Functional results in reverse shoulder arthroplasty

Abstract

The use of reverse shoulder prostheses is increasing worldwide mainly as a treatment for irreparable rotator cuff tear, complex proximal humeral fractures among other causes. Knowledge of indications, surgical technique, learning curve, as well as adverse effects, it currently made an adequate treatment for patients with multiple shoulder pathologies. They can have a good subsequent functionality. In Ecuador, there are no studies about functionality of a reverse shoulder prosthesis, so the objective of this study is to describe functional results in our patients who use as management a reverse shoulder prosthesis.

Material and methods: An observational descriptive study was carried out in a series of 24 cases in whom a reverse shoulder prosthesis was placed as treatment for an irreparable rotator cuff tear in 21 cases and 3 proximal humeral fractures to 4 fragments. Functional results were analyzed using CONSTANT and ASES scales in the preoperative period, at 3 and 6 months postoperative follow up. The data was measured by the correlation coefficient, and the VAS scale in the same periods. Friedman inferential statistics tests were used to compare times, Mann-Whitney U for medians, and a significance level of p 0.05 was established.

Results: 24 subjects were studied (p> 0.05), the mean age of men was 74.4 ± 4.1 years and in women 74.8 ± 6.2 years (p 0.855 NS). 58.3% (n = 14) were right shoulder and 66.7% (n= 16) with right dominance. 70.8% (n = 17) did not perform any sport activity before surgery, 87.5% (n = 21) of the subjects had a rotator cuff tear, while 12.5% w ere patients with 4-fragment complex proximal humeral fractures. Subscapularis reinsertion was performed in 79.2% (n = 19); There was no difference in surgical time between men and women (p> 0.05). Shoulder functionality improved from 23.7 to 77.4 on the ASES scale; while on the CONSTANT scale, the improvement ranged from 38.2 to 68.4 between the preoperative period and at 6 months follow up, with a statistically significant p <0.05.

There is a decrease in the VAS scale from 7 to 2 between the presurgical period and at 6 months postoperative time with a p <0.05.

Conclusions: The reverse shoulder prosthesis has encouraging results of functionality and pain management assessed at 6 months postoperative period. We could see some improvements in the range of motion, especially in anterior flexion, abduction, internal rotation, external rotation and pain. These values are statistically significant, so this system is considered useful and reproducible in our environment.