Abstract
Introduction
the aim of this study was to analyse the long-term radiological changes following tsa in order to better understand the mechanisms responsible for loosening.
Material and methods
between 1991 and 2003, in 10 European centers, 611 shoulder arthroplasties were performed for primary osteoarthritis using a third generation anatomic prosthesis with a cemented all-polyethylene keeled glenoid component. Full radiographic and clinical follow-up greater than 5 years was available for 518 shoulders. Kaplan-meier survivorship analysis was performed with glenoid revision for loosening and radiological loosening as end points; clinical outcome was assessed with the constant score, patient satisfaction score, subjective shoulder value and range of movement
Results
after a mean follow-up of 103,6 months (61-209 months),the constant score improved significantly(p<0,0001) from 30,1 points pre-operatively to 65,2 points at latest follow-up. the active anterior elevation increased from 91,5 to 138,1 degrees (p<0,0001),and active external rotation increased from 7,9 to 33,2 degrees (p<0,0001). 90,3% of patients were either very satisfied or satisfied with their outcome and the average ssv was 77,1%. radiological loosening was found in 166 cases(32%).three pattern of glenoid component migation were observed in 136 cases: superior tilting (10%), posterior tilting(6,3%), and a subsidence (7,9%) of the glenoid component. different risk factors were statistically associated with the migration of the glenoid component(p<0,001):proximal migration of the humeral head, excessive reaming of the glenoid, type of glenoid preparation for the keel (i.e. curettage technique described by neer in 1972 versus cancellous compaction tecnique described by gazielly in 2003).survivorship with the end-point being glenoid revision for loosening was 99,8% at 5 years,95,9% at 10 years, and 77,5% at 15 years. Conclusion- to reduce risk of loosening of the glenoid component, we recommand consideration of the following: optimization of the design and size of the implant, limit the amount of reaming so as to not sacrifice the subchondral glenoid bone, and prepare the glenoid with cancellous compaction rather than curettage technique.
