Do the radiological changes seen at mid term follow up of stemless shoulder prosthesis affect outcome?

BACKGROUND: The Eclipse® (Eclipse® is a trademark of Arthrex, Naples, Florida) stemless shoulder prosthesis offers the surgeon the advantage of bone stock preservation and at the same time avoids the drawbacks of a resurfacing arthroplasty. Previous studies have shown radiographic changes on serial follow up of the Eclipse prosthesis. This study attempts to assess the significance of these radiographic changes and effect of cuff related pathology on the mid-term outcome of the Eclipse prosthesis. METHODS: Between July 2005 and October 2008, 29 shoulders underwent shoulder arthroplasty with the Eclipse prosthesis; 23 shoulders, (seven women and 16 men) were available for the final follow up. The range of motion, Constant Score; age adjusted Constant Score, Subjective Shoulder Value and radiographs were assessed at serial follow-ups. RESULTS: Significant improvements were seen in the Constant Score (78.9 ±20.1) compared to pre-operative score (32.9 ±5.2); also forward elevation, abduction and external rotation improved to 142.9 ± 36.6 °, 135.2 ± 40.5 ° and 49.8 ± 21.9 ° at 72 months (p < 0.001). Radiolucent lines and localised osteopenia, did not statistically impact on the clinical outcome. Partial tears of the supraspinatus and subscapularis had a negative impact on the Subjective Shoulder Value (p < 0.05) Partial or complete tears of the subscapularis led to worse Constant Score on follow up (p < 0.05). CONCLUSIONS: The presence of radiolucent lines or localised osteopenia does not influence the mid term clinical outcome. Pre -operative partial supraspinatus tears or tears of the subscapularis lead to an inferior outcome.