Background: Glenoid component loosening continues to be a major
factor affecting the long-term survivorship of total shoulder replacements.
Radiolucent lines, cement fracture, migration, and loosening requiring
revision are common problems with cemented glenoid components. The purpose of
this study was to evaluate the results of total shoulder arthroplasty with an
uncemented glenoid component and to identify predictors of glenoid component
Methods: One hundred and forty-seven consecutive total shoulder
arthroplasties were performed in 132 patients (mean age, 63.3 years) with use
of an uncemented glenoid component fixed with screws between 1988 and 1996.
One hundred and forty shoulders in 124 patients were available for follow-up
at an average of 7.5 years. One shoulder in which the arthroplasty had failed
at 2.4 years and for which the duration of follow-up was four years was also
included for completeness. The preoperative diagnoses included osteoarthritis
in seventy-two shoulders and rheumatoid arthritis in fifty-five.
Results: Radiolucency was noted around the glenoid component and/or
screws in fifty-three of the 140 shoulders. The mean modified ASES (American
Shoulder and Elbow Surgeons) score (and standard deviation) improved from 15.6
± 11.8 points preoperatively to 75.8 ± 17.5 points at the time
of follow-up. Eighty-five shoulders were not painful, forty-two were slightly
or mildly painful, ten were moderately painful, and three were severely
painful. Fifteen (11%) of the glenoid components failed clinically, and ten of
them also had radiographic signs of failure. Eleven other shoulders had
radiographic signs of failure but no symptoms at the time of writing. Three
factors had a significant independent association with clinical failure: male
gender (p = 0.02), pain (p < 0.01), and radiolucency adjacent to the flat
tray (p < 0.001). In addition, the annual risk of implant revision was
nearly seven times higher for patients with radiographic signs of failure.
Clinical survivorship was 95% at five years and 85% at ten years.
Conclusions: The failure rates of the total shoulder arthroplasties
in this study were higher than those in previously reported studies of
cemented polyethylene components with similar durations of follow-up. Screw
breakage and excessive polyethylene wear were common problems that may lead to
additional failures of these uncemented glenoid components in the future.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.