior elevation improved by 34° (p = 0.001) and the mean abduction, by
46° (p = 0.006). Two patients had symptomatic glenoid loosening requiring
revision. Twenty-one of the forty-seven shoulders had radiographic lucency
around the glenoid pegs, and nine had progression of the lucency by at least
two grades. Computed tomography detected lucencies, primarily at the
bone-cement interface, in thirty-six shoulders. The scores for the lucencies
seen on the computed tomography scans were associated with the radiographic
lucency scores (p < 0.001), pain scores (p = 0.04), and abduction strength
(p = 0.02). Computed tomography was more sensitive than radiography with
regard to identifying the number of pegs associated with lucency and the size
of the lucencies. The overall reproducibility of the scoring based on the
computed tomography was higher than that of the radiographic scoring.
Conclusions: Computed tomography provided a more sensitive and
reproducible tool for the assessment of loosening of pegged glenoid components
than did fluoroscopically guided conventional radiography. Further improvement
in implant design and fixation technique appears to be necessary for long-term
success of cemented glenoid components.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.

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F. A. Matsen III, J. Clinton, J. Lynch, A. Bertelsen, and M. L. Richardson
Glenoid Component Failure in Total Shoulder Arthroplasty
J. Bone Joint Surg. Am.,
April 1, 2008;
90(4):
885 - 896.
[Abstract]
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