Functional and clinical outcome of total shoulder arthroplasty with oversized glenoid

The Epoca-Reconstruction-(Reco)^®-Glenoid has been developed to treat patients with cuff-tear-arthropathy. The glenoid component of this system has a hemispheric shape that canopies the humeral head. This design is believed to provide a stable fulcrum and restore normal deltoid function. The purpose of this study was to analyse strengths and disadvantages of the Epoca-Reco^®-Glenoid in cuff-tear-arthropathy patients. Changes in functional outcome using Constant-Murley-Scoring(CMS), CMS sub-scoring parameters and radiological outcome were analysed. For this purpose, a classification for radiologic lucency was proposed. Diverging results, influencing factors and alternative treatment options have been discussed to analyse weaknesses and enhance future development of this arthroplastic model.

23 patients aged 68 ± 8.4 years with irreparable cuff-tear-arthropathy refractory to physiotherapeutic treatment were treated with Reco-Glenoid Total-Shoulder-Arthroplasty (TSA). Pre-operative standardized evaluations included history, physical examination, radiographs, computer tomography and clinical scorings. The post-operative controls included physical examination with CMS, video documentation and radiological evaluation.

After a median follow-up time of 38 ± 18 months, the CMS had been significantly improved (p < 0.001) from (17.4 ± 5.8) to (43.2 ± 19.2) points. Significant improvement in pain, activities of daily life, range of motion (p < 0.001) and power (p = 0.006) was achieved. Significantly, inferior results in functional outcome and higher lucency rates were observed in female patients and in patients treated with small glenoid components. The follow-up rate was 100 %.

The semi-constraint reconstruction glenoid prosthesis model in cuff-tear-arthropathy patients significantly improves shoulder function, however, it yields controversial results, with satisfactory results in male and poor results in female patients. Revision rate of the female cohort and loosening of the glenoid component in this short-term follow-up is of concern. Further investigations taking BMD, osteopenic conditions and influence of surface area in smaller individuals into consideration are recommended, to determine whether this is the underlying cause of the inferior results in females.