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

Abstract

BackgroundThe 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.MethodsBetween 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.ResultsSignificant 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).ConclusionsThe 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.

Mid-term results of Eclipse total shoulder arthroplasty

“…It is feasible that RLLs represent stress shielding due to load transfer passing predominantly through the cage screw and this is something seen by other surgeons using the Eclipse implant. 20,23 When comparing our results with those available for other stemless anatomical TSA designs, we again found ours to be higher than those reported by the designers of those implants. Huguet et al, 24 from the TESS Group, found no radiolucencies at a mean of 45 months' follow-up in his series of 63 patients.…”

“…Our strict criteria for radiological inclusion reduces our total number of included radiographs, and may be responsible for our higher incidence of RLLs. Moursy et al 20 noted a similarly higher rate of RLLs than Habermeyer et al 8 in their small series, when reviewing mid-term results. They also reviewed stress-shielding using MRI studies but found neither RLLs nor stress-shielding to affect patient outcome.…”

“…They also reviewed stress-shielding using MRI studies but found neither RLLs nor stress-shielding to affect patient outcome. 20 The cause of RLLs is unclear but we hypothesize a possible iatrogenic cause, such as retractor use at the time of glenoid preparation or imperfect metaphyseal neck cut. This would correspond with the disproportionate frequency of RLLs in axillary zone A.…”

“…Mid-term outcomes have until now been consigned to those available from designer series or very small series from independent centres. 8,[18][19][20] Habermeyer et al, 8 in a series of 78 patients at a mean follow-up of six years with both Eclipse TSA and hemiarthroplasty, demonstrated good clinical and functional improvement. ROM improved to 141° of forward elevation and 44° of external rotation, which is comparable with our results.…”

Anatomic total shoulder arthroplasty using a stem-free ellipsoid humeral implant in patients of all ages

“…The clinical significance of stress shielding under a stemless implant is unknown and could possibly be explained by a radiographic phenomenon rather than actual bone loss. 14,20,24,40 We did not include evaluation of axillary radiographs in this study as the majority were performed at one of several outside community radiology clinics and inconsistency in arm positioning did not allow for reliable grading with this method. This also limited our ability to evaluate ''recentering'' the glenohumeral joint.…”